mongo data

.idea/goext.iml

@@ -1,6 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="WEB_MODULE" version="4">
-  <component name="Go" enabled="true" />
+  <component name="Go" enabled="true">
+    <buildTags>
+      <option name="goVersion" value="1.19" />
+    </buildTags>
+  </component>
   <component name="NewModuleRootManager">
     <content url="file://$MODULE_DIR$" />
     <orderEntry type="inheritedJdk" />

.idea/inspectionProfiles/Project_Default.xml

@@ -1,6 +1,7 @@
 <component name="InspectionProjectProfileManager">
   <profile version="1.0">
     <option name="myName" value="Project Default" />
+    <inspection_tool class="GoMixedReceiverTypes" enabled="false" level="WEAK WARNING" enabled_by_default="false" />
     <inspection_tool class="LanguageDetectionInspection" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="SpellCheckingInspection" enabled="false" level="TYPO" enabled_by_default="false">
       <option name="processCode" value="true" />

Makefile

@@ -0,0 +1,16 @@
+
+.PHONY: run test version update-mongo
+
+run:
+	echo "This is a library - can't be run" && false
+
+test:
+	# go test ./...
+	which gotestsum || go install gotest.tools/gotestsum@latest
+	gotestsum --format "testname" -- -tags="timetzdata sqlite_fts5 sqlite_foreign_keys" "./test"
+
+version:
+	_data/version.sh
+
+update-mongo:
+	_data/update-mongo.sh

README.md

@@ -5,4 +5,37 @@ A collection of general & useful library methods
 
 This should not have any heavy dependencies (gin, mongo, etc) and add missing basic language features...
 
-Potentially needs `export GOPRIVATE="gogs.mikescher.com"`
+Potentially needs `export GOPRIVATE="gogs.mikescher.com"`
+
+
+### Packages:
+
+| Name         | Maintainer | Description                                                                                                   |
+|--------------|------------|---------------------------------------------------------------------------------------------------------------|
+| langext      | Mike       | General uttility/helper functions, (everything thats missing from go standard library)                        |
+| mathext      | Mike       | Utility/Helper functions for math                                                                             |
+| cryptext     | Mike       | Utility/Helper functions for encryption                                                                       |
+| syncext      | Mike       | Utility/Helper funtions for multi-threading / mutex / channels                                                |
+| dataext      | Mike       | Various useful data structures                                                                                |
+| zipext       | Mike       | Utility for zip/gzip/tar etc                                                                                  |
+| reflectext   | Mike       | Utility for golagn reflection                                                                                 |
+|              |            |                                                                                                               |
+| mongoext     | Mike       | Utility/Helper functions for mongodb                                                                          |
+| cursortoken  | Mike       | MongoDB cursortoken implementation                                                                            |
+|              |            |                                                                                                               |
+| totpext      | Mike       | Implementation of TOTP (2-Factor-Auth)                                                                        |
+| termext      | Mike       | Utilities for terminals (mostly color output)                                                                 |
+| confext      | Mike       | Parses environment configuration into structs                                                                 |
+| cmdext       | Mike       | Runner for external commands/processes                                                                        |
+|              |            |                                                                                                               |
+| sq           | Mike       | Utility functions for sql based databases                                                                     |
+| tst          | Mike       | Utility functions for unit tests                                                                              |
+|              |            |                                                                                                               |
+| rfctime      | Mike       | Classes for time seriallization, with different marshallign method for mongo and json                         |
+| gojson       | Mike       | Same interface for marshalling/unmarshalling as go/json, except with proper serialization of null arrays/maps |
+|              |            |                                                                                                               |
+| bfcodegen    | Mike       | Various codegen tools (run via go generate)                                                                   |
+|              |            |                                                                                                               |
+| rext         | Mike       | Regex Wrapper, wraps regexp with a better interface                                                           |
+| wmo          | Mike       | Mongo Wrapper, wraps mongodb with a better interface                                                          |
+|              |            |                                                                                                               |

TODO.md

@@ -0,0 +1,13 @@
+
+
+ - cronext
+
+ - cursortoken
+
+ - typed/geenric mongo wrapper
+
+ - error package
+
+- rfctime.DateOnly
+- rfctime.HMSTimeOnly
+- rfctime.NanoTimeOnly

_data/mongo.patch

@@ -0,0 +1,80 @@
+diff --git a/mongo/bson/bsoncodec/struct_codec.go b/mongo/bson/bsoncodec/struct_codec.go
+--- a/mongo/bson/bsoncodec/struct_codec.go
++++ b/mongo/bson/bsoncodec/struct_codec.go
+@@ -122,6 +122,10 @@ func (sc *StructCodec) EncodeValue(r EncodeContext, vw bsonrw.ValueWriter, val r
+ 	}
+ 	var rv reflect.Value
+ 	for _, desc := range sd.fl {
++		if desc.omitAlways {
++			continue
++		}
++
+ 		if desc.inline == nil {
+ 			rv = val.Field(desc.idx)
+ 		} else {
+@@ -400,15 +404,16 @@ type structDescription struct {
+ }
+ 
+ type fieldDescription struct {
+-	name      string // BSON key name
+-	fieldName string // struct field name
+-	idx       int
+-	omitEmpty bool
+-	minSize   bool
+-	truncate  bool
+-	inline    []int
+-	encoder   ValueEncoder
+-	decoder   ValueDecoder
++	name       string // BSON key name
++	fieldName  string // struct field name
++	idx        int
++	omitEmpty  bool
++	omitAlways bool
++	minSize    bool
++	truncate   bool
++	inline     []int
++	encoder    ValueEncoder
++	decoder    ValueDecoder
+ }
+ 
+ type byIndex []fieldDescription
+@@ -491,6 +496,7 @@ func (sc *StructCodec) describeStruct(r *Registry, t reflect.Type) (*structDescr
+ 		}
+ 		description.name = stags.Name
+ 		description.omitEmpty = stags.OmitEmpty
++		description.omitAlways = stags.OmitAlways
+ 		description.minSize = stags.MinSize
+ 		description.truncate = stags.Truncate
+ 
+diff --git a/mongo/bson/bsoncodec/struct_tag_parser.go b/mongo/bson/bsoncodec/struct_tag_parser.go
+--- a/mongo/bson/bsoncodec/struct_tag_parser.go
++++ b/mongo/bson/bsoncodec/struct_tag_parser.go
+@@ -52,12 +52,13 @@ func (stpf StructTagParserFunc) ParseStructTags(sf reflect.StructField) (StructT
+ //
+ // TODO(skriptble): Add tags for undefined as nil and for null as nil.
+ type StructTags struct {
+-	Name      string
+-	OmitEmpty bool
+-	MinSize   bool
+-	Truncate  bool
+-	Inline    bool
+-	Skip      bool
++	Name       string
++	OmitEmpty  bool
++	OmitAlways bool
++	MinSize    bool
++	Truncate   bool
++	Inline     bool
++	Skip       bool
+ }
+ 
+ // DefaultStructTagParser is the StructTagParser used by the StructCodec by default.
+@@ -108,6 +109,8 @@ func parseTags(key string, tag string) (StructTags, error) {
+ 		switch str {
+ 		case "omitempty":
+ 			st.OmitEmpty = true
++		case "omitalways":
++			st.OmitAlways = true
+ 		case "minsize":
+ 			st.MinSize = true
+ 		case "truncate":

_data/update-mongo.sh

@@ -0,0 +1,95 @@
+#!/bin/bash
+
+
+    set -o nounset   # disallow usage of unset vars  ( set -u )
+    set -o errexit   # Exit immediately if a pipeline returns non-zero.  ( set -e )
+    set -o errtrace  # Allow the above trap be inherited by all functions in the script.  ( set -E )
+    set -o pipefail  # Return value of a pipeline is the value of the last (rightmost) command to exit with a non-zero status
+    IFS=$'\n\t'      # Set $IFS to only newline and tab.
+
+
+
+dir="/tmp/mongo_repo_$( uuidgen )"
+
+echo ""
+echo "> Clone https://github.dev/mongodb/mongo-go-driver"
+echo ""
+
+git clone "https://github.com/mongodb/mongo-go-driver" "$dir"
+
+pushd "$dir"
+
+git fetch --tags
+
+latestTag="$( git describe --tags `git rev-list --tags --max-count=1` )"
+
+git -c "advice.detachedHead=false" checkout $latestTag
+
+latestSHA="$( git rev-parse HEAD )"
+
+popd
+
+existingTag=$( cat mongoPatchVersion.go | grep -oP "(?<=const MongoCloneTag = \")([A-Za-z0-9.]+)(?=\")" )
+existingSHA=$( cat mongoPatchVersion.go | grep -oP "(?<=const MongoCloneCommit = \")([A-Za-z0-9.]+)(?=\")" )
+
+echo "===================================="
+echo "ID  (online) $latestSHA"
+echo "ID  (local)  $existingSHA"
+echo "Tag (online) $latestTag"
+echo "Tag (local)  $existingTag"
+echo "===================================="
+
+if [[ "$latestTag" == "$existingTag" ]]; then
+  echo "Nothing to do"
+  rm -rf "$dir"
+  exit 0
+fi
+
+echo ""
+echo "> Copy repository"
+echo ""
+
+rm -rf mongo
+cp -r "$dir" "mongo"
+rm -rf "$dir"
+
+echo ""
+echo "> Clean repository"
+echo ""
+
+rm -rf "mongo/.git"
+rm -rf "mongo/.evergreen"
+rm -rf "mongo/cmd"
+rm -rf "mongo/docs"
+rm -rf "mongo/etc"
+rm -rf "mongo/examples"
+rm -rf "mongo/testdata"
+rm -rf "mongo/benchmark"
+rm -rf "mongo/vendor"
+rm -rf "mongo/internal/test"
+rm -rf "mongo/go.mod"
+rm -rf "mongo/go.sum"
+
+echo ""
+echo "> Update mongoPatchVersion.go"
+echo ""
+
+{
+
+  printf "package goext\n"
+  printf "\n"
+  printf "// %s\n" "$( date +"%Y-%m-%d %H:%M:%S%z" )"
+  printf "\n"
+  printf "const MongoCloneTag = \"%s\"\n" "$latestTag"
+  printf "const MongoCloneCommit = \"%s\"\n" "$latestSHA"
+
+} > mongoPatchVersion.go
+
+echo ""
+echo "> Patch mongo"
+echo ""
+
+git apply -v _data/mongo.patch
+
+echo ""
+echo "Done."

_data/version.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+set -o nounset   # disallow usage of unset vars  ( set -u )
+set -o errexit   # Exit immediately if a pipeline returns non-zero.  ( set -e )
+set -o errtrace  # Allow the above trap be inherited by all functions in the script.  ( set -E )
+set -o pipefail  # Return value of a pipeline is the value of the last (rightmost) command to exit with a non-zero status
+IFS=$'\n\t'      # Set $IFS to only newline and tab.
+
+
+function black() { echo -e "\x1B[30m $1 \x1B[0m"; }
+function red()   { echo -e "\x1B[31m $1 \x1B[0m"; }
+function green() { echo -e "\x1B[32m $1 \x1B[0m"; }
+function yellow(){ echo -e "\x1B[33m $1 \x1B[0m"; }
+function blue()  { echo -e "\x1B[34m $1 \x1B[0m"; }
+function purple(){ echo -e "\x1B[35m $1 \x1B[0m"; }
+function cyan()  { echo -e "\x1B[36m $1 \x1B[0m"; }
+function white() { echo -e "\x1B[37m $1 \x1B[0m"; }
+
+if [ "$( git rev-parse --abbrev-ref HEAD )" != "master" ]; then
+  >&2 red "[ERROR] Can only create versions of <master>"
+  exit 1
+fi
+
+git pull --ff
+
+go get -u ./...
+
+curr_vers=$(git describe --tags --abbrev=0 | sed 's/v//g')
+
+next_ver=$(echo "$curr_vers" | awk -F. -v OFS=. 'NF==1{print ++$NF}; NF>1{if(length($NF+1)>length($NF))$(NF-1)++; $NF=sprintf("%0*d", length($NF), ($NF+1)%(10^length($NF))); print}')
+
+echo ""
+echo "> Current Version: ${curr_vers}"
+echo "> Next    Version: ${next_ver}"
+echo ""
+
+printf "package goext\n\nconst GoextVersion = \"%s\"\n\nconst GoextVersionTimestamp = \"%s\"\n" "${next_ver}" "$( date +"%Y-%m-%dT%H:%M:%S%z" )" > "goextVersion.go"
+
+git add --verbose .
+
+msg="v${next_ver}"
+
+if [ $# -gt 0 ]; then
+  msg="$1"
+fi
+
+git commit -a -m "${msg}"
+
+git tag "v${next_ver}"
+
+git push
+git push --tags
+

bfcodegen/enum-generate.go

@@ -0,0 +1,364 @@
+package bfcodegen
+
+import (
+	"errors"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext"
+	"gogs.mikescher.com/BlackForestBytes/goext/cmdext"
+	"gogs.mikescher.com/BlackForestBytes/goext/cryptext"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/rext"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"time"
+)
+
+type EnumDefVal struct {
+	VarName     string
+	Value       string
+	Description *string
+}
+
+type EnumDef struct {
+	File         string
+	FileRelative string
+	EnumTypeName string
+	Type         string
+	Values       []EnumDefVal
+}
+
+var rexPackage = rext.W(regexp.MustCompile("^package\\s+(?P<name>[A-Za-z0-9_]+)\\s*$"))
+
+var rexEnumDef = rext.W(regexp.MustCompile("^\\s*type\\s+(?P<name>[A-Za-z0-9_]+)\\s+(?P<type>[A-Za-z0-9_]+)\\s*//\\s*(@enum:type).*$"))
+
+var rexValueDef = rext.W(regexp.MustCompile("^\\s*(?P<name>[A-Za-z0-9_]+)\\s+(?P<type>[A-Za-z0-9_]+)\\s*=\\s*(?P<value>(\"[A-Za-z0-9_:]+\"|[0-9]+))\\s*(//(?P<descr>.*))?.*$"))
+
+var rexChecksumConst = rext.W(regexp.MustCompile("const ChecksumGenerator = \"(?P<cs>[A-Za-z0-9_]*)\""))
+
+func GenerateEnumSpecs(sourceDir string, destFile string) error {
+
+	files, err := os.ReadDir(sourceDir)
+	if err != nil {
+		return err
+	}
+
+	oldChecksum := "N/A"
+	if _, err := os.Stat(destFile); !os.IsNotExist(err) {
+		content, err := os.ReadFile(destFile)
+		if err != nil {
+			return err
+		}
+		if m, ok := rexChecksumConst.MatchFirst(string(content)); ok {
+			oldChecksum = m.GroupByName("cs").Value()
+		}
+	}
+
+	files = langext.ArrFilter(files, func(v os.DirEntry) bool { return v.Name() != path.Base(destFile) })
+	files = langext.ArrFilter(files, func(v os.DirEntry) bool { return strings.HasSuffix(v.Name(), ".go") })
+	langext.SortBy(files, func(v os.DirEntry) string { return v.Name() })
+
+	newChecksumStr := goext.GoextVersion
+	for _, f := range files {
+		content, err := os.ReadFile(path.Join(sourceDir, f.Name()))
+		if err != nil {
+			return err
+		}
+		newChecksumStr += "\n" + f.Name() + "\t" + cryptext.BytesSha256(content)
+	}
+
+	newChecksum := cryptext.BytesSha256([]byte(newChecksumStr))
+
+	if newChecksum != oldChecksum {
+		fmt.Printf("[EnumGenerate] Checksum has changed ( %s -> %s ), will generate new file\n\n", oldChecksum, newChecksum)
+	} else {
+		fmt.Printf("[EnumGenerate] Checksum unchanged ( %s ), nothing to do\n", oldChecksum)
+		return nil
+	}
+
+	allEnums := make([]EnumDef, 0)
+
+	pkgname := ""
+
+	for _, f := range files {
+		fmt.Printf("========= %s =========\n\n", f.Name())
+		fileEnums, pn, err := processFile(sourceDir, path.Join(sourceDir, f.Name()))
+		if err != nil {
+			return err
+		}
+
+		fmt.Printf("\n")
+
+		allEnums = append(allEnums, fileEnums...)
+
+		if pn != "" {
+			pkgname = pn
+		}
+	}
+
+	if pkgname == "" {
+		return errors.New("no package name found in any file")
+	}
+
+	err = os.WriteFile(destFile, []byte(fmtOutput(newChecksum, allEnums, pkgname)), 0o755)
+	if err != nil {
+		return err
+	}
+
+	res, err := cmdext.RunCommand("go", []string{"fmt", destFile}, langext.Ptr(2*time.Second))
+	if err != nil {
+		return err
+	}
+
+	if res.CommandTimedOut {
+		fmt.Println(res.StdCombined)
+		return errors.New("go fmt timed out")
+	}
+	if res.ExitCode != 0 {
+		fmt.Println(res.StdCombined)
+		return errors.New("go fmt did not succeed")
+	}
+
+	return nil
+}
+
+func processFile(basedir string, fn string) ([]EnumDef, string, error) {
+	file, err := os.Open(fn)
+	if err != nil {
+		return nil, "", err
+	}
+
+	defer func() { _ = file.Close() }()
+
+	bin, err := io.ReadAll(file)
+	if err != nil {
+		return nil, "", err
+	}
+
+	lines := strings.Split(string(bin), "\n")
+
+	enums := make([]EnumDef, 0)
+
+	pkgname := ""
+
+	for i, line := range lines {
+		if i == 0 && strings.HasPrefix(line, "// Code generated by") {
+			break
+		}
+
+		if match, ok := rexPackage.MatchFirst(line); i == 0 && ok {
+			pkgname = match.GroupByName("name").Value()
+			continue
+		}
+
+		if match, ok := rexEnumDef.MatchFirst(line); ok {
+
+			rfp, err := filepath.Rel(basedir, fn)
+			if err != nil {
+				return nil, "", err
+			}
+
+			def := EnumDef{
+				File:         fn,
+				FileRelative: rfp,
+				EnumTypeName: match.GroupByName("name").Value(),
+				Type:         match.GroupByName("type").Value(),
+				Values:       make([]EnumDefVal, 0),
+			}
+			enums = append(enums, def)
+			fmt.Printf("Found enum definition { '%s' -> '%s' }\n", def.EnumTypeName, def.Type)
+		}
+
+		if match, ok := rexValueDef.MatchFirst(line); ok {
+			typename := match.GroupByName("type").Value()
+			def := EnumDefVal{
+				VarName:     match.GroupByName("name").Value(),
+				Value:       match.GroupByName("value").Value(),
+				Description: match.GroupByNameOrEmpty("descr").ValueOrNil(),
+			}
+
+			found := false
+			for i, v := range enums {
+				if v.EnumTypeName == typename {
+					enums[i].Values = append(enums[i].Values, def)
+					found = true
+					if def.Description != nil {
+						fmt.Printf("Found enum value [%s] for '%s'  ('%s')\n", def.Value, def.VarName, *def.Description)
+					} else {
+						fmt.Printf("Found enum value [%s] for '%s'\n", def.Value, def.VarName)
+					}
+					break
+				}
+			}
+			if !found {
+				fmt.Printf("Found non-enum value [%s] for '%s' ( looks like enum value, but no matching @enum:type )\n", def.Value, def.VarName)
+			}
+		}
+	}
+
+	return enums, pkgname, nil
+}
+
+func fmtOutput(cs string, enums []EnumDef, pkgname string) string {
+	str := "// Code generated by enum-generate.go DO NOT EDIT.\n"
+	str += "\n"
+	str += "package " + pkgname + "\n"
+	str += "\n"
+
+	str += "import \"gogs.mikescher.com/BlackForestBytes/goext/langext\"" + "\n"
+	str += "\n"
+
+	str += "const ChecksumGenerator = \"" + cs + "\"" + "\n"
+	str += "\n"
+
+	str += "type Enum interface {" + "\n"
+	str += "    Valid() bool" + "\n"
+	str += "    ValuesAny() []any" + "\n"
+	str += "    ValuesMeta() []EnumMetaValue" + "\n"
+	str += "    VarName() string" + "\n"
+	str += "}" + "\n"
+	str += "" + "\n"
+
+	str += "type StringEnum interface {" + "\n"
+	str += "    Enum" + "\n"
+	str += "    String() string" + "\n"
+	str += "}" + "\n"
+	str += "" + "\n"
+
+	str += "type DescriptionEnum interface {" + "\n"
+	str += "    Enum" + "\n"
+	str += "    Description() string" + "\n"
+	str += "}" + "\n"
+	str += "\n"
+
+	str += "type EnumMetaValue struct {" + "\n"
+	str += "    VarName     string  `json:\"varName\"`" + "\n"
+	str += "    Value       any     `json:\"value\"`" + "\n"
+	str += "    Description *string `json:\"description\"`" + "\n"
+	str += "}" + "\n"
+	str += "\n"
+
+	for _, enumdef := range enums {
+
+		hasDescr := langext.ArrAll(enumdef.Values, func(val EnumDefVal) bool { return val.Description != nil })
+		hasStr := enumdef.Type == "string"
+
+		str += "// ================================ " + enumdef.EnumTypeName + " ================================" + "\n"
+		str += "//" + "\n"
+		str += "// File:       " + enumdef.FileRelative + "\n"
+		str += "// StringEnum: " + langext.Conditional(hasStr, "true", "false") + "\n"
+		str += "// DescrEnum:  " + langext.Conditional(hasDescr, "true", "false") + "\n"
+		str += "//" + "\n"
+		str += "" + "\n"
+
+		str += "var __" + enumdef.EnumTypeName + "Values = []" + enumdef.EnumTypeName + "{" + "\n"
+		for _, v := range enumdef.Values {
+			str += "    " + v.VarName + "," + "\n"
+		}
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		if hasDescr {
+			str += "var __" + enumdef.EnumTypeName + "Descriptions = map[" + enumdef.EnumTypeName + "]string{" + "\n"
+			for _, v := range enumdef.Values {
+				str += "    " + v.VarName + ": \"" + strings.TrimSpace(*v.Description) + "\"," + "\n"
+			}
+			str += "}" + "\n"
+			str += "" + "\n"
+		}
+
+		str += "var __" + enumdef.EnumTypeName + "Varnames = map[" + enumdef.EnumTypeName + "]string{" + "\n"
+		for _, v := range enumdef.Values {
+			str += "    " + v.VarName + ": \"" + v.VarName + "\"," + "\n"
+		}
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func (e " + enumdef.EnumTypeName + ") Valid() bool {" + "\n"
+		str += "    return langext.InArray(e, __" + enumdef.EnumTypeName + "Values)" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func (e " + enumdef.EnumTypeName + ") Values() []" + enumdef.EnumTypeName + " {" + "\n"
+		str += "    return __" + enumdef.EnumTypeName + "Values" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func (e " + enumdef.EnumTypeName + ") ValuesAny() []any {" + "\n"
+		str += "    return langext.ArrCastToAny(__" + enumdef.EnumTypeName + "Values)" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func (e " + enumdef.EnumTypeName + ") ValuesMeta() []EnumMetaValue {" + "\n"
+		str += "    return []EnumMetaValue{" + "\n"
+		for _, v := range enumdef.Values {
+			if hasDescr {
+				str += "        " + fmt.Sprintf("EnumMetaValue{VarName: \"%s\", Value: %s, Description: langext.Ptr(\"%s\")},", v.VarName, v.VarName, strings.TrimSpace(*v.Description)) + "\n"
+			} else {
+				str += "        " + fmt.Sprintf("EnumMetaValue{VarName: \"%s\", Value: %s, Description: nil},", v.VarName, v.VarName) + "\n"
+			}
+		}
+		str += "    }" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		if hasStr {
+			str += "func (e " + enumdef.EnumTypeName + ") String() string {" + "\n"
+			str += "    return string(e)" + "\n"
+			str += "}" + "\n"
+			str += "" + "\n"
+		}
+
+		if hasDescr {
+			str += "func (e " + enumdef.EnumTypeName + ") Description() string {" + "\n"
+			str += "    if d, ok := __" + enumdef.EnumTypeName + "Descriptions[e]; ok {" + "\n"
+			str += "        return d" + "\n"
+			str += "    }" + "\n"
+			str += "    return \"\"" + "\n"
+			str += "}" + "\n"
+			str += "" + "\n"
+		}
+
+		str += "func (e " + enumdef.EnumTypeName + ") VarName() string {" + "\n"
+		str += "    if d, ok := __" + enumdef.EnumTypeName + "Varnames[e]; ok {" + "\n"
+		str += "        return d" + "\n"
+		str += "    }" + "\n"
+		str += "    return \"\"" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func Parse" + enumdef.EnumTypeName + "(vv string) (" + enumdef.EnumTypeName + ", bool) {" + "\n"
+		str += "    for _, ev := range __" + enumdef.EnumTypeName + "Values {" + "\n"
+		str += "        if string(ev) == vv {" + "\n"
+		str += "            return ev, true" + "\n"
+		str += "        }" + "\n"
+		str += "    }" + "\n"
+		str += "    return \"\", false" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func " + enumdef.EnumTypeName + "Values() []" + enumdef.EnumTypeName + " {" + "\n"
+		str += "    return __" + enumdef.EnumTypeName + "Values" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+		str += "func " + enumdef.EnumTypeName + "ValuesMeta() []EnumMetaValue {" + "\n"
+		str += "    return []EnumMetaValue{" + "\n"
+		for _, v := range enumdef.Values {
+			if hasDescr {
+				str += "        " + fmt.Sprintf("EnumMetaValue{VarName: \"%s\", Value: %s, Description: langext.Ptr(\"%s\")},", v.VarName, v.VarName, strings.TrimSpace(*v.Description)) + "\n"
+			} else {
+				str += "        " + fmt.Sprintf("EnumMetaValue{VarName: \"%s\", Value: %s, Description: nil},", v.VarName, v.VarName) + "\n"
+			}
+		}
+		str += "    }" + "\n"
+		str += "}" + "\n"
+		str += "" + "\n"
+
+	}
+
+	return str
+}

bfcodegen/enum-generate_test.go

@@ -0,0 +1,15 @@
+package bfcodegen
+
+import (
+	"testing"
+)
+
+func TestApplyEnvOverridesSimple(t *testing.T) {
+
+	err := GenerateEnumSpecs("/home/mike/Code/reiff/badennet/bnet-backend/models", "/home/mike/Code/reiff/badennet/bnet-backend/models/enums_gen.go")
+	if err != nil {
+		t.Error(err)
+		t.Fail()
+	}
+
+}

cmdext/builder.go

@@ -0,0 +1,93 @@
+package cmdext
+
+import (
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"time"
+)
+
+type CommandRunner struct {
+	program          string
+	args             []string
+	timeout          *time.Duration
+	env              []string
+	listener         []CommandListener
+	enforceExitCodes *[]int
+	enforceNoTimeout bool
+}
+
+func Runner(program string) *CommandRunner {
+	return &CommandRunner{
+		program:          program,
+		args:             make([]string, 0),
+		timeout:          nil,
+		env:              make([]string, 0),
+		listener:         make([]CommandListener, 0),
+		enforceExitCodes: nil,
+		enforceNoTimeout: false,
+	}
+}
+
+func (r *CommandRunner) Arg(arg string) *CommandRunner {
+	r.args = append(r.args, arg)
+	return r
+}
+
+func (r *CommandRunner) Args(arg []string) *CommandRunner {
+	r.args = append(r.args, arg...)
+	return r
+}
+
+func (r *CommandRunner) Timeout(timeout time.Duration) *CommandRunner {
+	r.timeout = &timeout
+	return r
+}
+
+func (r *CommandRunner) Env(key, value string) *CommandRunner {
+	r.env = append(r.env, fmt.Sprintf("%s=%s", key, value))
+	return r
+}
+
+func (r *CommandRunner) RawEnv(env string) *CommandRunner {
+	r.env = append(r.env, env)
+	return r
+}
+
+func (r *CommandRunner) Envs(env []string) *CommandRunner {
+	r.env = append(r.env, env...)
+	return r
+}
+
+func (r *CommandRunner) EnsureExitcode(arg ...int) *CommandRunner {
+	r.enforceExitCodes = langext.Ptr(langext.ForceArray(arg))
+	return r
+}
+
+func (r *CommandRunner) FailOnExitCode() *CommandRunner {
+	r.enforceExitCodes = langext.Ptr([]int{0})
+	return r
+}
+
+func (r *CommandRunner) FailOnTimeout() *CommandRunner {
+	r.enforceNoTimeout = true
+	return r
+}
+
+func (r *CommandRunner) Listen(lstr CommandListener) *CommandRunner {
+	r.listener = append(r.listener, lstr)
+	return r
+}
+
+func (r *CommandRunner) ListenStdout(lstr func(string)) *CommandRunner {
+	r.listener = append(r.listener, genericCommandListener{_readStdoutLine: &lstr})
+	return r
+}
+
+func (r *CommandRunner) ListenStderr(lstr func(string)) *CommandRunner {
+	r.listener = append(r.listener, genericCommandListener{_readStderrLine: &lstr})
+	return r
+}
+
+func (r *CommandRunner) Run() (CommandResult, error) {
+	return run(*r)
+}

cmdext/cmdrunner.go

@@ -0,0 +1,154 @@
+package cmdext
+
+import (
+	"errors"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/mathext"
+	"gogs.mikescher.com/BlackForestBytes/goext/syncext"
+	"os/exec"
+	"time"
+)
+
+var ErrExitCode = errors.New("process exited with an unexpected exitcode")
+var ErrTimeout = errors.New("process did not exit after the specified timeout")
+
+type CommandResult struct {
+	StdOut          string
+	StdErr          string
+	StdCombined     string
+	ExitCode        int
+	CommandTimedOut bool
+}
+
+func run(opt CommandRunner) (CommandResult, error) {
+	cmd := exec.Command(opt.program, opt.args...)
+
+	cmd.Env = append(cmd.Env, opt.env...)
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return CommandResult{}, err
+	}
+
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		return CommandResult{}, err
+	}
+
+	preader := pipeReader{
+		lineBufferSize: langext.Ptr(128 * 1024 * 1024), // 128MB max size of a single line, is hopefully enough....
+		stdout:         stdoutPipe,
+		stderr:         stderrPipe,
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return CommandResult{}, err
+	}
+
+	type resultObj struct {
+		stdout      string
+		stderr      string
+		stdcombined string
+		err         error
+	}
+
+	outputChan := make(chan resultObj)
+	go func() {
+		// we need to first fully read the pipes and then call Wait
+		// see https://pkg.go.dev/os/exec#Cmd.StdoutPipe
+
+		stdout, stderr, stdcombined, err := preader.Read(opt.listener)
+		if err != nil {
+			outputChan <- resultObj{stdout, stderr, stdcombined, err}
+			_ = cmd.Process.Kill()
+			return
+		}
+
+		err = cmd.Wait()
+		if err != nil {
+			outputChan <- resultObj{stdout, stderr, stdcombined, err}
+		} else {
+			outputChan <- resultObj{stdout, stderr, stdcombined, nil}
+		}
+
+	}()
+
+	var timeoutChan <-chan time.Time = make(chan time.Time, 1)
+	if opt.timeout != nil {
+		timeoutChan = time.After(*opt.timeout)
+	}
+
+	select {
+
+	case <-timeoutChan:
+		_ = cmd.Process.Kill()
+		for _, lstr := range opt.listener {
+			lstr.Timeout()
+		}
+
+		if fallback, ok := syncext.ReadChannelWithTimeout(outputChan, mathext.Min(32*time.Millisecond, *opt.timeout)); ok {
+			// most of the time the cmd.Process.Kill() should also ahve finished the pipereader
+			// and we can at least return the already collected stdout, stderr, etc
+			res := CommandResult{
+				StdOut:          fallback.stdout,
+				StdErr:          fallback.stderr,
+				StdCombined:     fallback.stdcombined,
+				ExitCode:        -1,
+				CommandTimedOut: true,
+			}
+			if opt.enforceNoTimeout {
+				return res, ErrTimeout
+			}
+			return res, nil
+		} else {
+			res := CommandResult{
+				StdOut:          "",
+				StdErr:          "",
+				StdCombined:     "",
+				ExitCode:        -1,
+				CommandTimedOut: true,
+			}
+			if opt.enforceNoTimeout {
+				return res, ErrTimeout
+			}
+			return res, nil
+		}
+
+	case outobj := <-outputChan:
+		if exiterr, ok := outobj.err.(*exec.ExitError); ok {
+			excode := exiterr.ExitCode()
+			for _, lstr := range opt.listener {
+				lstr.Finished(excode)
+			}
+			res := CommandResult{
+				StdOut:          outobj.stdout,
+				StdErr:          outobj.stderr,
+				StdCombined:     outobj.stdcombined,
+				ExitCode:        excode,
+				CommandTimedOut: false,
+			}
+			if opt.enforceExitCodes != nil && !langext.InArray(excode, *opt.enforceExitCodes) {
+				return res, ErrExitCode
+			}
+			return res, nil
+		} else if err != nil {
+			return CommandResult{}, err
+		} else {
+			for _, lstr := range opt.listener {
+				lstr.Finished(0)
+			}
+			res := CommandResult{
+				StdOut:          outobj.stdout,
+				StdErr:          outobj.stderr,
+				StdCombined:     outobj.stdcombined,
+				ExitCode:        0,
+				CommandTimedOut: false,
+			}
+			if opt.enforceExitCodes != nil && !langext.InArray(0, *opt.enforceExitCodes) {
+				return res, ErrExitCode
+			}
+			return res, nil
+		}
+	}
+}

cmdext/cmdrunner_test.go

@@ -0,0 +1,323 @@
+package cmdext
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestStdout(t *testing.T) {
+
+	res1, err := Runner("printf").Arg("hello").Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "hello" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "hello\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestStderr(t *testing.T) {
+
+	res1, err := Runner("python").Arg("-c").Arg("import sys; print(\"error\", file=sys.stderr, end='')").Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+	if res1.StdErr != "error" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "error\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestStdcombined(t *testing.T) {
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"1\", file=sys.stderr, flush=True); time.sleep(0.1); print(\"2\", file=sys.stdout, flush=True); time.sleep(0.1); print(\"3\", file=sys.stderr, flush=True)").
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+	if res1.StdErr != "1\n3\n" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "2\n" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "1\n2\n3\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestPartialRead(t *testing.T) {
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", flush=True); time.sleep(5); print(\"cant see me\", flush=True);").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "first message\n" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestPartialReadStderr(t *testing.T) {
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", file=sys.stderr, flush=True); time.sleep(5); print(\"cant see me\", file=sys.stderr, flush=True);").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "first message\n" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestReadUnflushedStdout(t *testing.T) {
+
+	res1, err := Runner("python").Arg("-c").Arg("import sys; print(\"message101\", file=sys.stdout, end='')").Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "message101" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "message101\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestReadUnflushedStderr(t *testing.T) {
+
+	res1, err := Runner("python").Arg("-c").Arg("import sys; print(\"message101\", file=sys.stderr, end='')").Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+	if res1.StdErr != "message101" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "message101\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestPartialReadUnflushed(t *testing.T) {
+	t.SkipNow()
+
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", end=''); time.sleep(5); print(\"cant see me\", end='');").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "first message" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestPartialReadUnflushedStderr(t *testing.T) {
+	t.SkipNow()
+
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", file=sys.stderr, end=''); time.sleep(5); print(\"cant see me\", file=sys.stderr, end='');").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "first message" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestListener(t *testing.T) {
+
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys;" +
+			"import time;" +
+			"print(\"message 1\", flush=True);" +
+			"time.sleep(1);" +
+			"print(\"message 2\", flush=True);" +
+			"time.sleep(1);" +
+			"print(\"message 3\", flush=True);" +
+			"time.sleep(1);" +
+			"print(\"message 4\", file=sys.stderr, flush=True);" +
+			"time.sleep(1);" +
+			"print(\"message 5\", flush=True);" +
+			"time.sleep(1);" +
+			"print(\"final\");").
+		ListenStdout(func(s string) { fmt.Printf("@@STDOUT <<- %v (%v)\n", s, time.Now().Format(time.RFC3339Nano)) }).
+		ListenStderr(func(s string) { fmt.Printf("@@STDERR <<- %v (%v)\n", s, time.Now().Format(time.RFC3339Nano)) }).
+		Timeout(10 * time.Second).
+		Run()
+
+	if err != nil {
+		panic(err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+}
+
+func TestLongStdout(t *testing.T) {
+
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"X\" * 125001 + \"\\n\"); print(\"Y\" * 125001 + \"\\n\"); print(\"Z\" * 125001 + \"\\n\");").
+		Timeout(5000 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.CommandTimedOut {
+		t.Errorf("Timeout")
+	}
+	if res1.ExitCode != 0 {
+		t.Errorf("res1.ExitCode == %v", res1.ExitCode)
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if len(res1.StdOut) != 375009 {
+		t.Errorf("len(res1.StdOut) == '%v'", len(res1.StdOut))
+	}
+
+}
+
+func TestFailOnTimeout(t *testing.T) {
+
+	_, err := Runner("sleep").Arg("2").Timeout(200 * time.Millisecond).FailOnTimeout().Run()
+	if err != ErrTimeout {
+		t.Errorf("wrong err := %v", err)
+	}
+
+}
+
+func TestFailOnExitcode(t *testing.T) {
+
+	_, err := Runner("false").Timeout(200 * time.Millisecond).FailOnExitCode().Run()
+	if err != ErrExitCode {
+		t.Errorf("wrong err := %v", err)
+	}
+
+}
+
+func TestEnsureExitcode1(t *testing.T) {
+
+	_, err := Runner("false").Timeout(200 * time.Millisecond).EnsureExitcode(1).Run()
+	if err != nil {
+		t.Errorf("wrong err := %v", err)
+	}
+
+}
+
+func TestEnsureExitcode2(t *testing.T) {
+
+	_, err := Runner("false").Timeout(200*time.Millisecond).EnsureExitcode(0, 2, 3).Run()
+	if err != ErrExitCode {
+		t.Errorf("wrong err := %v", err)
+	}
+
+}

cmdext/helper.go

@@ -0,0 +1,12 @@
+package cmdext
+
+import "time"
+
+func RunCommand(program string, args []string, timeout *time.Duration) (CommandResult, error) {
+	b := Runner(program)
+	b = b.Args(args)
+	if timeout != nil {
+		b = b.Timeout(*timeout)
+	}
+	return b.Run()
+}

cmdext/listener.go

@@ -0,0 +1,57 @@
+package cmdext
+
+type CommandListener interface {
+	ReadRawStdout([]byte)
+	ReadRawStderr([]byte)
+
+	ReadStdoutLine(string)
+	ReadStderrLine(string)
+
+	Finished(int)
+	Timeout()
+}
+
+type genericCommandListener struct {
+	_readRawStdout  *func([]byte)
+	_readRawStderr  *func([]byte)
+	_readStdoutLine *func(string)
+	_readStderrLine *func(string)
+	_finished       *func(int)
+	_timeout        *func()
+}
+
+func (g genericCommandListener) ReadRawStdout(v []byte) {
+	if g._readRawStdout != nil {
+		(*g._readRawStdout)(v)
+	}
+}
+
+func (g genericCommandListener) ReadRawStderr(v []byte) {
+	if g._readRawStderr != nil {
+		(*g._readRawStderr)(v)
+	}
+}
+
+func (g genericCommandListener) ReadStdoutLine(v string) {
+	if g._readStdoutLine != nil {
+		(*g._readStdoutLine)(v)
+	}
+}
+
+func (g genericCommandListener) ReadStderrLine(v string) {
+	if g._readStderrLine != nil {
+		(*g._readStderrLine)(v)
+	}
+}
+
+func (g genericCommandListener) Finished(v int) {
+	if g._finished != nil {
+		(*g._finished)(v)
+	}
+}
+
+func (g genericCommandListener) Timeout() {
+	if g._timeout != nil {
+		(*g._timeout)()
+	}
+}

cmdext/pipereader.go

@@ -0,0 +1,158 @@
+package cmdext
+
+import (
+	"bufio"
+	"gogs.mikescher.com/BlackForestBytes/goext/syncext"
+	"io"
+	"sync"
+)
+
+type pipeReader struct {
+	lineBufferSize *int
+	stdout         io.ReadCloser
+	stderr         io.ReadCloser
+}
+
+// Read ready stdout and stdin until finished
+// also splits both pipes into lines and calld the listener
+func (pr *pipeReader) Read(listener []CommandListener) (string, string, string, error) {
+	type combevt struct {
+		line string
+		stop bool
+	}
+
+	errch := make(chan error, 8)
+
+	wg := sync.WaitGroup{}
+
+	// [1] read raw stdout
+
+	wg.Add(1)
+	stdoutBufferReader, stdoutBufferWriter := io.Pipe()
+	stdout := ""
+	go func() {
+		buf := make([]byte, 128)
+		for true {
+			n, out := pr.stdout.Read(buf)
+			if n > 0 {
+				txt := string(buf[:n])
+				stdout += txt
+				_, _ = stdoutBufferWriter.Write(buf[:n])
+				for _, lstr := range listener {
+					lstr.ReadRawStdout(buf[:n])
+				}
+			}
+			if out == io.EOF {
+				break
+			}
+			if out != nil {
+				errch <- out
+				break
+			}
+		}
+		_ = stdoutBufferWriter.Close()
+		wg.Done()
+	}()
+
+	// [2] read raw stderr
+
+	wg.Add(1)
+	stderrBufferReader, stderrBufferWriter := io.Pipe()
+	stderr := ""
+	go func() {
+		buf := make([]byte, 128)
+		for true {
+			n, err := pr.stderr.Read(buf)
+
+			if n > 0 {
+				txt := string(buf[:n])
+				stderr += txt
+				_, _ = stderrBufferWriter.Write(buf[:n])
+				for _, lstr := range listener {
+					lstr.ReadRawStderr(buf[:n])
+				}
+			}
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				errch <- err
+				break
+			}
+		}
+		_ = stderrBufferWriter.Close()
+		wg.Done()
+	}()
+
+	combch := make(chan combevt, 32)
+
+	// [3] collect stdout line-by-line
+
+	wg.Add(1)
+	go func() {
+		scanner := bufio.NewScanner(stdoutBufferReader)
+		if pr.lineBufferSize != nil {
+			scanner.Buffer([]byte{}, *pr.lineBufferSize)
+		}
+		for scanner.Scan() {
+			txt := scanner.Text()
+			for _, lstr := range listener {
+				lstr.ReadStdoutLine(txt)
+			}
+			combch <- combevt{txt, false}
+		}
+		if err := scanner.Err(); err != nil {
+			errch <- err
+		}
+		combch <- combevt{"", true}
+		wg.Done()
+	}()
+
+	// [4] collect stderr line-by-line
+
+	wg.Add(1)
+	go func() {
+		scanner := bufio.NewScanner(stderrBufferReader)
+		if pr.lineBufferSize != nil {
+			scanner.Buffer([]byte{}, *pr.lineBufferSize)
+		}
+		for scanner.Scan() {
+			txt := scanner.Text()
+			for _, lstr := range listener {
+				lstr.ReadStderrLine(txt)
+			}
+			combch <- combevt{txt, false}
+		}
+		if err := scanner.Err(); err != nil {
+			errch <- err
+		}
+		combch <- combevt{"", true}
+		wg.Done()
+	}()
+
+	// [5] combine stdcombined
+
+	wg.Add(1)
+	stdcombined := ""
+	go func() {
+		stopctr := 0
+		for stopctr < 2 {
+			vvv := <-combch
+			if vvv.stop {
+				stopctr++
+			} else {
+				stdcombined += vvv.line + "\n" // this comes from bufio.Scanner and has no newlines...
+			}
+		}
+		wg.Done()
+	}()
+
+	// wait for all (5) goroutines to finish
+	wg.Wait()
+
+	if err, ok := syncext.ReadNonBlocking(errch); ok {
+		return "", "", "", err
+	}
+
+	return stdout, stderr, stdcombined, nil
+}

confext/confParser.go

@@ -0,0 +1,198 @@
+package confext
+
+import (
+	"errors"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/timeext"
+	"math/bits"
+	"os"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ApplyEnvOverrides overrides field values from environment variables
+//
+// fields must be tagged with `env:"env_key"`
+//
+// only works on exported fields
+//
+// fields without an env tag are ignored
+// fields with an `env:"-"` tag are ignore
+//
+// sub-structs are recursively parsed (if they have an env tag) and the env-variable keys are delimited by the delim parameter
+// sub-structs with `env:""` are also parsed, but the delimited is skipped (they are handled as if they were one level higher)
+func ApplyEnvOverrides[T any](prefix string, c *T, delim string) error {
+	rval := reflect.ValueOf(c).Elem()
+
+	return processEnvOverrides(rval, delim, prefix)
+}
+
+func processEnvOverrides(rval reflect.Value, delim string, prefix string) error {
+	rtyp := rval.Type()
+
+	for i := 0; i < rtyp.NumField(); i++ {
+
+		rsfield := rtyp.Field(i)
+		rvfield := rval.Field(i)
+
+		if !rsfield.IsExported() {
+			continue
+		}
+
+		if rvfield.Kind() == reflect.Struct {
+
+			envkey, found := rsfield.Tag.Lookup("env")
+			if !found || envkey == "-" {
+				continue
+			}
+
+			subPrefix := prefix
+			if envkey != "" {
+				subPrefix = subPrefix + envkey + delim
+			}
+
+			err := processEnvOverrides(rvfield, delim, subPrefix)
+			if err != nil {
+				return err
+			}
+		}
+
+		envkey := rsfield.Tag.Get("env")
+		if envkey == "" || envkey == "-" {
+			continue
+		}
+
+		fullEnvKey := prefix + envkey
+
+		envval, efound := os.LookupEnv(fullEnvKey)
+		if !efound {
+			continue
+		}
+
+		if rvfield.Type().Kind() == reflect.Pointer {
+
+			newval, err := parseEnvToValue(envval, fullEnvKey, rvfield.Type().Elem())
+			if err != nil {
+				return err
+			}
+
+			// converts reflect.Value to pointer
+			ptrval := reflect.New(rvfield.Type().Elem())
+			ptrval.Elem().Set(newval)
+
+			rvfield.Set(ptrval)
+
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
+
+		} else {
+
+			newval, err := parseEnvToValue(envval, fullEnvKey, rvfield.Type())
+			if err != nil {
+				return err
+			}
+
+			rvfield.Set(newval)
+			fmt.Printf("[CONF] Overwrite config '%s' with '%s'\n", fullEnvKey, envval)
+
+		}
+
+	}
+
+	return nil
+}
+
+func parseEnvToValue(envval string, fullEnvKey string, rvtype reflect.Type) (reflect.Value, error) {
+	if rvtype == reflect.TypeOf("") {
+
+		return reflect.ValueOf(envval), nil
+
+	} else if rvtype == reflect.TypeOf(int(0)) {
+
+		envint, err := strconv.ParseInt(envval, 10, bits.UintSize)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int (value := '%s')", fullEnvKey, envval))
+		}
+
+		return reflect.ValueOf(int(envint)), nil
+
+	} else if rvtype == reflect.TypeOf(int64(0)) {
+
+		envint, err := strconv.ParseInt(envval, 10, 64)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int64 (value := '%s')", fullEnvKey, envval))
+		}
+
+		return reflect.ValueOf(int64(envint)), nil
+
+	} else if rvtype == reflect.TypeOf(int32(0)) {
+
+		envint, err := strconv.ParseInt(envval, 10, 32)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", fullEnvKey, envval))
+		}
+
+		return reflect.ValueOf(int32(envint)), nil
+
+	} else if rvtype == reflect.TypeOf(int8(0)) {
+
+		envint, err := strconv.ParseInt(envval, 10, 8)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to int32 (value := '%s')", fullEnvKey, envval))
+		}
+
+		return reflect.ValueOf(int8(envint)), nil
+
+	} else if rvtype == reflect.TypeOf(time.Duration(0)) {
+
+		dur, err := timeext.ParseDurationShortString(envval)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to duration (value := '%s')", fullEnvKey, envval))
+		}
+
+		return reflect.ValueOf(dur), nil
+
+	} else if rvtype == reflect.TypeOf(time.UnixMilli(0)) {
+
+		tim, err := time.Parse(time.RFC3339Nano, envval)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to time.time (value := '%s')", fullEnvKey, envval))
+		}
+
+		return reflect.ValueOf(tim), nil
+
+	} else if rvtype.ConvertibleTo(reflect.TypeOf(int(0))) {
+
+		envint, err := strconv.ParseInt(envval, 10, 8)
+		if err != nil {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to <%s, ,int> (value := '%s')", rvtype.Name(), fullEnvKey, envval))
+		}
+
+		envcvl := reflect.ValueOf(envint).Convert(rvtype)
+
+		return envcvl, nil
+
+	} else if rvtype.ConvertibleTo(reflect.TypeOf(false)) {
+
+		if strings.TrimSpace(strings.ToLower(envval)) == "true" {
+			return reflect.ValueOf(true).Convert(rvtype), nil
+		} else if strings.TrimSpace(strings.ToLower(envval)) == "false" {
+			return reflect.ValueOf(false).Convert(rvtype), nil
+		} else if strings.TrimSpace(strings.ToLower(envval)) == "1" {
+			return reflect.ValueOf(true).Convert(rvtype), nil
+		} else if strings.TrimSpace(strings.ToLower(envval)) == "0" {
+			return reflect.ValueOf(false).Convert(rvtype), nil
+		} else {
+			return reflect.Value{}, errors.New(fmt.Sprintf("Failed to parse env-config variable '%s' to <%s, ,bool> (value := '%s')", rvtype.Name(), fullEnvKey, envval))
+		}
+
+	} else if rvtype.ConvertibleTo(reflect.TypeOf("")) {
+
+		envcvl := reflect.ValueOf(envval).Convert(rvtype)
+		return envcvl, nil
+
+	} else {
+		return reflect.Value{}, errors.New(fmt.Sprintf("Unknown kind/type in config: [ %s | %s ]", rvtype.Kind().String(), rvtype.String()))
+	}
+}

confext/confParser_test.go

@@ -0,0 +1,282 @@
+package confext
+
+import (
+	"gogs.mikescher.com/BlackForestBytes/goext/timeext"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"testing"
+	"time"
+)
+
+func TestApplyEnvOverridesNoop(t *testing.T) {
+
+	type aliasint int
+	type aliasstring string
+
+	type testdata struct {
+		V1 int           `env:"TEST_V1"`
+		VX string        ``
+		V2 string        `env:"TEST_V2"`
+		V3 int8          `env:"TEST_V3"`
+		V4 int32         `env:"TEST_V4"`
+		V5 int64         `env:"TEST_V5"`
+		V6 aliasint      `env:"TEST_V6"`
+		VY aliasint      ``
+		V7 aliasstring   `env:"TEST_V7"`
+		V8 time.Duration `env:"TEST_V8"`
+		V9 time.Time     `env:"TEST_V9"`
+	}
+
+	input := testdata{
+		V1: 1,
+		VX: "X",
+		V2: "2",
+		V3: 3,
+		V4: 4,
+		V5: 5,
+		V6: 6,
+		VY: 99,
+		V7: "7",
+		V8: 9,
+		V9: time.Unix(1671102873, 0),
+	}
+
+	output := input
+
+	err := ApplyEnvOverrides("", &output, ".")
+	if err != nil {
+		t.Errorf("%v", err)
+		t.FailNow()
+	}
+
+	tst.AssertEqual(t, input, output)
+}
+
+func TestApplyEnvOverridesSimple(t *testing.T) {
+
+	type aliasint int
+	type aliasstring string
+
+	type testdata struct {
+		V1 int           `env:"TEST_V1"`
+		VX string        ``
+		V2 string        `env:"TEST_V2"`
+		V3 int8          `env:"TEST_V3"`
+		V4 int32         `env:"TEST_V4"`
+		V5 int64         `env:"TEST_V5"`
+		V6 aliasint      `env:"TEST_V6"`
+		VY aliasint      ``
+		V7 aliasstring   `env:"TEST_V7"`
+		V8 time.Duration `env:"TEST_V8"`
+		V9 time.Time     `env:"TEST_V9"`
+		VA bool          `env:"TEST_VA"`
+	}
+
+	data := testdata{
+		V1: 1,
+		VX: "X",
+		V2: "2",
+		V3: 3,
+		V4: 4,
+		V5: 5,
+		V6: 6,
+		VY: 99,
+		V7: "7",
+		V8: 9,
+		V9: time.Unix(1671102873, 0),
+		VA: false,
+	}
+
+	t.Setenv("TEST_V1", "846")
+	t.Setenv("TEST_V2", "hello_world")
+	t.Setenv("TEST_V3", "6")
+	t.Setenv("TEST_V4", "333")
+	t.Setenv("TEST_V5", "-937")
+	t.Setenv("TEST_V6", "070")
+	t.Setenv("TEST_V7", "AAAAAA")
+	t.Setenv("TEST_V8", "1min4s")
+	t.Setenv("TEST_V9", "2009-11-10T23:00:00Z")
+	t.Setenv("TEST_VA", "true")
+
+	err := ApplyEnvOverrides("", &data, ".")
+	if err != nil {
+		t.Errorf("%v", err)
+		t.FailNow()
+	}
+
+	tst.AssertEqual(t, data.V1, 846)
+	tst.AssertEqual(t, data.V2, "hello_world")
+	tst.AssertEqual(t, data.V3, 6)
+	tst.AssertEqual(t, data.V4, 333)
+	tst.AssertEqual(t, data.V5, -937)
+	tst.AssertEqual(t, data.V6, 70)
+	tst.AssertEqual(t, data.V7, "AAAAAA")
+	tst.AssertEqual(t, data.V8, time.Second*64)
+	tst.AssertEqual(t, data.V9, time.Unix(1257894000, 0).UTC())
+	tst.AssertEqual(t, data.VA, true)
+}
+
+func TestApplyEnvOverridesRecursive(t *testing.T) {
+
+	type subdata struct {
+		V1 int           `env:"SUB_V1"`
+		VX string        ``
+		V2 string        `env:"SUB_V2"`
+		V8 time.Duration `env:"SUB_V3"`
+		V9 time.Time     `env:"SUB_V4"`
+	}
+
+	type testdata struct {
+		V1   int     `env:"TEST_V1"`
+		VX   string  ``
+		Sub1 subdata ``
+		Sub2 subdata `env:"TEST_V2"`
+		Sub3 subdata `env:"TEST_V3"`
+		Sub4 subdata `env:""`
+		V5   string  `env:"-"`
+	}
+
+	data := testdata{
+		V1: 1,
+		VX: "2",
+		V5: "no",
+		Sub1: subdata{
+			V1: 3,
+			VX: "4",
+			V2: "5",
+			V8: 6 * time.Second,
+			V9: time.Date(2000, 1, 7, 1, 1, 1, 0, time.UTC),
+		},
+		Sub2: subdata{
+			V1: 8,
+			VX: "9",
+			V2: "10",
+			V8: 11 * time.Second,
+			V9: time.Date(2000, 1, 12, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+		Sub3: subdata{
+			V1: 13,
+			VX: "14",
+			V2: "15",
+			V8: 16 * time.Second,
+			V9: time.Date(2000, 1, 17, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+		Sub4: subdata{
+			V1: 18,
+			VX: "19",
+			V2: "20",
+			V8: 21 * time.Second,
+			V9: time.Date(2000, 1, 22, 1, 1, 1, 0, timeext.TimezoneBerlin),
+		},
+	}
+
+	t.Setenv("TEST_V1", "999")
+	t.Setenv("-", "yes")
+
+	t.Setenv("TEST_V2_SUB_V1", "846")
+	t.Setenv("TEST_V2_SUB_V2", "222_hello_world")
+	t.Setenv("TEST_V2_SUB_V3", "1min4s")
+	t.Setenv("TEST_V2_SUB_V4", "2009-11-10T23:00:00Z")
+
+	t.Setenv("TEST_V3_SUB_V1", "33846")
+	t.Setenv("TEST_V3_SUB_V2", "33_hello_world")
+	t.Setenv("TEST_V3_SUB_V3", "33min4s")
+	t.Setenv("TEST_V3_SUB_V4", "2033-11-10T23:00:00Z")
+
+	t.Setenv("SUB_V1", "11")
+	t.Setenv("SUB_V2", "22")
+	t.Setenv("SUB_V3", "33min")
+	t.Setenv("SUB_V4", "2044-01-01T00:00:00Z")
+
+	err := ApplyEnvOverrides("", &data, "_")
+	if err != nil {
+		t.Errorf("%v", err)
+		t.FailNow()
+	}
+
+	tst.AssertEqual(t, data.V1, 999)
+	tst.AssertEqual(t, data.VX, "2")
+	tst.AssertEqual(t, data.V5, "no")
+	tst.AssertEqual(t, data.Sub1.V1, 3)
+	tst.AssertEqual(t, data.Sub1.VX, "4")
+	tst.AssertEqual(t, data.Sub1.V2, "5")
+	tst.AssertEqual(t, data.Sub1.V8, time.Second*6)
+	tst.AssertEqual(t, data.Sub1.V9, time.Unix(947206861, 0).UTC())
+	tst.AssertEqual(t, data.Sub2.V1, 846)
+	tst.AssertEqual(t, data.Sub2.VX, "9")
+	tst.AssertEqual(t, data.Sub2.V2, "222_hello_world")
+	tst.AssertEqual(t, data.Sub2.V8, time.Second*64)
+	tst.AssertEqual(t, data.Sub2.V9, time.Unix(1257894000, 0).UTC())
+	tst.AssertEqual(t, data.Sub3.V1, 33846)
+	tst.AssertEqual(t, data.Sub3.VX, "14")
+	tst.AssertEqual(t, data.Sub3.V2, "33_hello_world")
+	tst.AssertEqual(t, data.Sub3.V8, time.Second*1984)
+	tst.AssertEqual(t, data.Sub3.V9, time.Unix(2015276400, 0).UTC())
+	tst.AssertEqual(t, data.Sub4.V1, 11)
+	tst.AssertEqual(t, data.Sub4.VX, "19")
+	tst.AssertEqual(t, data.Sub4.V2, "22")
+	tst.AssertEqual(t, data.Sub4.V8, time.Second*1980)
+	tst.AssertEqual(t, data.Sub4.V9, time.Unix(2335219200, 0).UTC())
+}
+
+func TestApplyEnvOverridesPointer(t *testing.T) {
+
+	type aliasint int
+	type aliasstring string
+
+	type testdata struct {
+		V1 *int           `env:"TEST_V1"`
+		VX *string        ``
+		V2 *string        `env:"TEST_V2"`
+		V3 *int8          `env:"TEST_V3"`
+		V4 *int32         `env:"TEST_V4"`
+		V5 *int64         `env:"TEST_V5"`
+		V6 *aliasint      `env:"TEST_V6"`
+		VY *aliasint      ``
+		V7 *aliasstring   `env:"TEST_V7"`
+		V8 *time.Duration `env:"TEST_V8"`
+		V9 *time.Time     `env:"TEST_V9"`
+	}
+
+	data := testdata{}
+
+	t.Setenv("TEST_V1", "846")
+	t.Setenv("TEST_V2", "hello_world")
+	t.Setenv("TEST_V3", "6")
+	t.Setenv("TEST_V4", "333")
+	t.Setenv("TEST_V5", "-937")
+	t.Setenv("TEST_V6", "070")
+	t.Setenv("TEST_V7", "AAAAAA")
+	t.Setenv("TEST_V8", "1min4s")
+	t.Setenv("TEST_V9", "2009-11-10T23:00:00Z")
+
+	err := ApplyEnvOverrides("", &data, ".")
+	if err != nil {
+		t.Errorf("%v", err)
+		t.FailNow()
+	}
+
+	tst.AssertDeRefEqual(t, data.V1, 846)
+	tst.AssertDeRefEqual(t, data.V2, "hello_world")
+	tst.AssertDeRefEqual(t, data.V3, 6)
+	tst.AssertDeRefEqual(t, data.V4, 333)
+	tst.AssertDeRefEqual(t, data.V5, -937)
+	tst.AssertDeRefEqual(t, data.V6, 70)
+	tst.AssertDeRefEqual(t, data.V7, "AAAAAA")
+	tst.AssertDeRefEqual(t, data.V8, time.Second*64)
+	tst.AssertDeRefEqual(t, data.V9, time.Unix(1257894000, 0).UTC())
+}
+
+func assertEqual[T comparable](t *testing.T, actual T, expected T) {
+	if actual != expected {
+		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actual, expected)
+	}
+}
+
+func assertPtrEqual[T comparable](t *testing.T, actual *T, expected T) {
+	if actual == nil {
+		t.Errorf("values differ: Actual: NIL, Expected: '%v'", expected)
+	}
+	if *actual != expected {
+		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actual, expected)
+	}
+}

cryptext/aes.go

@@ -0,0 +1,132 @@
+package cryptext
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base32"
+	"encoding/json"
+	"errors"
+	"golang.org/x/crypto/scrypt"
+	"io"
+)
+
+// https://stackoverflow.com/a/18819040/1761622
+
+type aesPayload struct {
+	Salt    []byte `json:"s"`
+	IV      []byte `json:"i"`
+	Data    []byte `json:"d"`
+	Rounds  int    `json:"r"`
+	Version uint   `json:"v"`
+}
+
+func EncryptAESSimple(password []byte, data []byte, rounds int) (string, error) {
+
+	salt := make([]byte, 8)
+	_, err := io.ReadFull(rand.Reader, salt)
+	if err != nil {
+		return "", err
+	}
+
+	key, err := scrypt.Key(password, salt, rounds, 8, 1, 32)
+	if err != nil {
+		return "", err
+	}
+
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return "", err
+	}
+
+	h := sha256.New()
+	h.Write(data)
+	checksum := h.Sum(nil)
+	if len(checksum) != 32 {
+		return "", errors.New("wrong cs size")
+	}
+
+	ciphertext := make([]byte, 32+len(data))
+
+	iv := make([]byte, aes.BlockSize)
+	_, err = io.ReadFull(rand.Reader, iv)
+	if err != nil {
+		return "", err
+	}
+
+	combinedData := make([]byte, 0, 32+len(data))
+	combinedData = append(combinedData, checksum...)
+	combinedData = append(combinedData, data...)
+
+	cfb := cipher.NewCFBEncrypter(block, iv)
+	cfb.XORKeyStream(ciphertext, combinedData)
+
+	pl := aesPayload{
+		Salt:    salt,
+		IV:      iv,
+		Data:    ciphertext,
+		Version: 1,
+		Rounds:  rounds,
+	}
+
+	jbin, err := json.Marshal(pl)
+	if err != nil {
+		return "", err
+	}
+
+	res := base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(jbin)
+
+	return res, nil
+}
+
+func DecryptAESSimple(password []byte, encText string) ([]byte, error) {
+
+	jbin, err := base32.StdEncoding.WithPadding(base32.NoPadding).DecodeString(encText)
+	if err != nil {
+		return nil, err
+	}
+
+	var pl aesPayload
+	err = json.Unmarshal(jbin, &pl)
+	if err != nil {
+		return nil, err
+	}
+
+	if pl.Version != 1 {
+		return nil, errors.New("unsupported version")
+	}
+
+	key, err := scrypt.Key(password, pl.Salt, pl.Rounds, 8, 1, 32) // this is not 100% correct, rounds too low and salt is missing
+	if err != nil {
+		return nil, err
+	}
+
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	dest := make([]byte, len(pl.Data))
+
+	cfb := cipher.NewCFBDecrypter(block, pl.IV)
+	cfb.XORKeyStream(dest, pl.Data)
+
+	if len(dest) < 32 {
+		return nil, errors.New("payload too small")
+	}
+
+	chck := dest[:32]
+	data := dest[32:]
+
+	h := sha256.New()
+	h.Write(data)
+	chck2 := h.Sum(nil)
+
+	if !bytes.Equal(chck, chck2) {
+		return nil, errors.New("checksum mismatch")
+	}
+
+	return data, nil
+}

cryptext/aes_test.go

@@ -0,0 +1,36 @@
+package cryptext
+
+import (
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"testing"
+)
+
+func TestEncryptAESSimple(t *testing.T) {
+
+	pw := []byte("hunter12")
+
+	str1 := []byte("Hello World")
+
+	str2, err := EncryptAESSimple(pw, str1, 512)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Printf("%s\n", str2)
+
+	str3, err := DecryptAESSimple(pw, str2)
+	if err != nil {
+		panic(err)
+	}
+
+	tst.AssertEqual(t, string(str1), string(str3))
+
+	str4, err := EncryptAESSimple(pw, str3, 512)
+	if err != nil {
+		panic(err)
+	}
+
+	tst.AssertNotEqual(t, string(str2), string(str4))
+
+}

cryptext/hash_test.go

@@ -1,25 +1,20 @@
 package cryptext
 
 import (
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
 	"testing"
 )
 
 func TestStrSha256(t *testing.T) {
-	assertEqual(t, StrSha256(""), "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
-	assertEqual(t, StrSha256("0"), "5feceb66ffc86f38d952786c6d696c79c2dbc239dd4e91b46729d73a27fb57e9")
-	assertEqual(t, StrSha256("80085"), "b3786e141d65638ad8a98173e26b5f6a53c927737b23ff31fb1843937250f44b")
-	assertEqual(t, StrSha256("Hello World"), "a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e")
+	tst.AssertEqual(t, StrSha256(""), "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
+	tst.AssertEqual(t, StrSha256("0"), "5feceb66ffc86f38d952786c6d696c79c2dbc239dd4e91b46729d73a27fb57e9")
+	tst.AssertEqual(t, StrSha256("80085"), "b3786e141d65638ad8a98173e26b5f6a53c927737b23ff31fb1843937250f44b")
+	tst.AssertEqual(t, StrSha256("Hello World"), "a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e")
 }
 
 func TestBytesSha256(t *testing.T) {
-	assertEqual(t, BytesSha256([]byte{}), "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
-	assertEqual(t, BytesSha256([]byte{0}), "6e340b9cffb37a989ca544e6bb780a2c78901d3fb33738768511a30617afa01d")
-	assertEqual(t, BytesSha256([]byte{128}), "76be8b528d0075f7aae98d6fa57a6d3c83ae480a8469e668d7b0af968995ac71")
-	assertEqual(t, BytesSha256([]byte{0, 1, 2, 4, 8, 16, 32, 64, 128, 255}), "55016a318ba538e00123c736b2a8b6db368d00e7e25727547655b653e5853603")
-}
-
-func assertEqual(t *testing.T, actual string, expected string) {
-	if actual != expected {
-		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actual, expected)
-	}
+	tst.AssertEqual(t, BytesSha256([]byte{}), "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
+	tst.AssertEqual(t, BytesSha256([]byte{0}), "6e340b9cffb37a989ca544e6bb780a2c78901d3fb33738768511a30617afa01d")
+	tst.AssertEqual(t, BytesSha256([]byte{128}), "76be8b528d0075f7aae98d6fa57a6d3c83ae480a8469e668d7b0af968995ac71")
+	tst.AssertEqual(t, BytesSha256([]byte{0, 1, 2, 4, 8, 16, 32, 64, 128, 255}), "55016a318ba538e00123c736b2a8b6db368d00e7e25727547655b653e5853603")
 }

cryptext/passHash.go

@@ -0,0 +1,365 @@
+package cryptext
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/totpext"
+	"golang.org/x/crypto/bcrypt"
+	"strconv"
+	"strings"
+)
+
+const LatestPassHashVersion = 4
+
+// PassHash
+// - [v0]: plaintext password ( `0|...` )
+// - [v1]: sha256(plaintext)
+// - [v2]: seed | sha256<seed>(plaintext)
+// - [v3]: seed | sha256<seed>(plaintext) | [hex(totp)]
+// - [v4]: bcrypt(plaintext) | [hex(totp)]
+type PassHash string
+
+func (ph PassHash) Valid() bool {
+	_, _, _, _, _, valid := ph.Data()
+	return valid
+}
+
+func (ph PassHash) HasTOTP() bool {
+	_, _, _, otp, _, _ := ph.Data()
+	return otp
+}
+
+func (ph PassHash) Data() (_version int, _seed []byte, _payload []byte, _totp bool, _totpsecret []byte, _valid bool) {
+
+	split := strings.Split(string(ph), "|")
+	if len(split) == 0 {
+		return -1, nil, nil, false, nil, false
+	}
+
+	version, err := strconv.ParseInt(split[0], 10, 32)
+	if err != nil {
+		return -1, nil, nil, false, nil, false
+	}
+
+	if version == 0 {
+		if len(split) != 2 {
+			return -1, nil, nil, false, nil, false
+		}
+		return int(version), nil, []byte(split[1]), false, nil, true
+	}
+
+	if version == 1 {
+		if len(split) != 2 {
+			return -1, nil, nil, false, nil, false
+		}
+		payload, err := base64.RawStdEncoding.DecodeString(split[1])
+		if err != nil {
+			return -1, nil, nil, false, nil, false
+		}
+		return int(version), nil, payload, false, nil, true
+	}
+
+	//
+	if version == 2 {
+		if len(split) != 3 {
+			return -1, nil, nil, false, nil, false
+		}
+		seed, err := base64.RawStdEncoding.DecodeString(split[1])
+		if err != nil {
+			return -1, nil, nil, false, nil, false
+		}
+		payload, err := base64.RawStdEncoding.DecodeString(split[2])
+		if err != nil {
+			return -1, nil, nil, false, nil, false
+		}
+		return int(version), seed, payload, false, nil, true
+	}
+
+	if version == 3 {
+		if len(split) != 4 {
+			return -1, nil, nil, false, nil, false
+		}
+		seed, err := base64.RawStdEncoding.DecodeString(split[1])
+		if err != nil {
+			return -1, nil, nil, false, nil, false
+		}
+		payload, err := base64.RawStdEncoding.DecodeString(split[2])
+		if err != nil {
+			return -1, nil, nil, false, nil, false
+		}
+		totp := false
+		totpsecret := make([]byte, 0)
+		if split[3] != "0" {
+			totpsecret, err = hex.DecodeString(split[3])
+			totp = true
+		}
+		return int(version), seed, payload, totp, totpsecret, true
+	}
+
+	if version == 4 {
+		if len(split) != 3 {
+			return -1, nil, nil, false, nil, false
+		}
+		payload := []byte(split[1])
+		totp := false
+		totpsecret := make([]byte, 0)
+		if split[2] != "0" {
+			totpsecret, err = hex.DecodeString(split[3])
+			totp = true
+		}
+		return int(version), nil, payload, totp, totpsecret, true
+	}
+
+	return -1, nil, nil, false, nil, false
+}
+
+func (ph PassHash) Verify(plainpass string, totp *string) bool {
+	version, seed, payload, hastotp, totpsecret, valid := ph.Data()
+	if !valid {
+		return false
+	}
+
+	if hastotp && totp == nil {
+		return false
+	}
+
+	if version == 0 {
+		return langext.ArrEqualsExact([]byte(plainpass), payload)
+	}
+
+	if version == 1 {
+		return langext.ArrEqualsExact(hash256(plainpass), payload)
+	}
+
+	if version == 2 {
+		return langext.ArrEqualsExact(hash256Seeded(plainpass, seed), payload)
+	}
+
+	if version == 3 {
+		if !hastotp {
+			return langext.ArrEqualsExact(hash256Seeded(plainpass, seed), payload)
+		} else {
+			return langext.ArrEqualsExact(hash256Seeded(plainpass, seed), payload) && totpext.Validate(totpsecret, *totp)
+		}
+	}
+
+	if version == 4 {
+		if !hastotp {
+			return bcrypt.CompareHashAndPassword(payload, []byte(plainpass)) == nil
+		} else {
+			return bcrypt.CompareHashAndPassword(payload, []byte(plainpass)) == nil && totpext.Validate(totpsecret, *totp)
+		}
+	}
+
+	return false
+}
+
+func (ph PassHash) NeedsPasswordUpgrade() bool {
+	version, _, _, _, _, valid := ph.Data()
+	return valid && version < LatestPassHashVersion
+}
+
+func (ph PassHash) Upgrade(plainpass string) (PassHash, error) {
+	version, _, _, hastotp, totpsecret, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid password")
+	}
+	if version == LatestPassHashVersion {
+		return ph, nil
+	}
+	if hastotp {
+		return HashPassword(plainpass, totpsecret)
+	} else {
+		return HashPassword(plainpass, nil)
+	}
+}
+
+func (ph PassHash) ClearTOTP() (PassHash, error) {
+	version, _, _, _, _, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid PassHash")
+	}
+
+	if version == 0 {
+		return ph, nil
+	}
+
+	if version == 1 {
+		return ph, nil
+	}
+
+	if version == 2 {
+		return ph, nil
+	}
+
+	if version == 3 {
+		split := strings.Split(string(ph), "|")
+		split[3] = "0"
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	if version == 4 {
+		split := strings.Split(string(ph), "|")
+		split[2] = "0"
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	return "", errors.New("unknown version")
+}
+
+func (ph PassHash) WithTOTP(totpSecret []byte) (PassHash, error) {
+	version, _, _, _, _, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid PassHash")
+	}
+
+	if version == 0 {
+		return "", errors.New("version does not support totp, needs upgrade")
+	}
+
+	if version == 1 {
+		return "", errors.New("version does not support totp, needs upgrade")
+	}
+
+	if version == 2 {
+		return "", errors.New("version does not support totp, needs upgrade")
+	}
+
+	if version == 3 {
+		split := strings.Split(string(ph), "|")
+		split[3] = hex.EncodeToString(totpSecret)
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	if version == 4 {
+		split := strings.Split(string(ph), "|")
+		split[2] = hex.EncodeToString(totpSecret)
+		return PassHash(strings.Join(split, "|")), nil
+	}
+
+	return "", errors.New("unknown version")
+}
+
+func (ph PassHash) Change(newPlainPass string) (PassHash, error) {
+	version, _, _, hastotp, totpsecret, valid := ph.Data()
+	if !valid {
+		return "", errors.New("invalid PassHash")
+	}
+
+	if version == 0 {
+		return HashPasswordV0(newPlainPass)
+	}
+
+	if version == 1 {
+		return HashPasswordV1(newPlainPass)
+	}
+
+	if version == 2 {
+		return HashPasswordV2(newPlainPass)
+	}
+
+	if version == 3 {
+		return HashPasswordV3(newPlainPass, langext.Conditional(hastotp, totpsecret, nil))
+	}
+
+	if version == 4 {
+		return HashPasswordV4(newPlainPass, langext.Conditional(hastotp, totpsecret, nil))
+	}
+
+	return "", errors.New("unknown version")
+}
+
+func (ph PassHash) String() string {
+	return string(ph)
+}
+
+func HashPassword(plainpass string, totpSecret []byte) (PassHash, error) {
+	return HashPasswordV4(plainpass, totpSecret)
+}
+
+func HashPasswordV4(plainpass string, totpSecret []byte) (PassHash, error) {
+	var strtotp string
+
+	if totpSecret == nil {
+		strtotp = "0"
+	} else {
+		strtotp = hex.EncodeToString(totpSecret)
+	}
+
+	payload, err := bcrypt.GenerateFromPassword([]byte(plainpass), bcrypt.MinCost)
+	if err != nil {
+		return "", err
+	}
+
+	return PassHash(fmt.Sprintf("4|%s|%s", string(payload), strtotp)), nil
+}
+
+func HashPasswordV3(plainpass string, totpSecret []byte) (PassHash, error) {
+	var strtotp string
+
+	if totpSecret == nil {
+		strtotp = "0"
+	} else {
+		strtotp = hex.EncodeToString(totpSecret)
+	}
+
+	seed, err := newSeed()
+	if err != nil {
+		return "", err
+	}
+
+	checksum := hash256Seeded(plainpass, seed)
+
+	return PassHash(fmt.Sprintf("3|%s|%s|%s",
+		base64.RawStdEncoding.EncodeToString(seed),
+		base64.RawStdEncoding.EncodeToString(checksum),
+		strtotp)), nil
+}
+
+func HashPasswordV2(plainpass string) (PassHash, error) {
+	seed, err := newSeed()
+	if err != nil {
+		return "", err
+	}
+
+	checksum := hash256Seeded(plainpass, seed)
+
+	return PassHash(fmt.Sprintf("2|%s|%s", base64.RawStdEncoding.EncodeToString(seed), base64.RawStdEncoding.EncodeToString(checksum))), nil
+}
+
+func HashPasswordV1(plainpass string) (PassHash, error) {
+	return PassHash(fmt.Sprintf("1|%s", base64.RawStdEncoding.EncodeToString(hash256(plainpass)))), nil
+}
+
+func HashPasswordV0(plainpass string) (PassHash, error) {
+	return PassHash(fmt.Sprintf("0|%s", plainpass)), nil
+}
+
+func hash256(s string) []byte {
+	h := sha256.New()
+	h.Write([]byte(s))
+	bs := h.Sum(nil)
+	return bs
+}
+
+func hash256Seeded(s string, seed []byte) []byte {
+	h := sha256.New()
+	h.Write(seed)
+	h.Write([]byte(s))
+	bs := h.Sum(nil)
+	return bs
+}
+
+func newSeed() ([]byte, error) {
+	secret := make([]byte, 32)
+	_, err := rand.Read(secret)
+	if err != nil {
+		return nil, err
+	}
+	return secret, nil
+}

cursortoken/direction.go

@@ -0,0 +1,8 @@
+package cursortoken
+
+type SortDirection string //@enum:type
+
+const (
+	SortASC  SortDirection = "ASC"
+	SortDESC SortDirection = "DESC"
+)

cursortoken/filter.go

@@ -0,0 +1,10 @@
+package cursortoken
+
+import (
+	"go.mongodb.org/mongo-driver/mongo"
+)
+
+type Filter interface {
+	FilterQuery() mongo.Pipeline
+	Pagination() (string, SortDirection, string, SortDirection)
+}

cursortoken/token.go

@@ -0,0 +1,184 @@
+package cursortoken
+
+import (
+	"encoding/base32"
+	"encoding/json"
+	"errors"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"strings"
+	"time"
+)
+
+type Mode string
+
+const (
+	CTMStart  Mode = "START"
+	CTMNormal Mode = "NORMAL"
+	CTMEnd    Mode = "END"
+)
+
+type Extra struct {
+	Timestamp *time.Time
+	Id        *string
+	Page      *int
+	PageSize  *int
+}
+
+type CursorToken struct {
+	Mode               Mode
+	ValuePrimary       string
+	ValueSecondary     string
+	Direction          SortDirection
+	DirectionSecondary SortDirection
+	PageSize           int
+	Extra              Extra
+}
+
+type cursorTokenSerialize struct {
+	ValuePrimary       *string        `json:"v1,omitempty"`
+	ValueSecondary     *string        `json:"v2,omitempty"`
+	Direction          *SortDirection `json:"dir,omitempty"`
+	DirectionSecondary *SortDirection `json:"dir2,omitempty"`
+	PageSize           *int           `json:"size,omitempty"`
+
+	ExtraTimestamp *time.Time `json:"ts,omitempty"`
+	ExtraId        *string    `json:"id,omitempty"`
+	ExtraPage      *int       `json:"pg,omitempty"`
+	ExtraPageSize  *int       `json:"sz,omitempty"`
+}
+
+func Start() CursorToken {
+	return CursorToken{
+		Mode:               CTMStart,
+		ValuePrimary:       "",
+		ValueSecondary:     "",
+		Direction:          "",
+		DirectionSecondary: "",
+		PageSize:           0,
+		Extra:              Extra{},
+	}
+}
+
+func End() CursorToken {
+	return CursorToken{
+		Mode:               CTMEnd,
+		ValuePrimary:       "",
+		ValueSecondary:     "",
+		Direction:          "",
+		DirectionSecondary: "",
+		PageSize:           0,
+		Extra:              Extra{},
+	}
+}
+
+func (c *CursorToken) Token() string {
+	if c.Mode == CTMStart {
+		return "@start"
+	}
+	if c.Mode == CTMEnd {
+		return "@end"
+	}
+
+	// We kinda manually implement omitempty for the CursorToken here
+	// because omitempty does not work for time.Time and otherwise we would always
+	// get weird time values when decoding a token that initially didn't have an Timestamp set
+	// For this usecase we treat Unix=0 as an empty timestamp
+
+	sertok := cursorTokenSerialize{}
+
+	if c.ValuePrimary != "" {
+		sertok.ValuePrimary = &c.ValuePrimary
+	}
+	if c.ValueSecondary != "" {
+		sertok.ValueSecondary = &c.ValueSecondary
+	}
+	if c.Direction != "" {
+		sertok.Direction = &c.Direction
+	}
+	if c.DirectionSecondary != "" {
+		sertok.DirectionSecondary = &c.DirectionSecondary
+	}
+	if c.PageSize != 0 {
+		sertok.PageSize = &c.PageSize
+	}
+
+	sertok.ExtraTimestamp = c.Extra.Timestamp
+	sertok.ExtraId = c.Extra.Id
+	sertok.ExtraPage = c.Extra.Page
+	sertok.ExtraPageSize = c.Extra.PageSize
+
+	body, err := json.Marshal(sertok)
+	if err != nil {
+		panic(err)
+	}
+
+	return "tok_" + base32.StdEncoding.EncodeToString(body)
+}
+
+func Decode(tok string) (CursorToken, error) {
+	if tok == "" {
+		return Start(), nil
+	}
+	if strings.ToLower(tok) == "@start" {
+		return Start(), nil
+	}
+	if strings.ToLower(tok) == "@end" {
+		return End(), nil
+	}
+
+	if !strings.HasPrefix(tok, "tok_") {
+		return CursorToken{}, errors.New("could not decode token, missing prefix")
+	}
+
+	body, err := base32.StdEncoding.DecodeString(tok[len("tok_"):])
+	if err != nil {
+		return CursorToken{}, err
+	}
+
+	var tokenDeserialize cursorTokenSerialize
+	err = json.Unmarshal(body, &tokenDeserialize)
+	if err != nil {
+		return CursorToken{}, err
+	}
+
+	token := CursorToken{Mode: CTMNormal}
+
+	if tokenDeserialize.ValuePrimary != nil {
+		token.ValuePrimary = *tokenDeserialize.ValuePrimary
+	}
+	if tokenDeserialize.ValueSecondary != nil {
+		token.ValueSecondary = *tokenDeserialize.ValueSecondary
+	}
+	if tokenDeserialize.Direction != nil {
+		token.Direction = *tokenDeserialize.Direction
+	}
+	if tokenDeserialize.DirectionSecondary != nil {
+		token.DirectionSecondary = *tokenDeserialize.DirectionSecondary
+	}
+	if tokenDeserialize.PageSize != nil {
+		token.PageSize = *tokenDeserialize.PageSize
+	}
+
+	token.Extra.Timestamp = tokenDeserialize.ExtraTimestamp
+	token.Extra.Id = tokenDeserialize.ExtraId
+	token.Extra.Page = tokenDeserialize.ExtraPage
+	token.Extra.PageSize = tokenDeserialize.ExtraPageSize
+
+	return token, nil
+}
+
+func (c *CursorToken) ValuePrimaryObjectId() (primitive.ObjectID, bool) {
+	if oid, err := primitive.ObjectIDFromHex(c.ValuePrimary); err == nil {
+		return oid, true
+	} else {
+		return primitive.ObjectID{}, false
+	}
+}
+
+func (c *CursorToken) ValueSecondaryObjectId() (primitive.ObjectID, bool) {
+	if oid, err := primitive.ObjectIDFromHex(c.ValueSecondary); err == nil {
+		return oid, true
+	} else {
+		return primitive.ObjectID{}, false
+	}
+}

dataext/bufferedReadCloser.go

@@ -1,56 +1,157 @@
 package dataext
 
-import "io"
+import (
+	"errors"
+	"io"
+)
+
+type brcMode int
+
+const (
+	modeSourceReading  brcMode = 0
+	modeSourceFinished brcMode = 1
+	modeBufferReading  brcMode = 2
+	modeBufferFinished brcMode = 3
+)
 
 type BufferedReadCloser interface {
 	io.ReadCloser
 	BufferedAll() ([]byte, error)
+	Reset() error
 }
 
 type bufferedReadCloser struct {
-	buffer   []byte
-	inner    io.ReadCloser
-	finished bool
-}
-
-func (b *bufferedReadCloser) Read(p []byte) (int, error) {
-
-	n, err := b.inner.Read(p)
-	if n > 0 {
-		b.buffer = append(b.buffer, p[0:n]...)
-	}
-
-	if err == io.EOF {
-		b.finished = true
-	}
-
-	return n, err
+	buffer []byte
+	inner  io.ReadCloser
+	mode   brcMode
+	off    int
 }
 
 func NewBufferedReadCloser(sub io.ReadCloser) BufferedReadCloser {
 	return &bufferedReadCloser{
-		buffer:   make([]byte, 0, 1024),
-		inner:    sub,
-		finished: false,
+		buffer: make([]byte, 0, 1024),
+		inner:  sub,
+		mode:   modeSourceReading,
+		off:    0,
+	}
+}
+
+func (b *bufferedReadCloser) Read(p []byte) (int, error) {
+	switch b.mode {
+	case modeSourceReading:
+		n, err := b.inner.Read(p)
+		if n > 0 {
+			b.buffer = append(b.buffer, p[0:n]...)
+		}
+
+		if err == io.EOF {
+			b.mode = modeSourceFinished
+		}
+
+		return n, err
+
+	case modeSourceFinished:
+		return 0, io.EOF
+
+	case modeBufferReading:
+
+		if len(b.buffer) <= b.off {
+			b.mode = modeBufferFinished
+			if len(p) == 0 {
+				return 0, nil
+			}
+			return 0, io.EOF
+		}
+
+		n := copy(p, b.buffer[b.off:])
+		b.off += n
+		return n, nil
+
+	case modeBufferFinished:
+		return 0, io.EOF
+
+	default:
+		return 0, errors.New("object in undefined status")
 	}
 }
 
 func (b *bufferedReadCloser) Close() error {
-	err := b.inner.Close()
-	if err != nil {
-		b.finished = true
+	switch b.mode {
+	case modeSourceReading:
+		_, err := b.BufferedAll()
+		if err != nil {
+			return err
+		}
+		err = b.inner.Close()
+		if err != nil {
+			return err
+		}
+		b.mode = modeSourceFinished
+		return nil
+
+	case modeSourceFinished:
+		return nil
+
+	case modeBufferReading:
+		b.mode = modeBufferFinished
+		return nil
+
+	case modeBufferFinished:
+		return nil
+
+	default:
+		return errors.New("object in undefined status")
 	}
-	return err
+
 }
 
 func (b *bufferedReadCloser) BufferedAll() ([]byte, error) {
-	arr := make([]byte, 1024)
-	for !b.finished {
-		_, err := b.Read(arr)
-		if err != nil && err != io.EOF {
-			return nil, err
+	switch b.mode {
+	case modeSourceReading:
+		arr := make([]byte, 1024)
+		for b.mode == modeSourceReading {
+			_, err := b.Read(arr)
+			if err != nil && err != io.EOF {
+				return nil, err
+			}
 		}
-	}
+		return b.buffer, nil
 
-	return b.buffer, nil
+	case modeSourceFinished:
+		return b.buffer, nil
+
+	case modeBufferReading:
+		return b.buffer, nil
+
+	case modeBufferFinished:
+		return b.buffer, nil
+
+	default:
+		return nil, errors.New("object in undefined status")
+	}
+}
+
+func (b *bufferedReadCloser) Reset() error {
+	switch b.mode {
+	case modeSourceReading:
+		fallthrough
+	case modeSourceFinished:
+		err := b.Close()
+		if err != nil {
+			return err
+		}
+		b.mode = modeBufferReading
+		b.off = 0
+		return nil
+
+	case modeBufferReading:
+		fallthrough
+	case modeBufferFinished:
+		b.mode = modeBufferReading
+		b.off = 0
+		return nil
+
+	default:
+		return errors.New("object in undefined status")
+	}
 }

dataext/lruMap.go

@@ -19,40 +19,38 @@ import (
 // There are also a bunch of unit tests to ensure that the cache is always in a consistent state
 //
 
-type LRUData interface{}
-
-type LRUMap struct {
+type LRUMap[TKey comparable, TData any] struct {
 	maxsize int
 	lock    sync.Mutex
 
-	cache map[string]*cacheNode
+	cache map[TKey]*cacheNode[TKey, TData]
 
-	lfuHead *cacheNode
-	lfuTail *cacheNode
+	lfuHead *cacheNode[TKey, TData]
+	lfuTail *cacheNode[TKey, TData]
 }
 
-type cacheNode struct {
-	key    string
-	data   LRUData
-	parent *cacheNode
-	child  *cacheNode
+type cacheNode[TKey comparable, TData any] struct {
+	key    TKey
+	data   TData
+	parent *cacheNode[TKey, TData]
+	child  *cacheNode[TKey, TData]
 }
 
-func NewLRUMap(size int) *LRUMap {
+func NewLRUMap[TKey comparable, TData any](size int) *LRUMap[TKey, TData] {
 	if size <= 2 && size != 0 {
 		panic("Size must be > 2  (or 0)")
 	}
 
-	return &LRUMap{
+	return &LRUMap[TKey, TData]{
 		maxsize: size,
 		lock:    sync.Mutex{},
-		cache:   make(map[string]*cacheNode, size+1),
+		cache:   make(map[TKey]*cacheNode[TKey, TData], size+1),
 		lfuHead: nil,
 		lfuTail: nil,
 	}
 }
 
-func (c *LRUMap) Put(key string, value LRUData) {
+func (c *LRUMap[TKey, TData]) Put(key TKey, value TData) {
 	if c.maxsize == 0 {
 		return // cache disabled
 	}
@@ -70,7 +68,7 @@ func (c *LRUMap) Put(key string, value LRUData) {
 	}
 
 	// key does not exist: insert into map and add to top of LFU
-	node = &cacheNode{
+	node = &cacheNode[TKey, TData]{
 		key:    key,
 		data:   value,
 		parent: nil,
@@ -95,9 +93,9 @@ func (c *LRUMap) Put(key string, value LRUData) {
 	}
 }
 
-func (c *LRUMap) TryGet(key string) (LRUData, bool) {
+func (c *LRUMap[TKey, TData]) TryGet(key TKey) (TData, bool) {
 	if c.maxsize == 0 {
-		return nil, false // cache disabled
+		return *new(TData), false // cache disabled
 	}
 
 	c.lock.Lock()
@@ -105,13 +103,13 @@ func (c *LRUMap) TryGet(key string) (LRUData, bool) {
 
 	val, ok := c.cache[key]
 	if !ok {
-		return nil, false
+		return *new(TData), false
 	}
 	c.moveNodeToTop(val)
 	return val.data, ok
 }
 
-func (c *LRUMap) moveNodeToTop(node *cacheNode) {
+func (c *LRUMap[TKey, TData]) moveNodeToTop(node *cacheNode[TKey, TData]) {
 	// (only called in critical section !)
 
 	if c.lfuHead == node { // fast case
@@ -144,7 +142,7 @@ func (c *LRUMap) moveNodeToTop(node *cacheNode) {
 	}
 }
 
-func (c *LRUMap) Size() int {
+func (c *LRUMap[TKey, TData]) Size() int {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 	return len(c.cache)

dataext/lruMap_test.go

@@ -12,7 +12,7 @@ func init() {
 }
 
 func TestResultCache1(t *testing.T) {
-	cache := NewLRUMap(8)
+	cache := NewLRUMap[string, string](8)
 	verifyLRUList(cache, t)
 
 	key := randomKey()
@@ -39,7 +39,7 @@ func TestResultCache1(t *testing.T) {
 	if !ok {
 		t.Errorf("cache TryGet returned no value")
 	}
-	if !eq(cacheval, val) {
+	if cacheval != val {
 		t.Errorf("cache TryGet returned different value (%+v <> %+v)", cacheval, val)
 	}
 
@@ -50,7 +50,7 @@ func TestResultCache1(t *testing.T) {
 }
 
 func TestResultCache2(t *testing.T) {
-	cache := NewLRUMap(8)
+	cache := NewLRUMap[string, string](8)
 	verifyLRUList(cache, t)
 
 	key1 := "key1"
@@ -150,7 +150,7 @@ func TestResultCache2(t *testing.T) {
 }
 
 func TestResultCache3(t *testing.T) {
-	cache := NewLRUMap(8)
+	cache := NewLRUMap[string, string](8)
 	verifyLRUList(cache, t)
 
 	key1 := "key1"
@@ -160,20 +160,20 @@ func TestResultCache3(t *testing.T) {
 	cache.Put(key1, val1)
 	verifyLRUList(cache, t)
 
-	if val, ok := cache.TryGet(key1); !ok || !eq(val, val1) {
+	if val, ok := cache.TryGet(key1); !ok || val != val1 {
 		t.Errorf("Value in cache should be [val1]")
 	}
 
 	cache.Put(key1, val2)
 	verifyLRUList(cache, t)
 
-	if val, ok := cache.TryGet(key1); !ok || !eq(val, val2) {
+	if val, ok := cache.TryGet(key1); !ok || val != val2 {
 		t.Errorf("Value in cache should be [val2]")
 	}
 }
 
 // does a basic consistency check over the internal cache representation
-func verifyLRUList(cache *LRUMap, t *testing.T) {
+func verifyLRUList[TKey comparable, TData any](cache *LRUMap[TKey, TData], t *testing.T) {
 	size := 0
 
 	tailFound := false
@@ -250,23 +250,10 @@ func randomKey() string {
 	return strconv.FormatInt(rand.Int63(), 16)
 }
 
-func randomVal() LRUData {
+func randomVal() string {
 	v, err := langext.NewHexUUID()
 	if err != nil {
 		panic(err)
 	}
-	return &v
-}
-
-func eq(a LRUData, b LRUData) bool {
-	v1, ok1 := a.(*string)
-	v2, ok2 := b.(*string)
-	if ok1 && ok2 {
-		if v1 == nil || v2 == nil {
-			return false
-		}
-		return v1 == v2
-	}
-
-	return false
+	return v
 }

dataext/merge.go

@@ -0,0 +1,35 @@
+package dataext
+
+import (
+	"reflect"
+)
+
+func ObjectMerge[T1 any, T2 any](base T1, override T2) T1 {
+
+	reflBase := reflect.ValueOf(&base).Elem()
+	reflOvrd := reflect.ValueOf(&override).Elem()
+
+	for i := 0; i < reflBase.NumField(); i++ {
+
+		fieldBase := reflBase.Field(i)
+		fieldOvrd := reflOvrd.Field(i)
+
+		if fieldBase.Kind() != reflect.Ptr || fieldOvrd.Kind() != reflect.Ptr {
+			continue
+		}
+
+		kindBase := fieldBase.Type().Elem().Kind()
+		kindOvrd := fieldOvrd.Type().Elem().Kind()
+
+		if kindBase != kindOvrd {
+			continue
+		}
+
+		if !fieldOvrd.IsNil() {
+			fieldBase.Set(fieldOvrd.Elem().Addr())
+		}
+
+	}
+
+	return base
+}

dataext/merge_test.go

@@ -0,0 +1,71 @@
+package dataext
+
+import (
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"testing"
+)
+
+func TestObjectMerge(t *testing.T) {
+	type A struct {
+		Field1   *int
+		Field2   *string
+		Field3   *float64
+		Field4   *bool
+		OnlyA    int64
+		DiffType int
+	}
+	type B struct {
+		Field1   *int
+		Field2   *string
+		Field3   *float64
+		Field4   *bool
+		OnlyB    int64
+		DiffType string
+	}
+
+	valueA := A{
+		Field1:   nil,
+		Field2:   langext.Ptr("99"),
+		Field3:   langext.Ptr(12.2),
+		Field4:   nil,
+		OnlyA:    1,
+		DiffType: 2,
+	}
+
+	valueB := B{
+		Field1:   langext.Ptr(12),
+		Field2:   nil,
+		Field3:   langext.Ptr(13.2),
+		Field4:   nil,
+		OnlyB:    1,
+		DiffType: "X",
+	}
+
+	valueMerge := ObjectMerge(valueA, valueB)
+
+	tst.AssertIdentPtrEqual(t, "Field1", valueMerge.Field1, valueB.Field1)
+	tst.AssertIdentPtrEqual(t, "Field2", valueMerge.Field2, valueA.Field2)
+	tst.AssertIdentPtrEqual(t, "Field3", valueMerge.Field3, valueB.Field3)
+	tst.AssertIdentPtrEqual(t, "Field4", valueMerge.Field4, nil)
+
+}
+
+func assertPtrEqual[T1 comparable](t *testing.T, ident string, actual *T1, expected *T1) {
+	if actual == nil && expected == nil {
+		return
+	}
+	if actual != nil && expected != nil {
+		if *actual != *expected {
+			t.Errorf("[%s] values differ: Actual: '%v', Expected: '%v'", ident, *actual, *expected)
+		} else {
+			return
+		}
+	}
+	if actual == nil && expected != nil {
+		t.Errorf("[%s] values differ: Actual: nil, Expected: not-nil", ident)
+	}
+	if actual != nil && expected == nil {
+		t.Errorf("[%s] values differ: Actual: not-nil, Expected: nil", ident)
+	}
+}

dataext/stack.go

@@ -0,0 +1,116 @@
+package dataext
+
+import (
+	"errors"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"sync"
+)
+
+var ErrEmptyStack = errors.New("stack is empty")
+
+type Stack[T any] struct {
+	lock *sync.Mutex
+	data []T
+}
+
+func NewStack[T any](threadsafe bool, initialCapacity int) *Stack[T] {
+	var lck *sync.Mutex = nil
+	if threadsafe {
+		lck = &sync.Mutex{}
+	}
+	return &Stack[T]{
+		lock: lck,
+		data: make([]T, 0, initialCapacity),
+	}
+}
+
+func (s *Stack[T]) Push(v T) {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	s.data = append(s.data, v)
+}
+
+func (s *Stack[T]) Pop() (T, error) {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	l := len(s.data)
+	if l == 0 {
+		return *new(T), ErrEmptyStack
+	}
+
+	result := s.data[l-1]
+	s.data = s.data[:l-1]
+
+	return result, nil
+}
+
+func (s *Stack[T]) OptPop() *T {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	l := len(s.data)
+	if l == 0 {
+		return nil
+	}
+
+	result := s.data[l-1]
+	s.data = s.data[:l-1]
+
+	return langext.Ptr(result)
+}
+
+func (s *Stack[T]) Peek() (T, error) {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	l := len(s.data)
+
+	if l == 0 {
+		return *new(T), ErrEmptyStack
+	}
+
+	return s.data[l-1], nil
+}
+
+func (s *Stack[T]) OptPeek() *T {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	l := len(s.data)
+
+	if l == 0 {
+		return nil
+	}
+
+	return langext.Ptr(s.data[l-1])
+}
+
+func (s *Stack[T]) Length() int {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	return len(s.data)
+}
+
+func (s *Stack[T]) Empty() bool {
+	if s.lock != nil {
+		s.lock.Lock()
+		defer s.lock.Unlock()
+	}
+
+	return len(s.data) == 0
+}

dataext/structHash.go

@@ -0,0 +1,254 @@
+package dataext
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"hash"
+	"io"
+	"reflect"
+	"sort"
+)
+
+type StructHashOptions struct {
+	HashAlgo    hash.Hash
+	Tag         *string
+	SkipChannel bool
+	SkipFunc    bool
+}
+
+func StructHash(dat any, opt ...StructHashOptions) (r []byte, err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			r = nil
+			err = errors.New(fmt.Sprintf("recovered panic: %v", rec))
+		}
+	}()
+
+	shopt := StructHashOptions{}
+	if len(opt) > 1 {
+		return nil, errors.New("multiple options supplied")
+	} else if len(opt) == 1 {
+		shopt = opt[0]
+	}
+
+	if shopt.HashAlgo == nil {
+		shopt.HashAlgo = sha256.New()
+	}
+
+	writer := new(bytes.Buffer)
+
+	if langext.IsNil(dat) {
+		shopt.HashAlgo.Reset()
+		shopt.HashAlgo.Write(writer.Bytes())
+		res := shopt.HashAlgo.Sum(nil)
+		return res, nil
+	}
+
+	err = binarize(writer, reflect.ValueOf(dat), shopt)
+	if err != nil {
+		return nil, err
+	}
+
+	shopt.HashAlgo.Reset()
+	shopt.HashAlgo.Write(writer.Bytes())
+	res := shopt.HashAlgo.Sum(nil)
+
+	return res, nil
+}
+
+func writeBinarized(writer io.Writer, dat any) error {
+	tmp := bytes.Buffer{}
+	err := binary.Write(&tmp, binary.LittleEndian, dat)
+	if err != nil {
+		return err
+	}
+	err = binary.Write(writer, binary.LittleEndian, uint64(tmp.Len()))
+	if err != nil {
+		return err
+	}
+	_, err = writer.Write(tmp.Bytes())
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func binarize(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	var err error
+
+	err = binary.Write(writer, binary.LittleEndian, uint8(dat.Kind()))
+	switch dat.Kind() {
+	case reflect.Ptr, reflect.Map, reflect.Array, reflect.Chan, reflect.Slice, reflect.Interface:
+		if dat.IsNil() {
+			err = binary.Write(writer, binary.LittleEndian, uint64(0))
+			if err != nil {
+				return err
+			}
+			return nil
+		}
+	}
+
+	err = binary.Write(writer, binary.LittleEndian, uint64(len(dat.Type().String())))
+	if err != nil {
+		return err
+	}
+	_, err = writer.Write([]byte(dat.Type().String()))
+	if err != nil {
+		return err
+	}
+
+	switch dat.Type().Kind() {
+	case reflect.Invalid:
+		return errors.New("cannot binarize value of kind <Invalid>")
+	case reflect.Bool:
+		return writeBinarized(writer, dat.Bool())
+	case reflect.Int:
+		return writeBinarized(writer, int64(dat.Int()))
+	case reflect.Int8:
+		fallthrough
+	case reflect.Int16:
+		fallthrough
+	case reflect.Int32:
+		fallthrough
+	case reflect.Int64:
+		return writeBinarized(writer, dat.Interface())
+	case reflect.Uint:
+		return writeBinarized(writer, uint64(dat.Int()))
+	case reflect.Uint8:
+		fallthrough
+	case reflect.Uint16:
+		fallthrough
+	case reflect.Uint32:
+		fallthrough
+	case reflect.Uint64:
+		return writeBinarized(writer, dat.Interface())
+	case reflect.Uintptr:
+		return errors.New("cannot binarize value of kind <Uintptr>")
+	case reflect.Float32:
+		fallthrough
+	case reflect.Float64:
+		return writeBinarized(writer, dat.Interface())
+	case reflect.Complex64:
+		return errors.New("cannot binarize value of kind <Complex64>")
+	case reflect.Complex128:
+		return errors.New("cannot binarize value of kind <Complex128>")
+	case reflect.Slice:
+		fallthrough
+	case reflect.Array:
+		return binarizeArrayOrSlice(writer, dat, opt)
+	case reflect.Chan:
+		if opt.SkipChannel {
+			return nil
+		}
+		return errors.New("cannot binarize value of kind <Chan>")
+	case reflect.Func:
+		if opt.SkipFunc {
+			return nil
+		}
+		return errors.New("cannot binarize value of kind <Func>")
+	case reflect.Interface:
+		return binarize(writer, dat.Elem(), opt)
+	case reflect.Map:
+		return binarizeMap(writer, dat, opt)
+	case reflect.Pointer:
+		return binarize(writer, dat.Elem(), opt)
+	case reflect.String:
+		v := dat.String()
+		err = binary.Write(writer, binary.LittleEndian, uint64(len(v)))
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write([]byte(v))
+		if err != nil {
+			return err
+		}
+		return nil
+	case reflect.Struct:
+		return binarizeStruct(writer, dat, opt)
+	case reflect.UnsafePointer:
+		return errors.New("cannot binarize value of kind <UnsafePointer>")
+	default:
+		return errors.New("cannot binarize value of unknown kind <" + dat.Type().Kind().String() + ">")
+	}
+}
+
+func binarizeStruct(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	err := binary.Write(writer, binary.LittleEndian, uint64(dat.NumField()))
+	if err != nil {
+		return err
+	}
+
+	for i := 0; i < dat.NumField(); i++ {
+
+		if opt.Tag != nil {
+			if _, ok := dat.Type().Field(i).Tag.Lookup(*opt.Tag); !ok {
+				continue
+			}
+		}
+
+		err = binary.Write(writer, binary.LittleEndian, uint64(len(dat.Type().Field(i).Name)))
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write([]byte(dat.Type().Field(i).Name))
+		if err != nil {
+			return err
+		}
+
+		err = binarize(writer, dat.Field(i), opt)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func binarizeArrayOrSlice(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	err := binary.Write(writer, binary.LittleEndian, uint64(dat.Len()))
+	if err != nil {
+		return err
+	}
+
+	for i := 0; i < dat.Len(); i++ {
+		err := binarize(writer, dat.Index(i), opt)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func binarizeMap(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	err := binary.Write(writer, binary.LittleEndian, uint64(dat.Len()))
+	if err != nil {
+		return err
+	}
+
+	sub := make([][]byte, 0, dat.Len())
+
+	for _, k := range dat.MapKeys() {
+		tmp := bytes.Buffer{}
+		err = binarize(&tmp, dat.MapIndex(k), opt)
+		if err != nil {
+			return err
+		}
+		sub = append(sub, tmp.Bytes())
+	}
+
+	sort.Slice(sub, func(i1, i2 int) bool { return bytes.Compare(sub[i1], sub[i2]) < 0 })
+
+	for _, v := range sub {
+		_, err = writer.Write(v)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

dataext/structHash_test.go

@@ -0,0 +1,136 @@
+package dataext
+
+import (
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"testing"
+)
+
+func noErrStructHash(t *testing.T, dat any, opt ...StructHashOptions) []byte {
+	res, err := StructHash(dat, opt...)
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+		return nil
+	}
+	return res
+}
+
+func TestStructHashSimple(t *testing.T) {
+
+	tst.AssertHexEqual(t, "209bf774af36cc3a045c152d9f1269ef3684ad819c1359ee73ff0283a308fefa", noErrStructHash(t, "Hello"))
+	tst.AssertHexEqual(t, "c32f3626b981ae2997db656f3acad3f1dc9d30ef6b6d14296c023e391b25f71a", noErrStructHash(t, 0))
+	tst.AssertHexEqual(t, "01b781b03e9586b257d387057dfc70d9f06051e7d3c1e709a57e13cc8daf3e35", noErrStructHash(t, []byte{}))
+	tst.AssertHexEqual(t, "93e1dcd45c732fe0079b0fb3204c7c803f0921835f6bfee2e6ff263e73eed53c", noErrStructHash(t, []int{}))
+	tst.AssertHexEqual(t, "54f637a376aad55b3160d98ebbcae8099b70d91b9400df23fb3709855d59800a", noErrStructHash(t, []int{1, 2, 3}))
+	tst.AssertHexEqual(t, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", noErrStructHash(t, nil))
+	tst.AssertHexEqual(t, "349a7db91aa78fd30bbaa7c7f9c7bfb2fcfe72869b4861162a96713a852f60d3", noErrStructHash(t, []any{1, "", nil}))
+	tst.AssertHexEqual(t, "ca51aab87808bf0062a4a024de6aac0c2bad54275cc857a4944569f89fd245ad", noErrStructHash(t, struct{}{}))
+
+}
+
+func TestStructHashSimpleStruct(t *testing.T) {
+
+	type t0 struct {
+		F1 int
+		F2 []string
+		F3 *int
+	}
+
+	tst.AssertHexEqual(t, "a90bff751c70c738bb5cfc9b108e783fa9c19c0bc9273458e0aaee6e74aa1b92", noErrStructHash(t, t0{
+		F1: 10,
+		F2: []string{"1", "2", "3"},
+		F3: nil,
+	}))
+
+	tst.AssertHexEqual(t, "5d09090dc34ac59dd645f197a255f653387723de3afa1b614721ea5a081c675f", noErrStructHash(t, t0{
+		F1: 10,
+		F2: []string{"1", "2", "3"},
+		F3: langext.Ptr(99),
+	}))
+
+}
+
+func TestStructHashLayeredStruct(t *testing.T) {
+
+	type t1_1 struct {
+		F10 float32
+		F12 float64
+		F15 bool
+	}
+	type t1_2 struct {
+		SV1 *t1_1
+		SV2 *t1_1
+		SV3 t1_1
+	}
+
+	tst.AssertHexEqual(t, "fd4ca071fb40a288fee4b7a3dfdaab577b30cb8f80f81ec511e7afd72dc3b469", noErrStructHash(t, t1_2{
+		SV1: nil,
+		SV2: nil,
+		SV3: t1_1{
+			F10: 1,
+			F12: 2,
+			F15: false,
+		},
+	}))
+	tst.AssertHexEqual(t, "3fbf7c67d8121deda075cc86319a4e32d71744feb2cebf89b43bc682f072a029", noErrStructHash(t, t1_2{
+		SV1: nil,
+		SV2: &t1_1{},
+		SV3: t1_1{
+			F10: 3,
+			F12: 4,
+			F15: true,
+		},
+	}))
+	tst.AssertHexEqual(t, "b1791ccd1b346c3ede5bbffda85555adcd8216b93ffca23f14fe175ec47c5104", noErrStructHash(t, t1_2{
+		SV1: &t1_1{},
+		SV2: &t1_1{},
+		SV3: t1_1{
+			F10: 5,
+			F12: 6,
+			F15: false,
+		},
+	}))
+
+}
+
+func TestStructHashMap(t *testing.T) {
+
+	type t0 struct {
+		F1 int
+		F2 map[string]int
+	}
+
+	tst.AssertHexEqual(t, "d50c53ad1fafb448c33fddd5aca01a86a2edf669ce2ecab07ba6fe877951d824", noErrStructHash(t, t0{
+		F1: 10,
+		F2: map[string]int{
+			"x": 1,
+			"0": 2,
+			"a": 99,
+		},
+	}))
+
+	tst.AssertHexEqual(t, "d50c53ad1fafb448c33fddd5aca01a86a2edf669ce2ecab07ba6fe877951d824", noErrStructHash(t, t0{
+		F1: 10,
+		F2: map[string]int{
+			"a": 99,
+			"x": 1,
+			"0": 2,
+		},
+	}))
+
+	m3 := make(map[string]int, 99)
+	m3["a"] = 0
+	m3["x"] = 0
+	m3["0"] = 0
+
+	m3["0"] = 99
+	m3["x"] = 1
+	m3["a"] = 2
+
+	tst.AssertHexEqual(t, "d50c53ad1fafb448c33fddd5aca01a86a2edf669ce2ecab07ba6fe877951d824", noErrStructHash(t, t0{
+		F1: 10,
+		F2: m3,
+	}))
+
+}

dataext/syncSet.go

@@ -2,17 +2,17 @@ package dataext
 
 import "sync"
 
-type SyncStringSet struct {
-	data map[string]bool
+type SyncSet[TData comparable] struct {
+	data map[TData]bool
 	lock sync.Mutex
 }
 
-func (s *SyncStringSet) Add(value string) bool {
+func (s *SyncSet[TData]) Add(value TData) bool {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
 	if s.data == nil {
-		s.data = make(map[string]bool)
+		s.data = make(map[TData]bool)
 	}
 
 	_, ok := s.data[value]
@@ -21,12 +21,12 @@ func (s *SyncStringSet) Add(value string) bool {
 	return !ok
 }
 
-func (s *SyncStringSet) AddAll(values []string) {
+func (s *SyncSet[TData]) AddAll(values []TData) {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
 	if s.data == nil {
-		s.data = make(map[string]bool)
+		s.data = make(map[TData]bool)
 	}
 
 	for _, value := range values {
@@ -34,12 +34,12 @@ func (s *SyncStringSet) AddAll(values []string) {
 	}
 }
 
-func (s *SyncStringSet) Contains(value string) bool {
+func (s *SyncSet[TData]) Contains(value TData) bool {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
 	if s.data == nil {
-		s.data = make(map[string]bool)
+		s.data = make(map[TData]bool)
 	}
 
 	_, ok := s.data[value]
@@ -47,15 +47,15 @@ func (s *SyncStringSet) Contains(value string) bool {
 	return ok
 }
 
-func (s *SyncStringSet) Get() []string {
+func (s *SyncSet[TData]) Get() []TData {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
 	if s.data == nil {
-		s.data = make(map[string]bool)
+		s.data = make(map[TData]bool)
 	}
 
-	r := make([]string, 0, len(s.data))
+	r := make([]TData, 0, len(s.data))
 
 	for k := range s.data {
 		r = append(r, k)

go.mod

@@ -3,7 +3,30 @@ module gogs.mikescher.com/BlackForestBytes/goext
 go 1.19
 
 require (
-	golang.org/x/term v0.1.0
+	github.com/golang/snappy v0.0.4
+	github.com/google/go-cmp v0.5.9
+	github.com/jmoiron/sqlx v1.3.5
+	github.com/klauspost/compress v1.16.6
+	github.com/kr/pretty v0.1.0
+	github.com/montanaflynn/stats v0.7.1
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.8.4
+	github.com/tidwall/pretty v1.0.0
+	github.com/xdg-go/scram v1.1.2
+	github.com/xdg-go/stringprep v1.0.4
+	github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a
+	go.mongodb.org/mongo-driver v1.11.7
+	golang.org/x/crypto v0.10.0
+	golang.org/x/sync v0.3.0
+	golang.org/x/sys v0.9.0
+	golang.org/x/term v0.9.0
 )
 
-require golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/kr/text v0.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
+	golang.org/x/text v0.10.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -1,42 +1,99 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-sql-driver/mysql v1.6.0 h1:BCTh4TKNUYmOmMUcQ3IipzF5prigylS7XXjEkfCHuOE=
+github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
-github.com/google/go-cmp v0.5.2 h1:X2ev0eStA3AbceY54o37/0PQ/UWqKEiiO2dKL5OPaFM=
+github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
+github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/jmoiron/sqlx v1.3.5 h1:vFFPA71p1o5gAeqtEAwLU4dnX2napprKtHr7PYIcN3g=
+github.com/jmoiron/sqlx v1.3.5/go.mod h1:nRVWtLre0KfCLJvgxzCsLVMogSvQ1zNJtpYr2Ccp0mQ=
 github.com/klauspost/compress v1.13.6/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
+github.com/klauspost/compress v1.16.6 h1:91SKEy4K37vkp255cJ8QesJhjyRO0hn9i9G0GoUwLsk=
+github.com/klauspost/compress v1.16.6/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/lib/pq v1.2.0 h1:LXpIM/LZ5xGFhOpXAQUIMM1HdyqzVYM13zNdjCEEcA0=
+github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
+github.com/mattn/go-sqlite3 v1.14.6 h1:dNPt6NO46WmLVt2DLNpwczCmdV5boIZ6g/tlDrlRUbg=
+github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/montanaflynn/stats v0.0.0-20171201202039-1bf9dbcd8cbe/go.mod h1:wL8QJuTMNUDYhXwkmfOly8iTdp5TEcJFWZD2D7SIkUc=
+github.com/montanaflynn/stats v0.7.1 h1:etflOAAHORrCC44V+aR6Ftzort912ZU+YLiSTuV8eaE=
+github.com/montanaflynn/stats v0.7.1/go.mod h1:etXPPgVO6n31NxCd9KQUMvCM+ve0ruNzt6R8Bnaayow=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/tidwall/pretty v1.0.0 h1:HsD+QiTn7sK6flMKIvNmpqz1qrpP3Ps6jOKIKMooyg4=
 github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhVysOjyk=
+github.com/xdg-go/pbkdf2 v1.0.0 h1:Su7DPu48wXMwC3bs7MCNG+z4FhcyEuz5dlvchbq0B0c=
 github.com/xdg-go/pbkdf2 v1.0.0/go.mod h1:jrpuAogTd400dnrH08LKmI/xc1MbPOebTwRqcT5RDeI=
 github.com/xdg-go/scram v1.1.1/go.mod h1:RaEWvsqvNKKvBPvcKeFjrG2cJqOkHTiyTpzz23ni57g=
+github.com/xdg-go/scram v1.1.2 h1:FHX5I5B4i4hKRVRBCFRxq1iQRej7WO3hhBuJf+UUySY=
+github.com/xdg-go/scram v1.1.2/go.mod h1:RT/sEzTbU5y00aCK8UOx6R7YryM0iF1N2MOmC3kKLN4=
 github.com/xdg-go/stringprep v1.0.3/go.mod h1:W3f5j4i+9rC0kuIEJL0ky1VpHXQU3ocBgklLGvcBnW8=
+github.com/xdg-go/stringprep v1.0.4 h1:XLI/Ng3O1Atzq0oBs3TWm+5ZVgkq2aqdlvP9JtoZ6c8=
+github.com/xdg-go/stringprep v1.0.4/go.mod h1:mPGuuIYwz7CmR2bT9j4GbQqutWS1zV24gijq1dTyGkM=
 github.com/youmark/pkcs8 v0.0.0-20181117223130-1be2e3e5546d/go.mod h1:rHwXgn7JulP+udvsHwJoVG1YGAP6VLg4y9I5dyZdqmA=
-go.mongodb.org/mongo-driver v1.10.3 h1:XDQEvmh6z1EUsXuIkXE9TaVeqHw6SwS1uf93jFs0HBA=
-go.mongodb.org/mongo-driver v1.10.3/go.mod h1:z4XpeoU6w+9Vht+jAFyLgVrD+jGSQQe0+CBWFHNiHt8=
+github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a h1:fZHgsYlfvtyqToslyjUt3VOPF4J7aK/3MPcK7xp3PDk=
+github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a/go.mod h1:ul22v+Nro/R083muKhosV54bj5niojjWZvU8xrevuH4=
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 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
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 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
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goextVersion.go

@@ -0,0 +1,5 @@
+package goext
+
+const GoextVersion = "0.0.166"
+
+const GoextVersionTimestamp = "2023-06-19T10:25:41+0200"

gojson/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

gojson/README.md

@@ -0,0 +1,12 @@
+
+
+JSON serializer which serializes nil-Arrays as `[]` and nil-maps als `{}`.
+
+Idea from: https://github.com/homelight/json
+
+Forked from https://github.com/golang/go/tree/547e8e22fe565d65d1fd4d6e71436a5a855447b0/src/encoding/json ( tag go1.20.2 )
+
+Added:
+
+ - `MarshalSafeCollections()` method
+ - `Encoder.nilSafeSlices` and `Encoder.nilSafeMaps` fields

gojson/example_marshaling_test.go

@@ -0,0 +1,73 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"strings"
+)
+
+type Animal int
+
+const (
+	Unknown Animal = iota
+	Gopher
+	Zebra
+)
+
+func (a *Animal) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	switch strings.ToLower(s) {
+	default:
+		*a = Unknown
+	case "gopher":
+		*a = Gopher
+	case "zebra":
+		*a = Zebra
+	}
+
+	return nil
+}
+
+func (a Animal) MarshalJSON() ([]byte, error) {
+	var s string
+	switch a {
+	default:
+		s = "unknown"
+	case Gopher:
+		s = "gopher"
+	case Zebra:
+		s = "zebra"
+	}
+
+	return json.Marshal(s)
+}
+
+func Example_customMarshalJSON() {
+	blob := `["gopher","armadillo","zebra","unknown","gopher","bee","gopher","zebra"]`
+	var zoo []Animal
+	if err := json.Unmarshal([]byte(blob), &zoo); err != nil {
+		log.Fatal(err)
+	}
+
+	census := make(map[Animal]int)
+	for _, animal := range zoo {
+		census[animal] += 1
+	}
+
+	fmt.Printf("Zoo Census:\n* Gophers: %d\n* Zebras:  %d\n* Unknown: %d\n",
+		census[Gopher], census[Zebra], census[Unknown])
+
+	// Output:
+	// Zoo Census:
+	// * Gophers: 3
+	// * Zebras:  2
+	// * Unknown: 3
+}

gojson/example_test.go

@@ -0,0 +1,310 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json_test
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strings"
+)
+
+func ExampleMarshal() {
+	type ColorGroup struct {
+		ID     int
+		Name   string
+		Colors []string
+	}
+	group := ColorGroup{
+		ID:     1,
+		Name:   "Reds",
+		Colors: []string{"Crimson", "Red", "Ruby", "Maroon"},
+	}
+	b, err := json.Marshal(group)
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	os.Stdout.Write(b)
+	// Output:
+	// {"ID":1,"Name":"Reds","Colors":["Crimson","Red","Ruby","Maroon"]}
+}
+
+func ExampleUnmarshal() {
+	var jsonBlob = []byte(`[
+	{"Name": "Platypus", "Order": "Monotremata"},
+	{"Name": "Quoll",    "Order": "Dasyuromorphia"}
+]`)
+	type Animal struct {
+		Name  string
+		Order string
+	}
+	var animals []Animal
+	err := json.Unmarshal(jsonBlob, &animals)
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	fmt.Printf("%+v", animals)
+	// Output:
+	// [{Name:Platypus Order:Monotremata} {Name:Quoll Order:Dasyuromorphia}]
+}
+
+// This example uses a Decoder to decode a stream of distinct JSON values.
+func ExampleDecoder() {
+	const jsonStream = `
+	{"Name": "Ed", "Text": "Knock knock."}
+	{"Name": "Sam", "Text": "Who's there?"}
+	{"Name": "Ed", "Text": "Go fmt."}
+	{"Name": "Sam", "Text": "Go fmt who?"}
+	{"Name": "Ed", "Text": "Go fmt yourself!"}
+`
+	type Message struct {
+		Name, Text string
+	}
+	dec := json.NewDecoder(strings.NewReader(jsonStream))
+	for {
+		var m Message
+		if err := dec.Decode(&m); err == io.EOF {
+			break
+		} else if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("%s: %s\n", m.Name, m.Text)
+	}
+	// Output:
+	// Ed: Knock knock.
+	// Sam: Who's there?
+	// Ed: Go fmt.
+	// Sam: Go fmt who?
+	// Ed: Go fmt yourself!
+}
+
+// This example uses a Decoder to decode a stream of distinct JSON values.
+func ExampleDecoder_Token() {
+	const jsonStream = `
+	{"Message": "Hello", "Array": [1, 2, 3], "Null": null, "Number": 1.234}
+`
+	dec := json.NewDecoder(strings.NewReader(jsonStream))
+	for {
+		t, err := dec.Token()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("%T: %v", t, t)
+		if dec.More() {
+			fmt.Printf(" (more)")
+		}
+		fmt.Printf("\n")
+	}
+	// Output:
+	// json.Delim: { (more)
+	// string: Message (more)
+	// string: Hello (more)
+	// string: Array (more)
+	// json.Delim: [ (more)
+	// float64: 1 (more)
+	// float64: 2 (more)
+	// float64: 3
+	// json.Delim: ] (more)
+	// string: Null (more)
+	// <nil>: <nil> (more)
+	// string: Number (more)
+	// float64: 1.234
+	// json.Delim: }
+}
+
+// This example uses a Decoder to decode a streaming array of JSON objects.
+func ExampleDecoder_Decode_stream() {
+	const jsonStream = `
+	[
+		{"Name": "Ed", "Text": "Knock knock."},
+		{"Name": "Sam", "Text": "Who's there?"},
+		{"Name": "Ed", "Text": "Go fmt."},
+		{"Name": "Sam", "Text": "Go fmt who?"},
+		{"Name": "Ed", "Text": "Go fmt yourself!"}
+	]
+`
+	type Message struct {
+		Name, Text string
+	}
+	dec := json.NewDecoder(strings.NewReader(jsonStream))
+
+	// read open bracket
+	t, err := dec.Token()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%T: %v\n", t, t)
+
+	// while the array contains values
+	for dec.More() {
+		var m Message
+		// decode an array value (Message)
+		err := dec.Decode(&m)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		fmt.Printf("%v: %v\n", m.Name, m.Text)
+	}
+
+	// read closing bracket
+	t, err = dec.Token()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("%T: %v\n", t, t)
+
+	// Output:
+	// json.Delim: [
+	// Ed: Knock knock.
+	// Sam: Who's there?
+	// Ed: Go fmt.
+	// Sam: Go fmt who?
+	// Ed: Go fmt yourself!
+	// json.Delim: ]
+}
+
+// This example uses RawMessage to delay parsing part of a JSON message.
+func ExampleRawMessage_unmarshal() {
+	type Color struct {
+		Space string
+		Point json.RawMessage // delay parsing until we know the color space
+	}
+	type RGB struct {
+		R uint8
+		G uint8
+		B uint8
+	}
+	type YCbCr struct {
+		Y  uint8
+		Cb int8
+		Cr int8
+	}
+
+	var j = []byte(`[
+	{"Space": "YCbCr", "Point": {"Y": 255, "Cb": 0, "Cr": -10}},
+	{"Space": "RGB",   "Point": {"R": 98, "G": 218, "B": 255}}
+]`)
+	var colors []Color
+	err := json.Unmarshal(j, &colors)
+	if err != nil {
+		log.Fatalln("error:", err)
+	}
+
+	for _, c := range colors {
+		var dst any
+		switch c.Space {
+		case "RGB":
+			dst = new(RGB)
+		case "YCbCr":
+			dst = new(YCbCr)
+		}
+		err := json.Unmarshal(c.Point, dst)
+		if err != nil {
+			log.Fatalln("error:", err)
+		}
+		fmt.Println(c.Space, dst)
+	}
+	// Output:
+	// YCbCr &{255 0 -10}
+	// RGB &{98 218 255}
+}
+
+// This example uses RawMessage to use a precomputed JSON during marshal.
+func ExampleRawMessage_marshal() {
+	h := json.RawMessage(`{"precomputed": true}`)
+
+	c := struct {
+		Header *json.RawMessage `json:"header"`
+		Body   string           `json:"body"`
+	}{Header: &h, Body: "Hello Gophers!"}
+
+	b, err := json.MarshalIndent(&c, "", "\t")
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+	os.Stdout.Write(b)
+
+	// Output:
+	// {
+	// 	"header": {
+	// 		"precomputed": true
+	// 	},
+	// 	"body": "Hello Gophers!"
+	// }
+}
+
+func ExampleIndent() {
+	type Road struct {
+		Name   string
+		Number int
+	}
+	roads := []Road{
+		{"Diamond Fork", 29},
+		{"Sheep Creek", 51},
+	}
+
+	b, err := json.Marshal(roads)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var out bytes.Buffer
+	json.Indent(&out, b, "=", "\t")
+	out.WriteTo(os.Stdout)
+	// Output:
+	// [
+	// =	{
+	// =		"Name": "Diamond Fork",
+	// =		"Number": 29
+	// =	},
+	// =	{
+	// =		"Name": "Sheep Creek",
+	// =		"Number": 51
+	// =	}
+	// =]
+}
+
+func ExampleMarshalIndent() {
+	data := map[string]int{
+		"a": 1,
+		"b": 2,
+	}
+
+	b, err := json.MarshalIndent(data, "<prefix>", "<indent>")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(string(b))
+	// Output:
+	// {
+	// <prefix><indent>"a": 1,
+	// <prefix><indent>"b": 2
+	// <prefix>}
+}
+
+func ExampleValid() {
+	goodJSON := `{"example": 1}`
+	badJSON := `{"example":2:]}}`
+
+	fmt.Println(json.Valid([]byte(goodJSON)), json.Valid([]byte(badJSON)))
+	// Output:
+	// true false
+}
+
+func ExampleHTMLEscape() {
+	var out bytes.Buffer
+	json.HTMLEscape(&out, []byte(`{"Name":"<b>HTML content</b>"}`))
+	out.WriteTo(os.Stdout)
+	// Output:
+	//{"Name":"\u003cb\u003eHTML content\u003c/b\u003e"}
+}

gojson/example_text_marshaling_test.go

@@ -0,0 +1,67 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"strings"
+)
+
+type Size int
+
+const (
+	Unrecognized Size = iota
+	Small
+	Large
+)
+
+func (s *Size) UnmarshalText(text []byte) error {
+	switch strings.ToLower(string(text)) {
+	default:
+		*s = Unrecognized
+	case "small":
+		*s = Small
+	case "large":
+		*s = Large
+	}
+	return nil
+}
+
+func (s Size) MarshalText() ([]byte, error) {
+	var name string
+	switch s {
+	default:
+		name = "unrecognized"
+	case Small:
+		name = "small"
+	case Large:
+		name = "large"
+	}
+	return []byte(name), nil
+}
+
+func Example_textMarshalJSON() {
+	blob := `["small","regular","large","unrecognized","small","normal","small","large"]`
+	var inventory []Size
+	if err := json.Unmarshal([]byte(blob), &inventory); err != nil {
+		log.Fatal(err)
+	}
+
+	counts := make(map[Size]int)
+	for _, size := range inventory {
+		counts[size] += 1
+	}
+
+	fmt.Printf("Inventory Counts:\n* Small:        %d\n* Large:        %d\n* Unrecognized: %d\n",
+		counts[Small], counts[Large], counts[Unrecognized])
+
+	// Output:
+	// Inventory Counts:
+	// * Small:        3
+	// * Large:        2
+	// * Unrecognized: 3
+}

gojson/fold.go

@@ -0,0 +1,141 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"unicode/utf8"
+)
+
+const (
+	caseMask     = ^byte(0x20) // Mask to ignore case in ASCII.
+	kelvin       = '\u212a'
+	smallLongEss = '\u017f'
+)
+
+// foldFunc returns one of four different case folding equivalence
+// functions, from most general (and slow) to fastest:
+//
+// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8
+// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S')
+// 3) asciiEqualFold, no special, but includes non-letters (including _)
+// 4) simpleLetterEqualFold, no specials, no non-letters.
+//
+// The letters S and K are special because they map to 3 runes, not just 2:
+//   - S maps to s and to U+017F 'ſ' Latin small letter long s
+//   - k maps to K and to U+212A 'K' Kelvin sign
+//
+// See https://play.golang.org/p/tTxjOc0OGo
+//
+// The returned function is specialized for matching against s and
+// should only be given s. It's not curried for performance reasons.
+func foldFunc(s []byte) func(s, t []byte) bool {
+	nonLetter := false
+	special := false // special letter
+	for _, b := range s {
+		if b >= utf8.RuneSelf {
+			return bytes.EqualFold
+		}
+		upper := b & caseMask
+		if upper < 'A' || upper > 'Z' {
+			nonLetter = true
+		} else if upper == 'K' || upper == 'S' {
+			// See above for why these letters are special.
+			special = true
+		}
+	}
+	if special {
+		return equalFoldRight
+	}
+	if nonLetter {
+		return asciiEqualFold
+	}
+	return simpleLetterEqualFold
+}
+
+// equalFoldRight is a specialization of bytes.EqualFold when s is
+// known to be all ASCII (including punctuation), but contains an 's',
+// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t.
+// See comments on foldFunc.
+func equalFoldRight(s, t []byte) bool {
+	for _, sb := range s {
+		if len(t) == 0 {
+			return false
+		}
+		tb := t[0]
+		if tb < utf8.RuneSelf {
+			if sb != tb {
+				sbUpper := sb & caseMask
+				if 'A' <= sbUpper && sbUpper <= 'Z' {
+					if sbUpper != tb&caseMask {
+						return false
+					}
+				} else {
+					return false
+				}
+			}
+			t = t[1:]
+			continue
+		}
+		// sb is ASCII and t is not. t must be either kelvin
+		// sign or long s; sb must be s, S, k, or K.
+		tr, size := utf8.DecodeRune(t)
+		switch sb {
+		case 's', 'S':
+			if tr != smallLongEss {
+				return false
+			}
+		case 'k', 'K':
+			if tr != kelvin {
+				return false
+			}
+		default:
+			return false
+		}
+		t = t[size:]
+
+	}
+	return len(t) == 0
+}
+
+// asciiEqualFold is a specialization of bytes.EqualFold for use when
+// s is all ASCII (but may contain non-letters) and contains no
+// special-folding letters.
+// See comments on foldFunc.
+func asciiEqualFold(s, t []byte) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i, sb := range s {
+		tb := t[i]
+		if sb == tb {
+			continue
+		}
+		if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') {
+			if sb&caseMask != tb&caseMask {
+				return false
+			}
+		} else {
+			return false
+		}
+	}
+	return true
+}
+
+// simpleLetterEqualFold is a specialization of bytes.EqualFold for
+// use when s is all ASCII letters (no underscores, etc) and also
+// doesn't contain 'k', 'K', 's', or 'S'.
+// See comments on foldFunc.
+func simpleLetterEqualFold(s, t []byte) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i, b := range s {
+		if b&caseMask != t[i]&caseMask {
+			return false
+		}
+	}
+	return true
+}

gojson/fold_test.go

@@ -0,0 +1,110 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+	"unicode/utf8"
+)
+
+var foldTests = []struct {
+	fn   func(s, t []byte) bool
+	s, t string
+	want bool
+}{
+	{equalFoldRight, "", "", true},
+	{equalFoldRight, "a", "a", true},
+	{equalFoldRight, "", "a", false},
+	{equalFoldRight, "a", "", false},
+	{equalFoldRight, "a", "A", true},
+	{equalFoldRight, "AB", "ab", true},
+	{equalFoldRight, "AB", "ac", false},
+	{equalFoldRight, "sbkKc", "ſbKKc", true},
+	{equalFoldRight, "SbKkc", "ſbKKc", true},
+	{equalFoldRight, "SbKkc", "ſbKK", false},
+	{equalFoldRight, "e", "é", false},
+	{equalFoldRight, "s", "S", true},
+
+	{simpleLetterEqualFold, "", "", true},
+	{simpleLetterEqualFold, "abc", "abc", true},
+	{simpleLetterEqualFold, "abc", "ABC", true},
+	{simpleLetterEqualFold, "abc", "ABCD", false},
+	{simpleLetterEqualFold, "abc", "xxx", false},
+
+	{asciiEqualFold, "a_B", "A_b", true},
+	{asciiEqualFold, "aa@", "aa`", false}, // verify 0x40 and 0x60 aren't case-equivalent
+}
+
+func TestFold(t *testing.T) {
+	for i, tt := range foldTests {
+		if got := tt.fn([]byte(tt.s), []byte(tt.t)); got != tt.want {
+			t.Errorf("%d. %q, %q = %v; want %v", i, tt.s, tt.t, got, tt.want)
+		}
+		truth := strings.EqualFold(tt.s, tt.t)
+		if truth != tt.want {
+			t.Errorf("strings.EqualFold doesn't agree with case %d", i)
+		}
+	}
+}
+
+func TestFoldAgainstUnicode(t *testing.T) {
+	var buf1, buf2 []byte
+	var runes []rune
+	for i := 0x20; i <= 0x7f; i++ {
+		runes = append(runes, rune(i))
+	}
+	runes = append(runes, kelvin, smallLongEss)
+
+	funcs := []struct {
+		name   string
+		fold   func(s, t []byte) bool
+		letter bool // must be ASCII letter
+		simple bool // must be simple ASCII letter (not 'S' or 'K')
+	}{
+		{
+			name: "equalFoldRight",
+			fold: equalFoldRight,
+		},
+		{
+			name:   "asciiEqualFold",
+			fold:   asciiEqualFold,
+			simple: true,
+		},
+		{
+			name:   "simpleLetterEqualFold",
+			fold:   simpleLetterEqualFold,
+			simple: true,
+			letter: true,
+		},
+	}
+
+	for _, ff := range funcs {
+		for _, r := range runes {
+			if r >= utf8.RuneSelf {
+				continue
+			}
+			if ff.letter && !isASCIILetter(byte(r)) {
+				continue
+			}
+			if ff.simple && (r == 's' || r == 'S' || r == 'k' || r == 'K') {
+				continue
+			}
+			for _, r2 := range runes {
+				buf1 = append(utf8.AppendRune(append(buf1[:0], 'x'), r), 'x')
+				buf2 = append(utf8.AppendRune(append(buf2[:0], 'x'), r2), 'x')
+				want := bytes.EqualFold(buf1, buf2)
+				if got := ff.fold(buf1, buf2); got != want {
+					t.Errorf("%s(%q, %q) = %v; want %v", ff.name, buf1, buf2, got, want)
+				}
+			}
+		}
+	}
+}
+
+func isASCIILetter(b byte) bool {
+	return ('A' <= b && b <= 'Z') || ('a' <= b && b <= 'z')
+}

gojson/fuzz.go

@@ -0,0 +1,42 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build gofuzz
+
+package json
+
+import (
+	"fmt"
+)
+
+func Fuzz(data []byte) (score int) {
+	for _, ctor := range []func() any{
+		func() any { return new(any) },
+		func() any { return new(map[string]any) },
+		func() any { return new([]any) },
+	} {
+		v := ctor()
+		err := Unmarshal(data, v)
+		if err != nil {
+			continue
+		}
+		score = 1
+
+		m, err := Marshal(v)
+		if err != nil {
+			fmt.Printf("v=%#v\n", v)
+			panic(err)
+		}
+
+		u := ctor()
+		err = Unmarshal(m, u)
+		if err != nil {
+			fmt.Printf("v=%#v\n", v)
+			fmt.Printf("m=%s\n", m)
+			panic(err)
+		}
+	}
+
+	return
+}

gojson/fuzz_test.go

@@ -0,0 +1,83 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+func FuzzUnmarshalJSON(f *testing.F) {
+	f.Add([]byte(`{
+"object": {
+	"slice": [
+		1,
+		2.0,
+		"3",
+		[4],
+		{5: {}}
+	]
+},
+"slice": [[]],
+"string": ":)",
+"int": 1e5,
+"float": 3e-9"
+}`))
+
+	f.Fuzz(func(t *testing.T, b []byte) {
+		for _, typ := range []func() interface{}{
+			func() interface{} { return new(interface{}) },
+			func() interface{} { return new(map[string]interface{}) },
+			func() interface{} { return new([]interface{}) },
+		} {
+			i := typ()
+			if err := Unmarshal(b, i); err != nil {
+				return
+			}
+
+			encoded, err := Marshal(i)
+			if err != nil {
+				t.Fatalf("failed to marshal: %s", err)
+			}
+
+			if err := Unmarshal(encoded, i); err != nil {
+				t.Fatalf("failed to roundtrip: %s", err)
+			}
+		}
+	})
+}
+
+func FuzzDecoderToken(f *testing.F) {
+	f.Add([]byte(`{
+"object": {
+	"slice": [
+		1,
+		2.0,
+		"3",
+		[4],
+		{5: {}}
+	]
+},
+"slice": [[]],
+"string": ":)",
+"int": 1e5,
+"float": 3e-9"
+}`))
+
+	f.Fuzz(func(t *testing.T, b []byte) {
+		r := bytes.NewReader(b)
+		d := NewDecoder(r)
+		for {
+			_, err := d.Token()
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+				return
+			}
+		}
+	})
+}

gojson/gionic.go

@@ -0,0 +1,44 @@
+package json
+
+import (
+	"net/http"
+)
+
+// Render interface is copied from github.com/gin-gonic/gin@v1.8.1/render/render.go
+type Render interface {
+	// Render writes data with custom ContentType.
+	Render(http.ResponseWriter) error
+	// WriteContentType writes custom ContentType.
+	WriteContentType(w http.ResponseWriter)
+}
+
+type GoJsonRender struct {
+	Data          any
+	NilSafeSlices bool
+	NilSafeMaps   bool
+	Indent        *IndentOpt
+}
+
+func (r GoJsonRender) Render(w http.ResponseWriter) error {
+	header := w.Header()
+	if val := header["Content-Type"]; len(val) == 0 {
+		header["Content-Type"] = []string{"application/json; charset=utf-8"}
+	}
+
+	jsonBytes, err := MarshalSafeCollections(r.Data, r.NilSafeSlices, r.NilSafeMaps, r.Indent)
+	if err != nil {
+		panic(err)
+	}
+	_, err = w.Write(jsonBytes)
+	if err != nil {
+		panic(err)
+	}
+	return nil
+}
+
+func (r GoJsonRender) WriteContentType(w http.ResponseWriter) {
+	header := w.Header()
+	if val := header["Content-Type"]; len(val) == 0 {
+		header["Content-Type"] = []string{"application/json; charset=utf-8"}
+	}
+}

gojson/indent.go

@@ -0,0 +1,143 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+)
+
+// Compact appends to dst the JSON-encoded src with
+// insignificant space characters elided.
+func Compact(dst *bytes.Buffer, src []byte) error {
+	return compact(dst, src, false)
+}
+
+func compact(dst *bytes.Buffer, src []byte, escape bool) error {
+	origLen := dst.Len()
+	scan := newScanner()
+	defer freeScanner(scan)
+	start := 0
+	for i, c := range src {
+		if escape && (c == '<' || c == '>' || c == '&') {
+			if start < i {
+				dst.Write(src[start:i])
+			}
+			dst.WriteString(`\u00`)
+			dst.WriteByte(hex[c>>4])
+			dst.WriteByte(hex[c&0xF])
+			start = i + 1
+		}
+		// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
+		if escape && c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
+			if start < i {
+				dst.Write(src[start:i])
+			}
+			dst.WriteString(`\u202`)
+			dst.WriteByte(hex[src[i+2]&0xF])
+			start = i + 3
+		}
+		v := scan.step(scan, c)
+		if v >= scanSkipSpace {
+			if v == scanError {
+				break
+			}
+			if start < i {
+				dst.Write(src[start:i])
+			}
+			start = i + 1
+		}
+	}
+	if scan.eof() == scanError {
+		dst.Truncate(origLen)
+		return scan.err
+	}
+	if start < len(src) {
+		dst.Write(src[start:])
+	}
+	return nil
+}
+
+func newline(dst *bytes.Buffer, prefix, indent string, depth int) {
+	dst.WriteByte('\n')
+	dst.WriteString(prefix)
+	for i := 0; i < depth; i++ {
+		dst.WriteString(indent)
+	}
+}
+
+// Indent appends to dst an indented form of the JSON-encoded src.
+// Each element in a JSON object or array begins on a new,
+// indented line beginning with prefix followed by one or more
+// copies of indent according to the indentation nesting.
+// The data appended to dst does not begin with the prefix nor
+// any indentation, to make it easier to embed inside other formatted JSON data.
+// Although leading space characters (space, tab, carriage return, newline)
+// at the beginning of src are dropped, trailing space characters
+// at the end of src are preserved and copied to dst.
+// For example, if src has no trailing spaces, neither will dst;
+// if src ends in a trailing newline, so will dst.
+func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
+	origLen := dst.Len()
+	scan := newScanner()
+	defer freeScanner(scan)
+	needIndent := false
+	depth := 0
+	for _, c := range src {
+		scan.bytes++
+		v := scan.step(scan, c)
+		if v == scanSkipSpace {
+			continue
+		}
+		if v == scanError {
+			break
+		}
+		if needIndent && v != scanEndObject && v != scanEndArray {
+			needIndent = false
+			depth++
+			newline(dst, prefix, indent, depth)
+		}
+
+		// Emit semantically uninteresting bytes
+		// (in particular, punctuation in strings) unmodified.
+		if v == scanContinue {
+			dst.WriteByte(c)
+			continue
+		}
+
+		// Add spacing around real punctuation.
+		switch c {
+		case '{', '[':
+			// delay indent so that empty object and array are formatted as {} and [].
+			needIndent = true
+			dst.WriteByte(c)
+
+		case ',':
+			dst.WriteByte(c)
+			newline(dst, prefix, indent, depth)
+
+		case ':':
+			dst.WriteByte(c)
+			dst.WriteByte(' ')
+
+		case '}', ']':
+			if needIndent {
+				// suppress indent in empty object/array
+				needIndent = false
+			} else {
+				depth--
+				newline(dst, prefix, indent, depth)
+			}
+			dst.WriteByte(c)
+
+		default:
+			dst.WriteByte(c)
+		}
+	}
+	if scan.eof() == scanError {
+		dst.Truncate(origLen)
+		return scan.err
+	}
+	return nil
+}

gojson/number_test.go

@@ -0,0 +1,118 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"regexp"
+	"testing"
+)
+
+func TestNumberIsValid(t *testing.T) {
+	// From: https://stackoverflow.com/a/13340826
+	var jsonNumberRegexp = regexp.MustCompile(`^-?(?:0|[1-9]\d*)(?:\.\d+)?(?:[eE][+-]?\d+)?$`)
+
+	validTests := []string{
+		"0",
+		"-0",
+		"1",
+		"-1",
+		"0.1",
+		"-0.1",
+		"1234",
+		"-1234",
+		"12.34",
+		"-12.34",
+		"12E0",
+		"12E1",
+		"12e34",
+		"12E-0",
+		"12e+1",
+		"12e-34",
+		"-12E0",
+		"-12E1",
+		"-12e34",
+		"-12E-0",
+		"-12e+1",
+		"-12e-34",
+		"1.2E0",
+		"1.2E1",
+		"1.2e34",
+		"1.2E-0",
+		"1.2e+1",
+		"1.2e-34",
+		"-1.2E0",
+		"-1.2E1",
+		"-1.2e34",
+		"-1.2E-0",
+		"-1.2e+1",
+		"-1.2e-34",
+		"0E0",
+		"0E1",
+		"0e34",
+		"0E-0",
+		"0e+1",
+		"0e-34",
+		"-0E0",
+		"-0E1",
+		"-0e34",
+		"-0E-0",
+		"-0e+1",
+		"-0e-34",
+	}
+
+	for _, test := range validTests {
+		if !isValidNumber(test) {
+			t.Errorf("%s should be valid", test)
+		}
+
+		var f float64
+		if err := Unmarshal([]byte(test), &f); err != nil {
+			t.Errorf("%s should be valid but Unmarshal failed: %v", test, err)
+		}
+
+		if !jsonNumberRegexp.MatchString(test) {
+			t.Errorf("%s should be valid but regexp does not match", test)
+		}
+	}
+
+	invalidTests := []string{
+		"",
+		"invalid",
+		"1.0.1",
+		"1..1",
+		"-1-2",
+		"012a42",
+		"01.2",
+		"012",
+		"12E12.12",
+		"1e2e3",
+		"1e+-2",
+		"1e--23",
+		"1e",
+		"e1",
+		"1e+",
+		"1ea",
+		"1a",
+		"1.a",
+		"1.",
+		"01",
+		"1.e1",
+	}
+
+	for _, test := range invalidTests {
+		if isValidNumber(test) {
+			t.Errorf("%s should be invalid", test)
+		}
+
+		var f float64
+		if err := Unmarshal([]byte(test), &f); err == nil {
+			t.Errorf("%s should be invalid but unmarshal wrote %v", test, f)
+		}
+
+		if jsonNumberRegexp.MatchString(test) {
+			t.Errorf("%s should be invalid but matches regexp", test)
+		}
+	}
+}

gojson/scanner.go

@@ -0,0 +1,610 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+// JSON value parser state machine.
+// Just about at the limit of what is reasonable to write by hand.
+// Some parts are a bit tedious, but overall it nicely factors out the
+// otherwise common code from the multiple scanning functions
+// in this package (Compact, Indent, checkValid, etc).
+//
+// This file starts with two simple examples using the scanner
+// before diving into the scanner itself.
+
+import (
+	"strconv"
+	"sync"
+)
+
+// Valid reports whether data is a valid JSON encoding.
+func Valid(data []byte) bool {
+	scan := newScanner()
+	defer freeScanner(scan)
+	return checkValid(data, scan) == nil
+}
+
+// checkValid verifies that data is valid JSON-encoded data.
+// scan is passed in for use by checkValid to avoid an allocation.
+// checkValid returns nil or a SyntaxError.
+func checkValid(data []byte, scan *scanner) error {
+	scan.reset()
+	for _, c := range data {
+		scan.bytes++
+		if scan.step(scan, c) == scanError {
+			return scan.err
+		}
+	}
+	if scan.eof() == scanError {
+		return scan.err
+	}
+	return nil
+}
+
+// A SyntaxError is a description of a JSON syntax error.
+// Unmarshal will return a SyntaxError if the JSON can't be parsed.
+type SyntaxError struct {
+	msg    string // description of error
+	Offset int64  // error occurred after reading Offset bytes
+}
+
+func (e *SyntaxError) Error() string { return e.msg }
+
+// A scanner is a JSON scanning state machine.
+// Callers call scan.reset and then pass bytes in one at a time
+// by calling scan.step(&scan, c) for each byte.
+// The return value, referred to as an opcode, tells the
+// caller about significant parsing events like beginning
+// and ending literals, objects, and arrays, so that the
+// caller can follow along if it wishes.
+// The return value scanEnd indicates that a single top-level
+// JSON value has been completed, *before* the byte that
+// just got passed in.  (The indication must be delayed in order
+// to recognize the end of numbers: is 123 a whole value or
+// the beginning of 12345e+6?).
+type scanner struct {
+	// The step is a func to be called to execute the next transition.
+	// Also tried using an integer constant and a single func
+	// with a switch, but using the func directly was 10% faster
+	// on a 64-bit Mac Mini, and it's nicer to read.
+	step func(*scanner, byte) int
+
+	// Reached end of top-level value.
+	endTop bool
+
+	// Stack of what we're in the middle of - array values, object keys, object values.
+	parseState []int
+
+	// Error that happened, if any.
+	err error
+
+	// total bytes consumed, updated by decoder.Decode (and deliberately
+	// not set to zero by scan.reset)
+	bytes int64
+}
+
+var scannerPool = sync.Pool{
+	New: func() any {
+		return &scanner{}
+	},
+}
+
+func newScanner() *scanner {
+	scan := scannerPool.Get().(*scanner)
+	// scan.reset by design doesn't set bytes to zero
+	scan.bytes = 0
+	scan.reset()
+	return scan
+}
+
+func freeScanner(scan *scanner) {
+	// Avoid hanging on to too much memory in extreme cases.
+	if len(scan.parseState) > 1024 {
+		scan.parseState = nil
+	}
+	scannerPool.Put(scan)
+}
+
+// These values are returned by the state transition functions
+// assigned to scanner.state and the method scanner.eof.
+// They give details about the current state of the scan that
+// callers might be interested to know about.
+// It is okay to ignore the return value of any particular
+// call to scanner.state: if one call returns scanError,
+// every subsequent call will return scanError too.
+const (
+	// Continue.
+	scanContinue     = iota // uninteresting byte
+	scanBeginLiteral        // end implied by next result != scanContinue
+	scanBeginObject         // begin object
+	scanObjectKey           // just finished object key (string)
+	scanObjectValue         // just finished non-last object value
+	scanEndObject           // end object (implies scanObjectValue if possible)
+	scanBeginArray          // begin array
+	scanArrayValue          // just finished array value
+	scanEndArray            // end array (implies scanArrayValue if possible)
+	scanSkipSpace           // space byte; can skip; known to be last "continue" result
+
+	// Stop.
+	scanEnd   // top-level value ended *before* this byte; known to be first "stop" result
+	scanError // hit an error, scanner.err.
+)
+
+// These values are stored in the parseState stack.
+// They give the current state of a composite value
+// being scanned. If the parser is inside a nested value
+// the parseState describes the nested state, outermost at entry 0.
+const (
+	parseObjectKey   = iota // parsing object key (before colon)
+	parseObjectValue        // parsing object value (after colon)
+	parseArrayValue         // parsing array value
+)
+
+// This limits the max nesting depth to prevent stack overflow.
+// This is permitted by https://tools.ietf.org/html/rfc7159#section-9
+const maxNestingDepth = 10000
+
+// reset prepares the scanner for use.
+// It must be called before calling s.step.
+func (s *scanner) reset() {
+	s.step = stateBeginValue
+	s.parseState = s.parseState[0:0]
+	s.err = nil
+	s.endTop = false
+}
+
+// eof tells the scanner that the end of input has been reached.
+// It returns a scan status just as s.step does.
+func (s *scanner) eof() int {
+	if s.err != nil {
+		return scanError
+	}
+	if s.endTop {
+		return scanEnd
+	}
+	s.step(s, ' ')
+	if s.endTop {
+		return scanEnd
+	}
+	if s.err == nil {
+		s.err = &SyntaxError{"unexpected end of JSON input", s.bytes}
+	}
+	return scanError
+}
+
+// pushParseState pushes a new parse state p onto the parse stack.
+// an error state is returned if maxNestingDepth was exceeded, otherwise successState is returned.
+func (s *scanner) pushParseState(c byte, newParseState int, successState int) int {
+	s.parseState = append(s.parseState, newParseState)
+	if len(s.parseState) <= maxNestingDepth {
+		return successState
+	}
+	return s.error(c, "exceeded max depth")
+}
+
+// popParseState pops a parse state (already obtained) off the stack
+// and updates s.step accordingly.
+func (s *scanner) popParseState() {
+	n := len(s.parseState) - 1
+	s.parseState = s.parseState[0:n]
+	if n == 0 {
+		s.step = stateEndTop
+		s.endTop = true
+	} else {
+		s.step = stateEndValue
+	}
+}
+
+func isSpace(c byte) bool {
+	return c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n')
+}
+
+// stateBeginValueOrEmpty is the state after reading `[`.
+func stateBeginValueOrEmpty(s *scanner, c byte) int {
+	if isSpace(c) {
+		return scanSkipSpace
+	}
+	if c == ']' {
+		return stateEndValue(s, c)
+	}
+	return stateBeginValue(s, c)
+}
+
+// stateBeginValue is the state at the beginning of the input.
+func stateBeginValue(s *scanner, c byte) int {
+	if isSpace(c) {
+		return scanSkipSpace
+	}
+	switch c {
+	case '{':
+		s.step = stateBeginStringOrEmpty
+		return s.pushParseState(c, parseObjectKey, scanBeginObject)
+	case '[':
+		s.step = stateBeginValueOrEmpty
+		return s.pushParseState(c, parseArrayValue, scanBeginArray)
+	case '"':
+		s.step = stateInString
+		return scanBeginLiteral
+	case '-':
+		s.step = stateNeg
+		return scanBeginLiteral
+	case '0': // beginning of 0.123
+		s.step = state0
+		return scanBeginLiteral
+	case 't': // beginning of true
+		s.step = stateT
+		return scanBeginLiteral
+	case 'f': // beginning of false
+		s.step = stateF
+		return scanBeginLiteral
+	case 'n': // beginning of null
+		s.step = stateN
+		return scanBeginLiteral
+	}
+	if '1' <= c && c <= '9' { // beginning of 1234.5
+		s.step = state1
+		return scanBeginLiteral
+	}
+	return s.error(c, "looking for beginning of value")
+}
+
+// stateBeginStringOrEmpty is the state after reading `{`.
+func stateBeginStringOrEmpty(s *scanner, c byte) int {
+	if isSpace(c) {
+		return scanSkipSpace
+	}
+	if c == '}' {
+		n := len(s.parseState)
+		s.parseState[n-1] = parseObjectValue
+		return stateEndValue(s, c)
+	}
+	return stateBeginString(s, c)
+}
+
+// stateBeginString is the state after reading `{"key": value,`.
+func stateBeginString(s *scanner, c byte) int {
+	if isSpace(c) {
+		return scanSkipSpace
+	}
+	if c == '"' {
+		s.step = stateInString
+		return scanBeginLiteral
+	}
+	return s.error(c, "looking for beginning of object key string")
+}
+
+// stateEndValue is the state after completing a value,
+// such as after reading `{}` or `true` or `["x"`.
+func stateEndValue(s *scanner, c byte) int {
+	n := len(s.parseState)
+	if n == 0 {
+		// Completed top-level before the current byte.
+		s.step = stateEndTop
+		s.endTop = true
+		return stateEndTop(s, c)
+	}
+	if isSpace(c) {
+		s.step = stateEndValue
+		return scanSkipSpace
+	}
+	ps := s.parseState[n-1]
+	switch ps {
+	case parseObjectKey:
+		if c == ':' {
+			s.parseState[n-1] = parseObjectValue
+			s.step = stateBeginValue
+			return scanObjectKey
+		}
+		return s.error(c, "after object key")
+	case parseObjectValue:
+		if c == ',' {
+			s.parseState[n-1] = parseObjectKey
+			s.step = stateBeginString
+			return scanObjectValue
+		}
+		if c == '}' {
+			s.popParseState()
+			return scanEndObject
+		}
+		return s.error(c, "after object key:value pair")
+	case parseArrayValue:
+		if c == ',' {
+			s.step = stateBeginValue
+			return scanArrayValue
+		}
+		if c == ']' {
+			s.popParseState()
+			return scanEndArray
+		}
+		return s.error(c, "after array element")
+	}
+	return s.error(c, "")
+}
+
+// stateEndTop is the state after finishing the top-level value,
+// such as after reading `{}` or `[1,2,3]`.
+// Only space characters should be seen now.
+func stateEndTop(s *scanner, c byte) int {
+	if !isSpace(c) {
+		// Complain about non-space byte on next call.
+		s.error(c, "after top-level value")
+	}
+	return scanEnd
+}
+
+// stateInString is the state after reading `"`.
+func stateInString(s *scanner, c byte) int {
+	if c == '"' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	if c == '\\' {
+		s.step = stateInStringEsc
+		return scanContinue
+	}
+	if c < 0x20 {
+		return s.error(c, "in string literal")
+	}
+	return scanContinue
+}
+
+// stateInStringEsc is the state after reading `"\` during a quoted string.
+func stateInStringEsc(s *scanner, c byte) int {
+	switch c {
+	case 'b', 'f', 'n', 'r', 't', '\\', '/', '"':
+		s.step = stateInString
+		return scanContinue
+	case 'u':
+		s.step = stateInStringEscU
+		return scanContinue
+	}
+	return s.error(c, "in string escape code")
+}
+
+// stateInStringEscU is the state after reading `"\u` during a quoted string.
+func stateInStringEscU(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInStringEscU1
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInStringEscU1 is the state after reading `"\u1` during a quoted string.
+func stateInStringEscU1(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInStringEscU12
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInStringEscU12 is the state after reading `"\u12` during a quoted string.
+func stateInStringEscU12(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInStringEscU123
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInStringEscU123 is the state after reading `"\u123` during a quoted string.
+func stateInStringEscU123(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInString
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateNeg is the state after reading `-` during a number.
+func stateNeg(s *scanner, c byte) int {
+	if c == '0' {
+		s.step = state0
+		return scanContinue
+	}
+	if '1' <= c && c <= '9' {
+		s.step = state1
+		return scanContinue
+	}
+	return s.error(c, "in numeric literal")
+}
+
+// state1 is the state after reading a non-zero integer during a number,
+// such as after reading `1` or `100` but not `0`.
+func state1(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		s.step = state1
+		return scanContinue
+	}
+	return state0(s, c)
+}
+
+// state0 is the state after reading `0` during a number.
+func state0(s *scanner, c byte) int {
+	if c == '.' {
+		s.step = stateDot
+		return scanContinue
+	}
+	if c == 'e' || c == 'E' {
+		s.step = stateE
+		return scanContinue
+	}
+	return stateEndValue(s, c)
+}
+
+// stateDot is the state after reading the integer and decimal point in a number,
+// such as after reading `1.`.
+func stateDot(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		s.step = stateDot0
+		return scanContinue
+	}
+	return s.error(c, "after decimal point in numeric literal")
+}
+
+// stateDot0 is the state after reading the integer, decimal point, and subsequent
+// digits of a number, such as after reading `3.14`.
+func stateDot0(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		return scanContinue
+	}
+	if c == 'e' || c == 'E' {
+		s.step = stateE
+		return scanContinue
+	}
+	return stateEndValue(s, c)
+}
+
+// stateE is the state after reading the mantissa and e in a number,
+// such as after reading `314e` or `0.314e`.
+func stateE(s *scanner, c byte) int {
+	if c == '+' || c == '-' {
+		s.step = stateESign
+		return scanContinue
+	}
+	return stateESign(s, c)
+}
+
+// stateESign is the state after reading the mantissa, e, and sign in a number,
+// such as after reading `314e-` or `0.314e+`.
+func stateESign(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		s.step = stateE0
+		return scanContinue
+	}
+	return s.error(c, "in exponent of numeric literal")
+}
+
+// stateE0 is the state after reading the mantissa, e, optional sign,
+// and at least one digit of the exponent in a number,
+// such as after reading `314e-2` or `0.314e+1` or `3.14e0`.
+func stateE0(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		return scanContinue
+	}
+	return stateEndValue(s, c)
+}
+
+// stateT is the state after reading `t`.
+func stateT(s *scanner, c byte) int {
+	if c == 'r' {
+		s.step = stateTr
+		return scanContinue
+	}
+	return s.error(c, "in literal true (expecting 'r')")
+}
+
+// stateTr is the state after reading `tr`.
+func stateTr(s *scanner, c byte) int {
+	if c == 'u' {
+		s.step = stateTru
+		return scanContinue
+	}
+	return s.error(c, "in literal true (expecting 'u')")
+}
+
+// stateTru is the state after reading `tru`.
+func stateTru(s *scanner, c byte) int {
+	if c == 'e' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	return s.error(c, "in literal true (expecting 'e')")
+}
+
+// stateF is the state after reading `f`.
+func stateF(s *scanner, c byte) int {
+	if c == 'a' {
+		s.step = stateFa
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 'a')")
+}
+
+// stateFa is the state after reading `fa`.
+func stateFa(s *scanner, c byte) int {
+	if c == 'l' {
+		s.step = stateFal
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 'l')")
+}
+
+// stateFal is the state after reading `fal`.
+func stateFal(s *scanner, c byte) int {
+	if c == 's' {
+		s.step = stateFals
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 's')")
+}
+
+// stateFals is the state after reading `fals`.
+func stateFals(s *scanner, c byte) int {
+	if c == 'e' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 'e')")
+}
+
+// stateN is the state after reading `n`.
+func stateN(s *scanner, c byte) int {
+	if c == 'u' {
+		s.step = stateNu
+		return scanContinue
+	}
+	return s.error(c, "in literal null (expecting 'u')")
+}
+
+// stateNu is the state after reading `nu`.
+func stateNu(s *scanner, c byte) int {
+	if c == 'l' {
+		s.step = stateNul
+		return scanContinue
+	}
+	return s.error(c, "in literal null (expecting 'l')")
+}
+
+// stateNul is the state after reading `nul`.
+func stateNul(s *scanner, c byte) int {
+	if c == 'l' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	return s.error(c, "in literal null (expecting 'l')")
+}
+
+// stateError is the state after reaching a syntax error,
+// such as after reading `[1}` or `5.1.2`.
+func stateError(s *scanner, c byte) int {
+	return scanError
+}
+
+// error records an error and switches to the error state.
+func (s *scanner) error(c byte, context string) int {
+	s.step = stateError
+	s.err = &SyntaxError{"invalid character " + quoteChar(c) + " " + context, s.bytes}
+	return scanError
+}
+
+// quoteChar formats c as a quoted character literal.
+func quoteChar(c byte) string {
+	// special cases - different from quoted strings
+	if c == '\'' {
+		return `'\''`
+	}
+	if c == '"' {
+		return `'"'`
+	}
+
+	// use quoted string with different quotation marks
+	s := strconv.Quote(string(c))
+	return "'" + s[1:len(s)-1] + "'"
+}

gojson/scanner_test.go

@@ -0,0 +1,301 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"math"
+	"math/rand"
+	"reflect"
+	"testing"
+)
+
+var validTests = []struct {
+	data string
+	ok   bool
+}{
+	{`foo`, false},
+	{`}{`, false},
+	{`{]`, false},
+	{`{}`, true},
+	{`{"foo":"bar"}`, true},
+	{`{"foo":"bar","bar":{"baz":["qux"]}}`, true},
+}
+
+func TestValid(t *testing.T) {
+	for _, tt := range validTests {
+		if ok := Valid([]byte(tt.data)); ok != tt.ok {
+			t.Errorf("Valid(%#q) = %v, want %v", tt.data, ok, tt.ok)
+		}
+	}
+}
+
+// Tests of simple examples.
+
+type example struct {
+	compact string
+	indent  string
+}
+
+var examples = []example{
+	{`1`, `1`},
+	{`{}`, `{}`},
+	{`[]`, `[]`},
+	{`{"":2}`, "{\n\t\"\": 2\n}"},
+	{`[3]`, "[\n\t3\n]"},
+	{`[1,2,3]`, "[\n\t1,\n\t2,\n\t3\n]"},
+	{`{"x":1}`, "{\n\t\"x\": 1\n}"},
+	{ex1, ex1i},
+	{"{\"\":\"<>&\u2028\u2029\"}", "{\n\t\"\": \"<>&\u2028\u2029\"\n}"}, // See golang.org/issue/34070
+}
+
+var ex1 = `[true,false,null,"x",1,1.5,0,-5e+2]`
+
+var ex1i = `[
+	true,
+	false,
+	null,
+	"x",
+	1,
+	1.5,
+	0,
+	-5e+2
+]`
+
+func TestCompact(t *testing.T) {
+	var buf bytes.Buffer
+	for _, tt := range examples {
+		buf.Reset()
+		if err := Compact(&buf, []byte(tt.compact)); err != nil {
+			t.Errorf("Compact(%#q): %v", tt.compact, err)
+		} else if s := buf.String(); s != tt.compact {
+			t.Errorf("Compact(%#q) = %#q, want original", tt.compact, s)
+		}
+
+		buf.Reset()
+		if err := Compact(&buf, []byte(tt.indent)); err != nil {
+			t.Errorf("Compact(%#q): %v", tt.indent, err)
+			continue
+		} else if s := buf.String(); s != tt.compact {
+			t.Errorf("Compact(%#q) = %#q, want %#q", tt.indent, s, tt.compact)
+		}
+	}
+}
+
+func TestCompactSeparators(t *testing.T) {
+	// U+2028 and U+2029 should be escaped inside strings.
+	// They should not appear outside strings.
+	tests := []struct {
+		in, compact string
+	}{
+		{"{\"\u2028\": 1}", "{\"\u2028\":1}"},
+		{"{\"\u2029\" :2}", "{\"\u2029\":2}"},
+	}
+	for _, tt := range tests {
+		var buf bytes.Buffer
+		if err := Compact(&buf, []byte(tt.in)); err != nil {
+			t.Errorf("Compact(%q): %v", tt.in, err)
+		} else if s := buf.String(); s != tt.compact {
+			t.Errorf("Compact(%q) = %q, want %q", tt.in, s, tt.compact)
+		}
+	}
+}
+
+func TestIndent(t *testing.T) {
+	var buf bytes.Buffer
+	for _, tt := range examples {
+		buf.Reset()
+		if err := Indent(&buf, []byte(tt.indent), "", "\t"); err != nil {
+			t.Errorf("Indent(%#q): %v", tt.indent, err)
+		} else if s := buf.String(); s != tt.indent {
+			t.Errorf("Indent(%#q) = %#q, want original", tt.indent, s)
+		}
+
+		buf.Reset()
+		if err := Indent(&buf, []byte(tt.compact), "", "\t"); err != nil {
+			t.Errorf("Indent(%#q): %v", tt.compact, err)
+			continue
+		} else if s := buf.String(); s != tt.indent {
+			t.Errorf("Indent(%#q) = %#q, want %#q", tt.compact, s, tt.indent)
+		}
+	}
+}
+
+// Tests of a large random structure.
+
+func TestCompactBig(t *testing.T) {
+	initBig()
+	var buf bytes.Buffer
+	if err := Compact(&buf, jsonBig); err != nil {
+		t.Fatalf("Compact: %v", err)
+	}
+	b := buf.Bytes()
+	if !bytes.Equal(b, jsonBig) {
+		t.Error("Compact(jsonBig) != jsonBig")
+		diff(t, b, jsonBig)
+		return
+	}
+}
+
+func TestIndentBig(t *testing.T) {
+	t.Parallel()
+	initBig()
+	var buf bytes.Buffer
+	if err := Indent(&buf, jsonBig, "", "\t"); err != nil {
+		t.Fatalf("Indent1: %v", err)
+	}
+	b := buf.Bytes()
+	if len(b) == len(jsonBig) {
+		// jsonBig is compact (no unnecessary spaces);
+		// indenting should make it bigger
+		t.Fatalf("Indent(jsonBig) did not get bigger")
+	}
+
+	// should be idempotent
+	var buf1 bytes.Buffer
+	if err := Indent(&buf1, b, "", "\t"); err != nil {
+		t.Fatalf("Indent2: %v", err)
+	}
+	b1 := buf1.Bytes()
+	if !bytes.Equal(b1, b) {
+		t.Error("Indent(Indent(jsonBig)) != Indent(jsonBig)")
+		diff(t, b1, b)
+		return
+	}
+
+	// should get back to original
+	buf1.Reset()
+	if err := Compact(&buf1, b); err != nil {
+		t.Fatalf("Compact: %v", err)
+	}
+	b1 = buf1.Bytes()
+	if !bytes.Equal(b1, jsonBig) {
+		t.Error("Compact(Indent(jsonBig)) != jsonBig")
+		diff(t, b1, jsonBig)
+		return
+	}
+}
+
+type indentErrorTest struct {
+	in  string
+	err error
+}
+
+var indentErrorTests = []indentErrorTest{
+	{`{"X": "foo", "Y"}`, &SyntaxError{"invalid character '}' after object key", 17}},
+	{`{"X": "foo" "Y": "bar"}`, &SyntaxError{"invalid character '\"' after object key:value pair", 13}},
+}
+
+func TestIndentErrors(t *testing.T) {
+	for i, tt := range indentErrorTests {
+		slice := make([]uint8, 0)
+		buf := bytes.NewBuffer(slice)
+		if err := Indent(buf, []uint8(tt.in), "", ""); err != nil {
+			if !reflect.DeepEqual(err, tt.err) {
+				t.Errorf("#%d: Indent: %#v", i, err)
+				continue
+			}
+		}
+	}
+}
+
+func diff(t *testing.T, a, b []byte) {
+	for i := 0; ; i++ {
+		if i >= len(a) || i >= len(b) || a[i] != b[i] {
+			j := i - 10
+			if j < 0 {
+				j = 0
+			}
+			t.Errorf("diverge at %d: «%s» vs «%s»", i, trim(a[j:]), trim(b[j:]))
+			return
+		}
+	}
+}
+
+func trim(b []byte) []byte {
+	if len(b) > 20 {
+		return b[0:20]
+	}
+	return b
+}
+
+// Generate a random JSON object.
+
+var jsonBig []byte
+
+func initBig() {
+	n := 10000
+	if testing.Short() {
+		n = 100
+	}
+	b, err := Marshal(genValue(n))
+	if err != nil {
+		panic(err)
+	}
+	jsonBig = b
+}
+
+func genValue(n int) any {
+	if n > 1 {
+		switch rand.Intn(2) {
+		case 0:
+			return genArray(n)
+		case 1:
+			return genMap(n)
+		}
+	}
+	switch rand.Intn(3) {
+	case 0:
+		return rand.Intn(2) == 0
+	case 1:
+		return rand.NormFloat64()
+	case 2:
+		return genString(30)
+	}
+	panic("unreachable")
+}
+
+func genString(stddev float64) string {
+	n := int(math.Abs(rand.NormFloat64()*stddev + stddev/2))
+	c := make([]rune, n)
+	for i := range c {
+		f := math.Abs(rand.NormFloat64()*64 + 32)
+		if f > 0x10ffff {
+			f = 0x10ffff
+		}
+		c[i] = rune(f)
+	}
+	return string(c)
+}
+
+func genArray(n int) []any {
+	f := int(math.Abs(rand.NormFloat64()) * math.Min(10, float64(n/2)))
+	if f > n {
+		f = n
+	}
+	if f < 1 {
+		f = 1
+	}
+	x := make([]any, f)
+	for i := range x {
+		x[i] = genValue(((i+1)*n)/f - (i*n)/f)
+	}
+	return x
+}
+
+func genMap(n int) map[string]any {
+	f := int(math.Abs(rand.NormFloat64()) * math.Min(10, float64(n/2)))
+	if f > n {
+		f = n
+	}
+	if n > 0 && f == 0 {
+		f = 1
+	}
+	x := make(map[string]any)
+	for i := 0; i < f; i++ {
+		x[genString(10)] = genValue(((i+1)*n)/f - (i*n)/f)
+	}
+	return x
+}

gojson/stream.go

@@ -0,0 +1,524 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"errors"
+	"io"
+)
+
+// A Decoder reads and decodes JSON values from an input stream.
+type Decoder struct {
+	r       io.Reader
+	buf     []byte
+	d       decodeState
+	scanp   int   // start of unread data in buf
+	scanned int64 // amount of data already scanned
+	scan    scanner
+	err     error
+
+	tokenState int
+	tokenStack []int
+}
+
+// NewDecoder returns a new decoder that reads from r.
+//
+// The decoder introduces its own buffering and may
+// read data from r beyond the JSON values requested.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{r: r}
+}
+
+// UseNumber causes the Decoder to unmarshal a number into an interface{} as a
+// Number instead of as a float64.
+func (dec *Decoder) UseNumber() { dec.d.useNumber = true }
+
+// DisallowUnknownFields causes the Decoder to return an error when the destination
+// is a struct and the input contains object keys which do not match any
+// non-ignored, exported fields in the destination.
+func (dec *Decoder) DisallowUnknownFields() { dec.d.disallowUnknownFields = true }
+
+// Decode reads the next JSON-encoded value from its
+// input and stores it in the value pointed to by v.
+//
+// See the documentation for Unmarshal for details about
+// the conversion of JSON into a Go value.
+func (dec *Decoder) Decode(v any) error {
+	if dec.err != nil {
+		return dec.err
+	}
+
+	if err := dec.tokenPrepareForDecode(); err != nil {
+		return err
+	}
+
+	if !dec.tokenValueAllowed() {
+		return &SyntaxError{msg: "not at beginning of value", Offset: dec.InputOffset()}
+	}
+
+	// Read whole value into buffer.
+	n, err := dec.readValue()
+	if err != nil {
+		return err
+	}
+	dec.d.init(dec.buf[dec.scanp : dec.scanp+n])
+	dec.scanp += n
+
+	// Don't save err from unmarshal into dec.err:
+	// the connection is still usable since we read a complete JSON
+	// object from it before the error happened.
+	err = dec.d.unmarshal(v)
+
+	// fixup token streaming state
+	dec.tokenValueEnd()
+
+	return err
+}
+
+// Buffered returns a reader of the data remaining in the Decoder's
+// buffer. The reader is valid until the next call to Decode.
+func (dec *Decoder) Buffered() io.Reader {
+	return bytes.NewReader(dec.buf[dec.scanp:])
+}
+
+// readValue reads a JSON value into dec.buf.
+// It returns the length of the encoding.
+func (dec *Decoder) readValue() (int, error) {
+	dec.scan.reset()
+
+	scanp := dec.scanp
+	var err error
+Input:
+	// help the compiler see that scanp is never negative, so it can remove
+	// some bounds checks below.
+	for scanp >= 0 {
+
+		// Look in the buffer for a new value.
+		for ; scanp < len(dec.buf); scanp++ {
+			c := dec.buf[scanp]
+			dec.scan.bytes++
+			switch dec.scan.step(&dec.scan, c) {
+			case scanEnd:
+				// scanEnd is delayed one byte so we decrement
+				// the scanner bytes count by 1 to ensure that
+				// this value is correct in the next call of Decode.
+				dec.scan.bytes--
+				break Input
+			case scanEndObject, scanEndArray:
+				// scanEnd is delayed one byte.
+				// We might block trying to get that byte from src,
+				// so instead invent a space byte.
+				if stateEndValue(&dec.scan, ' ') == scanEnd {
+					scanp++
+					break Input
+				}
+			case scanError:
+				dec.err = dec.scan.err
+				return 0, dec.scan.err
+			}
+		}
+
+		// Did the last read have an error?
+		// Delayed until now to allow buffer scan.
+		if err != nil {
+			if err == io.EOF {
+				if dec.scan.step(&dec.scan, ' ') == scanEnd {
+					break Input
+				}
+				if nonSpace(dec.buf) {
+					err = io.ErrUnexpectedEOF
+				}
+			}
+			dec.err = err
+			return 0, err
+		}
+
+		n := scanp - dec.scanp
+		err = dec.refill()
+		scanp = dec.scanp + n
+	}
+	return scanp - dec.scanp, nil
+}
+
+func (dec *Decoder) refill() error {
+	// Make room to read more into the buffer.
+	// First slide down data already consumed.
+	if dec.scanp > 0 {
+		dec.scanned += int64(dec.scanp)
+		n := copy(dec.buf, dec.buf[dec.scanp:])
+		dec.buf = dec.buf[:n]
+		dec.scanp = 0
+	}
+
+	// Grow buffer if not large enough.
+	const minRead = 512
+	if cap(dec.buf)-len(dec.buf) < minRead {
+		newBuf := make([]byte, len(dec.buf), 2*cap(dec.buf)+minRead)
+		copy(newBuf, dec.buf)
+		dec.buf = newBuf
+	}
+
+	// Read. Delay error for next iteration (after scan).
+	n, err := dec.r.Read(dec.buf[len(dec.buf):cap(dec.buf)])
+	dec.buf = dec.buf[0 : len(dec.buf)+n]
+
+	return err
+}
+
+func nonSpace(b []byte) bool {
+	for _, c := range b {
+		if !isSpace(c) {
+			return true
+		}
+	}
+	return false
+}
+
+// An Encoder writes JSON values to an output stream.
+type Encoder struct {
+	w             io.Writer
+	err           error
+	escapeHTML    bool
+	nilSafeSlices bool
+	nilSafeMaps   bool
+
+	indentBuf    *bytes.Buffer
+	indentPrefix string
+	indentValue  string
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{w: w, escapeHTML: true}
+}
+
+// Encode writes the JSON encoding of v to the stream,
+// followed by a newline character.
+//
+// See the documentation for Marshal for details about the
+// conversion of Go values to JSON.
+func (enc *Encoder) Encode(v any) error {
+	if enc.err != nil {
+		return enc.err
+	}
+
+	e := newEncodeState()
+	defer encodeStatePool.Put(e)
+
+	err := e.marshal(v, encOpts{escapeHTML: enc.escapeHTML, nilSafeMaps: enc.nilSafeMaps, nilSafeSlices: enc.nilSafeSlices})
+	if err != nil {
+		return err
+	}
+
+	// Terminate each value with a newline.
+	// This makes the output look a little nicer
+	// when debugging, and some kind of space
+	// is required if the encoded value was a number,
+	// so that the reader knows there aren't more
+	// digits coming.
+	e.WriteByte('\n')
+
+	b := e.Bytes()
+	if enc.indentPrefix != "" || enc.indentValue != "" {
+		if enc.indentBuf == nil {
+			enc.indentBuf = new(bytes.Buffer)
+		}
+		enc.indentBuf.Reset()
+		err = Indent(enc.indentBuf, b, enc.indentPrefix, enc.indentValue)
+		if err != nil {
+			return err
+		}
+		b = enc.indentBuf.Bytes()
+	}
+	if _, err = enc.w.Write(b); err != nil {
+		enc.err = err
+	}
+	return err
+}
+
+// SetIndent instructs the encoder to format each subsequent encoded
+// value as if indented by the package-level function Indent(dst, src, prefix, indent).
+// Calling SetIndent("", "") disables indentation.
+func (enc *Encoder) SetIndent(prefix, indent string) {
+	enc.indentPrefix = prefix
+	enc.indentValue = indent
+}
+
+// SetNilSafeCollection specifies whether to represent nil slices and maps as
+// '[]' or '{}' respectfully (flag on) instead of 'null' (default) when marshaling json.
+func (enc *Encoder) SetNilSafeCollection(nilSafeSlices bool, nilSafeMaps bool) {
+	enc.nilSafeSlices = nilSafeSlices
+	enc.nilSafeMaps = nilSafeMaps
+}
+
+// SetEscapeHTML specifies whether problematic HTML characters
+// should be escaped inside JSON quoted strings.
+// The default behavior is to escape &, <, and > to \u0026, \u003c, and \u003e
+// to avoid certain safety problems that can arise when embedding JSON in HTML.
+//
+// In non-HTML settings where the escaping interferes with the readability
+// of the output, SetEscapeHTML(false) disables this behavior.
+func (enc *Encoder) SetEscapeHTML(on bool) {
+	enc.escapeHTML = on
+}
+
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can
+// be used to delay JSON decoding or precompute a JSON encoding.
+type RawMessage []byte
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (m RawMessage) MarshalJSON() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	}
+	return m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("json.RawMessage: UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}
+
+var _ Marshaler = (*RawMessage)(nil)
+var _ Unmarshaler = (*RawMessage)(nil)
+
+// A Token holds a value of one of these types:
+//
+//	Delim, for the four JSON delimiters [ ] { }
+//	bool, for JSON booleans
+//	float64, for JSON numbers
+//	Number, for JSON numbers
+//	string, for JSON string literals
+//	nil, for JSON null
+type Token any
+
+const (
+	tokenTopValue = iota
+	tokenArrayStart
+	tokenArrayValue
+	tokenArrayComma
+	tokenObjectStart
+	tokenObjectKey
+	tokenObjectColon
+	tokenObjectValue
+	tokenObjectComma
+)
+
+// advance tokenstate from a separator state to a value state
+func (dec *Decoder) tokenPrepareForDecode() error {
+	// Note: Not calling peek before switch, to avoid
+	// putting peek into the standard Decode path.
+	// peek is only called when using the Token API.
+	switch dec.tokenState {
+	case tokenArrayComma:
+		c, err := dec.peek()
+		if err != nil {
+			return err
+		}
+		if c != ',' {
+			return &SyntaxError{"expected comma after array element", dec.InputOffset()}
+		}
+		dec.scanp++
+		dec.tokenState = tokenArrayValue
+	case tokenObjectColon:
+		c, err := dec.peek()
+		if err != nil {
+			return err
+		}
+		if c != ':' {
+			return &SyntaxError{"expected colon after object key", dec.InputOffset()}
+		}
+		dec.scanp++
+		dec.tokenState = tokenObjectValue
+	}
+	return nil
+}
+
+func (dec *Decoder) tokenValueAllowed() bool {
+	switch dec.tokenState {
+	case tokenTopValue, tokenArrayStart, tokenArrayValue, tokenObjectValue:
+		return true
+	}
+	return false
+}
+
+func (dec *Decoder) tokenValueEnd() {
+	switch dec.tokenState {
+	case tokenArrayStart, tokenArrayValue:
+		dec.tokenState = tokenArrayComma
+	case tokenObjectValue:
+		dec.tokenState = tokenObjectComma
+	}
+}
+
+// A Delim is a JSON array or object delimiter, one of [ ] { or }.
+type Delim rune
+
+func (d Delim) String() string {
+	return string(d)
+}
+
+// Token returns the next JSON token in the input stream.
+// At the end of the input stream, Token returns nil, io.EOF.
+//
+// Token guarantees that the delimiters [ ] { } it returns are
+// properly nested and matched: if Token encounters an unexpected
+// delimiter in the input, it will return an error.
+//
+// The input stream consists of basic JSON values—bool, string,
+// number, and null—along with delimiters [ ] { } of type Delim
+// to mark the start and end of arrays and objects.
+// Commas and colons are elided.
+func (dec *Decoder) Token() (Token, error) {
+	for {
+		c, err := dec.peek()
+		if err != nil {
+			return nil, err
+		}
+		switch c {
+		case '[':
+			if !dec.tokenValueAllowed() {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
+			dec.tokenState = tokenArrayStart
+			return Delim('['), nil
+
+		case ']':
+			if dec.tokenState != tokenArrayStart && dec.tokenState != tokenArrayComma {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
+			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
+			dec.tokenValueEnd()
+			return Delim(']'), nil
+
+		case '{':
+			if !dec.tokenValueAllowed() {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
+			dec.tokenState = tokenObjectStart
+			return Delim('{'), nil
+
+		case '}':
+			if dec.tokenState != tokenObjectStart && dec.tokenState != tokenObjectComma {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
+			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
+			dec.tokenValueEnd()
+			return Delim('}'), nil
+
+		case ':':
+			if dec.tokenState != tokenObjectColon {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenState = tokenObjectValue
+			continue
+
+		case ',':
+			if dec.tokenState == tokenArrayComma {
+				dec.scanp++
+				dec.tokenState = tokenArrayValue
+				continue
+			}
+			if dec.tokenState == tokenObjectComma {
+				dec.scanp++
+				dec.tokenState = tokenObjectKey
+				continue
+			}
+			return dec.tokenError(c)
+
+		case '"':
+			if dec.tokenState == tokenObjectStart || dec.tokenState == tokenObjectKey {
+				var x string
+				old := dec.tokenState
+				dec.tokenState = tokenTopValue
+				err := dec.Decode(&x)
+				dec.tokenState = old
+				if err != nil {
+					return nil, err
+				}
+				dec.tokenState = tokenObjectColon
+				return x, nil
+			}
+			fallthrough
+
+		default:
+			if !dec.tokenValueAllowed() {
+				return dec.tokenError(c)
+			}
+			var x any
+			if err := dec.Decode(&x); err != nil {
+				return nil, err
+			}
+			return x, nil
+		}
+	}
+}
+
+func (dec *Decoder) tokenError(c byte) (Token, error) {
+	var context string
+	switch dec.tokenState {
+	case tokenTopValue:
+		context = " looking for beginning of value"
+	case tokenArrayStart, tokenArrayValue, tokenObjectValue:
+		context = " looking for beginning of value"
+	case tokenArrayComma:
+		context = " after array element"
+	case tokenObjectKey:
+		context = " looking for beginning of object key string"
+	case tokenObjectColon:
+		context = " after object key"
+	case tokenObjectComma:
+		context = " after object key:value pair"
+	}
+	return nil, &SyntaxError{"invalid character " + quoteChar(c) + context, dec.InputOffset()}
+}
+
+// More reports whether there is another element in the
+// current array or object being parsed.
+func (dec *Decoder) More() bool {
+	c, err := dec.peek()
+	return err == nil && c != ']' && c != '}'
+}
+
+func (dec *Decoder) peek() (byte, error) {
+	var err error
+	for {
+		for i := dec.scanp; i < len(dec.buf); i++ {
+			c := dec.buf[i]
+			if isSpace(c) {
+				continue
+			}
+			dec.scanp = i
+			return c, nil
+		}
+		// buffer has been scanned, now report any error
+		if err != nil {
+			return 0, err
+		}
+		err = dec.refill()
+	}
+}
+
+// InputOffset returns the input stream byte offset of the current decoder position.
+// The offset gives the location of the end of the most recently returned token
+// and the beginning of the next token.
+func (dec *Decoder) InputOffset() int64 {
+	return dec.scanned + int64(dec.scanp)
+}

gojson/stream_test.go

@@ -0,0 +1,539 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"runtime/debug"
+	"strings"
+	"testing"
+)
+
+// Test values for the stream test.
+// One of each JSON kind.
+var streamTest = []any{
+	0.1,
+	"hello",
+	nil,
+	true,
+	false,
+	[]any{"a", "b", "c"},
+	map[string]any{"K": "Kelvin", "ß": "long s"},
+	3.14, // another value to make sure something can follow map
+}
+
+var streamEncoded = `0.1
+"hello"
+null
+true
+false
+["a","b","c"]
+{"ß":"long s","K":"Kelvin"}
+3.14
+`
+
+func TestEncoder(t *testing.T) {
+	for i := 0; i <= len(streamTest); i++ {
+		var buf strings.Builder
+		enc := NewEncoder(&buf)
+		// Check that enc.SetIndent("", "") turns off indentation.
+		enc.SetIndent(">", ".")
+		enc.SetIndent("", "")
+		for j, v := range streamTest[0:i] {
+			if err := enc.Encode(v); err != nil {
+				t.Fatalf("encode #%d: %v", j, err)
+			}
+		}
+		if have, want := buf.String(), nlines(streamEncoded, i); have != want {
+			t.Errorf("encoding %d items: mismatch", i)
+			diff(t, []byte(have), []byte(want))
+			break
+		}
+	}
+}
+
+func TestEncoderErrorAndReuseEncodeState(t *testing.T) {
+	// Disable the GC temporarily to prevent encodeState's in Pool being cleaned away during the test.
+	percent := debug.SetGCPercent(-1)
+	defer debug.SetGCPercent(percent)
+
+	// Trigger an error in Marshal with cyclic data.
+	type Dummy struct {
+		Name string
+		Next *Dummy
+	}
+	dummy := Dummy{Name: "Dummy"}
+	dummy.Next = &dummy
+
+	var buf bytes.Buffer
+	enc := NewEncoder(&buf)
+	if err := enc.Encode(dummy); err == nil {
+		t.Errorf("Encode(dummy) == nil; want error")
+	}
+
+	type Data struct {
+		A string
+		I int
+	}
+	data := Data{A: "a", I: 1}
+	if err := enc.Encode(data); err != nil {
+		t.Errorf("Marshal(%v) = %v", data, err)
+	}
+
+	var data2 Data
+	if err := Unmarshal(buf.Bytes(), &data2); err != nil {
+		t.Errorf("Unmarshal(%v) = %v", data2, err)
+	}
+	if data2 != data {
+		t.Errorf("expect: %v, but get: %v", data, data2)
+	}
+}
+
+var streamEncodedIndent = `0.1
+"hello"
+null
+true
+false
+[
+>."a",
+>."b",
+>."c"
+>]
+{
+>."ß": "long s",
+>."K": "Kelvin"
+>}
+3.14
+`
+
+func TestEncoderIndent(t *testing.T) {
+	var buf strings.Builder
+	enc := NewEncoder(&buf)
+	enc.SetIndent(">", ".")
+	for _, v := range streamTest {
+		enc.Encode(v)
+	}
+	if have, want := buf.String(), streamEncodedIndent; have != want {
+		t.Error("indented encoding mismatch")
+		diff(t, []byte(have), []byte(want))
+	}
+}
+
+type strMarshaler string
+
+func (s strMarshaler) MarshalJSON() ([]byte, error) {
+	return []byte(s), nil
+}
+
+type strPtrMarshaler string
+
+func (s *strPtrMarshaler) MarshalJSON() ([]byte, error) {
+	return []byte(*s), nil
+}
+
+func TestEncoderSetEscapeHTML(t *testing.T) {
+	var c C
+	var ct CText
+	var tagStruct struct {
+		Valid   int `json:"<>&#! "`
+		Invalid int `json:"\\"`
+	}
+
+	// This case is particularly interesting, as we force the encoder to
+	// take the address of the Ptr field to use its MarshalJSON method. This
+	// is why the '&' is important.
+	marshalerStruct := &struct {
+		NonPtr strMarshaler
+		Ptr    strPtrMarshaler
+	}{`"<str>"`, `"<str>"`}
+
+	// https://golang.org/issue/34154
+	stringOption := struct {
+		Bar string `json:"bar,string"`
+	}{`<html>foobar</html>`}
+
+	for _, tt := range []struct {
+		name       string
+		v          any
+		wantEscape string
+		want       string
+	}{
+		{"c", c, `"\u003c\u0026\u003e"`, `"<&>"`},
+		{"ct", ct, `"\"\u003c\u0026\u003e\""`, `"\"<&>\""`},
+		{`"<&>"`, "<&>", `"\u003c\u0026\u003e"`, `"<&>"`},
+		{
+			"tagStruct", tagStruct,
+			`{"\u003c\u003e\u0026#! ":0,"Invalid":0}`,
+			`{"<>&#! ":0,"Invalid":0}`,
+		},
+		{
+			`"<str>"`, marshalerStruct,
+			`{"NonPtr":"\u003cstr\u003e","Ptr":"\u003cstr\u003e"}`,
+			`{"NonPtr":"<str>","Ptr":"<str>"}`,
+		},
+		{
+			"stringOption", stringOption,
+			`{"bar":"\"\\u003chtml\\u003efoobar\\u003c/html\\u003e\""}`,
+			`{"bar":"\"<html>foobar</html>\""}`,
+		},
+	} {
+		var buf strings.Builder
+		enc := NewEncoder(&buf)
+		if err := enc.Encode(tt.v); err != nil {
+			t.Errorf("Encode(%s): %s", tt.name, err)
+			continue
+		}
+		if got := strings.TrimSpace(buf.String()); got != tt.wantEscape {
+			t.Errorf("Encode(%s) = %#q, want %#q", tt.name, got, tt.wantEscape)
+		}
+		buf.Reset()
+		enc.SetEscapeHTML(false)
+		if err := enc.Encode(tt.v); err != nil {
+			t.Errorf("SetEscapeHTML(false) Encode(%s): %s", tt.name, err)
+			continue
+		}
+		if got := strings.TrimSpace(buf.String()); got != tt.want {
+			t.Errorf("SetEscapeHTML(false) Encode(%s) = %#q, want %#q",
+				tt.name, got, tt.want)
+		}
+	}
+}
+
+func TestDecoder(t *testing.T) {
+	for i := 0; i <= len(streamTest); i++ {
+		// Use stream without newlines as input,
+		// just to stress the decoder even more.
+		// Our test input does not include back-to-back numbers.
+		// Otherwise stripping the newlines would
+		// merge two adjacent JSON values.
+		var buf bytes.Buffer
+		for _, c := range nlines(streamEncoded, i) {
+			if c != '\n' {
+				buf.WriteRune(c)
+			}
+		}
+		out := make([]any, i)
+		dec := NewDecoder(&buf)
+		for j := range out {
+			if err := dec.Decode(&out[j]); err != nil {
+				t.Fatalf("decode #%d/%d: %v", j, i, err)
+			}
+		}
+		if !reflect.DeepEqual(out, streamTest[0:i]) {
+			t.Errorf("decoding %d items: mismatch", i)
+			for j := range out {
+				if !reflect.DeepEqual(out[j], streamTest[j]) {
+					t.Errorf("#%d: have %v want %v", j, out[j], streamTest[j])
+				}
+			}
+			break
+		}
+	}
+}
+
+func TestDecoderBuffered(t *testing.T) {
+	r := strings.NewReader(`{"Name": "Gopher"} extra `)
+	var m struct {
+		Name string
+	}
+	d := NewDecoder(r)
+	err := d.Decode(&m)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m.Name != "Gopher" {
+		t.Errorf("Name = %q; want Gopher", m.Name)
+	}
+	rest, err := io.ReadAll(d.Buffered())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if g, w := string(rest), " extra "; g != w {
+		t.Errorf("Remaining = %q; want %q", g, w)
+	}
+}
+
+func nlines(s string, n int) string {
+	if n <= 0 {
+		return ""
+	}
+	for i, c := range s {
+		if c == '\n' {
+			if n--; n == 0 {
+				return s[0 : i+1]
+			}
+		}
+	}
+	return s
+}
+
+func TestRawMessage(t *testing.T) {
+	var data struct {
+		X  float64
+		Id RawMessage
+		Y  float32
+	}
+	const raw = `["\u0056",null]`
+	const msg = `{"X":0.1,"Id":["\u0056",null],"Y":0.2}`
+	err := Unmarshal([]byte(msg), &data)
+	if err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+	if string([]byte(data.Id)) != raw {
+		t.Fatalf("Raw mismatch: have %#q want %#q", []byte(data.Id), raw)
+	}
+	b, err := Marshal(&data)
+	if err != nil {
+		t.Fatalf("Marshal: %v", err)
+	}
+	if string(b) != msg {
+		t.Fatalf("Marshal: have %#q want %#q", b, msg)
+	}
+}
+
+func TestNullRawMessage(t *testing.T) {
+	var data struct {
+		X     float64
+		Id    RawMessage
+		IdPtr *RawMessage
+		Y     float32
+	}
+	const msg = `{"X":0.1,"Id":null,"IdPtr":null,"Y":0.2}`
+	err := Unmarshal([]byte(msg), &data)
+	if err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+	if want, got := "null", string(data.Id); want != got {
+		t.Fatalf("Raw mismatch: have %q, want %q", got, want)
+	}
+	if data.IdPtr != nil {
+		t.Fatalf("Raw pointer mismatch: have non-nil, want nil")
+	}
+	b, err := Marshal(&data)
+	if err != nil {
+		t.Fatalf("Marshal: %v", err)
+	}
+	if string(b) != msg {
+		t.Fatalf("Marshal: have %#q want %#q", b, msg)
+	}
+}
+
+var blockingTests = []string{
+	`{"x": 1}`,
+	`[1, 2, 3]`,
+}
+
+func TestBlocking(t *testing.T) {
+	for _, enc := range blockingTests {
+		r, w := net.Pipe()
+		go w.Write([]byte(enc))
+		var val any
+
+		// If Decode reads beyond what w.Write writes above,
+		// it will block, and the test will deadlock.
+		if err := NewDecoder(r).Decode(&val); err != nil {
+			t.Errorf("decoding %s: %v", enc, err)
+		}
+		r.Close()
+		w.Close()
+	}
+}
+
+type tokenStreamCase struct {
+	json      string
+	expTokens []any
+}
+
+type decodeThis struct {
+	v any
+}
+
+var tokenStreamCases = []tokenStreamCase{
+	// streaming token cases
+	{json: `10`, expTokens: []any{float64(10)}},
+	{json: ` [10] `, expTokens: []any{
+		Delim('['), float64(10), Delim(']')}},
+	{json: ` [false,10,"b"] `, expTokens: []any{
+		Delim('['), false, float64(10), "b", Delim(']')}},
+	{json: `{ "a": 1 }`, expTokens: []any{
+		Delim('{'), "a", float64(1), Delim('}')}},
+	{json: `{"a": 1, "b":"3"}`, expTokens: []any{
+		Delim('{'), "a", float64(1), "b", "3", Delim('}')}},
+	{json: ` [{"a": 1},{"a": 2}] `, expTokens: []any{
+		Delim('['),
+		Delim('{'), "a", float64(1), Delim('}'),
+		Delim('{'), "a", float64(2), Delim('}'),
+		Delim(']')}},
+	{json: `{"obj": {"a": 1}}`, expTokens: []any{
+		Delim('{'), "obj", Delim('{'), "a", float64(1), Delim('}'),
+		Delim('}')}},
+	{json: `{"obj": [{"a": 1}]}`, expTokens: []any{
+		Delim('{'), "obj", Delim('['),
+		Delim('{'), "a", float64(1), Delim('}'),
+		Delim(']'), Delim('}')}},
+
+	// streaming tokens with intermittent Decode()
+	{json: `{ "a": 1 }`, expTokens: []any{
+		Delim('{'), "a",
+		decodeThis{float64(1)},
+		Delim('}')}},
+	{json: ` [ { "a" : 1 } ] `, expTokens: []any{
+		Delim('['),
+		decodeThis{map[string]any{"a": float64(1)}},
+		Delim(']')}},
+	{json: ` [{"a": 1},{"a": 2}] `, expTokens: []any{
+		Delim('['),
+		decodeThis{map[string]any{"a": float64(1)}},
+		decodeThis{map[string]any{"a": float64(2)}},
+		Delim(']')}},
+	{json: `{ "obj" : [ { "a" : 1 } ] }`, expTokens: []any{
+		Delim('{'), "obj", Delim('['),
+		decodeThis{map[string]any{"a": float64(1)}},
+		Delim(']'), Delim('}')}},
+
+	{json: `{"obj": {"a": 1}}`, expTokens: []any{
+		Delim('{'), "obj",
+		decodeThis{map[string]any{"a": float64(1)}},
+		Delim('}')}},
+	{json: `{"obj": [{"a": 1}]}`, expTokens: []any{
+		Delim('{'), "obj",
+		decodeThis{[]any{
+			map[string]any{"a": float64(1)},
+		}},
+		Delim('}')}},
+	{json: ` [{"a": 1} {"a": 2}] `, expTokens: []any{
+		Delim('['),
+		decodeThis{map[string]any{"a": float64(1)}},
+		decodeThis{&SyntaxError{"expected comma after array element", 11}},
+	}},
+	{json: `{ "` + strings.Repeat("a", 513) + `" 1 }`, expTokens: []any{
+		Delim('{'), strings.Repeat("a", 513),
+		decodeThis{&SyntaxError{"expected colon after object key", 518}},
+	}},
+	{json: `{ "\a" }`, expTokens: []any{
+		Delim('{'),
+		&SyntaxError{"invalid character 'a' in string escape code", 3},
+	}},
+	{json: ` \a`, expTokens: []any{
+		&SyntaxError{"invalid character '\\\\' looking for beginning of value", 1},
+	}},
+}
+
+func TestDecodeInStream(t *testing.T) {
+	for ci, tcase := range tokenStreamCases {
+
+		dec := NewDecoder(strings.NewReader(tcase.json))
+		for i, etk := range tcase.expTokens {
+
+			var tk any
+			var err error
+
+			if dt, ok := etk.(decodeThis); ok {
+				etk = dt.v
+				err = dec.Decode(&tk)
+			} else {
+				tk, err = dec.Token()
+			}
+			if experr, ok := etk.(error); ok {
+				if err == nil || !reflect.DeepEqual(err, experr) {
+					t.Errorf("case %v: Expected error %#v in %q, but was %#v", ci, experr, tcase.json, err)
+				}
+				break
+			} else if err == io.EOF {
+				t.Errorf("case %v: Unexpected EOF in %q", ci, tcase.json)
+				break
+			} else if err != nil {
+				t.Errorf("case %v: Unexpected error '%#v' in %q", ci, err, tcase.json)
+				break
+			}
+			if !reflect.DeepEqual(tk, etk) {
+				t.Errorf(`case %v: %q @ %v expected %T(%v) was %T(%v)`, ci, tcase.json, i, etk, etk, tk, tk)
+				break
+			}
+		}
+	}
+}
+
+// Test from golang.org/issue/11893
+func TestHTTPDecoding(t *testing.T) {
+	const raw = `{ "foo": "bar" }`
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(raw))
+	}))
+	defer ts.Close()
+	res, err := http.Get(ts.URL)
+	if err != nil {
+		log.Fatalf("GET failed: %v", err)
+	}
+	defer res.Body.Close()
+
+	foo := struct {
+		Foo string
+	}{}
+
+	d := NewDecoder(res.Body)
+	err = d.Decode(&foo)
+	if err != nil {
+		t.Fatalf("Decode: %v", err)
+	}
+	if foo.Foo != "bar" {
+		t.Errorf("decoded %q; want \"bar\"", foo.Foo)
+	}
+
+	// make sure we get the EOF the second time
+	err = d.Decode(&foo)
+	if err != io.EOF {
+		t.Errorf("err = %v; want io.EOF", err)
+	}
+}
+
+func TestEncoderSetNilSafeCollection(t *testing.T) {
+	var (
+		nilSlice  []interface{}
+		pNilSlice *[]interface{}
+		nilMap    map[string]interface{}
+		pNilMap   *map[string]interface{}
+	)
+	for _, tt := range []struct {
+		name        string
+		v           interface{}
+		want        string
+		rescuedWant string
+	}{
+		{"nilSlice", nilSlice, "null", "[]"},
+		{"nonNilSlice", []interface{}{}, "[]", "[]"},
+		{"sliceWithValues", []interface{}{1, 2, 3}, "[1,2,3]", "[1,2,3]"},
+		{"pNilSlice", pNilSlice, "null", "null"},
+		{"nilMap", nilMap, "null", "{}"},
+		{"nonNilMap", map[string]interface{}{}, "{}", "{}"},
+		{"mapWithValues", map[string]interface{}{"1": 1, "2": 2, "3": 3}, "{\"1\":1,\"2\":2,\"3\":3}", "{\"1\":1,\"2\":2,\"3\":3}"},
+		{"pNilMap", pNilMap, "null", "null"},
+	} {
+		var buf bytes.Buffer
+		enc := NewEncoder(&buf)
+		if err := enc.Encode(tt.v); err != nil {
+			t.Fatalf("Encode(%s): %s", tt.name, err)
+		}
+		if got := strings.TrimSpace(buf.String()); got != tt.want {
+			t.Errorf("Encode(%s) = %#q, want %#q", tt.name, got, tt.want)
+		}
+		buf.Reset()
+		enc.SetNilSafeCollection(true, true)
+		if err := enc.Encode(tt.v); err != nil {
+			t.Fatalf("SetNilSafeCollection(true) Encode(%s): %s", tt.name, err)
+		}
+		if got := strings.TrimSpace(buf.String()); got != tt.rescuedWant {
+			t.Errorf("SetNilSafeCollection(true) Encode(%s) = %#q, want %#q",
+				tt.name, got, tt.want)
+		}
+	}
+}

gojson/tables.go

@@ -0,0 +1,218 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import "unicode/utf8"
+
+// safeSet holds the value true if the ASCII character with the given array
+// position can be represented inside a JSON string without any further
+// escaping.
+//
+// All values are true except for the ASCII control characters (0-31), the
+// double quote ("), and the backslash character ("\").
+var safeSet = [utf8.RuneSelf]bool{
+	' ':      true,
+	'!':      true,
+	'"':      false,
+	'#':      true,
+	'$':      true,
+	'%':      true,
+	'&':      true,
+	'\'':     true,
+	'(':      true,
+	')':      true,
+	'*':      true,
+	'+':      true,
+	',':      true,
+	'-':      true,
+	'.':      true,
+	'/':      true,
+	'0':      true,
+	'1':      true,
+	'2':      true,
+	'3':      true,
+	'4':      true,
+	'5':      true,
+	'6':      true,
+	'7':      true,
+	'8':      true,
+	'9':      true,
+	':':      true,
+	';':      true,
+	'<':      true,
+	'=':      true,
+	'>':      true,
+	'?':      true,
+	'@':      true,
+	'A':      true,
+	'B':      true,
+	'C':      true,
+	'D':      true,
+	'E':      true,
+	'F':      true,
+	'G':      true,
+	'H':      true,
+	'I':      true,
+	'J':      true,
+	'K':      true,
+	'L':      true,
+	'M':      true,
+	'N':      true,
+	'O':      true,
+	'P':      true,
+	'Q':      true,
+	'R':      true,
+	'S':      true,
+	'T':      true,
+	'U':      true,
+	'V':      true,
+	'W':      true,
+	'X':      true,
+	'Y':      true,
+	'Z':      true,
+	'[':      true,
+	'\\':     false,
+	']':      true,
+	'^':      true,
+	'_':      true,
+	'`':      true,
+	'a':      true,
+	'b':      true,
+	'c':      true,
+	'd':      true,
+	'e':      true,
+	'f':      true,
+	'g':      true,
+	'h':      true,
+	'i':      true,
+	'j':      true,
+	'k':      true,
+	'l':      true,
+	'm':      true,
+	'n':      true,
+	'o':      true,
+	'p':      true,
+	'q':      true,
+	'r':      true,
+	's':      true,
+	't':      true,
+	'u':      true,
+	'v':      true,
+	'w':      true,
+	'x':      true,
+	'y':      true,
+	'z':      true,
+	'{':      true,
+	'|':      true,
+	'}':      true,
+	'~':      true,
+	'\u007f': true,
+}
+
+// htmlSafeSet holds the value true if the ASCII character with the given
+// array position can be safely represented inside a JSON string, embedded
+// inside of HTML <script> tags, without any additional escaping.
+//
+// All values are true except for the ASCII control characters (0-31), the
+// double quote ("), the backslash character ("\"), HTML opening and closing
+// tags ("<" and ">"), and the ampersand ("&").
+var htmlSafeSet = [utf8.RuneSelf]bool{
+	' ':      true,
+	'!':      true,
+	'"':      false,
+	'#':      true,
+	'$':      true,
+	'%':      true,
+	'&':      false,
+	'\'':     true,
+	'(':      true,
+	')':      true,
+	'*':      true,
+	'+':      true,
+	',':      true,
+	'-':      true,
+	'.':      true,
+	'/':      true,
+	'0':      true,
+	'1':      true,
+	'2':      true,
+	'3':      true,
+	'4':      true,
+	'5':      true,
+	'6':      true,
+	'7':      true,
+	'8':      true,
+	'9':      true,
+	':':      true,
+	';':      true,
+	'<':      false,
+	'=':      true,
+	'>':      false,
+	'?':      true,
+	'@':      true,
+	'A':      true,
+	'B':      true,
+	'C':      true,
+	'D':      true,
+	'E':      true,
+	'F':      true,
+	'G':      true,
+	'H':      true,
+	'I':      true,
+	'J':      true,
+	'K':      true,
+	'L':      true,
+	'M':      true,
+	'N':      true,
+	'O':      true,
+	'P':      true,
+	'Q':      true,
+	'R':      true,
+	'S':      true,
+	'T':      true,
+	'U':      true,
+	'V':      true,
+	'W':      true,
+	'X':      true,
+	'Y':      true,
+	'Z':      true,
+	'[':      true,
+	'\\':     false,
+	']':      true,
+	'^':      true,
+	'_':      true,
+	'`':      true,
+	'a':      true,
+	'b':      true,
+	'c':      true,
+	'd':      true,
+	'e':      true,
+	'f':      true,
+	'g':      true,
+	'h':      true,
+	'i':      true,
+	'j':      true,
+	'k':      true,
+	'l':      true,
+	'm':      true,
+	'n':      true,
+	'o':      true,
+	'p':      true,
+	'q':      true,
+	'r':      true,
+	's':      true,
+	't':      true,
+	'u':      true,
+	'v':      true,
+	'w':      true,
+	'x':      true,
+	'y':      true,
+	'z':      true,
+	'{':      true,
+	'|':      true,
+	'}':      true,
+	'~':      true,
+	'\u007f': true,
+}

gojson/tagkey_test.go

@@ -0,0 +1,120 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"testing"
+)
+
+type basicLatin2xTag struct {
+	V string `json:"$%-/"`
+}
+
+type basicLatin3xTag struct {
+	V string `json:"0123456789"`
+}
+
+type basicLatin4xTag struct {
+	V string `json:"ABCDEFGHIJKLMO"`
+}
+
+type basicLatin5xTag struct {
+	V string `json:"PQRSTUVWXYZ_"`
+}
+
+type basicLatin6xTag struct {
+	V string `json:"abcdefghijklmno"`
+}
+
+type basicLatin7xTag struct {
+	V string `json:"pqrstuvwxyz"`
+}
+
+type miscPlaneTag struct {
+	V string `json:"色は匂へど"`
+}
+
+type percentSlashTag struct {
+	V string `json:"text/html%"` // https://golang.org/issue/2718
+}
+
+type punctuationTag struct {
+	V string `json:"!#$%&()*+-./:;<=>?@[]^_{|}~ "` // https://golang.org/issue/3546
+}
+
+type dashTag struct {
+	V string `json:"-,"`
+}
+
+type emptyTag struct {
+	W string
+}
+
+type misnamedTag struct {
+	X string `jsom:"Misnamed"`
+}
+
+type badFormatTag struct {
+	Y string `:"BadFormat"`
+}
+
+type badCodeTag struct {
+	Z string `json:" !\"#&'()*+,."`
+}
+
+type spaceTag struct {
+	Q string `json:"With space"`
+}
+
+type unicodeTag struct {
+	W string `json:"Ελλάδα"`
+}
+
+var structTagObjectKeyTests = []struct {
+	raw   any
+	value string
+	key   string
+}{
+	{basicLatin2xTag{"2x"}, "2x", "$%-/"},
+	{basicLatin3xTag{"3x"}, "3x", "0123456789"},
+	{basicLatin4xTag{"4x"}, "4x", "ABCDEFGHIJKLMO"},
+	{basicLatin5xTag{"5x"}, "5x", "PQRSTUVWXYZ_"},
+	{basicLatin6xTag{"6x"}, "6x", "abcdefghijklmno"},
+	{basicLatin7xTag{"7x"}, "7x", "pqrstuvwxyz"},
+	{miscPlaneTag{"いろはにほへと"}, "いろはにほへと", "色は匂へど"},
+	{dashTag{"foo"}, "foo", "-"},
+	{emptyTag{"Pour Moi"}, "Pour Moi", "W"},
+	{misnamedTag{"Animal Kingdom"}, "Animal Kingdom", "X"},
+	{badFormatTag{"Orfevre"}, "Orfevre", "Y"},
+	{badCodeTag{"Reliable Man"}, "Reliable Man", "Z"},
+	{percentSlashTag{"brut"}, "brut", "text/html%"},
+	{punctuationTag{"Union Rags"}, "Union Rags", "!#$%&()*+-./:;<=>?@[]^_{|}~ "},
+	{spaceTag{"Perreddu"}, "Perreddu", "With space"},
+	{unicodeTag{"Loukanikos"}, "Loukanikos", "Ελλάδα"},
+}
+
+func TestStructTagObjectKey(t *testing.T) {
+	for _, tt := range structTagObjectKeyTests {
+		b, err := Marshal(tt.raw)
+		if err != nil {
+			t.Fatalf("Marshal(%#q) failed: %v", tt.raw, err)
+		}
+		var f any
+		err = Unmarshal(b, &f)
+		if err != nil {
+			t.Fatalf("Unmarshal(%#q) failed: %v", b, err)
+		}
+		for i, v := range f.(map[string]any) {
+			switch i {
+			case tt.key:
+				if s, ok := v.(string); !ok || s != tt.value {
+					t.Fatalf("Unexpected value: %#q, want %v", s, tt.value)
+				}
+			default:
+				t.Fatalf("Unexpected key: %#q, from %#q", i, b)
+			}
+		}
+	}
+}

gojson/tags.go

@@ -0,0 +1,38 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"strings"
+)
+
+// tagOptions is the string following a comma in a struct field's "json"
+// tag, or the empty string. It does not include the leading comma.
+type tagOptions string
+
+// parseTag splits a struct field's json tag into its name and
+// comma-separated options.
+func parseTag(tag string) (string, tagOptions) {
+	tag, opt, _ := strings.Cut(tag, ",")
+	return tag, tagOptions(opt)
+}
+
+// Contains reports whether a comma-separated list of options
+// contains a particular substr flag. substr must be surrounded by a
+// string boundary or commas.
+func (o tagOptions) Contains(optionName string) bool {
+	if len(o) == 0 {
+		return false
+	}
+	s := string(o)
+	for s != "" {
+		var name string
+		name, s, _ = strings.Cut(s, ",")
+		if name == optionName {
+			return true
+		}
+	}
+	return false
+}

gojson/tags_test.go

@@ -0,0 +1,28 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"testing"
+)
+
+func TestTagParsing(t *testing.T) {
+	name, opts := parseTag("field,foobar,foo")
+	if name != "field" {
+		t.Fatalf("name = %q, want field", name)
+	}
+	for _, tt := range []struct {
+		opt  string
+		want bool
+	}{
+		{"foobar", true},
+		{"foo", true},
+		{"bar", false},
+	} {
+		if opts.Contains(tt.opt) != tt.want {
+			t.Errorf("Contains(%q) = %v", tt.opt, !tt.want)
+		}
+	}
+}

langext/array.go

@@ -1,6 +1,8 @@
 package langext
 
 import (
+	"errors"
+	"fmt"
 	"reflect"
 )
 
@@ -70,7 +72,73 @@ func ArrEqualsExact[T comparable](arr1 []T, arr2 []T) bool {
 	return true
 }
 
-func ArrAll(arr interface{}, fn func(int) bool) bool {
+func ArrAll[T any](arr []T, fn func(T) bool) bool {
+	for _, av := range arr {
+		if !fn(av) {
+			return false
+		}
+	}
+	return true
+}
+
+func ArrAllErr[T any](arr []T, fn func(T) (bool, error)) (bool, error) {
+	for _, av := range arr {
+		v, err := fn(av)
+		if err != nil {
+			return false, err
+		}
+		if !v {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+func ArrNone[T any](arr []T, fn func(T) bool) bool {
+	for _, av := range arr {
+		if fn(av) {
+			return false
+		}
+	}
+	return true
+}
+
+func ArrNoneErr[T any](arr []T, fn func(T) (bool, error)) (bool, error) {
+	for _, av := range arr {
+		v, err := fn(av)
+		if err != nil {
+			return false, err
+		}
+		if v {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+func ArrAny[T any](arr []T, fn func(T) bool) bool {
+	for _, av := range arr {
+		if fn(av) {
+			return true
+		}
+	}
+	return false
+}
+
+func ArrAnyErr[T any](arr []T, fn func(T) (bool, error)) (bool, error) {
+	for _, av := range arr {
+		v, err := fn(av)
+		if err != nil {
+			return false, err
+		}
+		if v {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+func ArrIdxAll(arr any, fn func(int) bool) bool {
 	av := reflect.ValueOf(arr)
 	for i := 0; i < av.Len(); i++ {
 		if !fn(i) {
@@ -80,7 +148,7 @@ func ArrAll(arr interface{}, fn func(int) bool) bool {
 	return true
 }
 
-func ArrAllErr(arr interface{}, fn func(int) (bool, error)) (bool, error) {
+func ArrIdxAllErr(arr any, fn func(int) (bool, error)) (bool, error) {
 	av := reflect.ValueOf(arr)
 	for i := 0; i < av.Len(); i++ {
 		v, err := fn(i)
@@ -94,7 +162,7 @@ func ArrAllErr(arr interface{}, fn func(int) (bool, error)) (bool, error) {
 	return true, nil
 }
 
-func ArrNone(arr interface{}, fn func(int) bool) bool {
+func ArrIdxNone(arr any, fn func(int) bool) bool {
 	av := reflect.ValueOf(arr)
 	for i := 0; i < av.Len(); i++ {
 		if fn(i) {
@@ -104,7 +172,7 @@ func ArrNone(arr interface{}, fn func(int) bool) bool {
 	return true
 }
 
-func ArrNoneErr(arr interface{}, fn func(int) (bool, error)) (bool, error) {
+func ArrIdxNoneErr(arr any, fn func(int) (bool, error)) (bool, error) {
 	av := reflect.ValueOf(arr)
 	for i := 0; i < av.Len(); i++ {
 		v, err := fn(i)
@@ -118,7 +186,7 @@ func ArrNoneErr(arr interface{}, fn func(int) (bool, error)) (bool, error) {
 	return true, nil
 }
 
-func ArrAny(arr interface{}, fn func(int) bool) bool {
+func ArrIdxAny(arr any, fn func(int) bool) bool {
 	av := reflect.ValueOf(arr)
 	for i := 0; i < av.Len(); i++ {
 		if fn(i) {
@@ -128,7 +196,7 @@ func ArrAny(arr interface{}, fn func(int) bool) bool {
 	return false
 }
 
-func ArrAnyErr(arr interface{}, fn func(int) (bool, error)) (bool, error) {
+func ArrIdxAnyErr(arr any, fn func(int) (bool, error)) (bool, error) {
 	av := reflect.ValueOf(arr)
 	for i := 0; i < av.Len(); i++ {
 		v, err := fn(i)
@@ -142,7 +210,7 @@ func ArrAnyErr(arr interface{}, fn func(int) (bool, error)) (bool, error) {
 	return false, nil
 }
 
-func ArrFirst[T comparable](arr []T, comp func(v T) bool) (T, bool) {
+func ArrFirst[T any](arr []T, comp func(v T) bool) (T, bool) {
 	for _, v := range arr {
 		if comp(v) {
 			return v, true
@@ -151,7 +219,16 @@ func ArrFirst[T comparable](arr []T, comp func(v T) bool) (T, bool) {
 	return *new(T), false
 }
 
-func ArrLast[T comparable](arr []T, comp func(v T) bool) (T, bool) {
+func ArrFirstOrNil[T any](arr []T, comp func(v T) bool) *T {
+	for _, v := range arr {
+		if comp(v) {
+			return Ptr(v)
+		}
+	}
+	return nil
+}
+
+func ArrLast[T any](arr []T, comp func(v T) bool) (T, bool) {
 	found := false
 	result := *new(T)
 	for _, v := range arr {
@@ -163,6 +240,41 @@ func ArrLast[T comparable](arr []T, comp func(v T) bool) (T, bool) {
 	return result, found
 }
 
+func ArrLastOrNil[T any](arr []T, comp func(v T) bool) *T {
+	found := false
+	result := *new(T)
+	for _, v := range arr {
+		if comp(v) {
+			found = true
+			result = v
+		}
+	}
+	if found {
+		return Ptr(result)
+	} else {
+		return nil
+	}
+}
+
+func ArrFirstIndex[T comparable](arr []T, needle T) int {
+	for i, v := range arr {
+		if v == needle {
+			return i
+		}
+	}
+	return -1
+}
+
+func ArrLastIndex[T comparable](arr []T, needle T) int {
+	result := -1
+	for i, v := range arr {
+		if v == needle {
+			result = i
+		}
+	}
+	return result
+}
+
 func AddToSet[T comparable](set []T, add T) []T {
 	for _, v := range set {
 		if v == add {
@@ -171,3 +283,160 @@ func AddToSet[T comparable](set []T, add T) []T {
 	}
 	return append(set, add)
 }
+
+func ArrMap[T1 any, T2 any](arr []T1, conv func(v T1) T2) []T2 {
+	r := make([]T2, len(arr))
+	for i, v := range arr {
+		r[i] = conv(v)
+	}
+	return r
+}
+
+func MapMap[TK comparable, TV any, TR any](inmap map[TK]TV, conv func(k TK, v TV) TR) []TR {
+	r := make([]TR, 0, len(inmap))
+	for k, v := range inmap {
+		r = append(r, conv(k, v))
+	}
+	return r
+}
+
+func MapMapErr[TK comparable, TV any, TR any](inmap map[TK]TV, conv func(k TK, v TV) (TR, error)) ([]TR, error) {
+	r := make([]TR, 0, len(inmap))
+	for k, v := range inmap {
+		elem, err := conv(k, v)
+		if err != nil {
+			return nil, err
+		}
+		r = append(r, elem)
+	}
+	return r, nil
+}
+
+func ArrMapExt[T1 any, T2 any](arr []T1, conv func(idx int, v T1) T2) []T2 {
+	r := make([]T2, len(arr))
+	for i, v := range arr {
+		r[i] = conv(i, v)
+	}
+	return r
+}
+
+func ArrMapErr[T1 any, T2 any](arr []T1, conv func(v T1) (T2, error)) ([]T2, error) {
+	var err error
+	r := make([]T2, len(arr))
+	for i, v := range arr {
+		r[i], err = conv(v)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return r, nil
+}
+
+func ArrFilterMap[T1 any, T2 any](arr []T1, filter func(v T1) bool, conv func(v T1) T2) []T2 {
+	r := make([]T2, 0, len(arr))
+	for _, v := range arr {
+		if filter(v) {
+			r = append(r, conv(v))
+		}
+	}
+	return r
+}
+
+func ArrFilter[T any](arr []T, filter func(v T) bool) []T {
+	r := make([]T, 0, len(arr))
+	for _, v := range arr {
+		if filter(v) {
+			r = append(r, v)
+		}
+	}
+	return r
+}
+
+func ArrSum[T NumberConstraint](arr []T) T {
+	var r T = 0
+	for _, v := range arr {
+		r += v
+	}
+	return r
+}
+
+func ArrFlatten[T1 any, T2 any](arr []T1, conv func(v T1) []T2) []T2 {
+	r := make([]T2, 0, len(arr))
+	for _, v1 := range arr {
+		r = append(r, conv(v1)...)
+	}
+	return r
+}
+
+func ArrFlattenDirect[T1 any](arr [][]T1) []T1 {
+	r := make([]T1, 0, len(arr))
+	for _, v1 := range arr {
+		r = append(r, v1...)
+	}
+	return r
+}
+
+func ArrCastToAny[T1 any](arr []T1) []any {
+	r := make([]any, len(arr))
+	for i, v := range arr {
+		r[i] = any(v)
+	}
+	return r
+}
+
+func ArrCastSafe[T1 any, T2 any](arr []T1) []T2 {
+	r := make([]T2, 0, len(arr))
+	for _, v := range arr {
+		if vcast, ok := any(v).(T2); ok {
+			r = append(r, vcast)
+		}
+	}
+	return r
+}
+
+func ArrCastErr[T1 any, T2 any](arr []T1) ([]T2, error) {
+	r := make([]T2, len(arr))
+	for i, v := range arr {
+		if vcast, ok := any(v).(T2); ok {
+			r[i] = vcast
+		} else {
+			return nil, errors.New(fmt.Sprintf("Cannot cast element %d of type %T to type %s", i, v, *new(T2)))
+		}
+	}
+	return r, nil
+}
+
+func ArrCastPanic[T1 any, T2 any](arr []T1) []T2 {
+	r := make([]T2, len(arr))
+	for i, v := range arr {
+		if vcast, ok := any(v).(T2); ok {
+			r[i] = vcast
+		} else {
+			panic(fmt.Sprintf("Cannot cast element %d of type %T to type %s", i, v, *new(T2)))
+		}
+	}
+	return r
+}
+
+func ArrConcat[T any](arr ...[]T) []T {
+	c := 0
+	for _, v := range arr {
+		c += len(v)
+	}
+	r := make([]T, c)
+	i := 0
+	for _, av := range arr {
+		for _, v := range av {
+			r[i] = v
+			i++
+		}
+	}
+	return r
+}
+
+// ArrCopy does a shallow copy of the 'in' array
+func ArrCopy[T any](in []T) []T {
+	out := make([]T, len(in))
+	copy(out, in)
+	return out
+}

langext/base58.go

@@ -0,0 +1,178 @@
+package langext
+
+import (
+	"bytes"
+	"errors"
+	"math/big"
+)
+
+// shamelessly stolen from https://github.com/btcsuite/
+
+type B58Encoding struct {
+	bigRadix     [11]*big.Int
+	bigRadix10   *big.Int
+	alphabet     string
+	alphabetIdx0 byte
+	b58          [256]byte
+}
+
+var Base58DefaultEncoding = newBase58Encoding("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz")
+var Base58FlickrEncoding = newBase58Encoding("123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ")
+var Base58RippleEncoding = newBase58Encoding("rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz")
+var Base58BitcoinEncoding = newBase58Encoding("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz")
+
+func newBase58Encoding(alphabet string) *B58Encoding {
+	bigRadix10 := big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58 * 58 * 58 * 58)
+	enc := &B58Encoding{
+		alphabet:     alphabet,
+		alphabetIdx0: '1',
+		bigRadix: [...]*big.Int{
+			big.NewInt(0),
+			big.NewInt(58),
+			big.NewInt(58 * 58),
+			big.NewInt(58 * 58 * 58),
+			big.NewInt(58 * 58 * 58 * 58),
+			big.NewInt(58 * 58 * 58 * 58 * 58),
+			big.NewInt(58 * 58 * 58 * 58 * 58 * 58),
+			big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58),
+			big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58 * 58),
+			big.NewInt(58 * 58 * 58 * 58 * 58 * 58 * 58 * 58 * 58),
+			bigRadix10,
+		},
+		bigRadix10: bigRadix10,
+	}
+
+	b58 := make([]byte, 0, 256)
+
+	for i := byte(0); i < 32; i++ {
+		for j := byte(0); j < 8; j++ {
+
+			b := i*8 + j
+
+			idx := bytes.IndexByte([]byte(alphabet), b)
+			if idx == -1 {
+				b58 = append(b58, 255)
+			} else {
+				b58 = append(b58, byte(idx))
+			}
+
+		}
+	}
+
+	enc.b58 = *((*[256]byte)(b58))
+
+	return enc
+}
+
+func (enc *B58Encoding) EncodeString(src string) (string, error) {
+	v, err := enc.Encode([]byte(src))
+	if err != nil {
+		return "", err
+	}
+	return string(v), nil
+}
+
+func (enc *B58Encoding) Encode(src []byte) ([]byte, error) {
+	x := new(big.Int)
+	x.SetBytes(src)
+
+	// maximum length of output is log58(2^(8*len(b))) == len(b) * 8 / log(58)
+	maxlen := int(float64(len(src))*1.365658237309761) + 1
+	answer := make([]byte, 0, maxlen)
+	mod := new(big.Int)
+	for x.Sign() > 0 {
+		// Calculating with big.Int is slow for each iteration.
+		//    x, mod = x / 58, x % 58
+		//
+		// Instead we can try to do as much calculations on int64.
+		//    x, mod = x / 58^10, x % 58^10
+		//
+		// Which will give us mod, which is 10 digit base58 number.
+		// We'll loop that 10 times to convert to the answer.
+
+		x.DivMod(x, enc.bigRadix10, mod)
+		if x.Sign() == 0 {
+			// When x = 0, we need to ensure we don't add any extra zeros.
+			m := mod.Int64()
+			for m > 0 {
+				answer = append(answer, enc.alphabet[m%58])
+				m /= 58
+			}
+		} else {
+			m := mod.Int64()
+			for i := 0; i < 10; i++ {
+				answer = append(answer, enc.alphabet[m%58])
+				m /= 58
+			}
+		}
+	}
+
+	// leading zero bytes
+	for _, i := range src {
+		if i != 0 {
+			break
+		}
+		answer = append(answer, enc.alphabetIdx0)
+	}
+
+	// reverse
+	alen := len(answer)
+	for i := 0; i < alen/2; i++ {
+		answer[i], answer[alen-1-i] = answer[alen-1-i], answer[i]
+	}
+
+	return answer, nil
+}
+
+func (enc *B58Encoding) DecodeString(src string) (string, error) {
+	v, err := enc.Decode([]byte(src))
+	if err != nil {
+		return "", err
+	}
+	return string(v), nil
+}
+
+func (enc *B58Encoding) Decode(src []byte) ([]byte, error) {
+	answer := big.NewInt(0)
+	scratch := new(big.Int)
+
+	for t := src; len(t) > 0; {
+		n := len(t)
+		if n > 10 {
+			n = 10
+		}
+
+		total := uint64(0)
+		for _, v := range t[:n] {
+			if v > 255 {
+				return []byte{}, errors.New("invalid char in input")
+			}
+
+			tmp := enc.b58[v]
+			if tmp == 255 {
+				return []byte{}, errors.New("invalid char in input")
+			}
+			total = total*58 + uint64(tmp)
+		}
+
+		answer.Mul(answer, enc.bigRadix[n])
+		scratch.SetUint64(total)
+		answer.Add(answer, scratch)
+
+		t = t[n:]
+	}
+
+	tmpval := answer.Bytes()
+
+	var numZeros int
+	for numZeros = 0; numZeros < len(src); numZeros++ {
+		if src[numZeros] != enc.alphabetIdx0 {
+			break
+		}
+	}
+	flen := numZeros + len(tmpval)
+	val := make([]byte, flen)
+	copy(val[numZeros:], tmpval)
+
+	return val, nil
+}

langext/base58_test.go

@@ -0,0 +1,67 @@
+package langext
+
+import (
+	"testing"
+)
+
+func _encStr(t *testing.T, enc *B58Encoding, v string) string {
+	v, err := enc.EncodeString(v)
+	if err != nil {
+		t.Error(err)
+	}
+	return v
+}
+
+func _decStr(t *testing.T, enc *B58Encoding, v string) string {
+	v, err := enc.DecodeString(v)
+	if err != nil {
+		t.Error(err)
+	}
+	return v
+}
+
+func TestBase58DefaultEncoding(t *testing.T) {
+	tst.AssertEqual(t, _encStr(t, Base58DefaultEncoding, "Hello"), "9Ajdvzr")
+	tst.AssertEqual(t, _encStr(t, Base58DefaultEncoding, "If debugging is the process of removing software bugs, then programming must be the process of putting them in."), "48638SMcJuah5okqPx4kCVf5d8QAdgbdNf28g7ReY13prUENNbMyssjq5GjsrJHF5zeZfqs4uJMUJHr7VbrU4XBUZ2Fw9DVtqtn9N1eXucEWSEZahXV6w4ysGSWqGdpeYTJf1MdDzTg8vfcQViifJjZX")
+}
+
+func TestBase58DefaultDecoding(t *testing.T) {
+	tst.AssertEqual(t, _decStr(t, Base58DefaultEncoding, "9Ajdvzr"), "Hello")
+	tst.AssertEqual(t, _decStr(t, Base58DefaultEncoding, "48638SMcJuah5okqPx4kCVf5d8QAdgbdNf28g7ReY13prUENNbMyssjq5GjsrJHF5zeZfqs4uJMUJHr7VbrU4XBUZ2Fw9DVtqtn9N1eXucEWSEZahXV6w4ysGSWqGdpeYTJf1MdDzTg8vfcQViifJjZX"), "If debugging is the process of removing software bugs, then programming must be the process of putting them in.")
+}
+
+func TestBase58RippleEncoding(t *testing.T) {
+	tst.AssertEqual(t, _encStr(t, Base58RippleEncoding, "Hello"), "9wjdvzi")
+	tst.AssertEqual(t, _encStr(t, Base58RippleEncoding, "If debugging is the process of removing software bugs, then programming must be the process of putting them in."), "h3as3SMcJu26nokqPxhkUVCnd3Qwdgbd4Cp3gfReYrsFi7N44bMy11jqnGj1iJHEnzeZCq1huJM7JHifVbi7hXB7ZpEA9DVtqt894reXucNWSNZ26XVaAhy1GSWqGdFeYTJCrMdDzTg3vCcQV55CJjZX")
+}
+
+func TestBase58RippleDecoding(t *testing.T) {
+	tst.AssertEqual(t, _decStr(t, Base58RippleEncoding, "9wjdvzi"), "Hello")
+	tst.AssertEqual(t, _decStr(t, Base58RippleEncoding, "h3as3SMcJu26nokqPxhkUVCnd3Qwdgbd4Cp3gfReYrsFi7N44bMy11jqnGj1iJHEnzeZCq1huJM7JHifVbi7hXB7ZpEA9DVtqt894reXucNWSNZ26XVaAhy1GSWqGdFeYTJCrMdDzTg3vCcQV55CJjZX"), "If debugging is the process of removing software bugs, then programming must be the process of putting them in.")
+}
+
+func TestBase58BitcoinEncoding(t *testing.T) {
+	tst.AssertEqual(t, _encStr(t, Base58BitcoinEncoding, "Hello"), "9Ajdvzr")
+	tst.AssertEqual(t, _encStr(t, Base58BitcoinEncoding, "If debugging is the process of removing software bugs, then programming must be the process of putting them in."), "48638SMcJuah5okqPx4kCVf5d8QAdgbdNf28g7ReY13prUENNbMyssjq5GjsrJHF5zeZfqs4uJMUJHr7VbrU4XBUZ2Fw9DVtqtn9N1eXucEWSEZahXV6w4ysGSWqGdpeYTJf1MdDzTg8vfcQViifJjZX")
+}
+
+func TestBase58BitcoinDecoding(t *testing.T) {
+	tst.AssertEqual(t, _decStr(t, Base58BitcoinEncoding, "9Ajdvzr"), "Hello")
+	tst.AssertEqual(t, _decStr(t, Base58BitcoinEncoding, "48638SMcJuah5okqPx4kCVf5d8QAdgbdNf28g7ReY13prUENNbMyssjq5GjsrJHF5zeZfqs4uJMUJHr7VbrU4XBUZ2Fw9DVtqtn9N1eXucEWSEZahXV6w4ysGSWqGdpeYTJf1MdDzTg8vfcQViifJjZX"), "If debugging is the process of removing software bugs, then programming must be the process of putting them in.")
+}
+
+func TestBase58FlickrEncoding(t *testing.T) {
+	tst.AssertEqual(t, _encStr(t, Base58FlickrEncoding, "Hello"), "9aJCVZR")
+	tst.AssertEqual(t, _encStr(t, Base58FlickrEncoding, "If debugging is the process of removing software bugs, then programming must be the process of putting them in."), "48638rmBiUzG5NKQoX4KcuE5C8paCFACnE28F7qDx13PRtennAmYSSJQ5gJSRihf5ZDyEQS4UimtihR7uARt4wbty2fW9duTQTM9n1DwUBevreyzGwu6W4YSgrvQgCPDxsiE1mCdZsF8VEBpuHHEiJyw")
+}
+
+func TestBase58FlickrDecoding(t *testing.T) {
+	tst.AssertEqual(t, _decStr(t, Base58FlickrEncoding, "9aJCVZR"), "Hello")
+	tst.AssertEqual(t, _decStr(t, Base58FlickrEncoding, "48638rmBiUzG5NKQoX4KcuE5C8paCFACnE28F7qDx13PRtennAmYSSJQ5gJSRihf5ZDyEQS4UimtihR7uARt4wbty2fW9duTQTM9n1DwUBevreyzGwu6W4YSgrvQgCPDxsiE1mCdZsF8VEBpuHHEiJyw"), "If debugging is the process of removing software bugs, then programming must be the process of putting them in.")
+}
+
+func tst.AssertEqual(t *testing.T, actual string, expected string) {
+	if actual != expected {
+		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actual, expected)
+	}
+}

langext/bool.go

@@ -7,3 +7,43 @@ func FormatBool(v bool, strTrue string, strFalse string) string {
 		return strFalse
 	}
 }
+
+func Conditional[T any](v bool, resTrue T, resFalse T) T {
+	if v {
+		return resTrue
+	} else {
+		return resFalse
+	}
+}
+
+func ConditionalFn00[T any](v bool, resTrue T, resFalse T) T {
+	if v {
+		return resTrue
+	} else {
+		return resFalse
+	}
+}
+
+func ConditionalFn10[T any](v bool, resTrue func() T, resFalse T) T {
+	if v {
+		return resTrue()
+	} else {
+		return resFalse
+	}
+}
+
+func ConditionalFn01[T any](v bool, resTrue T, resFalse func() T) T {
+	if v {
+		return resTrue
+	} else {
+		return resFalse()
+	}
+}
+
+func ConditionalFn11[T any](v bool, resTrue func() T, resFalse func() T) T {
+	if v {
+		return resTrue()
+	} else {
+		return resFalse()
+	}
+}

langext/coalesce.go

@@ -60,3 +60,12 @@ func CoalesceStringer(s fmt.Stringer, def string) string {
 		return s.String()
 	}
 }
+
+func SafeCast[T any](v any, def T) T {
+	switch r := v.(type) {
+	case T:
+		return r
+	default:
+		return def
+	}
+}

langext/compare.go

@@ -31,16 +31,16 @@ func CompareIntArr(arr1 []int, arr2 []int) bool {
 	return false
 }
 
-func CompareArr[T OrderedConstraint](arr1 []T, arr2 []T) bool {
+func CompareArr[T OrderedConstraint](arr1 []T, arr2 []T) int {
 
 	for i := 0; i < len(arr1) || i < len(arr2); i++ {
 
 		if i < len(arr1) && i < len(arr2) {
 
 			if arr1[i] < arr2[i] {
-				return true
+				return -1
 			} else if arr1[i] > arr2[i] {
-				return false
+				return +2
 			} else {
 				continue
 			}
@@ -49,15 +49,55 @@ func CompareArr[T OrderedConstraint](arr1 []T, arr2 []T) bool {
 
 		if i < len(arr1) {
 
-			return true
+			return +1
 
 		} else { // if i < len(arr2)
 
-			return false
+			return -1
 
 		}
 
 	}
 
-	return false
+	return 0
+}
+
+func CompareString(a, b string) int {
+	if a == b {
+		return 0
+	}
+	if a < b {
+		return -1
+	}
+	return +1
+}
+
+func CompareInt(a, b int) int {
+	if a == b {
+		return 0
+	}
+	if a < b {
+		return -1
+	}
+	return +1
+}
+
+func CompareInt64(a, b int64) int {
+	if a == b {
+		return 0
+	}
+	if a < b {
+		return -1
+	}
+	return +1
+}
+
+func Compare[T OrderedConstraint](a, b T) int {
+	if a == b {
+		return 0
+	}
+	if a < b {
+		return -1
+	}
+	return +1
 }

langext/maps.go

@@ -1,5 +1,10 @@
 package langext
 
+type MapEntry[T comparable, V any] struct {
+	Key   T
+	Value V
+}
+
 func MapKeyArr[T comparable, V any](v map[T]V) []T {
 	result := make([]T, 0, len(v))
 	for k := range v {
@@ -7,3 +12,46 @@ func MapKeyArr[T comparable, V any](v map[T]V) []T {
 	}
 	return result
 }
+
+func MapValueArr[T comparable, V any](v map[T]V) []V {
+	result := make([]V, 0, len(v))
+	for _, mv := range v {
+		result = append(result, mv)
+	}
+	return result
+}
+
+func ArrToMap[T comparable, V any](a []V, keyfunc func(V) T) map[T]V {
+	result := make(map[T]V, len(a))
+	for _, v := range a {
+		result[keyfunc(v)] = v
+	}
+	return result
+}
+
+func MapToArr[T comparable, V any](v map[T]V) []MapEntry[T, V] {
+	result := make([]MapEntry[T, V], 0, len(v))
+	for mk, mv := range v {
+		result = append(result, MapEntry[T, V]{
+			Key:   mk,
+			Value: mv,
+		})
+	}
+	return result
+}
+
+func CopyMap[K comparable, V any](a map[K]V) map[K]V {
+	result := make(map[K]V, len(a))
+	for k, v := range a {
+		result[k] = v
+	}
+	return result
+}
+
+func ForceMap[K comparable, V any](v map[K]V) map[K]V {
+	if v == nil {
+		return make(map[K]V, 0)
+	} else {
+		return v
+	}
+}

langext/panic.go

@@ -0,0 +1,71 @@
+package langext
+
+type PanicWrappedErr struct {
+	panic any
+}
+
+func (p PanicWrappedErr) Error() string {
+	return "A panic occured"
+}
+
+func (p PanicWrappedErr) ReoveredObj() any {
+	return p.panic
+}
+
+func RunPanicSafe(fn func()) (err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			err = PanicWrappedErr{panic: rec}
+		}
+	}()
+
+	fn()
+
+	return nil
+}
+
+func RunPanicSafeR1(fn func() error) (err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			err = PanicWrappedErr{panic: rec}
+		}
+	}()
+
+	return fn()
+}
+
+func RunPanicSafeR2[T1 any](fn func() (T1, error)) (r1 T1, err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			r1 = *new(T1)
+			err = PanicWrappedErr{panic: rec}
+		}
+	}()
+
+	return fn()
+}
+
+func RunPanicSafeR3[T1 any, T2 any](fn func() (T1, T2, error)) (r1 T1, r2 T2, err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			r1 = *new(T1)
+			r2 = *new(T2)
+			err = PanicWrappedErr{panic: rec}
+		}
+	}()
+
+	return fn()
+}
+
+func RunPanicSafeR4[T1 any, T2 any, T3 any](fn func() (T1, T2, T3, error)) (r1 T1, r2 T2, r3 T3, err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			r1 = *new(T1)
+			r2 = *new(T2)
+			r3 = *new(T3)
+			err = PanicWrappedErr{panic: rec}
+		}
+	}()
+
+	return fn()
+}

langext/pointer.go

@@ -4,6 +4,12 @@ import (
 	"reflect"
 )
 
+// PTrue := &true
+var PTrue = Ptr(true)
+
+// PFalse := &false
+var PFalse = Ptr(false)
+
 func Ptr[T any](v T) *T {
 	return &v
 }
@@ -34,3 +40,7 @@ func IsNil(i interface{}) bool {
 	}
 	return false
 }
+
+func PtrEquals[T comparable](v1 *T, v2 *T) bool {
+	return (v1 == nil && v2 == nil) || (v1 != nil && v2 != nil && *v1 == *v2)
+}

langext/sort.go

@@ -0,0 +1,57 @@
+package langext
+
+import "sort"
+
+func Sort[T OrderedConstraint](arr []T) {
+	sort.Slice(arr, func(i1, i2 int) bool {
+		return arr[i1] < arr[i2]
+	})
+}
+
+func SortStable[T OrderedConstraint](arr []T) {
+	sort.SliceStable(arr, func(i1, i2 int) bool {
+		return arr[i1] < arr[i2]
+	})
+}
+
+func IsSorted[T OrderedConstraint](arr []T) bool {
+	return sort.SliceIsSorted(arr, func(i1, i2 int) bool {
+		return arr[i1] < arr[i2]
+	})
+}
+
+func SortSlice[T any](arr []T, less func(v1, v2 T) bool) {
+	sort.Slice(arr, func(i1, i2 int) bool {
+		return less(arr[i1], arr[i2])
+	})
+}
+
+func SortSliceStable[T any](arr []T, less func(v1, v2 T) bool) {
+	sort.SliceStable(arr, func(i1, i2 int) bool {
+		return less(arr[i1], arr[i2])
+	})
+}
+
+func IsSliceSorted[T any](arr []T, less func(v1, v2 T) bool) bool {
+	return sort.SliceIsSorted(arr, func(i1, i2 int) bool {
+		return less(arr[i1], arr[i2])
+	})
+}
+
+func SortBy[TElem any, TSel OrderedConstraint](arr []TElem, selector func(v TElem) TSel) {
+	sort.Slice(arr, func(i1, i2 int) bool {
+		return selector(arr[i1]) < selector(arr[i2])
+	})
+}
+
+func SortByStable[TElem any, TSel OrderedConstraint](arr []TElem, selector func(v TElem) TSel) {
+	sort.SliceStable(arr, func(i1, i2 int) bool {
+		return selector(arr[i1]) < selector(arr[i2])
+	})
+}
+
+func IsSortedBy[TElem any, TSel OrderedConstraint](arr []TElem, selector func(v TElem) TSel) {
+	sort.SliceStable(arr, func(i1, i2 int) bool {
+		return selector(arr[i1]) < selector(arr[i2])
+	})
+}

langext/string.go

@@ -107,3 +107,11 @@ func NumToStringOpt[V IntConstraint](v *V, fallback string) string {
 		return fmt.Sprintf("%d", v)
 	}
 }
+
+func StrRepeat(val string, count int) string {
+	r := ""
+	for i := 0; i < count; i++ {
+		r += val
+	}
+	return r
+}

langext/uuid.go

@@ -41,6 +41,14 @@ func NewHexUUID() (string, error) {
 	return string(dst), nil
 }
 
+func MustHexUUID() string {
+	v, err := NewHexUUID()
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
 func NewUpperHexUUID() (string, error) {
 	uuid, err := NewUUID()
 	if err != nil {
@@ -64,6 +72,14 @@ func NewUpperHexUUID() (string, error) {
 	return strings.ToUpper(string(dst)), nil
 }
 
+func MustUpperHexUUID() string {
+	v, err := NewUpperHexUUID()
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
 func NewRawHexUUID() (string, error) {
 	uuid, err := NewUUID()
 	if err != nil {
@@ -83,6 +99,14 @@ func NewRawHexUUID() (string, error) {
 	return strings.ToUpper(string(dst)), nil
 }
 
+func MustRawHexUUID() string {
+	v, err := NewRawHexUUID()
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
 func NewBracesUUID() (string, error) {
 	uuid, err := NewUUID()
 	if err != nil {
@@ -108,6 +132,14 @@ func NewBracesUUID() (string, error) {
 	return strings.ToUpper(string(dst)), nil
 }
 
+func MustBracesUUID() string {
+	v, err := NewBracesUUID()
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
 func NewParensUUID() (string, error) {
 	uuid, err := NewUUID()
 	if err != nil {
@@ -132,3 +164,11 @@ func NewParensUUID() (string, error) {
 
 	return strings.ToUpper(string(dst)), nil
 }
+
+func MustParensUUID() string {
+	v, err := NewParensUUID()
+	if err != nil {
+		panic(err)
+	}
+	return v
+}

mathext/math.go

@@ -22,6 +22,31 @@ func Max[T langext.OrderedConstraint](v1 T, v2 T) T {
 	}
 }
 
+func Max3[T langext.OrderedConstraint](v1 T, v2 T, v3 T) T {
+	result := v1
+	if v2 > result {
+		result = v2
+	}
+	if v3 > result {
+		result = v3
+	}
+	return result
+}
+
+func Max4[T langext.OrderedConstraint](v1 T, v2 T, v3 T, v4 T) T {
+	result := v1
+	if v2 > result {
+		result = v2
+	}
+	if v3 > result {
+		result = v3
+	}
+	if v4 > result {
+		result = v4
+	}
+	return result
+}
+
 func Min[T langext.OrderedConstraint](v1 T, v2 T) T {
 	if v1 < v2 {
 		return v1
@@ -29,3 +54,46 @@ func Min[T langext.OrderedConstraint](v1 T, v2 T) T {
 		return v2
 	}
 }
+
+func Min3[T langext.OrderedConstraint](v1 T, v2 T, v3 T) T {
+	result := v1
+	if v2 < result {
+		result = v2
+	}
+	if v3 < result {
+		result = v3
+	}
+	return result
+}
+
+func Min4[T langext.OrderedConstraint](v1 T, v2 T, v3 T, v4 T) T {
+	result := v1
+	if v2 < result {
+		result = v2
+	}
+	if v3 < result {
+		result = v3
+	}
+	if v4 < result {
+		result = v4
+	}
+	return result
+}
+
+func Abs[T langext.NumberConstraint](v T) T {
+	if v < 0 {
+		return -v
+	} else {
+		return v
+	}
+}
+
+func Clamp[T langext.NumberConstraint](v T, min T, max T) T {
+	if v < min {
+		return min
+	} else if v > max {
+		return max
+	} else {
+		return v
+	}
+}

mongo/.errcheck-excludes

@@ -0,0 +1,16 @@
+(go.mongodb.org/mongo-driver/x/mongo/driver.Connection).Close
+(*go.mongodb.org/mongo-driver/x/network/connection.connection).Close
+(go.mongodb.org/mongo-driver/x/network/connection.Connection).Close
+(*go.mongodb.org/mongo-driver/x/mongo/driver/topology.connection).close
+(*go.mongodb.org/mongo-driver/x/mongo/driver/topology.Topology).Unsubscribe
+(*go.mongodb.org/mongo-driver/x/mongo/driver/topology.Server).Close
+(*go.mongodb.org/mongo-driver/x/network/connection.pool).closeConnection
+(*go.mongodb.org/mongo-driver/x/mongo/driver/topology.pool).close
+(go.mongodb.org/mongo-driver/x/network/wiremessage.ReadWriteCloser).Close
+(*go.mongodb.org/mongo-driver/mongo.Cursor).Close
+(*go.mongodb.org/mongo-driver/mongo.ChangeStream).Close
+(*go.mongodb.org/mongo-driver/mongo.Client).Disconnect
+(net.Conn).Close
+encoding/pem.Encode
+fmt.Fprintf
+fmt.Fprint

mongo/.gitignore

@@ -0,0 +1,13 @@
+.vscode
+debug
+.idea
+*.iml
+*.ipr
+*.iws
+.idea
+*.sublime-project
+*.sublime-workspace
+driver-test-data.tar.gz
+perf
+**mongocryptd.pid
+*.test

mongo/.gitmodules

@@ -0,0 +1,3 @@
+[submodule "specifications"]
+	path = specifications
+	url = git@github.com:mongodb/specifications.git

mongo/.golangci.yml

@@ -0,0 +1,123 @@
+run:
+  timeout: 5m
+
+linters:
+  disable-all: true
+  # TODO(GODRIVER-2156): Enable all commented-out linters.
+  enable:
+    - errcheck
+    # - errorlint
+    - gocritic
+    - goimports
+    - gosimple
+    - gosec
+    - govet
+    - ineffassign
+    - makezero
+    - misspell
+    - nakedret
+    - paralleltest
+    - prealloc
+    - revive
+    - staticcheck
+    - typecheck
+    - unused
+    - unconvert
+    - unparam
+
+linters-settings:
+  errcheck:
+    exclude: .errcheck-excludes
+  gocritic:
+    enabled-checks:
+      # Detects suspicious append result assignments. E.g. "b := append(a, 1, 2, 3)"
+      - appendAssign
+  govet:
+    disable:
+      - cgocall
+      - composites
+  paralleltest:
+    # Ignore missing calls to `t.Parallel()` and only report incorrect uses of `t.Parallel()`.
+    ignore-missing: true
+  staticcheck:
+    checks: [
+      "all",
+      "-SA1019", # Disable deprecation warnings for now.
+      "-SA1012", # Disable "do not pass a nil Context" to allow testing nil contexts in tests.
+    ]
+
+issues:
+  exclude-use-default: false
+  exclude:
+    # Add all default excluded issues except issues related to exported types/functions not having
+    # comments; we want those warnings. The defaults are copied from the "--exclude-use-default"
+    # documentation on https://golangci-lint.run/usage/configuration/#command-line-options
+    ## Defaults ##
+    # EXC0001 errcheck: Almost all programs ignore errors on these functions and in most cases it's ok
+    - Error return value of .((os\.)?std(out|err)\..*|.*Close|.*Flush|os\.Remove(All)?|.*print(f|ln)?|os\.(Un)?Setenv). is not checked
+    # EXC0003 golint: False positive when tests are defined in package 'test'
+    - func name will be used as test\.Test.* by other packages, and that stutters; consider calling this
+    # EXC0004 govet: Common false positives
+    - (possible misuse of unsafe.Pointer|should have signature)
+    # EXC0005 staticcheck: Developers tend to write in C-style with an explicit 'break' in a 'switch', so it's ok to ignore
+    - ineffective break statement. Did you mean to break out of the outer loop
+    # EXC0006 gosec: Too many false-positives on 'unsafe' usage
+    - Use of unsafe calls should be audited
+    # EXC0007 gosec: Too many false-positives for parametrized shell calls
+    - Subprocess launch(ed with variable|ing should be audited)
+    # EXC0008 gosec: Duplicated errcheck checks
+    - (G104|G307)
+    # EXC0009 gosec: Too many issues in popular repos
+    - (Expect directory permissions to be 0750 or less|Expect file permissions to be 0600 or less)
+    # EXC0010 gosec: False positive is triggered by 'src, err := ioutil.ReadFile(filename)'
+    - Potential file inclusion via variable
+    ## End Defaults ##
+
+    # Ignore capitalization warning for this weird field name.
+    - "var-naming: struct field CqCssWxW should be CqCSSWxW"
+    # Ignore warnings for common "wiremessage.Read..." usage because the safest way to use that API
+    # is by assigning possibly unused returned byte buffers.
+    - "SA4006: this value of `wm` is never used"
+    - "SA4006: this value of `rem` is never used"
+    - "ineffectual assignment to wm"
+    - "ineffectual assignment to rem"
+
+  skip-dirs-use-default: false
+  skip-dirs:
+    - (^|/)vendor($|/)
+    - (^|/)testdata($|/)
+    - (^|/)etc($|/)
+  exclude-rules:
+    # Ignore some linters for example code that is intentionally simplified.
+    - path: examples/
+      linters:
+        - revive
+        - errcheck
+    # Disable unused code linters for the copy/pasted "awsv4" package.
+    - path: x/mongo/driver/auth/internal/awsv4
+      linters:
+        - unused
+    # Disable "unused" linter for code files that depend on the "mongocrypt.MongoCrypt" type because
+    # the linter build doesn't work correctly with CGO enabled. As a result, all calls to a
+    # "mongocrypt.MongoCrypt" API appear to always panic (see mongocrypt_not_enabled.go), leading
+    # to confusing messages about unused code.
+    - path: x/mongo/driver/crypt.go|mongo/(crypt_retrievers|mongocryptd).go
+      linters:
+        - unused
+    # Ignore "TLS MinVersion too low", "TLS InsecureSkipVerify set true", and "Use of weak random
+    # number generator (math/rand instead of crypto/rand)" in tests.
+    - path: _test\.go
+      text: G401|G402|G404
+      linters:
+        - gosec
+    # Ignore missing comments for exported variable/function/type for code in the "internal" and
+    # "benchmark" directories.
+    - path: (internal\/|benchmark\/)
+      text: exported (.+) should have comment( \(or a comment on this block\))? or be unexported
+    # Ignore missing package comments for directories that aren't frequently used by external users.
+    - path: (internal\/|benchmark\/|x\/|cmd\/|mongo\/integration\/)
+      text: should have a package comment
+    # Disable unused linter for "golang.org/x/exp/rand" package in internal/randutil/rand.
+    - path: internal/randutil/rand
+      linters:
+        - unused

mongo/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
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+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

mongo/Makefile

@@ -0,0 +1,210 @@
+ATLAS_URIS = "$(ATLAS_FREE)" "$(ATLAS_REPLSET)" "$(ATLAS_SHARD)" "$(ATLAS_TLS11)" "$(ATLAS_TLS12)" "$(ATLAS_FREE_SRV)" "$(ATLAS_REPLSET_SRV)" "$(ATLAS_SHARD_SRV)" "$(ATLAS_TLS11_SRV)" "$(ATLAS_TLS12_SRV)" "$(ATLAS_SERVERLESS)" "$(ATLAS_SERVERLESS_SRV)"
+TEST_TIMEOUT = 1800
+
+### Utility targets. ###
+.PHONY: default
+default: build check-license check-fmt check-modules lint test-short
+
+.PHONY: add-license
+add-license:
+	etc/check_license.sh -a
+
+.PHONY: check-license
+check-license:
+	etc/check_license.sh
+
+.PHONY: build
+build: cross-compile build-tests build-compile-check
+	go build ./...
+	go build $(BUILD_TAGS) ./...
+
+# Use ^$ to match no tests so that no tests are actually run but all tests are
+# compiled. Run with -short to ensure none of the TestMain functions try to
+# connect to a server.
+.PHONY: build-tests
+build-tests:
+	go test -short $(BUILD_TAGS) -run ^$$ ./...
+
+.PHONY: build-compile-check
+build-compile-check:
+	etc/compile_check.sh
+
+# Cross-compiling on Linux for architectures 386, arm, arm64, amd64, ppc64le, and s390x.
+# Omit any build tags because we don't expect our build environment to support compiling the C
+# libraries for other architectures.
+.PHONY: cross-compile
+cross-compile:
+	GOOS=linux GOARCH=386 go build ./...
+	GOOS=linux GOARCH=arm go build ./...
+	GOOS=linux GOARCH=arm64 go build ./...
+	GOOS=linux GOARCH=amd64 go build ./...
+	GOOS=linux GOARCH=ppc64le go build ./...
+	GOOS=linux GOARCH=s390x go build ./...
+
+.PHONY: install-lll
+install-lll:
+	go install github.com/walle/lll/...@latest
+
+.PHONY: check-fmt
+check-fmt: install-lll
+	etc/check_fmt.sh
+
+# check-modules runs "go mod tidy" then "go mod vendor" and exits with a non-zero exit code if there
+# are any module or vendored modules changes. The intent is to confirm two properties:
+#
+# 1. Exactly the required modules are declared as dependencies. We should always be able to run
+# "go mod tidy" and expect that no unrelated changes are made to the "go.mod" file.
+#
+# 2. All required modules are copied into the vendor/ directory and are an exact copy of the
+# original module source code (i.e. the vendored modules are not modified from their original code).
+.PHONY: check-modules
+check-modules:
+	go mod tidy -v
+	go mod vendor
+	git diff --exit-code go.mod go.sum ./vendor
+
+.PHONY: doc
+doc:
+	godoc -http=:6060 -index
+
+.PHONY: fmt
+fmt:
+	go fmt ./...
+
+.PHONY: install-golangci-lint
+install-golangci-lint:
+	go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.51.0
+
+# Lint with various GOOS and GOARCH targets to catch static analysis failures that may only affect
+# specific operating systems or architectures. For example, staticcheck will only check for 64-bit
+# alignment of atomically accessed variables on 32-bit architectures (see
+# https://staticcheck.io/docs/checks#SA1027)
+.PHONY: lint
+lint: install-golangci-lint
+	GOOS=linux GOARCH=386 golangci-lint run --config .golangci.yml ./...
+	GOOS=linux GOARCH=arm golangci-lint run --config .golangci.yml ./...
+	GOOS=linux GOARCH=arm64 golangci-lint run --config .golangci.yml ./...
+	GOOS=linux GOARCH=amd64 golangci-lint run --config .golangci.yml ./...
+	GOOS=linux GOARCH=ppc64le golangci-lint run --config .golangci.yml ./...
+	GOOS=linux GOARCH=s390x golangci-lint run --config .golangci.yml ./...
+
+.PHONY: update-notices
+update-notices:
+	etc/generate_notices.pl > THIRD-PARTY-NOTICES
+
+### Local testing targets. ###
+.PHONY: test
+test:
+	go test $(BUILD_TAGS) -timeout $(TEST_TIMEOUT)s -p 1 ./...
+
+.PHONY: test-cover
+test-cover:
+	go test $(BUILD_TAGS) -timeout $(TEST_TIMEOUT)s -cover $(COVER_ARGS) -p 1 ./...
+
+.PHONY: test-race
+test-race:
+	go test $(BUILD_TAGS) -timeout $(TEST_TIMEOUT)s -race -p 1 ./...
+
+.PHONY: test-short
+test-short:
+	go test $(BUILD_TAGS) -timeout 60s -short ./...
+
+### Evergreen specific targets. ###
+.PHONY: build-aws-ecs-test
+build-aws-ecs-test:
+	go build $(BUILD_TAGS) ./cmd/testaws/main.go
+
+.PHONY: evg-test
+evg-test:
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s -p 1 ./... >> test.suite
+
+.PHONY: evg-test-atlas
+evg-test-atlas:
+	go run ./cmd/testatlas/main.go $(ATLAS_URIS)
+
+.PHONY: evg-test-atlas-data-lake
+evg-test-atlas-data-lake:
+	ATLAS_DATA_LAKE_INTEGRATION_TEST=true go test -v ./mongo/integration -run TestUnifiedSpecs/atlas-data-lake-testing >> spec_test.suite
+	ATLAS_DATA_LAKE_INTEGRATION_TEST=true go test -v ./mongo/integration -run TestAtlasDataLake >> spec_test.suite
+
+.PHONY: evg-test-enterprise-auth
+evg-test-enterprise-auth:
+	go run -tags gssapi ./cmd/testentauth/main.go
+
+.PHONY: evg-test-kmip
+evg-test-kmip:
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionSpec/kmipKMS >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionProse/data_key_and_double_encryption >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionProse/corpus >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionProse/custom_endpoint >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionProse/kms_tls_options_test >> test.suite
+
+.PHONY: evg-test-kms
+evg-test-kms:
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionProse/kms_tls_tests >> test.suite
+
+.PHONY: evg-test-load-balancers
+evg-test-load-balancers:
+	# Load balancer should be tested with all unified tests as well as tests in the following
+	# components: retryable reads, retryable writes, change streams, initial DNS seedlist discovery.
+	go test $(BUILD_TAGS) ./mongo/integration -run TestUnifiedSpecs/retryable-reads -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestRetryableWritesSpec -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestChangeStreamSpec -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestInitialDNSSeedlistDiscoverySpec/load_balanced -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestLoadBalancerSupport -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration/unified -run TestUnifiedSpec -v -timeout $(TEST_TIMEOUT)s >> test.suite
+
+.PHONY: evg-test-ocsp
+evg-test-ocsp:
+	go test -v ./mongo -run TestOCSP $(OCSP_TLS_SHOULD_SUCCEED) >> test.suite
+
+.PHONY: evg-test-serverless
+evg-test-serverless:
+	# Serverless should be tested with all unified tests as well as tests in the following components: CRUD, load balancer,
+	# retryable reads, retryable writes, sessions, transactions and cursor behavior.
+	go test $(BUILD_TAGS) ./mongo/integration -run TestCrudSpec -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestWriteErrorsWithLabels -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestWriteErrorsDetails -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestHintErrors -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestWriteConcernError -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestErrorsCodeNamePropagated -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestLoadBalancerSupport -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestUnifiedSpecs/retryable-reads -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestRetryableReadsProse -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestRetryableWritesSpec -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestRetryableWritesProse -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestUnifiedSpecs/sessions -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestSessionsProse -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestUnifiedSpecs/transactions/legacy -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestConvenientTransactions -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration -run TestCursor -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test $(BUILD_TAGS) ./mongo/integration/unified -run TestUnifiedSpec -v -timeout $(TEST_TIMEOUT)s >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionSpec >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration -run TestClientSideEncryptionProse >> test.suite
+
+.PHONY: evg-test-versioned-api
+evg-test-versioned-api:
+	# Versioned API related tests are in the mongo, integration and unified packages.
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration >> test.suite
+	go test -exec "env PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)" $(BUILD_TAGS) -v -timeout $(TEST_TIMEOUT)s ./mongo/integration/unified >> test.suite
+
+.PHONY: build-gcpkms-test
+build-gcpkms-test:
+	go build $(BUILD_TAGS) ./cmd/testgcpkms
+
+### Benchmark specific targets and support. ###
+.PHONY: benchmark
+benchmark:perf
+	go test $(BUILD_TAGS) -benchmem -bench=. ./benchmark
+
+.PHONY: driver-benchmark
+driver-benchmark:perf
+	@go run cmd/godriver-benchmark/main.go | tee perf.suite
+
+perf:driver-test-data.tar.gz
+	tar -zxf $< $(if $(eq $(UNAME_S),Darwin),-s , --transform=s)/testdata/perf/
+	@touch $@
+
+driver-test-data.tar.gz:
+	curl --retry 5 "https://s3.amazonaws.com/boxes.10gen.com/build/driver-test-data.tar.gz" -o driver-test-data.tar.gz --silent --max-time 120

mongo/README.md

@@ -0,0 +1,251 @@
+<p align="center"><img src="etc/assets/mongo-gopher.png" width="250"></p>
+<p align="center">
+  <a href="https://goreportcard.com/report/go.mongodb.org/mongo-driver"><img src="https://goreportcard.com/badge/go.mongodb.org/mongo-driver"></a>
+  <a href="https://pkg.go.dev/go.mongodb.org/mongo-driver/mongo"><img src="etc/assets/godev-mongo-blue.svg" alt="docs"></a>
+  <a href="https://pkg.go.dev/go.mongodb.org/mongo-driver/bson"><img src="etc/assets/godev-bson-blue.svg" alt="docs"></a>
+  <a href="https://www.mongodb.com/docs/drivers/go/current/"><img src="etc/assets/docs-mongodb-green.svg"></a>
+</p>
+
+# MongoDB Go Driver
+
+The MongoDB supported driver for Go.
+
+-------------------------
+- [Requirements](#requirements)
+- [Installation](#installation)
+- [Usage](#usage)
+- [Feedback](#feedback)
+- [Testing / Development](#testing--development)
+- [Continuous Integration](#continuous-integration)
+- [License](#license)
+
+-------------------------
+## Requirements
+
+- Go 1.13 or higher. We aim to support the latest versions of Go.
+  - Go 1.20 or higher is required to run the driver test suite.
+- MongoDB 3.6 and higher.
+
+-------------------------
+## Installation
+
+The recommended way to get started using the MongoDB Go driver is by using Go modules to install the dependency in
+your project. This can be done either by importing packages from `go.mongodb.org/mongo-driver` and having the build
+step install the dependency or by explicitly running
+
+```bash
+go get go.mongodb.org/mongo-driver/mongo
+```
+
+When using a version of Go that does not support modules, the driver can be installed using `dep` by running
+
+```bash
+dep ensure -add "go.mongodb.org/mongo-driver/mongo"
+```
+
+-------------------------
+## Usage
+
+To get started with the driver, import the `mongo` package and create a `mongo.Client` with the `Connect` function:
+
+```go
+import (
+    "context"
+    "time"
+
+    "go.mongodb.org/mongo-driver/mongo"
+    "go.mongodb.org/mongo-driver/mongo/options"
+    "go.mongodb.org/mongo-driver/mongo/readpref"
+)
+
+ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+defer cancel()
+client, err := mongo.Connect(ctx, options.Client().ApplyURI("mongodb://localhost:27017"))
+```
+
+Make sure to defer a call to `Disconnect` after instantiating your client:
+
+```go
+defer func() {
+    if err = client.Disconnect(ctx); err != nil {
+        panic(err)
+    }
+}()
+```
+
+For more advanced configuration and authentication, see the [documentation for mongo.Connect](https://pkg.go.dev/go.mongodb.org/mongo-driver/mongo#Connect).
+
+Calling `Connect` does not block for server discovery. If you wish to know if a MongoDB server has been found and connected to,
+use the `Ping` method:
+
+```go
+ctx, cancel = context.WithTimeout(context.Background(), 2*time.Second)
+defer cancel()
+err = client.Ping(ctx, readpref.Primary())
+```
+
+To insert a document into a collection, first retrieve a `Database` and then `Collection` instance from the `Client`:
+
+```go
+collection := client.Database("testing").Collection("numbers")
+```
+
+The `Collection` instance can then be used to insert documents:
+
+```go
+ctx, cancel = context.WithTimeout(context.Background(), 5*time.Second)
+defer cancel()
+res, err := collection.InsertOne(ctx, bson.D{{"name", "pi"}, {"value", 3.14159}})
+id := res.InsertedID
+```
+
+To use `bson.D`, you will need to add `"go.mongodb.org/mongo-driver/bson"` to your imports.
+
+Your import statement should now look like this:
+
+```go
+import (
+    "context"
+    "log"
+    "time"
+
+    "go.mongodb.org/mongo-driver/bson"
+    "go.mongodb.org/mongo-driver/mongo"
+    "go.mongodb.org/mongo-driver/mongo/options"
+    "go.mongodb.org/mongo-driver/mongo/readpref"
+)
+```
+
+Several query methods return a cursor, which can be used like this:
+
+```go
+ctx, cancel = context.WithTimeout(context.Background(), 30*time.Second)
+defer cancel()
+cur, err := collection.Find(ctx, bson.D{})
+if err != nil { log.Fatal(err) }
+defer cur.Close(ctx)
+for cur.Next(ctx) {
+    var result bson.D
+    err := cur.Decode(&result)
+    if err != nil { log.Fatal(err) }
+    // do something with result....
+}
+if err := cur.Err(); err != nil {
+    log.Fatal(err)
+}
+```
+
+For methods that return a single item, a `SingleResult` instance is returned:
+
+```go
+var result struct {
+    Value float64
+}
+filter := bson.D{{"name", "pi"}}
+ctx, cancel = context.WithTimeout(context.Background(), 5*time.Second)
+defer cancel()
+err = collection.FindOne(ctx, filter).Decode(&result)
+if err == mongo.ErrNoDocuments {
+    // Do something when no record was found
+    fmt.Println("record does not exist")
+} else if err != nil {
+    log.Fatal(err)
+}
+// Do something with result...
+```
+
+Additional examples and documentation can be found under the examples directory and [on the MongoDB Documentation website](https://www.mongodb.com/docs/drivers/go/current/).
+
+-------------------------
+## Feedback
+
+For help with the driver, please post in the [MongoDB Community Forums](https://developer.mongodb.com/community/forums/tag/golang/).
+
+New features and bugs can be reported on jira: https://jira.mongodb.org/browse/GODRIVER
+
+-------------------------
+## Testing / Development
+
+The driver tests can be run against several database configurations. The most simple configuration is a standalone mongod with no auth, no ssl, and no compression. To run these basic driver tests, make sure a standalone MongoDB server instance is running at localhost:27017. To run the tests, you can run `make` (on Windows, run `nmake`). This will run coverage, run go-lint, run go-vet, and build the examples.
+
+### Testing Different Topologies
+
+To test a **replica set** or **sharded cluster**, set `MONGODB_URI="<connection-string>"` for the `make` command.
+For example, for a local replica set named `rs1` comprised of three nodes on ports 27017, 27018, and 27019:
+
+```
+MONGODB_URI="mongodb://localhost:27017,localhost:27018,localhost:27019/?replicaSet=rs1" make
+```
+
+### Testing Auth and TLS
+
+To test authentication and TLS, first set up a MongoDB cluster with auth and TLS configured. Testing authentication requires a user with the `root` role on the `admin` database. Here is an example command that would run a mongod with TLS correctly configured for tests. Either set or replace PATH_TO_SERVER_KEY_FILE and PATH_TO_CA_FILE with paths to their respective files:
+
+```
+mongod \
+--auth \
+--tlsMode requireTLS \
+--tlsCertificateKeyFile $PATH_TO_SERVER_KEY_FILE \
+--tlsCAFile $PATH_TO_CA_FILE \
+--tlsAllowInvalidCertificates
+```
+
+To run the tests with `make`, set:
+- `MONGO_GO_DRIVER_CA_FILE` to the location of the CA file used by the database
+- `MONGO_GO_DRIVER_KEY_FILE` to the location of the client key file
+- `MONGO_GO_DRIVER_PKCS8_ENCRYPTED_KEY_FILE` to the location of the pkcs8 client key file encrypted with the password string: `password`
+- `MONGO_GO_DRIVER_PKCS8_UNENCRYPTED_KEY_FILE` to the location of the unencrypted pkcs8 key file
+- `MONGODB_URI` to the connection string of the server
+- `AUTH=auth`
+- `SSL=ssl`
+
+For example:
+
+```
+AUTH=auth SSL=ssl \
+MONGO_GO_DRIVER_CA_FILE=$PATH_TO_CA_FILE \
+MONGO_GO_DRIVER_KEY_FILE=$PATH_TO_CLIENT_KEY_FILE \
+MONGO_GO_DRIVER_PKCS8_ENCRYPTED_KEY_FILE=$PATH_TO_ENCRYPTED_KEY_FILE \
+MONGO_GO_DRIVER_PKCS8_UNENCRYPTED_KEY_FILE=$PATH_TO_UNENCRYPTED_KEY_FILE \
+MONGODB_URI="mongodb://user:password@localhost:27017/?authSource=admin" \
+make
+```
+
+Notes:
+- The `--tlsAllowInvalidCertificates` flag is required on the server for the test suite to work correctly.
+- The test suite requires the auth database to be set with `?authSource=admin`, not `/admin`.
+
+### Testing Compression
+
+The MongoDB Go Driver supports wire protocol compression using Snappy, zLib, or zstd. To run tests with wire protocol compression, set `MONGO_GO_DRIVER_COMPRESSOR` to `snappy`, `zlib`, or `zstd`.  For example:
+
+```
+MONGO_GO_DRIVER_COMPRESSOR=snappy make
+```
+
+Ensure the [`--networkMessageCompressors` flag](https://www.mongodb.com/docs/manual/reference/program/mongod/#cmdoption-mongod-networkmessagecompressors) on mongod or mongos includes `zlib` if testing zLib compression.
+
+-------------------------
+## Contribution
+
+Check out the [project page](https://jira.mongodb.org/browse/GODRIVER) for tickets that need completing. See our [contribution guidelines](docs/CONTRIBUTING.md) for details.
+
+-------------------------
+## Continuous Integration
+
+Commits to master are run automatically on [evergreen](https://evergreen.mongodb.com/waterfall/mongo-go-driver).
+
+-------------------------
+## Frequently Encountered Issues
+
+See our [common issues](docs/common-issues.md) documentation for troubleshooting frequently encountered issues.
+
+-------------------------
+## Thanks and Acknowledgement
+
+<a href="https://github.com/ashleymcnamara">@ashleymcnamara</a> - Mongo Gopher Artwork
+
+-------------------------
+## License
+
+The MongoDB Go Driver is licensed under the [Apache License](LICENSE).

mongo/bson/benchmark_test.go

@@ -0,0 +1,307 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bson
+
+import (
+	"compress/gzip"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"testing"
+)
+
+type encodetest struct {
+	Field1String  string
+	Field1Int64   int64
+	Field1Float64 float64
+	Field2String  string
+	Field2Int64   int64
+	Field2Float64 float64
+	Field3String  string
+	Field3Int64   int64
+	Field3Float64 float64
+	Field4String  string
+	Field4Int64   int64
+	Field4Float64 float64
+}
+
+type nestedtest1 struct {
+	Nested nestedtest2
+}
+
+type nestedtest2 struct {
+	Nested nestedtest3
+}
+
+type nestedtest3 struct {
+	Nested nestedtest4
+}
+
+type nestedtest4 struct {
+	Nested nestedtest5
+}
+
+type nestedtest5 struct {
+	Nested nestedtest6
+}
+
+type nestedtest6 struct {
+	Nested nestedtest7
+}
+
+type nestedtest7 struct {
+	Nested nestedtest8
+}
+
+type nestedtest8 struct {
+	Nested nestedtest9
+}
+
+type nestedtest9 struct {
+	Nested nestedtest10
+}
+
+type nestedtest10 struct {
+	Nested nestedtest11
+}
+
+type nestedtest11 struct {
+	Nested encodetest
+}
+
+var encodetestInstance = encodetest{
+	Field1String:  "foo",
+	Field1Int64:   1,
+	Field1Float64: 3.0,
+	Field2String:  "bar",
+	Field2Int64:   2,
+	Field2Float64: 3.1,
+	Field3String:  "baz",
+	Field3Int64:   3,
+	Field3Float64: 3.14,
+	Field4String:  "qux",
+	Field4Int64:   4,
+	Field4Float64: 3.141,
+}
+
+var nestedInstance = nestedtest1{
+	nestedtest2{
+		nestedtest3{
+			nestedtest4{
+				nestedtest5{
+					nestedtest6{
+						nestedtest7{
+							nestedtest8{
+								nestedtest9{
+									nestedtest10{
+										nestedtest11{
+											encodetest{
+												Field1String:  "foo",
+												Field1Int64:   1,
+												Field1Float64: 3.0,
+												Field2String:  "bar",
+												Field2Int64:   2,
+												Field2Float64: 3.1,
+												Field3String:  "baz",
+												Field3Int64:   3,
+												Field3Float64: 3.14,
+												Field4String:  "qux",
+												Field4Int64:   4,
+												Field4Float64: 3.141,
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	},
+}
+
+const extendedBSONDir = "../testdata/extended_bson"
+
+// readExtJSONFile reads the GZIP-compressed extended JSON document from the given filename in the
+// "extended BSON" test data directory (../testdata/extended_bson) and returns it as a
+// map[string]interface{}. It panics on any errors.
+func readExtJSONFile(filename string) map[string]interface{} {
+	filePath := path.Join(extendedBSONDir, filename)
+	file, err := os.Open(filePath)
+	if err != nil {
+		panic(fmt.Sprintf("error opening file %q: %s", filePath, err))
+	}
+	defer func() {
+		_ = file.Close()
+	}()
+
+	gz, err := gzip.NewReader(file)
+	if err != nil {
+		panic(fmt.Sprintf("error creating GZIP reader: %s", err))
+	}
+	defer func() {
+		_ = gz.Close()
+	}()
+
+	data, err := ioutil.ReadAll(gz)
+	if err != nil {
+		panic(fmt.Sprintf("error reading GZIP contents of file: %s", err))
+	}
+
+	var v map[string]interface{}
+	err = UnmarshalExtJSON(data, false, &v)
+	if err != nil {
+		panic(fmt.Sprintf("error unmarshalling extended JSON: %s", err))
+	}
+
+	return v
+}
+
+func BenchmarkMarshal(b *testing.B) {
+	cases := []struct {
+		desc  string
+		value interface{}
+	}{
+		{
+			desc:  "simple struct",
+			value: encodetestInstance,
+		},
+		{
+			desc:  "nested struct",
+			value: nestedInstance,
+		},
+		{
+			desc:  "deep_bson.json.gz",
+			value: readExtJSONFile("deep_bson.json.gz"),
+		},
+		{
+			desc:  "flat_bson.json.gz",
+			value: readExtJSONFile("flat_bson.json.gz"),
+		},
+		{
+			desc:  "full_bson.json.gz",
+			value: readExtJSONFile("full_bson.json.gz"),
+		},
+	}
+
+	for _, tc := range cases {
+		b.Run(tc.desc, func(b *testing.B) {
+			b.Run("BSON", func(b *testing.B) {
+				for i := 0; i < b.N; i++ {
+					_, err := Marshal(tc.value)
+					if err != nil {
+						b.Errorf("error marshalling BSON: %s", err)
+					}
+				}
+			})
+
+			b.Run("extJSON", func(b *testing.B) {
+				for i := 0; i < b.N; i++ {
+					_, err := MarshalExtJSON(tc.value, true, false)
+					if err != nil {
+						b.Errorf("error marshalling extended JSON: %s", err)
+					}
+				}
+			})
+
+			b.Run("JSON", func(b *testing.B) {
+				for i := 0; i < b.N; i++ {
+					_, err := json.Marshal(tc.value)
+					if err != nil {
+						b.Errorf("error marshalling JSON: %s", err)
+					}
+				}
+			})
+		})
+	}
+}
+
+func BenchmarkUnmarshal(b *testing.B) {
+	cases := []struct {
+		desc  string
+		value interface{}
+	}{
+		{
+			desc:  "simple struct",
+			value: encodetestInstance,
+		},
+		{
+			desc:  "nested struct",
+			value: nestedInstance,
+		},
+		{
+			desc:  "deep_bson.json.gz",
+			value: readExtJSONFile("deep_bson.json.gz"),
+		},
+		{
+			desc:  "flat_bson.json.gz",
+			value: readExtJSONFile("flat_bson.json.gz"),
+		},
+		{
+			desc:  "full_bson.json.gz",
+			value: readExtJSONFile("full_bson.json.gz"),
+		},
+	}
+
+	for _, tc := range cases {
+		b.Run(tc.desc, func(b *testing.B) {
+			b.Run("BSON", func(b *testing.B) {
+				data, err := Marshal(tc.value)
+				if err != nil {
+					b.Errorf("error marshalling BSON: %s", err)
+					return
+				}
+
+				b.ResetTimer()
+				var v2 map[string]interface{}
+				for i := 0; i < b.N; i++ {
+					err := Unmarshal(data, &v2)
+					if err != nil {
+						b.Errorf("error unmarshalling BSON: %s", err)
+					}
+				}
+			})
+
+			b.Run("extJSON", func(b *testing.B) {
+				data, err := MarshalExtJSON(tc.value, true, false)
+				if err != nil {
+					b.Errorf("error marshalling extended JSON: %s", err)
+					return
+				}
+
+				b.ResetTimer()
+				var v2 map[string]interface{}
+				for i := 0; i < b.N; i++ {
+					err := UnmarshalExtJSON(data, true, &v2)
+					if err != nil {
+						b.Errorf("error unmarshalling extended JSON: %s", err)
+					}
+				}
+			})
+
+			b.Run("JSON", func(b *testing.B) {
+				data, err := json.Marshal(tc.value)
+				if err != nil {
+					b.Errorf("error marshalling JSON: %s", err)
+					return
+				}
+
+				b.ResetTimer()
+				var v2 map[string]interface{}
+				for i := 0; i < b.N; i++ {
+					err := json.Unmarshal(data, &v2)
+					if err != nil {
+						b.Errorf("error unmarshalling JSON: %s", err)
+					}
+				}
+			})
+		})
+	}
+}

mongo/bson/bson.go

@@ -0,0 +1,50 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+//
+// Based on gopkg.in/mgo.v2/bson by Gustavo Niemeyer
+// See THIRD-PARTY-NOTICES for original license terms.
+
+package bson // import "go.mongodb.org/mongo-driver/bson"
+
+import (
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+// Zeroer allows custom struct types to implement a report of zero
+// state. All struct types that don't implement Zeroer or where IsZero
+// returns false are considered to be not zero.
+type Zeroer interface {
+	IsZero() bool
+}
+
+// D is an ordered representation of a BSON document. This type should be used when the order of the elements matters,
+// such as MongoDB command documents. If the order of the elements does not matter, an M should be used instead.
+//
+// A D should not be constructed with duplicate key names, as that can cause undefined server behavior.
+//
+// Example usage:
+//
+//	bson.D{{"foo", "bar"}, {"hello", "world"}, {"pi", 3.14159}}
+type D = primitive.D
+
+// E represents a BSON element for a D. It is usually used inside a D.
+type E = primitive.E
+
+// M is an unordered representation of a BSON document. This type should be used when the order of the elements does not
+// matter. This type is handled as a regular map[string]interface{} when encoding and decoding. Elements will be
+// serialized in an undefined, random order. If the order of the elements matters, a D should be used instead.
+//
+// Example usage:
+//
+//	bson.M{"foo": "bar", "hello": "world", "pi": 3.14159}
+type M = primitive.M
+
+// An A is an ordered representation of a BSON array.
+//
+// Example usage:
+//
+//	bson.A{"bar", "world", 3.14159, bson.D{{"qux", 12345}}}
+type A = primitive.A

mongo/bson/bson_corpus_spec_test.go

@@ -0,0 +1,530 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bson
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"math"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+	"testing"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/pretty"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.mongodb.org/mongo-driver/internal/testutil/assert"
+)
+
+type testCase struct {
+	Description  string                `json:"description"`
+	BsonType     string                `json:"bson_type"`
+	TestKey      *string               `json:"test_key"`
+	Valid        []validityTestCase    `json:"valid"`
+	DecodeErrors []decodeErrorTestCase `json:"decodeErrors"`
+	ParseErrors  []parseErrorTestCase  `json:"parseErrors"`
+	Deprecated   *bool                 `json:"deprecated"`
+}
+
+type validityTestCase struct {
+	Description       string  `json:"description"`
+	CanonicalBson     string  `json:"canonical_bson"`
+	CanonicalExtJSON  string  `json:"canonical_extjson"`
+	RelaxedExtJSON    *string `json:"relaxed_extjson"`
+	DegenerateBSON    *string `json:"degenerate_bson"`
+	DegenerateExtJSON *string `json:"degenerate_extjson"`
+	ConvertedBSON     *string `json:"converted_bson"`
+	ConvertedExtJSON  *string `json:"converted_extjson"`
+	Lossy             *bool   `json:"lossy"`
+}
+
+type decodeErrorTestCase struct {
+	Description string `json:"description"`
+	Bson        string `json:"bson"`
+}
+
+type parseErrorTestCase struct {
+	Description string `json:"description"`
+	String      string `json:"string"`
+}
+
+const dataDir = "../testdata/bson-corpus/"
+
+func findJSONFilesInDir(dir string) ([]string, error) {
+	files := make([]string, 0)
+
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, entry := range entries {
+		if entry.IsDir() || path.Ext(entry.Name()) != ".json" {
+			continue
+		}
+
+		files = append(files, entry.Name())
+	}
+
+	return files, nil
+}
+
+// seedExtJSON will add the byte representation of the "extJSON" string to the fuzzer's coprus.
+func seedExtJSON(f *testing.F, extJSON string, extJSONType string, desc string) {
+	jbytes, err := jsonToBytes(extJSON, extJSONType, desc)
+	if err != nil {
+		f.Fatalf("failed to convert JSON to bytes: %v", err)
+	}
+
+	f.Add(jbytes)
+}
+
+// seedTestCase will add the byte representation for each "extJSON" string of each valid test case to the fuzzer's
+// corpus.
+func seedTestCase(f *testing.F, tcase *testCase) {
+	for _, vtc := range tcase.Valid {
+		seedExtJSON(f, vtc.CanonicalExtJSON, "canonical", vtc.Description)
+
+		// Seed the relaxed extended JSON.
+		if vtc.RelaxedExtJSON != nil {
+			seedExtJSON(f, *vtc.RelaxedExtJSON, "relaxed", vtc.Description)
+		}
+
+		// Seed the degenerate extended JSON.
+		if vtc.DegenerateExtJSON != nil {
+			seedExtJSON(f, *vtc.DegenerateExtJSON, "degenerate", vtc.Description)
+		}
+
+		// Seed the converted extended JSON.
+		if vtc.ConvertedExtJSON != nil {
+			seedExtJSON(f, *vtc.ConvertedExtJSON, "converted", vtc.Description)
+		}
+	}
+}
+
+// seedBSONCorpus will unmarshal the data from "testdata/bson-corpus" into a slice of "testCase" structs and then
+// marshal the "*_extjson" field of each "validityTestCase" into a slice of bytes to seed the fuzz corpus.
+func seedBSONCorpus(f *testing.F) {
+	fileNames, err := findJSONFilesInDir(dataDir)
+	if err != nil {
+		f.Fatalf("failed to find JSON files in directory %q: %v", dataDir, err)
+	}
+
+	for _, fileName := range fileNames {
+		filePath := path.Join(dataDir, fileName)
+
+		file, err := os.Open(filePath)
+		if err != nil {
+			f.Fatalf("failed to open file %q: %v", filePath, err)
+		}
+
+		var tcase testCase
+		if err := json.NewDecoder(file).Decode(&tcase); err != nil {
+			f.Fatal(err)
+		}
+
+		seedTestCase(f, &tcase)
+	}
+}
+
+func needsEscapedUnicode(bsonType string) bool {
+	return bsonType == "0x02" || bsonType == "0x0D" || bsonType == "0x0E" || bsonType == "0x0F"
+}
+
+func unescapeUnicode(s, bsonType string) string {
+	if !needsEscapedUnicode(bsonType) {
+		return s
+	}
+
+	newS := ""
+
+	for i := 0; i < len(s); i++ {
+		c := s[i]
+		switch c {
+		case '\\':
+			switch s[i+1] {
+			case 'u':
+				us := s[i : i+6]
+				u, err := strconv.Unquote(strings.Replace(strconv.Quote(us), `\\u`, `\u`, 1))
+				if err != nil {
+					return ""
+				}
+				for _, r := range u {
+					if r < ' ' {
+						newS += fmt.Sprintf(`\u%04x`, r)
+					} else {
+						newS += string(r)
+					}
+				}
+				i += 5
+			default:
+				newS += string(c)
+			}
+		default:
+			if c > unicode.MaxASCII {
+				r, size := utf8.DecodeRune([]byte(s[i:]))
+				newS += string(r)
+				i += size - 1
+			} else {
+				newS += string(c)
+			}
+		}
+	}
+
+	return newS
+}
+
+func formatDouble(f float64) string {
+	var s string
+	if math.IsInf(f, 1) {
+		s = "Infinity"
+	} else if math.IsInf(f, -1) {
+		s = "-Infinity"
+	} else if math.IsNaN(f) {
+		s = "NaN"
+	} else {
+		// Print exactly one decimalType place for integers; otherwise, print as many are necessary to
+		// perfectly represent it.
+		s = strconv.FormatFloat(f, 'G', -1, 64)
+		if !strings.ContainsRune(s, 'E') && !strings.ContainsRune(s, '.') {
+			s += ".0"
+		}
+	}
+
+	return s
+}
+
+func normalizeCanonicalDouble(t *testing.T, key string, cEJ string) string {
+	// Unmarshal string into map
+	cEJMap := make(map[string]map[string]string)
+	err := json.Unmarshal([]byte(cEJ), &cEJMap)
+	require.NoError(t, err)
+
+	// Parse the float contained by the map.
+	expectedString := cEJMap[key]["$numberDouble"]
+	expectedFloat, err := strconv.ParseFloat(expectedString, 64)
+	require.NoError(t, err)
+
+	// Normalize the string
+	return fmt.Sprintf(`{"%s":{"$numberDouble":"%s"}}`, key, formatDouble(expectedFloat))
+}
+
+func normalizeRelaxedDouble(t *testing.T, key string, rEJ string) string {
+	// Unmarshal string into map
+	rEJMap := make(map[string]float64)
+	err := json.Unmarshal([]byte(rEJ), &rEJMap)
+	if err != nil {
+		return normalizeCanonicalDouble(t, key, rEJ)
+	}
+
+	// Parse the float contained by the map.
+	expectedFloat := rEJMap[key]
+
+	// Normalize the string
+	return fmt.Sprintf(`{"%s":%s}`, key, formatDouble(expectedFloat))
+}
+
+// bsonToNative decodes the BSON bytes (b) into a native Document
+func bsonToNative(t *testing.T, b []byte, bType, testDesc string) D {
+	var doc D
+	err := Unmarshal(b, &doc)
+	expectNoError(t, err, fmt.Sprintf("%s: decoding %s BSON", testDesc, bType))
+	return doc
+}
+
+// nativeToBSON encodes the native Document (doc) into canonical BSON and compares it to the expected
+// canonical BSON (cB)
+func nativeToBSON(t *testing.T, cB []byte, doc D, testDesc, bType, docSrcDesc string) {
+	actual, err := Marshal(doc)
+	expectNoError(t, err, fmt.Sprintf("%s: encoding %s BSON", testDesc, bType))
+
+	if diff := cmp.Diff(cB, actual); diff != "" {
+		t.Errorf("%s: 'native_to_bson(%s) = cB' failed (-want, +got):\n-%v\n+%v\n",
+			testDesc, docSrcDesc, cB, actual)
+		t.FailNow()
+	}
+}
+
+// jsonToNative decodes the extended JSON string (ej) into a native Document
+func jsonToNative(ej, ejType, testDesc string) (D, error) {
+	var doc D
+	if err := UnmarshalExtJSON([]byte(ej), ejType != "relaxed", &doc); err != nil {
+		return nil, fmt.Errorf("%s: decoding %s extended JSON: %w", testDesc, ejType, err)
+	}
+	return doc, nil
+}
+
+// jsonToBytes decodes the extended JSON string (ej) into canonical BSON and then encodes it into a byte slice.
+func jsonToBytes(ej, ejType, testDesc string) ([]byte, error) {
+	native, err := jsonToNative(ej, ejType, testDesc)
+	if err != nil {
+		return nil, err
+	}
+
+	b, err := Marshal(native)
+	if err != nil {
+		return nil, fmt.Errorf("%s: encoding %s BSON: %w", testDesc, ejType, err)
+	}
+
+	return b, nil
+}
+
+// nativeToJSON encodes the native Document (doc) into an extended JSON string
+func nativeToJSON(t *testing.T, ej string, doc D, testDesc, ejType, ejShortName, docSrcDesc string) {
+	actualEJ, err := MarshalExtJSON(doc, ejType != "relaxed", true)
+	expectNoError(t, err, fmt.Sprintf("%s: encoding %s extended JSON", testDesc, ejType))
+
+	if diff := cmp.Diff(ej, string(actualEJ)); diff != "" {
+		t.Errorf("%s: 'native_to_%s_extended_json(%s) = %s' failed (-want, +got):\n%s\n",
+			testDesc, ejType, docSrcDesc, ejShortName, diff)
+		t.FailNow()
+	}
+}
+
+func runTest(t *testing.T, file string) {
+	filepath := path.Join(dataDir, file)
+	content, err := os.ReadFile(filepath)
+	require.NoError(t, err)
+
+	// Remove ".json" from filename.
+	file = file[:len(file)-5]
+	testName := "bson_corpus--" + file
+
+	t.Run(testName, func(t *testing.T) {
+		var test testCase
+		require.NoError(t, json.Unmarshal(content, &test))
+
+		t.Run("valid", func(t *testing.T) {
+			for _, v := range test.Valid {
+				t.Run(v.Description, func(t *testing.T) {
+					// get canonical BSON
+					cB, err := hex.DecodeString(v.CanonicalBson)
+					expectNoError(t, err, fmt.Sprintf("%s: reading canonical BSON", v.Description))
+
+					// get canonical extended JSON
+					cEJ := unescapeUnicode(string(pretty.Ugly([]byte(v.CanonicalExtJSON))), test.BsonType)
+					if test.BsonType == "0x01" {
+						cEJ = normalizeCanonicalDouble(t, *test.TestKey, cEJ)
+					}
+
+					/*** canonical BSON round-trip tests ***/
+					doc := bsonToNative(t, cB, "canonical", v.Description)
+
+					// native_to_bson(bson_to_native(cB)) = cB
+					nativeToBSON(t, cB, doc, v.Description, "canonical", "bson_to_native(cB)")
+
+					// native_to_canonical_extended_json(bson_to_native(cB)) = cEJ
+					nativeToJSON(t, cEJ, doc, v.Description, "canonical", "cEJ", "bson_to_native(cB)")
+
+					// native_to_relaxed_extended_json(bson_to_native(cB)) = rEJ (if rEJ exists)
+					if v.RelaxedExtJSON != nil {
+						rEJ := unescapeUnicode(string(pretty.Ugly([]byte(*v.RelaxedExtJSON))), test.BsonType)
+						if test.BsonType == "0x01" {
+							rEJ = normalizeRelaxedDouble(t, *test.TestKey, rEJ)
+						}
+
+						nativeToJSON(t, rEJ, doc, v.Description, "relaxed", "rEJ", "bson_to_native(cB)")
+
+						/*** relaxed extended JSON round-trip tests (if exists) ***/
+						doc, err = jsonToNative(rEJ, "relaxed", v.Description)
+						require.NoError(t, err)
+
+						// native_to_relaxed_extended_json(json_to_native(rEJ)) = rEJ
+						nativeToJSON(t, rEJ, doc, v.Description, "relaxed", "eJR", "json_to_native(rEJ)")
+					}
+
+					/*** canonical extended JSON round-trip tests ***/
+					doc, err = jsonToNative(cEJ, "canonical", v.Description)
+					require.NoError(t, err)
+
+					// native_to_canonical_extended_json(json_to_native(cEJ)) = cEJ
+					nativeToJSON(t, cEJ, doc, v.Description, "canonical", "cEJ", "json_to_native(cEJ)")
+
+					// native_to_bson(json_to_native(cEJ)) = cb (unless lossy)
+					if v.Lossy == nil || !*v.Lossy {
+						nativeToBSON(t, cB, doc, v.Description, "canonical", "json_to_native(cEJ)")
+					}
+
+					/*** degenerate BSON round-trip tests (if exists) ***/
+					if v.DegenerateBSON != nil {
+						dB, err := hex.DecodeString(*v.DegenerateBSON)
+						expectNoError(t, err, fmt.Sprintf("%s: reading degenerate BSON", v.Description))
+
+						doc = bsonToNative(t, dB, "degenerate", v.Description)
+
+						// native_to_bson(bson_to_native(dB)) = cB
+						nativeToBSON(t, cB, doc, v.Description, "degenerate", "bson_to_native(dB)")
+					}
+
+					/*** degenerate JSON round-trip tests (if exists) ***/
+					if v.DegenerateExtJSON != nil {
+						dEJ := unescapeUnicode(string(pretty.Ugly([]byte(*v.DegenerateExtJSON))), test.BsonType)
+						if test.BsonType == "0x01" {
+							dEJ = normalizeCanonicalDouble(t, *test.TestKey, dEJ)
+						}
+
+						doc, err = jsonToNative(dEJ, "degenerate canonical", v.Description)
+						require.NoError(t, err)
+
+						// native_to_canonical_extended_json(json_to_native(dEJ)) = cEJ
+						nativeToJSON(t, cEJ, doc, v.Description, "degenerate canonical", "cEJ", "json_to_native(dEJ)")
+
+						// native_to_bson(json_to_native(dEJ)) = cB (unless lossy)
+						if v.Lossy == nil || !*v.Lossy {
+							nativeToBSON(t, cB, doc, v.Description, "canonical", "json_to_native(dEJ)")
+						}
+					}
+				})
+			}
+		})
+
+		t.Run("decode error", func(t *testing.T) {
+			for _, d := range test.DecodeErrors {
+				t.Run(d.Description, func(t *testing.T) {
+					b, err := hex.DecodeString(d.Bson)
+					expectNoError(t, err, d.Description)
+
+					var doc D
+					err = Unmarshal(b, &doc)
+
+					// The driver unmarshals invalid UTF-8 strings without error. Loop over the unmarshalled elements
+					// and assert that there was no error if any of the string or DBPointer values contain invalid UTF-8
+					// characters.
+					for _, elem := range doc {
+						str, ok := elem.Value.(string)
+						invalidString := ok && !utf8.ValidString(str)
+						dbPtr, ok := elem.Value.(primitive.DBPointer)
+						invalidDBPtr := ok && !utf8.ValidString(dbPtr.DB)
+
+						if invalidString || invalidDBPtr {
+							expectNoError(t, err, d.Description)
+							return
+						}
+					}
+
+					expectError(t, err, fmt.Sprintf("%s: expected decode error", d.Description))
+				})
+			}
+		})
+
+		t.Run("parse error", func(t *testing.T) {
+			for _, p := range test.ParseErrors {
+				t.Run(p.Description, func(t *testing.T) {
+					s := unescapeUnicode(p.String, test.BsonType)
+					if test.BsonType == "0x13" {
+						s = fmt.Sprintf(`{"decimal128": {"$numberDecimal": "%s"}}`, s)
+					}
+
+					switch test.BsonType {
+					case "0x00", "0x05", "0x13":
+						var doc D
+						err := UnmarshalExtJSON([]byte(s), true, &doc)
+						// Null bytes are validated when marshaling to BSON
+						if strings.Contains(p.Description, "Null") {
+							_, err = Marshal(doc)
+						}
+						expectError(t, err, fmt.Sprintf("%s: expected parse error", p.Description))
+					default:
+						t.Errorf("Update test to check for parse errors for type %s", test.BsonType)
+						t.Fail()
+					}
+				})
+			}
+		})
+	})
+}
+
+func Test_BsonCorpus(t *testing.T) {
+	jsonFiles, err := findJSONFilesInDir(dataDir)
+	if err != nil {
+		t.Fatalf("error finding JSON files in %s: %v", dataDir, err)
+	}
+
+	for _, file := range jsonFiles {
+		runTest(t, file)
+	}
+}
+
+func expectNoError(t *testing.T, err error, desc string) {
+	if err != nil {
+		t.Helper()
+		t.Errorf("%s: Unepexted error: %v", desc, err)
+		t.FailNow()
+	}
+}
+
+func expectError(t *testing.T, err error, desc string) {
+	if err == nil {
+		t.Helper()
+		t.Errorf("%s: Expected error", desc)
+		t.FailNow()
+	}
+}
+
+func TestRelaxedUUIDValidation(t *testing.T) {
+	testCases := []struct {
+		description       string
+		canonicalExtJSON  string
+		degenerateExtJSON string
+		expectedErr       string
+	}{
+		{
+			"valid uuid",
+			"{\"x\" : { \"$binary\" : {\"base64\" : \"c//SZESzTGmQ6OfR38A11A==\", \"subType\" : \"04\"}}}",
+			"{\"x\" : { \"$uuid\" : \"73ffd264-44b3-4c69-90e8-e7d1dfc035d4\"}}",
+			"",
+		},
+		{
+			"invalid uuid--no hyphens",
+			"",
+			"{\"x\" : { \"$uuid\" : \"73ffd26444b34c6990e8e7d1dfc035d4\"}}",
+			"$uuid value does not follow RFC 4122 format regarding length and hyphens",
+		},
+		{
+			"invalid uuid--trailing hyphens",
+			"",
+			"{\"x\" : { \"$uuid\" : \"73ffd264-44b3-4c69-90e8-e7d1dfc035--\"}}",
+			"$uuid value does not follow RFC 4122 format regarding length and hyphens",
+		},
+		{
+			"invalid uuid--malformed hex",
+			"",
+			"{\"x\" : { \"$uuid\" : \"q3@fd26l-44b3-4c69-90e8-e7d1dfc035d4\"}}",
+			"$uuid value does not follow RFC 4122 format regarding hex bytes: encoding/hex: invalid byte: U+0071 'q'",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			// get canonical extended JSON
+			cEJ := unescapeUnicode(string(pretty.Ugly([]byte(tc.canonicalExtJSON))), "0x05")
+
+			// get degenerate extended JSON
+			dEJ := unescapeUnicode(string(pretty.Ugly([]byte(tc.degenerateExtJSON))), "0x05")
+
+			// convert dEJ to native doc
+			var doc D
+			err := UnmarshalExtJSON([]byte(dEJ), true, &doc)
+
+			if tc.expectedErr != "" {
+				assert.Equal(t, tc.expectedErr, err.Error(), "expected error %v, got %v", tc.expectedErr, err)
+			} else {
+				assert.Nil(t, err, "expected no error, got error: %v", err)
+
+				// Marshal doc into extended JSON and compare with cEJ
+				nativeToJSON(t, cEJ, doc, tc.description, "degenerate canonical", "cEJ", "json_to_native(dEJ)")
+			}
+		})
+	}
+
+}

mongo/bson/bson_test.go

@@ -0,0 +1,279 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bson
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"go.mongodb.org/mongo-driver/bson/bsoncodec"
+	"go.mongodb.org/mongo-driver/bson/bsonoptions"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/internal/testutil/assert"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+func noerr(t *testing.T, err error) {
+	if err != nil {
+		t.Helper()
+		t.Errorf("Unexpected error: (%T)%v", err, err)
+		t.FailNow()
+	}
+}
+
+func TestTimeRoundTrip(t *testing.T) {
+	val := struct {
+		Value time.Time
+		ID    string
+	}{
+		ID: "time-rt-test",
+	}
+
+	if !val.Value.IsZero() {
+		t.Errorf("Did not get zero time as expected.")
+	}
+
+	bsonOut, err := Marshal(val)
+	noerr(t, err)
+	rtval := struct {
+		Value time.Time
+		ID    string
+	}{}
+
+	err = Unmarshal(bsonOut, &rtval)
+	noerr(t, err)
+	if !cmp.Equal(val, rtval) {
+		t.Errorf("Did not round trip properly. got %v; want %v", val, rtval)
+	}
+	if !rtval.Value.IsZero() {
+		t.Errorf("Did not get zero time as expected.")
+	}
+}
+
+func TestNonNullTimeRoundTrip(t *testing.T) {
+	now := time.Now()
+	now = time.Unix(now.Unix(), 0)
+	val := struct {
+		Value time.Time
+		ID    string
+	}{
+		ID:    "time-rt-test",
+		Value: now,
+	}
+
+	bsonOut, err := Marshal(val)
+	noerr(t, err)
+	rtval := struct {
+		Value time.Time
+		ID    string
+	}{}
+
+	err = Unmarshal(bsonOut, &rtval)
+	noerr(t, err)
+	if !cmp.Equal(val, rtval) {
+		t.Errorf("Did not round trip properly. got %v; want %v", val, rtval)
+	}
+}
+
+func TestD(t *testing.T) {
+	t.Run("can marshal", func(t *testing.T) {
+		d := D{{"foo", "bar"}, {"hello", "world"}, {"pi", 3.14159}}
+		idx, want := bsoncore.AppendDocumentStart(nil)
+		want = bsoncore.AppendStringElement(want, "foo", "bar")
+		want = bsoncore.AppendStringElement(want, "hello", "world")
+		want = bsoncore.AppendDoubleElement(want, "pi", 3.14159)
+		want, err := bsoncore.AppendDocumentEnd(want, idx)
+		noerr(t, err)
+		got, err := Marshal(d)
+		noerr(t, err)
+		if !bytes.Equal(got, want) {
+			t.Errorf("Marshaled documents do not match. got %v; want %v", Raw(got), Raw(want))
+		}
+	})
+	t.Run("can unmarshal", func(t *testing.T) {
+		want := D{{"foo", "bar"}, {"hello", "world"}, {"pi", 3.14159}}
+		idx, doc := bsoncore.AppendDocumentStart(nil)
+		doc = bsoncore.AppendStringElement(doc, "foo", "bar")
+		doc = bsoncore.AppendStringElement(doc, "hello", "world")
+		doc = bsoncore.AppendDoubleElement(doc, "pi", 3.14159)
+		doc, err := bsoncore.AppendDocumentEnd(doc, idx)
+		noerr(t, err)
+		var got D
+		err = Unmarshal(doc, &got)
+		noerr(t, err)
+		if !cmp.Equal(got, want) {
+			t.Errorf("Unmarshaled documents do not match. got %v; want %v", got, want)
+		}
+	})
+}
+
+type stringerString string
+
+func (ss stringerString) String() string {
+	return "bar"
+}
+
+type keyBool bool
+
+func (kb keyBool) MarshalKey() (string, error) {
+	return fmt.Sprintf("%v", kb), nil
+}
+
+func (kb *keyBool) UnmarshalKey(key string) error {
+	switch key {
+	case "true":
+		*kb = true
+	case "false":
+		*kb = false
+	default:
+		return fmt.Errorf("invalid bool value %v", key)
+	}
+	return nil
+}
+
+type keyStruct struct {
+	val int64
+}
+
+func (k keyStruct) MarshalText() (text []byte, err error) {
+	str := strconv.FormatInt(k.val, 10)
+
+	return []byte(str), nil
+}
+
+func (k *keyStruct) UnmarshalText(text []byte) error {
+	val, err := strconv.ParseInt(string(text), 10, 64)
+	if err != nil {
+		return err
+	}
+
+	*k = keyStruct{
+		val: val,
+	}
+
+	return nil
+}
+
+func TestMapCodec(t *testing.T) {
+	t.Run("EncodeKeysWithStringer", func(t *testing.T) {
+		strstr := stringerString("foo")
+		mapObj := map[stringerString]int{strstr: 1}
+		testCases := []struct {
+			name string
+			opts *bsonoptions.MapCodecOptions
+			key  string
+		}{
+			{"default", bsonoptions.MapCodec(), "foo"},
+			{"true", bsonoptions.MapCodec().SetEncodeKeysWithStringer(true), "bar"},
+			{"false", bsonoptions.MapCodec().SetEncodeKeysWithStringer(false), "foo"},
+		}
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				mapCodec := bsoncodec.NewMapCodec(tc.opts)
+				mapRegistry := NewRegistryBuilder().RegisterDefaultEncoder(reflect.Map, mapCodec).Build()
+				val, err := MarshalWithRegistry(mapRegistry, mapObj)
+				assert.Nil(t, err, "Marshal error: %v", err)
+				assert.True(t, strings.Contains(string(val), tc.key), "expected result to contain %v, got: %v", tc.key, string(val))
+			})
+		}
+	})
+
+	t.Run("keys implements keyMarshaler and keyUnmarshaler", func(t *testing.T) {
+		mapObj := map[keyBool]int{keyBool(true): 1}
+
+		doc, err := Marshal(mapObj)
+		assert.Nil(t, err, "Marshal error: %v", err)
+		idx, want := bsoncore.AppendDocumentStart(nil)
+		want = bsoncore.AppendInt32Element(want, "true", 1)
+		want, _ = bsoncore.AppendDocumentEnd(want, idx)
+		assert.Equal(t, want, doc, "expected result %v, got %v", string(want), string(doc))
+
+		var got map[keyBool]int
+		err = Unmarshal(doc, &got)
+		assert.Nil(t, err, "Unmarshal error: %v", err)
+		assert.Equal(t, mapObj, got, "expected result %v, got %v", mapObj, got)
+
+	})
+
+	t.Run("keys implements encoding.TextMarshaler and encoding.TextUnmarshaler", func(t *testing.T) {
+		mapObj := map[keyStruct]int{
+			{val: 10}: 100,
+		}
+
+		doc, err := Marshal(mapObj)
+		assert.Nil(t, err, "Marshal error: %v", err)
+		idx, want := bsoncore.AppendDocumentStart(nil)
+		want = bsoncore.AppendInt32Element(want, "10", 100)
+		want, _ = bsoncore.AppendDocumentEnd(want, idx)
+		assert.Equal(t, want, doc, "expected result %v, got %v", string(want), string(doc))
+
+		var got map[keyStruct]int
+		err = Unmarshal(doc, &got)
+		assert.Nil(t, err, "Unmarshal error: %v", err)
+		assert.Equal(t, mapObj, got, "expected result %v, got %v", mapObj, got)
+
+	})
+}
+
+func TestExtJSONEscapeKey(t *testing.T) {
+	doc := D{{Key: "\\usb#", Value: int32(1)}}
+	b, err := MarshalExtJSON(&doc, false, false)
+	noerr(t, err)
+
+	want := "{\"\\\\usb#\":1}"
+	if diff := cmp.Diff(want, string(b)); diff != "" {
+		t.Errorf("Marshaled documents do not match. got %v, want %v", string(b), want)
+	}
+
+	var got D
+	err = UnmarshalExtJSON(b, false, &got)
+	noerr(t, err)
+	if !cmp.Equal(got, doc) {
+		t.Errorf("Unmarshaled documents do not match. got %v; want %v", got, doc)
+	}
+}
+
+func TestBsoncoreArray(t *testing.T) {
+	type BSONDocumentArray struct {
+		Array []D `bson:"array"`
+	}
+
+	type BSONArray struct {
+		Array bsoncore.Array `bson:"array"`
+	}
+
+	bda := BSONDocumentArray{
+		Array: []D{
+			{{"x", 1}},
+			{{"x", 2}},
+			{{"x", 3}},
+		},
+	}
+
+	expectedBSON, err := Marshal(bda)
+	assert.Nil(t, err, "Marshal bsoncore.Document array error: %v", err)
+
+	var ba BSONArray
+	err = Unmarshal(expectedBSON, &ba)
+	assert.Nil(t, err, "Unmarshal error: %v", err)
+
+	actualBSON, err := Marshal(ba)
+	assert.Nil(t, err, "Marshal bsoncore.Array error: %v", err)
+
+	assert.Equal(t, expectedBSON, actualBSON,
+		"expected BSON to be %v after Marshalling again; got %v", expectedBSON, actualBSON)
+
+	doc := bsoncore.Document(actualBSON)
+	v := doc.Lookup("array")
+	assert.Equal(t, bsontype.Array, v.Type, "expected type array, got %v", v.Type)
+}

mongo/bson/bsoncodec/array_codec.go

@@ -0,0 +1,50 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"reflect"
+
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+// ArrayCodec is the Codec used for bsoncore.Array values.
+type ArrayCodec struct{}
+
+var defaultArrayCodec = NewArrayCodec()
+
+// NewArrayCodec returns an ArrayCodec.
+func NewArrayCodec() *ArrayCodec {
+	return &ArrayCodec{}
+}
+
+// EncodeValue is the ValueEncoder for bsoncore.Array values.
+func (ac *ArrayCodec) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tCoreArray {
+		return ValueEncoderError{Name: "CoreArrayEncodeValue", Types: []reflect.Type{tCoreArray}, Received: val}
+	}
+
+	arr := val.Interface().(bsoncore.Array)
+	return bsonrw.Copier{}.CopyArrayFromBytes(vw, arr)
+}
+
+// DecodeValue is the ValueDecoder for bsoncore.Array values.
+func (ac *ArrayCodec) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tCoreArray {
+		return ValueDecoderError{Name: "CoreArrayDecodeValue", Types: []reflect.Type{tCoreArray}, Received: val}
+	}
+
+	if val.IsNil() {
+		val.Set(reflect.MakeSlice(val.Type(), 0, 0))
+	}
+
+	val.SetLen(0)
+	arr, err := bsonrw.Copier{}.AppendArrayBytes(val.Interface().(bsoncore.Array), vr)
+	val.Set(reflect.ValueOf(arr))
+	return err
+}

mongo/bson/bsoncodec/bsoncodec.go

@@ -0,0 +1,238 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec // import "go.mongodb.org/mongo-driver/bson/bsoncodec"
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+var (
+	emptyValue = reflect.Value{}
+)
+
+// Marshaler is an interface implemented by types that can marshal themselves
+// into a BSON document represented as bytes. The bytes returned must be a valid
+// BSON document if the error is nil.
+type Marshaler interface {
+	MarshalBSON() ([]byte, error)
+}
+
+// ValueMarshaler is an interface implemented by types that can marshal
+// themselves into a BSON value as bytes. The type must be the valid type for
+// the bytes returned. The bytes and byte type together must be valid if the
+// error is nil.
+type ValueMarshaler interface {
+	MarshalBSONValue() (bsontype.Type, []byte, error)
+}
+
+// Unmarshaler is an interface implemented by types that can unmarshal a BSON
+// document representation of themselves. The BSON bytes can be assumed to be
+// valid. UnmarshalBSON must copy the BSON bytes if it wishes to retain the data
+// after returning.
+type Unmarshaler interface {
+	UnmarshalBSON([]byte) error
+}
+
+// ValueUnmarshaler is an interface implemented by types that can unmarshal a
+// BSON value representation of themselves. The BSON bytes and type can be
+// assumed to be valid. UnmarshalBSONValue must copy the BSON value bytes if it
+// wishes to retain the data after returning.
+type ValueUnmarshaler interface {
+	UnmarshalBSONValue(bsontype.Type, []byte) error
+}
+
+// ValueEncoderError is an error returned from a ValueEncoder when the provided value can't be
+// encoded by the ValueEncoder.
+type ValueEncoderError struct {
+	Name     string
+	Types    []reflect.Type
+	Kinds    []reflect.Kind
+	Received reflect.Value
+}
+
+func (vee ValueEncoderError) Error() string {
+	typeKinds := make([]string, 0, len(vee.Types)+len(vee.Kinds))
+	for _, t := range vee.Types {
+		typeKinds = append(typeKinds, t.String())
+	}
+	for _, k := range vee.Kinds {
+		if k == reflect.Map {
+			typeKinds = append(typeKinds, "map[string]*")
+			continue
+		}
+		typeKinds = append(typeKinds, k.String())
+	}
+	received := vee.Received.Kind().String()
+	if vee.Received.IsValid() {
+		received = vee.Received.Type().String()
+	}
+	return fmt.Sprintf("%s can only encode valid %s, but got %s", vee.Name, strings.Join(typeKinds, ", "), received)
+}
+
+// ValueDecoderError is an error returned from a ValueDecoder when the provided value can't be
+// decoded by the ValueDecoder.
+type ValueDecoderError struct {
+	Name     string
+	Types    []reflect.Type
+	Kinds    []reflect.Kind
+	Received reflect.Value
+}
+
+func (vde ValueDecoderError) Error() string {
+	typeKinds := make([]string, 0, len(vde.Types)+len(vde.Kinds))
+	for _, t := range vde.Types {
+		typeKinds = append(typeKinds, t.String())
+	}
+	for _, k := range vde.Kinds {
+		if k == reflect.Map {
+			typeKinds = append(typeKinds, "map[string]*")
+			continue
+		}
+		typeKinds = append(typeKinds, k.String())
+	}
+	received := vde.Received.Kind().String()
+	if vde.Received.IsValid() {
+		received = vde.Received.Type().String()
+	}
+	return fmt.Sprintf("%s can only decode valid and settable %s, but got %s", vde.Name, strings.Join(typeKinds, ", "), received)
+}
+
+// EncodeContext is the contextual information required for a Codec to encode a
+// value.
+type EncodeContext struct {
+	*Registry
+	MinSize bool
+}
+
+// DecodeContext is the contextual information required for a Codec to decode a
+// value.
+type DecodeContext struct {
+	*Registry
+	Truncate bool
+
+	// Ancestor is the type of a containing document. This is mainly used to determine what type
+	// should be used when decoding an embedded document into an empty interface. For example, if
+	// Ancestor is a bson.M, BSON embedded document values being decoded into an empty interface
+	// will be decoded into a bson.M.
+	//
+	// Deprecated: Use DefaultDocumentM or DefaultDocumentD instead.
+	Ancestor reflect.Type
+
+	// defaultDocumentType specifies the Go type to decode top-level and nested BSON documents into. In particular, the
+	// usage for this field is restricted to data typed as "interface{}" or "map[string]interface{}". If DocumentType is
+	// set to a type that a BSON document cannot be unmarshaled into (e.g. "string"), unmarshalling will result in an
+	// error. DocumentType overrides the Ancestor field.
+	defaultDocumentType reflect.Type
+}
+
+// DefaultDocumentM will decode empty documents using the primitive.M type. This behavior is restricted to data typed as
+// "interface{}" or "map[string]interface{}".
+func (dc *DecodeContext) DefaultDocumentM() {
+	dc.defaultDocumentType = reflect.TypeOf(primitive.M{})
+}
+
+// DefaultDocumentD will decode empty documents using the primitive.D type. This behavior is restricted to data typed as
+// "interface{}" or "map[string]interface{}".
+func (dc *DecodeContext) DefaultDocumentD() {
+	dc.defaultDocumentType = reflect.TypeOf(primitive.D{})
+}
+
+// ValueCodec is the interface that groups the methods to encode and decode
+// values.
+type ValueCodec interface {
+	ValueEncoder
+	ValueDecoder
+}
+
+// ValueEncoder is the interface implemented by types that can handle the encoding of a value.
+type ValueEncoder interface {
+	EncodeValue(EncodeContext, bsonrw.ValueWriter, reflect.Value) error
+}
+
+// ValueEncoderFunc is an adapter function that allows a function with the correct signature to be
+// used as a ValueEncoder.
+type ValueEncoderFunc func(EncodeContext, bsonrw.ValueWriter, reflect.Value) error
+
+// EncodeValue implements the ValueEncoder interface.
+func (fn ValueEncoderFunc) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	return fn(ec, vw, val)
+}
+
+// ValueDecoder is the interface implemented by types that can handle the decoding of a value.
+type ValueDecoder interface {
+	DecodeValue(DecodeContext, bsonrw.ValueReader, reflect.Value) error
+}
+
+// ValueDecoderFunc is an adapter function that allows a function with the correct signature to be
+// used as a ValueDecoder.
+type ValueDecoderFunc func(DecodeContext, bsonrw.ValueReader, reflect.Value) error
+
+// DecodeValue implements the ValueDecoder interface.
+func (fn ValueDecoderFunc) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	return fn(dc, vr, val)
+}
+
+// typeDecoder is the interface implemented by types that can handle the decoding of a value given its type.
+type typeDecoder interface {
+	decodeType(DecodeContext, bsonrw.ValueReader, reflect.Type) (reflect.Value, error)
+}
+
+// typeDecoderFunc is an adapter function that allows a function with the correct signature to be used as a typeDecoder.
+type typeDecoderFunc func(DecodeContext, bsonrw.ValueReader, reflect.Type) (reflect.Value, error)
+
+func (fn typeDecoderFunc) decodeType(dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) {
+	return fn(dc, vr, t)
+}
+
+// decodeAdapter allows two functions with the correct signatures to be used as both a ValueDecoder and typeDecoder.
+type decodeAdapter struct {
+	ValueDecoderFunc
+	typeDecoderFunc
+}
+
+var _ ValueDecoder = decodeAdapter{}
+var _ typeDecoder = decodeAdapter{}
+
+// decodeTypeOrValue calls decoder.decodeType is decoder is a typeDecoder. Otherwise, it allocates a new element of type
+// t and calls decoder.DecodeValue on it.
+func decodeTypeOrValue(decoder ValueDecoder, dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) {
+	td, _ := decoder.(typeDecoder)
+	return decodeTypeOrValueWithInfo(decoder, td, dc, vr, t, true)
+}
+
+func decodeTypeOrValueWithInfo(vd ValueDecoder, td typeDecoder, dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type, convert bool) (reflect.Value, error) {
+	if td != nil {
+		val, err := td.decodeType(dc, vr, t)
+		if err == nil && convert && val.Type() != t {
+			// This conversion step is necessary for slices and maps. If a user declares variables like:
+			//
+			// type myBool bool
+			// var m map[string]myBool
+			//
+			// and tries to decode BSON bytes into the map, the decoding will fail if this conversion is not present
+			// because we'll try to assign a value of type bool to one of type myBool.
+			val = val.Convert(t)
+		}
+		return val, err
+	}
+
+	val := reflect.New(t).Elem()
+	err := vd.DecodeValue(dc, vr, val)
+	return val, err
+}
+
+// CodecZeroer is the interface implemented by Codecs that can also determine if
+// a value of the type that would be encoded is zero.
+type CodecZeroer interface {
+	IsTypeZero(interface{}) bool
+}

mongo/bson/bsoncodec/bsoncodec_test.go

@@ -0,0 +1,143 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+func ExampleValueEncoder() {
+	var _ ValueEncoderFunc = func(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+		if val.Kind() != reflect.String {
+			return ValueEncoderError{Name: "StringEncodeValue", Kinds: []reflect.Kind{reflect.String}, Received: val}
+		}
+
+		return vw.WriteString(val.String())
+	}
+}
+
+func ExampleValueDecoder() {
+	var _ ValueDecoderFunc = func(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+		if !val.CanSet() || val.Kind() != reflect.String {
+			return ValueDecoderError{Name: "StringDecodeValue", Kinds: []reflect.Kind{reflect.String}, Received: val}
+		}
+
+		if vr.Type() != bsontype.String {
+			return fmt.Errorf("cannot decode %v into a string type", vr.Type())
+		}
+
+		str, err := vr.ReadString()
+		if err != nil {
+			return err
+		}
+		val.SetString(str)
+		return nil
+	}
+}
+
+func noerr(t *testing.T, err error) {
+	if err != nil {
+		t.Helper()
+		t.Errorf("Unexpected error: (%T)%v", err, err)
+		t.FailNow()
+	}
+}
+
+func compareTime(t1, t2 time.Time) bool {
+	if t1.Location() != t2.Location() {
+		return false
+	}
+	return t1.Equal(t2)
+}
+
+func compareErrors(err1, err2 error) bool {
+	if err1 == nil && err2 == nil {
+		return true
+	}
+
+	if err1 == nil || err2 == nil {
+		return false
+	}
+
+	if err1.Error() != err2.Error() {
+		return false
+	}
+
+	return true
+}
+
+func compareDecimal128(d1, d2 primitive.Decimal128) bool {
+	d1H, d1L := d1.GetBytes()
+	d2H, d2L := d2.GetBytes()
+
+	if d1H != d2H {
+		return false
+	}
+
+	if d1L != d2L {
+		return false
+	}
+
+	return true
+}
+
+type noPrivateFields struct {
+	a string
+}
+
+func compareNoPrivateFields(npf1, npf2 noPrivateFields) bool {
+	return npf1.a != npf2.a // We don't want these to be equal
+}
+
+type zeroTest struct {
+	reportZero bool
+}
+
+func (z zeroTest) IsZero() bool { return z.reportZero }
+
+func compareZeroTest(_, _ zeroTest) bool { return true }
+
+type nonZeroer struct {
+	value bool
+}
+
+type llCodec struct {
+	t         *testing.T
+	decodeval interface{}
+	encodeval interface{}
+	err       error
+}
+
+func (llc *llCodec) EncodeValue(_ EncodeContext, _ bsonrw.ValueWriter, i interface{}) error {
+	if llc.err != nil {
+		return llc.err
+	}
+
+	llc.encodeval = i
+	return nil
+}
+
+func (llc *llCodec) DecodeValue(_ DecodeContext, _ bsonrw.ValueReader, val reflect.Value) error {
+	if llc.err != nil {
+		return llc.err
+	}
+
+	if !reflect.TypeOf(llc.decodeval).AssignableTo(val.Type()) {
+		llc.t.Errorf("decodeval must be assignable to val provided to DecodeValue, but is not. decodeval %T; val %T", llc.decodeval, val)
+		return nil
+	}
+
+	val.Set(reflect.ValueOf(llc.decodeval))
+	return nil
+}

mongo/bson/bsoncodec/byte_slice_codec.go

@@ -0,0 +1,111 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"fmt"
+	"reflect"
+
+	"go.mongodb.org/mongo-driver/bson/bsonoptions"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+// ByteSliceCodec is the Codec used for []byte values.
+type ByteSliceCodec struct {
+	EncodeNilAsEmpty bool
+}
+
+var (
+	defaultByteSliceCodec = NewByteSliceCodec()
+
+	_ ValueCodec  = defaultByteSliceCodec
+	_ typeDecoder = defaultByteSliceCodec
+)
+
+// NewByteSliceCodec returns a StringCodec with options opts.
+func NewByteSliceCodec(opts ...*bsonoptions.ByteSliceCodecOptions) *ByteSliceCodec {
+	byteSliceOpt := bsonoptions.MergeByteSliceCodecOptions(opts...)
+	codec := ByteSliceCodec{}
+	if byteSliceOpt.EncodeNilAsEmpty != nil {
+		codec.EncodeNilAsEmpty = *byteSliceOpt.EncodeNilAsEmpty
+	}
+	return &codec
+}
+
+// EncodeValue is the ValueEncoder for []byte.
+func (bsc *ByteSliceCodec) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tByteSlice {
+		return ValueEncoderError{Name: "ByteSliceEncodeValue", Types: []reflect.Type{tByteSlice}, Received: val}
+	}
+	if val.IsNil() && !bsc.EncodeNilAsEmpty {
+		return vw.WriteNull()
+	}
+	return vw.WriteBinary(val.Interface().([]byte))
+}
+
+func (bsc *ByteSliceCodec) decodeType(dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) {
+	if t != tByteSlice {
+		return emptyValue, ValueDecoderError{
+			Name:     "ByteSliceDecodeValue",
+			Types:    []reflect.Type{tByteSlice},
+			Received: reflect.Zero(t),
+		}
+	}
+
+	var data []byte
+	var err error
+	switch vrType := vr.Type(); vrType {
+	case bsontype.String:
+		str, err := vr.ReadString()
+		if err != nil {
+			return emptyValue, err
+		}
+		data = []byte(str)
+	case bsontype.Symbol:
+		sym, err := vr.ReadSymbol()
+		if err != nil {
+			return emptyValue, err
+		}
+		data = []byte(sym)
+	case bsontype.Binary:
+		var subtype byte
+		data, subtype, err = vr.ReadBinary()
+		if err != nil {
+			return emptyValue, err
+		}
+		if subtype != bsontype.BinaryGeneric && subtype != bsontype.BinaryBinaryOld {
+			return emptyValue, decodeBinaryError{subtype: subtype, typeName: "[]byte"}
+		}
+	case bsontype.Null:
+		err = vr.ReadNull()
+	case bsontype.Undefined:
+		err = vr.ReadUndefined()
+	default:
+		return emptyValue, fmt.Errorf("cannot decode %v into a []byte", vrType)
+	}
+	if err != nil {
+		return emptyValue, err
+	}
+
+	return reflect.ValueOf(data), nil
+}
+
+// DecodeValue is the ValueDecoder for []byte.
+func (bsc *ByteSliceCodec) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tByteSlice {
+		return ValueDecoderError{Name: "ByteSliceDecodeValue", Types: []reflect.Type{tByteSlice}, Received: val}
+	}
+
+	elem, err := bsc.decodeType(dc, vr, tByteSlice)
+	if err != nil {
+		return err
+	}
+
+	val.Set(elem)
+	return nil
+}

mongo/bson/bsoncodec/cond_addr_codec.go

@@ -0,0 +1,63 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"reflect"
+
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+)
+
+// condAddrEncoder is the encoder used when a pointer to the encoding value has an encoder.
+type condAddrEncoder struct {
+	canAddrEnc ValueEncoder
+	elseEnc    ValueEncoder
+}
+
+var _ ValueEncoder = (*condAddrEncoder)(nil)
+
+// newCondAddrEncoder returns an condAddrEncoder.
+func newCondAddrEncoder(canAddrEnc, elseEnc ValueEncoder) *condAddrEncoder {
+	encoder := condAddrEncoder{canAddrEnc: canAddrEnc, elseEnc: elseEnc}
+	return &encoder
+}
+
+// EncodeValue is the ValueEncoderFunc for a value that may be addressable.
+func (cae *condAddrEncoder) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if val.CanAddr() {
+		return cae.canAddrEnc.EncodeValue(ec, vw, val)
+	}
+	if cae.elseEnc != nil {
+		return cae.elseEnc.EncodeValue(ec, vw, val)
+	}
+	return ErrNoEncoder{Type: val.Type()}
+}
+
+// condAddrDecoder is the decoder used when a pointer to the value has a decoder.
+type condAddrDecoder struct {
+	canAddrDec ValueDecoder
+	elseDec    ValueDecoder
+}
+
+var _ ValueDecoder = (*condAddrDecoder)(nil)
+
+// newCondAddrDecoder returns an CondAddrDecoder.
+func newCondAddrDecoder(canAddrDec, elseDec ValueDecoder) *condAddrDecoder {
+	decoder := condAddrDecoder{canAddrDec: canAddrDec, elseDec: elseDec}
+	return &decoder
+}
+
+// DecodeValue is the ValueDecoderFunc for a value that may be addressable.
+func (cad *condAddrDecoder) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if val.CanAddr() {
+		return cad.canAddrDec.DecodeValue(dc, vr, val)
+	}
+	if cad.elseDec != nil {
+		return cad.elseDec.DecodeValue(dc, vr, val)
+	}
+	return ErrNoDecoder{Type: val.Type()}
+}

mongo/bson/bsoncodec/cond_addr_codec_test.go

@@ -0,0 +1,97 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"reflect"
+	"testing"
+
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsonrw/bsonrwtest"
+	"go.mongodb.org/mongo-driver/internal/testutil/assert"
+)
+
+func TestCondAddrCodec(t *testing.T) {
+	var inner int
+	canAddrVal := reflect.ValueOf(&inner)
+	addressable := canAddrVal.Elem()
+	unaddressable := reflect.ValueOf(inner)
+	rw := &bsonrwtest.ValueReaderWriter{}
+
+	t.Run("addressEncode", func(t *testing.T) {
+		invoked := 0
+		encode1 := ValueEncoderFunc(func(EncodeContext, bsonrw.ValueWriter, reflect.Value) error {
+			invoked = 1
+			return nil
+		})
+		encode2 := ValueEncoderFunc(func(EncodeContext, bsonrw.ValueWriter, reflect.Value) error {
+			invoked = 2
+			return nil
+		})
+		condEncoder := newCondAddrEncoder(encode1, encode2)
+
+		testCases := []struct {
+			name    string
+			val     reflect.Value
+			invoked int
+		}{
+			{"canAddr", addressable, 1},
+			{"else", unaddressable, 2},
+		}
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				err := condEncoder.EncodeValue(EncodeContext{}, rw, tc.val)
+				assert.Nil(t, err, "CondAddrEncoder error: %v", err)
+
+				assert.Equal(t, invoked, tc.invoked, "Expected function %v to be called, called %v", tc.invoked, invoked)
+			})
+		}
+
+		t.Run("error", func(t *testing.T) {
+			errEncoder := newCondAddrEncoder(encode1, nil)
+			err := errEncoder.EncodeValue(EncodeContext{}, rw, unaddressable)
+			want := ErrNoEncoder{Type: unaddressable.Type()}
+			assert.Equal(t, err, want, "expected error %v, got %v", want, err)
+		})
+	})
+	t.Run("addressDecode", func(t *testing.T) {
+		invoked := 0
+		decode1 := ValueDecoderFunc(func(DecodeContext, bsonrw.ValueReader, reflect.Value) error {
+			invoked = 1
+			return nil
+		})
+		decode2 := ValueDecoderFunc(func(DecodeContext, bsonrw.ValueReader, reflect.Value) error {
+			invoked = 2
+			return nil
+		})
+		condDecoder := newCondAddrDecoder(decode1, decode2)
+
+		testCases := []struct {
+			name    string
+			val     reflect.Value
+			invoked int
+		}{
+			{"canAddr", addressable, 1},
+			{"else", unaddressable, 2},
+		}
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				err := condDecoder.DecodeValue(DecodeContext{}, rw, tc.val)
+				assert.Nil(t, err, "CondAddrDecoder error: %v", err)
+
+				assert.Equal(t, invoked, tc.invoked, "Expected function %v to be called, called %v", tc.invoked, invoked)
+			})
+		}
+
+		t.Run("error", func(t *testing.T) {
+			errDecoder := newCondAddrDecoder(decode1, nil)
+			err := errDecoder.DecodeValue(DecodeContext{}, rw, unaddressable)
+			want := ErrNoDecoder{Type: unaddressable.Type()}
+			assert.Equal(t, err, want, "expected error %v, got %v", want, err)
+		})
+	})
+}

mongo/bson/bsoncodec/default_value_encoders.go

@@ -0,0 +1,766 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"net/url"
+	"reflect"
+	"sync"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.mongodb.org/mongo-driver/x/bsonx/bsoncore"
+)
+
+var defaultValueEncoders DefaultValueEncoders
+
+var bvwPool = bsonrw.NewBSONValueWriterPool()
+
+var errInvalidValue = errors.New("cannot encode invalid element")
+
+var sliceWriterPool = sync.Pool{
+	New: func() interface{} {
+		sw := make(bsonrw.SliceWriter, 0)
+		return &sw
+	},
+}
+
+func encodeElement(ec EncodeContext, dw bsonrw.DocumentWriter, e primitive.E) error {
+	vw, err := dw.WriteDocumentElement(e.Key)
+	if err != nil {
+		return err
+	}
+
+	if e.Value == nil {
+		return vw.WriteNull()
+	}
+	encoder, err := ec.LookupEncoder(reflect.TypeOf(e.Value))
+	if err != nil {
+		return err
+	}
+
+	err = encoder.EncodeValue(ec, vw, reflect.ValueOf(e.Value))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// DefaultValueEncoders is a namespace type for the default ValueEncoders used
+// when creating a registry.
+type DefaultValueEncoders struct{}
+
+// RegisterDefaultEncoders will register the encoder methods attached to DefaultValueEncoders with
+// the provided RegistryBuilder.
+func (dve DefaultValueEncoders) RegisterDefaultEncoders(rb *RegistryBuilder) {
+	if rb == nil {
+		panic(errors.New("argument to RegisterDefaultEncoders must not be nil"))
+	}
+	rb.
+		RegisterTypeEncoder(tByteSlice, defaultByteSliceCodec).
+		RegisterTypeEncoder(tTime, defaultTimeCodec).
+		RegisterTypeEncoder(tEmpty, defaultEmptyInterfaceCodec).
+		RegisterTypeEncoder(tCoreArray, defaultArrayCodec).
+		RegisterTypeEncoder(tOID, ValueEncoderFunc(dve.ObjectIDEncodeValue)).
+		RegisterTypeEncoder(tDecimal, ValueEncoderFunc(dve.Decimal128EncodeValue)).
+		RegisterTypeEncoder(tJSONNumber, ValueEncoderFunc(dve.JSONNumberEncodeValue)).
+		RegisterTypeEncoder(tURL, ValueEncoderFunc(dve.URLEncodeValue)).
+		RegisterTypeEncoder(tJavaScript, ValueEncoderFunc(dve.JavaScriptEncodeValue)).
+		RegisterTypeEncoder(tSymbol, ValueEncoderFunc(dve.SymbolEncodeValue)).
+		RegisterTypeEncoder(tBinary, ValueEncoderFunc(dve.BinaryEncodeValue)).
+		RegisterTypeEncoder(tUndefined, ValueEncoderFunc(dve.UndefinedEncodeValue)).
+		RegisterTypeEncoder(tDateTime, ValueEncoderFunc(dve.DateTimeEncodeValue)).
+		RegisterTypeEncoder(tNull, ValueEncoderFunc(dve.NullEncodeValue)).
+		RegisterTypeEncoder(tRegex, ValueEncoderFunc(dve.RegexEncodeValue)).
+		RegisterTypeEncoder(tDBPointer, ValueEncoderFunc(dve.DBPointerEncodeValue)).
+		RegisterTypeEncoder(tTimestamp, ValueEncoderFunc(dve.TimestampEncodeValue)).
+		RegisterTypeEncoder(tMinKey, ValueEncoderFunc(dve.MinKeyEncodeValue)).
+		RegisterTypeEncoder(tMaxKey, ValueEncoderFunc(dve.MaxKeyEncodeValue)).
+		RegisterTypeEncoder(tCoreDocument, ValueEncoderFunc(dve.CoreDocumentEncodeValue)).
+		RegisterTypeEncoder(tCodeWithScope, ValueEncoderFunc(dve.CodeWithScopeEncodeValue)).
+		RegisterDefaultEncoder(reflect.Bool, ValueEncoderFunc(dve.BooleanEncodeValue)).
+		RegisterDefaultEncoder(reflect.Int, ValueEncoderFunc(dve.IntEncodeValue)).
+		RegisterDefaultEncoder(reflect.Int8, ValueEncoderFunc(dve.IntEncodeValue)).
+		RegisterDefaultEncoder(reflect.Int16, ValueEncoderFunc(dve.IntEncodeValue)).
+		RegisterDefaultEncoder(reflect.Int32, ValueEncoderFunc(dve.IntEncodeValue)).
+		RegisterDefaultEncoder(reflect.Int64, ValueEncoderFunc(dve.IntEncodeValue)).
+		RegisterDefaultEncoder(reflect.Uint, defaultUIntCodec).
+		RegisterDefaultEncoder(reflect.Uint8, defaultUIntCodec).
+		RegisterDefaultEncoder(reflect.Uint16, defaultUIntCodec).
+		RegisterDefaultEncoder(reflect.Uint32, defaultUIntCodec).
+		RegisterDefaultEncoder(reflect.Uint64, defaultUIntCodec).
+		RegisterDefaultEncoder(reflect.Float32, ValueEncoderFunc(dve.FloatEncodeValue)).
+		RegisterDefaultEncoder(reflect.Float64, ValueEncoderFunc(dve.FloatEncodeValue)).
+		RegisterDefaultEncoder(reflect.Array, ValueEncoderFunc(dve.ArrayEncodeValue)).
+		RegisterDefaultEncoder(reflect.Map, defaultMapCodec).
+		RegisterDefaultEncoder(reflect.Slice, defaultSliceCodec).
+		RegisterDefaultEncoder(reflect.String, defaultStringCodec).
+		RegisterDefaultEncoder(reflect.Struct, newDefaultStructCodec()).
+		RegisterDefaultEncoder(reflect.Ptr, NewPointerCodec()).
+		RegisterHookEncoder(tValueMarshaler, ValueEncoderFunc(dve.ValueMarshalerEncodeValue)).
+		RegisterHookEncoder(tMarshaler, ValueEncoderFunc(dve.MarshalerEncodeValue)).
+		RegisterHookEncoder(tProxy, ValueEncoderFunc(dve.ProxyEncodeValue))
+}
+
+// BooleanEncodeValue is the ValueEncoderFunc for bool types.
+func (dve DefaultValueEncoders) BooleanEncodeValue(ectx EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Kind() != reflect.Bool {
+		return ValueEncoderError{Name: "BooleanEncodeValue", Kinds: []reflect.Kind{reflect.Bool}, Received: val}
+	}
+	return vw.WriteBoolean(val.Bool())
+}
+
+func fitsIn32Bits(i int64) bool {
+	return math.MinInt32 <= i && i <= math.MaxInt32
+}
+
+// IntEncodeValue is the ValueEncoderFunc for int types.
+func (dve DefaultValueEncoders) IntEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	switch val.Kind() {
+	case reflect.Int8, reflect.Int16, reflect.Int32:
+		return vw.WriteInt32(int32(val.Int()))
+	case reflect.Int:
+		i64 := val.Int()
+		if fitsIn32Bits(i64) {
+			return vw.WriteInt32(int32(i64))
+		}
+		return vw.WriteInt64(i64)
+	case reflect.Int64:
+		i64 := val.Int()
+		if ec.MinSize && fitsIn32Bits(i64) {
+			return vw.WriteInt32(int32(i64))
+		}
+		return vw.WriteInt64(i64)
+	}
+
+	return ValueEncoderError{
+		Name:     "IntEncodeValue",
+		Kinds:    []reflect.Kind{reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int},
+		Received: val,
+	}
+}
+
+// UintEncodeValue is the ValueEncoderFunc for uint types.
+//
+// Deprecated: UintEncodeValue is not registered by default. Use UintCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) UintEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	switch val.Kind() {
+	case reflect.Uint8, reflect.Uint16:
+		return vw.WriteInt32(int32(val.Uint()))
+	case reflect.Uint, reflect.Uint32, reflect.Uint64:
+		u64 := val.Uint()
+		if ec.MinSize && u64 <= math.MaxInt32 {
+			return vw.WriteInt32(int32(u64))
+		}
+		if u64 > math.MaxInt64 {
+			return fmt.Errorf("%d overflows int64", u64)
+		}
+		return vw.WriteInt64(int64(u64))
+	}
+
+	return ValueEncoderError{
+		Name:     "UintEncodeValue",
+		Kinds:    []reflect.Kind{reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint},
+		Received: val,
+	}
+}
+
+// FloatEncodeValue is the ValueEncoderFunc for float types.
+func (dve DefaultValueEncoders) FloatEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	switch val.Kind() {
+	case reflect.Float32, reflect.Float64:
+		return vw.WriteDouble(val.Float())
+	}
+
+	return ValueEncoderError{Name: "FloatEncodeValue", Kinds: []reflect.Kind{reflect.Float32, reflect.Float64}, Received: val}
+}
+
+// StringEncodeValue is the ValueEncoderFunc for string types.
+//
+// Deprecated: StringEncodeValue is not registered by default. Use StringCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) StringEncodeValue(ectx EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if val.Kind() != reflect.String {
+		return ValueEncoderError{
+			Name:     "StringEncodeValue",
+			Kinds:    []reflect.Kind{reflect.String},
+			Received: val,
+		}
+	}
+
+	return vw.WriteString(val.String())
+}
+
+// ObjectIDEncodeValue is the ValueEncoderFunc for primitive.ObjectID.
+func (dve DefaultValueEncoders) ObjectIDEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tOID {
+		return ValueEncoderError{Name: "ObjectIDEncodeValue", Types: []reflect.Type{tOID}, Received: val}
+	}
+	return vw.WriteObjectID(val.Interface().(primitive.ObjectID))
+}
+
+// Decimal128EncodeValue is the ValueEncoderFunc for primitive.Decimal128.
+func (dve DefaultValueEncoders) Decimal128EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tDecimal {
+		return ValueEncoderError{Name: "Decimal128EncodeValue", Types: []reflect.Type{tDecimal}, Received: val}
+	}
+	return vw.WriteDecimal128(val.Interface().(primitive.Decimal128))
+}
+
+// JSONNumberEncodeValue is the ValueEncoderFunc for json.Number.
+func (dve DefaultValueEncoders) JSONNumberEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tJSONNumber {
+		return ValueEncoderError{Name: "JSONNumberEncodeValue", Types: []reflect.Type{tJSONNumber}, Received: val}
+	}
+	jsnum := val.Interface().(json.Number)
+
+	// Attempt int first, then float64
+	if i64, err := jsnum.Int64(); err == nil {
+		return dve.IntEncodeValue(ec, vw, reflect.ValueOf(i64))
+	}
+
+	f64, err := jsnum.Float64()
+	if err != nil {
+		return err
+	}
+
+	return dve.FloatEncodeValue(ec, vw, reflect.ValueOf(f64))
+}
+
+// URLEncodeValue is the ValueEncoderFunc for url.URL.
+func (dve DefaultValueEncoders) URLEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tURL {
+		return ValueEncoderError{Name: "URLEncodeValue", Types: []reflect.Type{tURL}, Received: val}
+	}
+	u := val.Interface().(url.URL)
+	return vw.WriteString(u.String())
+}
+
+// TimeEncodeValue is the ValueEncoderFunc for time.TIme.
+//
+// Deprecated: TimeEncodeValue is not registered by default. Use TimeCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) TimeEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tTime {
+		return ValueEncoderError{Name: "TimeEncodeValue", Types: []reflect.Type{tTime}, Received: val}
+	}
+	tt := val.Interface().(time.Time)
+	dt := primitive.NewDateTimeFromTime(tt)
+	return vw.WriteDateTime(int64(dt))
+}
+
+// ByteSliceEncodeValue is the ValueEncoderFunc for []byte.
+//
+// Deprecated: ByteSliceEncodeValue is not registered by default. Use ByteSliceCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) ByteSliceEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tByteSlice {
+		return ValueEncoderError{Name: "ByteSliceEncodeValue", Types: []reflect.Type{tByteSlice}, Received: val}
+	}
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+	return vw.WriteBinary(val.Interface().([]byte))
+}
+
+// MapEncodeValue is the ValueEncoderFunc for map[string]* types.
+//
+// Deprecated: MapEncodeValue is not registered by default. Use MapCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) MapEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Kind() != reflect.Map || val.Type().Key().Kind() != reflect.String {
+		return ValueEncoderError{Name: "MapEncodeValue", Kinds: []reflect.Kind{reflect.Map}, Received: val}
+	}
+
+	if val.IsNil() {
+		// If we have a nill map but we can't WriteNull, that means we're probably trying to encode
+		// to a TopLevel document. We can't currently tell if this is what actually happened, but if
+		// there's a deeper underlying problem, the error will also be returned from WriteDocument,
+		// so just continue. The operations on a map reflection value are valid, so we can call
+		// MapKeys within mapEncodeValue without a problem.
+		err := vw.WriteNull()
+		if err == nil {
+			return nil
+		}
+	}
+
+	dw, err := vw.WriteDocument()
+	if err != nil {
+		return err
+	}
+
+	return dve.mapEncodeValue(ec, dw, val, nil)
+}
+
+// mapEncodeValue handles encoding of the values of a map. The collisionFn returns
+// true if the provided key exists, this is mainly used for inline maps in the
+// struct codec.
+func (dve DefaultValueEncoders) mapEncodeValue(ec EncodeContext, dw bsonrw.DocumentWriter, val reflect.Value, collisionFn func(string) bool) error {
+
+	elemType := val.Type().Elem()
+	encoder, err := ec.LookupEncoder(elemType)
+	if err != nil && elemType.Kind() != reflect.Interface {
+		return err
+	}
+
+	keys := val.MapKeys()
+	for _, key := range keys {
+		if collisionFn != nil && collisionFn(key.String()) {
+			return fmt.Errorf("Key %s of inlined map conflicts with a struct field name", key)
+		}
+
+		currEncoder, currVal, lookupErr := dve.lookupElementEncoder(ec, encoder, val.MapIndex(key))
+		if lookupErr != nil && lookupErr != errInvalidValue {
+			return lookupErr
+		}
+
+		vw, err := dw.WriteDocumentElement(key.String())
+		if err != nil {
+			return err
+		}
+
+		if lookupErr == errInvalidValue {
+			err = vw.WriteNull()
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		err = currEncoder.EncodeValue(ec, vw, currVal)
+		if err != nil {
+			return err
+		}
+	}
+
+	return dw.WriteDocumentEnd()
+}
+
+// ArrayEncodeValue is the ValueEncoderFunc for array types.
+func (dve DefaultValueEncoders) ArrayEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Kind() != reflect.Array {
+		return ValueEncoderError{Name: "ArrayEncodeValue", Kinds: []reflect.Kind{reflect.Array}, Received: val}
+	}
+
+	// If we have a []primitive.E we want to treat it as a document instead of as an array.
+	if val.Type().Elem() == tE {
+		dw, err := vw.WriteDocument()
+		if err != nil {
+			return err
+		}
+
+		for idx := 0; idx < val.Len(); idx++ {
+			e := val.Index(idx).Interface().(primitive.E)
+			err = encodeElement(ec, dw, e)
+			if err != nil {
+				return err
+			}
+		}
+
+		return dw.WriteDocumentEnd()
+	}
+
+	// If we have a []byte we want to treat it as a binary instead of as an array.
+	if val.Type().Elem() == tByte {
+		var byteSlice []byte
+		for idx := 0; idx < val.Len(); idx++ {
+			byteSlice = append(byteSlice, val.Index(idx).Interface().(byte))
+		}
+		return vw.WriteBinary(byteSlice)
+	}
+
+	aw, err := vw.WriteArray()
+	if err != nil {
+		return err
+	}
+
+	elemType := val.Type().Elem()
+	encoder, err := ec.LookupEncoder(elemType)
+	if err != nil && elemType.Kind() != reflect.Interface {
+		return err
+	}
+
+	for idx := 0; idx < val.Len(); idx++ {
+		currEncoder, currVal, lookupErr := dve.lookupElementEncoder(ec, encoder, val.Index(idx))
+		if lookupErr != nil && lookupErr != errInvalidValue {
+			return lookupErr
+		}
+
+		vw, err := aw.WriteArrayElement()
+		if err != nil {
+			return err
+		}
+
+		if lookupErr == errInvalidValue {
+			err = vw.WriteNull()
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		err = currEncoder.EncodeValue(ec, vw, currVal)
+		if err != nil {
+			return err
+		}
+	}
+	return aw.WriteArrayEnd()
+}
+
+// SliceEncodeValue is the ValueEncoderFunc for slice types.
+//
+// Deprecated: SliceEncodeValue is not registered by default. Use SliceCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) SliceEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Kind() != reflect.Slice {
+		return ValueEncoderError{Name: "SliceEncodeValue", Kinds: []reflect.Kind{reflect.Slice}, Received: val}
+	}
+
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+
+	// If we have a []primitive.E we want to treat it as a document instead of as an array.
+	if val.Type().ConvertibleTo(tD) {
+		d := val.Convert(tD).Interface().(primitive.D)
+
+		dw, err := vw.WriteDocument()
+		if err != nil {
+			return err
+		}
+
+		for _, e := range d {
+			err = encodeElement(ec, dw, e)
+			if err != nil {
+				return err
+			}
+		}
+
+		return dw.WriteDocumentEnd()
+	}
+
+	aw, err := vw.WriteArray()
+	if err != nil {
+		return err
+	}
+
+	elemType := val.Type().Elem()
+	encoder, err := ec.LookupEncoder(elemType)
+	if err != nil && elemType.Kind() != reflect.Interface {
+		return err
+	}
+
+	for idx := 0; idx < val.Len(); idx++ {
+		currEncoder, currVal, lookupErr := dve.lookupElementEncoder(ec, encoder, val.Index(idx))
+		if lookupErr != nil && lookupErr != errInvalidValue {
+			return lookupErr
+		}
+
+		vw, err := aw.WriteArrayElement()
+		if err != nil {
+			return err
+		}
+
+		if lookupErr == errInvalidValue {
+			err = vw.WriteNull()
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		err = currEncoder.EncodeValue(ec, vw, currVal)
+		if err != nil {
+			return err
+		}
+	}
+	return aw.WriteArrayEnd()
+}
+
+func (dve DefaultValueEncoders) lookupElementEncoder(ec EncodeContext, origEncoder ValueEncoder, currVal reflect.Value) (ValueEncoder, reflect.Value, error) {
+	if origEncoder != nil || (currVal.Kind() != reflect.Interface) {
+		return origEncoder, currVal, nil
+	}
+	currVal = currVal.Elem()
+	if !currVal.IsValid() {
+		return nil, currVal, errInvalidValue
+	}
+	currEncoder, err := ec.LookupEncoder(currVal.Type())
+
+	return currEncoder, currVal, err
+}
+
+// EmptyInterfaceEncodeValue is the ValueEncoderFunc for interface{}.
+//
+// Deprecated: EmptyInterfaceEncodeValue is not registered by default. Use EmptyInterfaceCodec.EncodeValue instead.
+func (dve DefaultValueEncoders) EmptyInterfaceEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tEmpty {
+		return ValueEncoderError{Name: "EmptyInterfaceEncodeValue", Types: []reflect.Type{tEmpty}, Received: val}
+	}
+
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+	encoder, err := ec.LookupEncoder(val.Elem().Type())
+	if err != nil {
+		return err
+	}
+
+	return encoder.EncodeValue(ec, vw, val.Elem())
+}
+
+// ValueMarshalerEncodeValue is the ValueEncoderFunc for ValueMarshaler implementations.
+func (dve DefaultValueEncoders) ValueMarshalerEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	// Either val or a pointer to val must implement ValueMarshaler
+	switch {
+	case !val.IsValid():
+		return ValueEncoderError{Name: "ValueMarshalerEncodeValue", Types: []reflect.Type{tValueMarshaler}, Received: val}
+	case val.Type().Implements(tValueMarshaler):
+		// If ValueMarshaler is implemented on a concrete type, make sure that val isn't a nil pointer
+		if isImplementationNil(val, tValueMarshaler) {
+			return vw.WriteNull()
+		}
+	case reflect.PtrTo(val.Type()).Implements(tValueMarshaler) && val.CanAddr():
+		val = val.Addr()
+	default:
+		return ValueEncoderError{Name: "ValueMarshalerEncodeValue", Types: []reflect.Type{tValueMarshaler}, Received: val}
+	}
+
+	fn := val.Convert(tValueMarshaler).MethodByName("MarshalBSONValue")
+	returns := fn.Call(nil)
+	if !returns[2].IsNil() {
+		return returns[2].Interface().(error)
+	}
+	t, data := returns[0].Interface().(bsontype.Type), returns[1].Interface().([]byte)
+	return bsonrw.Copier{}.CopyValueFromBytes(vw, t, data)
+}
+
+// MarshalerEncodeValue is the ValueEncoderFunc for Marshaler implementations.
+func (dve DefaultValueEncoders) MarshalerEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	// Either val or a pointer to val must implement Marshaler
+	switch {
+	case !val.IsValid():
+		return ValueEncoderError{Name: "MarshalerEncodeValue", Types: []reflect.Type{tMarshaler}, Received: val}
+	case val.Type().Implements(tMarshaler):
+		// If Marshaler is implemented on a concrete type, make sure that val isn't a nil pointer
+		if isImplementationNil(val, tMarshaler) {
+			return vw.WriteNull()
+		}
+	case reflect.PtrTo(val.Type()).Implements(tMarshaler) && val.CanAddr():
+		val = val.Addr()
+	default:
+		return ValueEncoderError{Name: "MarshalerEncodeValue", Types: []reflect.Type{tMarshaler}, Received: val}
+	}
+
+	fn := val.Convert(tMarshaler).MethodByName("MarshalBSON")
+	returns := fn.Call(nil)
+	if !returns[1].IsNil() {
+		return returns[1].Interface().(error)
+	}
+	data := returns[0].Interface().([]byte)
+	return bsonrw.Copier{}.CopyValueFromBytes(vw, bsontype.EmbeddedDocument, data)
+}
+
+// ProxyEncodeValue is the ValueEncoderFunc for Proxy implementations.
+func (dve DefaultValueEncoders) ProxyEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	// Either val or a pointer to val must implement Proxy
+	switch {
+	case !val.IsValid():
+		return ValueEncoderError{Name: "ProxyEncodeValue", Types: []reflect.Type{tProxy}, Received: val}
+	case val.Type().Implements(tProxy):
+		// If Proxy is implemented on a concrete type, make sure that val isn't a nil pointer
+		if isImplementationNil(val, tProxy) {
+			return vw.WriteNull()
+		}
+	case reflect.PtrTo(val.Type()).Implements(tProxy) && val.CanAddr():
+		val = val.Addr()
+	default:
+		return ValueEncoderError{Name: "ProxyEncodeValue", Types: []reflect.Type{tProxy}, Received: val}
+	}
+
+	fn := val.Convert(tProxy).MethodByName("ProxyBSON")
+	returns := fn.Call(nil)
+	if !returns[1].IsNil() {
+		return returns[1].Interface().(error)
+	}
+	data := returns[0]
+	var encoder ValueEncoder
+	var err error
+	if data.Elem().IsValid() {
+		encoder, err = ec.LookupEncoder(data.Elem().Type())
+	} else {
+		encoder, err = ec.LookupEncoder(nil)
+	}
+	if err != nil {
+		return err
+	}
+	return encoder.EncodeValue(ec, vw, data.Elem())
+}
+
+// JavaScriptEncodeValue is the ValueEncoderFunc for the primitive.JavaScript type.
+func (DefaultValueEncoders) JavaScriptEncodeValue(ectx EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tJavaScript {
+		return ValueEncoderError{Name: "JavaScriptEncodeValue", Types: []reflect.Type{tJavaScript}, Received: val}
+	}
+
+	return vw.WriteJavascript(val.String())
+}
+
+// SymbolEncodeValue is the ValueEncoderFunc for the primitive.Symbol type.
+func (DefaultValueEncoders) SymbolEncodeValue(ectx EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tSymbol {
+		return ValueEncoderError{Name: "SymbolEncodeValue", Types: []reflect.Type{tSymbol}, Received: val}
+	}
+
+	return vw.WriteSymbol(val.String())
+}
+
+// BinaryEncodeValue is the ValueEncoderFunc for Binary.
+func (DefaultValueEncoders) BinaryEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tBinary {
+		return ValueEncoderError{Name: "BinaryEncodeValue", Types: []reflect.Type{tBinary}, Received: val}
+	}
+	b := val.Interface().(primitive.Binary)
+
+	return vw.WriteBinaryWithSubtype(b.Data, b.Subtype)
+}
+
+// UndefinedEncodeValue is the ValueEncoderFunc for Undefined.
+func (DefaultValueEncoders) UndefinedEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tUndefined {
+		return ValueEncoderError{Name: "UndefinedEncodeValue", Types: []reflect.Type{tUndefined}, Received: val}
+	}
+
+	return vw.WriteUndefined()
+}
+
+// DateTimeEncodeValue is the ValueEncoderFunc for DateTime.
+func (DefaultValueEncoders) DateTimeEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tDateTime {
+		return ValueEncoderError{Name: "DateTimeEncodeValue", Types: []reflect.Type{tDateTime}, Received: val}
+	}
+
+	return vw.WriteDateTime(val.Int())
+}
+
+// NullEncodeValue is the ValueEncoderFunc for Null.
+func (DefaultValueEncoders) NullEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tNull {
+		return ValueEncoderError{Name: "NullEncodeValue", Types: []reflect.Type{tNull}, Received: val}
+	}
+
+	return vw.WriteNull()
+}
+
+// RegexEncodeValue is the ValueEncoderFunc for Regex.
+func (DefaultValueEncoders) RegexEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tRegex {
+		return ValueEncoderError{Name: "RegexEncodeValue", Types: []reflect.Type{tRegex}, Received: val}
+	}
+
+	regex := val.Interface().(primitive.Regex)
+
+	return vw.WriteRegex(regex.Pattern, regex.Options)
+}
+
+// DBPointerEncodeValue is the ValueEncoderFunc for DBPointer.
+func (DefaultValueEncoders) DBPointerEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tDBPointer {
+		return ValueEncoderError{Name: "DBPointerEncodeValue", Types: []reflect.Type{tDBPointer}, Received: val}
+	}
+
+	dbp := val.Interface().(primitive.DBPointer)
+
+	return vw.WriteDBPointer(dbp.DB, dbp.Pointer)
+}
+
+// TimestampEncodeValue is the ValueEncoderFunc for Timestamp.
+func (DefaultValueEncoders) TimestampEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tTimestamp {
+		return ValueEncoderError{Name: "TimestampEncodeValue", Types: []reflect.Type{tTimestamp}, Received: val}
+	}
+
+	ts := val.Interface().(primitive.Timestamp)
+
+	return vw.WriteTimestamp(ts.T, ts.I)
+}
+
+// MinKeyEncodeValue is the ValueEncoderFunc for MinKey.
+func (DefaultValueEncoders) MinKeyEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tMinKey {
+		return ValueEncoderError{Name: "MinKeyEncodeValue", Types: []reflect.Type{tMinKey}, Received: val}
+	}
+
+	return vw.WriteMinKey()
+}
+
+// MaxKeyEncodeValue is the ValueEncoderFunc for MaxKey.
+func (DefaultValueEncoders) MaxKeyEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tMaxKey {
+		return ValueEncoderError{Name: "MaxKeyEncodeValue", Types: []reflect.Type{tMaxKey}, Received: val}
+	}
+
+	return vw.WriteMaxKey()
+}
+
+// CoreDocumentEncodeValue is the ValueEncoderFunc for bsoncore.Document.
+func (DefaultValueEncoders) CoreDocumentEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tCoreDocument {
+		return ValueEncoderError{Name: "CoreDocumentEncodeValue", Types: []reflect.Type{tCoreDocument}, Received: val}
+	}
+
+	cdoc := val.Interface().(bsoncore.Document)
+
+	return bsonrw.Copier{}.CopyDocumentFromBytes(vw, cdoc)
+}
+
+// CodeWithScopeEncodeValue is the ValueEncoderFunc for CodeWithScope.
+func (dve DefaultValueEncoders) CodeWithScopeEncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tCodeWithScope {
+		return ValueEncoderError{Name: "CodeWithScopeEncodeValue", Types: []reflect.Type{tCodeWithScope}, Received: val}
+	}
+
+	cws := val.Interface().(primitive.CodeWithScope)
+
+	dw, err := vw.WriteCodeWithScope(string(cws.Code))
+	if err != nil {
+		return err
+	}
+
+	sw := sliceWriterPool.Get().(*bsonrw.SliceWriter)
+	defer sliceWriterPool.Put(sw)
+	*sw = (*sw)[:0]
+
+	scopeVW := bvwPool.Get(sw)
+	defer bvwPool.Put(scopeVW)
+
+	encoder, err := ec.LookupEncoder(reflect.TypeOf(cws.Scope))
+	if err != nil {
+		return err
+	}
+
+	err = encoder.EncodeValue(ec, scopeVW, reflect.ValueOf(cws.Scope))
+	if err != nil {
+		return err
+	}
+
+	err = bsonrw.Copier{}.CopyBytesToDocumentWriter(dw, *sw)
+	if err != nil {
+		return err
+	}
+	return dw.WriteDocumentEnd()
+}
+
+// isImplementationNil returns if val is a nil pointer and inter is implemented on a concrete type
+func isImplementationNil(val reflect.Value, inter reflect.Type) bool {
+	vt := val.Type()
+	for vt.Kind() == reflect.Ptr {
+		vt = vt.Elem()
+	}
+	return vt.Implements(inter) && val.Kind() == reflect.Ptr && val.IsNil()
+}

mongo/bson/bsoncodec/doc.go

@@ -0,0 +1,90 @@
+// Copyright (C) MongoDB, Inc. 2022-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+// Package bsoncodec provides a system for encoding values to BSON representations and decoding
+// values from BSON representations. This package considers both binary BSON and ExtendedJSON as
+// BSON representations. The types in this package enable a flexible system for handling this
+// encoding and decoding.
+//
+// The codec system is composed of two parts:
+//
+// 1) ValueEncoders and ValueDecoders that handle encoding and decoding Go values to and from BSON
+// representations.
+//
+// 2) A Registry that holds these ValueEncoders and ValueDecoders and provides methods for
+// retrieving them.
+//
+// # ValueEncoders and ValueDecoders
+//
+// The ValueEncoder interface is implemented by types that can encode a provided Go type to BSON.
+// The value to encode is provided as a reflect.Value and a bsonrw.ValueWriter is used within the
+// EncodeValue method to actually create the BSON representation. For convenience, ValueEncoderFunc
+// is provided to allow use of a function with the correct signature as a ValueEncoder. An
+// EncodeContext instance is provided to allow implementations to lookup further ValueEncoders and
+// to provide configuration information.
+//
+// The ValueDecoder interface is the inverse of the ValueEncoder. Implementations should ensure that
+// the value they receive is settable. Similar to ValueEncoderFunc, ValueDecoderFunc is provided to
+// allow the use of a function with the correct signature as a ValueDecoder. A DecodeContext
+// instance is provided and serves similar functionality to the EncodeContext.
+//
+// # Registry and RegistryBuilder
+//
+// A Registry is an immutable store for ValueEncoders, ValueDecoders, and a type map. See the Registry type
+// documentation for examples of registering various custom encoders and decoders. A Registry can be constructed using a
+// RegistryBuilder, which handles three main types of codecs:
+//
+// 1. Type encoders/decoders - These can be registered using the RegisterTypeEncoder and RegisterTypeDecoder methods.
+// The registered codec will be invoked when encoding/decoding a value whose type matches the registered type exactly.
+// If the registered type is an interface, the codec will be invoked when encoding or decoding values whose type is the
+// interface, but not for values with concrete types that implement the interface.
+//
+// 2. Hook encoders/decoders - These can be registered using the RegisterHookEncoder and RegisterHookDecoder methods.
+// These methods only accept interface types and the registered codecs will be invoked when encoding or decoding values
+// whose types implement the interface. An example of a hook defined by the driver is bson.Marshaler. The driver will
+// call the MarshalBSON method for any value whose type implements bson.Marshaler, regardless of the value's concrete
+// type.
+//
+// 3. Type map entries - This can be used to associate a BSON type with a Go type. These type associations are used when
+// decoding into a bson.D/bson.M or a struct field of type interface{}. For example, by default, BSON int32 and int64
+// values decode as Go int32 and int64 instances, respectively, when decoding into a bson.D. The following code would
+// change the behavior so these values decode as Go int instances instead:
+//
+//	intType := reflect.TypeOf(int(0))
+//	registryBuilder.RegisterTypeMapEntry(bsontype.Int32, intType).RegisterTypeMapEntry(bsontype.Int64, intType)
+//
+// 4. Kind encoder/decoders - These can be registered using the RegisterDefaultEncoder and RegisterDefaultDecoder
+// methods. The registered codec will be invoked when encoding or decoding values whose reflect.Kind matches the
+// registered reflect.Kind as long as the value's type doesn't match a registered type or hook encoder/decoder first.
+// These methods should be used to change the behavior for all values for a specific kind.
+//
+// # Registry Lookup Procedure
+//
+// When looking up an encoder in a Registry, the precedence rules are as follows:
+//
+// 1. A type encoder registered for the exact type of the value.
+//
+// 2. A hook encoder registered for an interface that is implemented by the value or by a pointer to the value. If the
+// value matches multiple hooks (e.g. the type implements bsoncodec.Marshaler and bsoncodec.ValueMarshaler), the first
+// one registered will be selected. Note that registries constructed using bson.NewRegistryBuilder have driver-defined
+// hooks registered for the bsoncodec.Marshaler, bsoncodec.ValueMarshaler, and bsoncodec.Proxy interfaces, so those
+// will take precedence over any new hooks.
+//
+// 3. A kind encoder registered for the value's kind.
+//
+// If all of these lookups fail to find an encoder, an error of type ErrNoEncoder is returned. The same precedence
+// rules apply for decoders, with the exception that an error of type ErrNoDecoder will be returned if no decoder is
+// found.
+//
+// # DefaultValueEncoders and DefaultValueDecoders
+//
+// The DefaultValueEncoders and DefaultValueDecoders types provide a full set of ValueEncoders and
+// ValueDecoders for handling a wide range of Go types, including all of the types within the
+// primitive package. To make registering these codecs easier, a helper method on each type is
+// provided. For the DefaultValueEncoders type the method is called RegisterDefaultEncoders and for
+// the DefaultValueDecoders type the method is called RegisterDefaultDecoders, this method also
+// handles registering type map entries for each BSON type.
+package bsoncodec

mongo/bson/bsoncodec/empty_interface_codec.go

@@ -0,0 +1,147 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"reflect"
+
+	"go.mongodb.org/mongo-driver/bson/bsonoptions"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+)
+
+// EmptyInterfaceCodec is the Codec used for interface{} values.
+type EmptyInterfaceCodec struct {
+	DecodeBinaryAsSlice bool
+}
+
+var (
+	defaultEmptyInterfaceCodec = NewEmptyInterfaceCodec()
+
+	_ ValueCodec  = defaultEmptyInterfaceCodec
+	_ typeDecoder = defaultEmptyInterfaceCodec
+)
+
+// NewEmptyInterfaceCodec returns a EmptyInterfaceCodec with options opts.
+func NewEmptyInterfaceCodec(opts ...*bsonoptions.EmptyInterfaceCodecOptions) *EmptyInterfaceCodec {
+	interfaceOpt := bsonoptions.MergeEmptyInterfaceCodecOptions(opts...)
+
+	codec := EmptyInterfaceCodec{}
+	if interfaceOpt.DecodeBinaryAsSlice != nil {
+		codec.DecodeBinaryAsSlice = *interfaceOpt.DecodeBinaryAsSlice
+	}
+	return &codec
+}
+
+// EncodeValue is the ValueEncoderFunc for interface{}.
+func (eic EmptyInterfaceCodec) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Type() != tEmpty {
+		return ValueEncoderError{Name: "EmptyInterfaceEncodeValue", Types: []reflect.Type{tEmpty}, Received: val}
+	}
+
+	if val.IsNil() {
+		return vw.WriteNull()
+	}
+	encoder, err := ec.LookupEncoder(val.Elem().Type())
+	if err != nil {
+		return err
+	}
+
+	return encoder.EncodeValue(ec, vw, val.Elem())
+}
+
+func (eic EmptyInterfaceCodec) getEmptyInterfaceDecodeType(dc DecodeContext, valueType bsontype.Type) (reflect.Type, error) {
+	isDocument := valueType == bsontype.Type(0) || valueType == bsontype.EmbeddedDocument
+	if isDocument {
+		if dc.defaultDocumentType != nil {
+			// If the bsontype is an embedded document and the DocumentType is set on the DecodeContext, then return
+			// that type.
+			return dc.defaultDocumentType, nil
+		}
+		if dc.Ancestor != nil {
+			// Using ancestor information rather than looking up the type map entry forces consistent decoding.
+			// If we're decoding into a bson.D, subdocuments should also be decoded as bson.D, even if a type map entry
+			// has been registered.
+			return dc.Ancestor, nil
+		}
+	}
+
+	rtype, err := dc.LookupTypeMapEntry(valueType)
+	if err == nil {
+		return rtype, nil
+	}
+
+	if isDocument {
+		// For documents, fallback to looking up a type map entry for bsontype.Type(0) or bsontype.EmbeddedDocument,
+		// depending on the original valueType.
+		var lookupType bsontype.Type
+		switch valueType {
+		case bsontype.Type(0):
+			lookupType = bsontype.EmbeddedDocument
+		case bsontype.EmbeddedDocument:
+			lookupType = bsontype.Type(0)
+		}
+
+		rtype, err = dc.LookupTypeMapEntry(lookupType)
+		if err == nil {
+			return rtype, nil
+		}
+	}
+
+	return nil, err
+}
+
+func (eic EmptyInterfaceCodec) decodeType(dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) {
+	if t != tEmpty {
+		return emptyValue, ValueDecoderError{Name: "EmptyInterfaceDecodeValue", Types: []reflect.Type{tEmpty}, Received: reflect.Zero(t)}
+	}
+
+	rtype, err := eic.getEmptyInterfaceDecodeType(dc, vr.Type())
+	if err != nil {
+		switch vr.Type() {
+		case bsontype.Null:
+			return reflect.Zero(t), vr.ReadNull()
+		default:
+			return emptyValue, err
+		}
+	}
+
+	decoder, err := dc.LookupDecoder(rtype)
+	if err != nil {
+		return emptyValue, err
+	}
+
+	elem, err := decodeTypeOrValue(decoder, dc, vr, rtype)
+	if err != nil {
+		return emptyValue, err
+	}
+
+	if eic.DecodeBinaryAsSlice && rtype == tBinary {
+		binElem := elem.Interface().(primitive.Binary)
+		if binElem.Subtype == bsontype.BinaryGeneric || binElem.Subtype == bsontype.BinaryBinaryOld {
+			elem = reflect.ValueOf(binElem.Data)
+		}
+	}
+
+	return elem, nil
+}
+
+// DecodeValue is the ValueDecoderFunc for interface{}.
+func (eic EmptyInterfaceCodec) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if !val.CanSet() || val.Type() != tEmpty {
+		return ValueDecoderError{Name: "EmptyInterfaceDecodeValue", Types: []reflect.Type{tEmpty}, Received: val}
+	}
+
+	elem, err := eic.decodeType(dc, vr, val.Type())
+	if err != nil {
+		return err
+	}
+
+	val.Set(elem)
+	return nil
+}

mongo/bson/bsoncodec/map_codec.go

@@ -0,0 +1,309 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"encoding"
+	"fmt"
+	"reflect"
+	"strconv"
+
+	"go.mongodb.org/mongo-driver/bson/bsonoptions"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"go.mongodb.org/mongo-driver/bson/bsontype"
+)
+
+var defaultMapCodec = NewMapCodec()
+
+// MapCodec is the Codec used for map values.
+type MapCodec struct {
+	DecodeZerosMap         bool
+	EncodeNilAsEmpty       bool
+	EncodeKeysWithStringer bool
+}
+
+var _ ValueCodec = &MapCodec{}
+
+// KeyMarshaler is the interface implemented by an object that can marshal itself into a string key.
+// This applies to types used as map keys and is similar to encoding.TextMarshaler.
+type KeyMarshaler interface {
+	MarshalKey() (key string, err error)
+}
+
+// KeyUnmarshaler is the interface implemented by an object that can unmarshal a string representation
+// of itself. This applies to types used as map keys and is similar to encoding.TextUnmarshaler.
+//
+// UnmarshalKey must be able to decode the form generated by MarshalKey.
+// UnmarshalKey must copy the text if it wishes to retain the text
+// after returning.
+type KeyUnmarshaler interface {
+	UnmarshalKey(key string) error
+}
+
+// NewMapCodec returns a MapCodec with options opts.
+func NewMapCodec(opts ...*bsonoptions.MapCodecOptions) *MapCodec {
+	mapOpt := bsonoptions.MergeMapCodecOptions(opts...)
+
+	codec := MapCodec{}
+	if mapOpt.DecodeZerosMap != nil {
+		codec.DecodeZerosMap = *mapOpt.DecodeZerosMap
+	}
+	if mapOpt.EncodeNilAsEmpty != nil {
+		codec.EncodeNilAsEmpty = *mapOpt.EncodeNilAsEmpty
+	}
+	if mapOpt.EncodeKeysWithStringer != nil {
+		codec.EncodeKeysWithStringer = *mapOpt.EncodeKeysWithStringer
+	}
+	return &codec
+}
+
+// EncodeValue is the ValueEncoder for map[*]* types.
+func (mc *MapCodec) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error {
+	if !val.IsValid() || val.Kind() != reflect.Map {
+		return ValueEncoderError{Name: "MapEncodeValue", Kinds: []reflect.Kind{reflect.Map}, Received: val}
+	}
+
+	if val.IsNil() && !mc.EncodeNilAsEmpty {
+		// If we have a nil map but we can't WriteNull, that means we're probably trying to encode
+		// to a TopLevel document. We can't currently tell if this is what actually happened, but if
+		// there's a deeper underlying problem, the error will also be returned from WriteDocument,
+		// so just continue. The operations on a map reflection value are valid, so we can call
+		// MapKeys within mapEncodeValue without a problem.
+		err := vw.WriteNull()
+		if err == nil {
+			return nil
+		}
+	}
+
+	dw, err := vw.WriteDocument()
+	if err != nil {
+		return err
+	}
+
+	return mc.mapEncodeValue(ec, dw, val, nil)
+}
+
+// mapEncodeValue handles encoding of the values of a map. The collisionFn returns
+// true if the provided key exists, this is mainly used for inline maps in the
+// struct codec.
+func (mc *MapCodec) mapEncodeValue(ec EncodeContext, dw bsonrw.DocumentWriter, val reflect.Value, collisionFn func(string) bool) error {
+
+	elemType := val.Type().Elem()
+	encoder, err := ec.LookupEncoder(elemType)
+	if err != nil && elemType.Kind() != reflect.Interface {
+		return err
+	}
+
+	keys := val.MapKeys()
+	for _, key := range keys {
+		keyStr, err := mc.encodeKey(key)
+		if err != nil {
+			return err
+		}
+
+		if collisionFn != nil && collisionFn(keyStr) {
+			return fmt.Errorf("Key %s of inlined map conflicts with a struct field name", key)
+		}
+
+		currEncoder, currVal, lookupErr := defaultValueEncoders.lookupElementEncoder(ec, encoder, val.MapIndex(key))
+		if lookupErr != nil && lookupErr != errInvalidValue {
+			return lookupErr
+		}
+
+		vw, err := dw.WriteDocumentElement(keyStr)
+		if err != nil {
+			return err
+		}
+
+		if lookupErr == errInvalidValue {
+			err = vw.WriteNull()
+			if err != nil {
+				return err
+			}
+			continue
+		}
+
+		err = currEncoder.EncodeValue(ec, vw, currVal)
+		if err != nil {
+			return err
+		}
+	}
+
+	return dw.WriteDocumentEnd()
+}
+
+// DecodeValue is the ValueDecoder for map[string/decimal]* types.
+func (mc *MapCodec) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if val.Kind() != reflect.Map || (!val.CanSet() && val.IsNil()) {
+		return ValueDecoderError{Name: "MapDecodeValue", Kinds: []reflect.Kind{reflect.Map}, Received: val}
+	}
+
+	switch vrType := vr.Type(); vrType {
+	case bsontype.Type(0), bsontype.EmbeddedDocument:
+	case bsontype.Null:
+		val.Set(reflect.Zero(val.Type()))
+		return vr.ReadNull()
+	case bsontype.Undefined:
+		val.Set(reflect.Zero(val.Type()))
+		return vr.ReadUndefined()
+	default:
+		return fmt.Errorf("cannot decode %v into a %s", vrType, val.Type())
+	}
+
+	dr, err := vr.ReadDocument()
+	if err != nil {
+		return err
+	}
+
+	if val.IsNil() {
+		val.Set(reflect.MakeMap(val.Type()))
+	}
+
+	if val.Len() > 0 && mc.DecodeZerosMap {
+		clearMap(val)
+	}
+
+	eType := val.Type().Elem()
+	decoder, err := dc.LookupDecoder(eType)
+	if err != nil {
+		return err
+	}
+	eTypeDecoder, _ := decoder.(typeDecoder)
+
+	if eType == tEmpty {
+		dc.Ancestor = val.Type()
+	}
+
+	keyType := val.Type().Key()
+
+	for {
+		key, vr, err := dr.ReadElement()
+		if err == bsonrw.ErrEOD {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		k, err := mc.decodeKey(key, keyType)
+		if err != nil {
+			return err
+		}
+
+		elem, err := decodeTypeOrValueWithInfo(decoder, eTypeDecoder, dc, vr, eType, true)
+		if err != nil {
+			return newDecodeError(key, err)
+		}
+
+		val.SetMapIndex(k, elem)
+	}
+	return nil
+}
+
+func clearMap(m reflect.Value) {
+	var none reflect.Value
+	for _, k := range m.MapKeys() {
+		m.SetMapIndex(k, none)
+	}
+}
+
+func (mc *MapCodec) encodeKey(val reflect.Value) (string, error) {
+	if mc.EncodeKeysWithStringer {
+		return fmt.Sprint(val), nil
+	}
+
+	// keys of any string type are used directly
+	if val.Kind() == reflect.String {
+		return val.String(), nil
+	}
+	// KeyMarshalers are marshaled
+	if km, ok := val.Interface().(KeyMarshaler); ok {
+		if val.Kind() == reflect.Ptr && val.IsNil() {
+			return "", nil
+		}
+		buf, err := km.MarshalKey()
+		if err == nil {
+			return buf, nil
+		}
+		return "", err
+	}
+	// keys implement encoding.TextMarshaler are marshaled.
+	if km, ok := val.Interface().(encoding.TextMarshaler); ok {
+		if val.Kind() == reflect.Ptr && val.IsNil() {
+			return "", nil
+		}
+
+		buf, err := km.MarshalText()
+		if err != nil {
+			return "", err
+		}
+
+		return string(buf), nil
+	}
+
+	switch val.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return strconv.FormatInt(val.Int(), 10), nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return strconv.FormatUint(val.Uint(), 10), nil
+	}
+	return "", fmt.Errorf("unsupported key type: %v", val.Type())
+}
+
+var keyUnmarshalerType = reflect.TypeOf((*KeyUnmarshaler)(nil)).Elem()
+var textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+
+func (mc *MapCodec) decodeKey(key string, keyType reflect.Type) (reflect.Value, error) {
+	keyVal := reflect.ValueOf(key)
+	var err error
+	switch {
+	// First, if EncodeKeysWithStringer is not enabled, try to decode withKeyUnmarshaler
+	case !mc.EncodeKeysWithStringer && reflect.PtrTo(keyType).Implements(keyUnmarshalerType):
+		keyVal = reflect.New(keyType)
+		v := keyVal.Interface().(KeyUnmarshaler)
+		err = v.UnmarshalKey(key)
+		keyVal = keyVal.Elem()
+	// Try to decode encoding.TextUnmarshalers.
+	case reflect.PtrTo(keyType).Implements(textUnmarshalerType):
+		keyVal = reflect.New(keyType)
+		v := keyVal.Interface().(encoding.TextUnmarshaler)
+		err = v.UnmarshalText([]byte(key))
+		keyVal = keyVal.Elem()
+	// Otherwise, go to type specific behavior
+	default:
+		switch keyType.Kind() {
+		case reflect.String:
+			keyVal = reflect.ValueOf(key).Convert(keyType)
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			n, parseErr := strconv.ParseInt(key, 10, 64)
+			if parseErr != nil || reflect.Zero(keyType).OverflowInt(n) {
+				err = fmt.Errorf("failed to unmarshal number key %v", key)
+			}
+			keyVal = reflect.ValueOf(n).Convert(keyType)
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			n, parseErr := strconv.ParseUint(key, 10, 64)
+			if parseErr != nil || reflect.Zero(keyType).OverflowUint(n) {
+				err = fmt.Errorf("failed to unmarshal number key %v", key)
+				break
+			}
+			keyVal = reflect.ValueOf(n).Convert(keyType)
+		case reflect.Float32, reflect.Float64:
+			if mc.EncodeKeysWithStringer {
+				parsed, err := strconv.ParseFloat(key, 64)
+				if err != nil {
+					return keyVal, fmt.Errorf("Map key is defined to be a decimal type (%v) but got error %v", keyType.Kind(), err)
+				}
+				keyVal = reflect.ValueOf(parsed)
+				break
+			}
+			fallthrough
+		default:
+			return keyVal, fmt.Errorf("unsupported key type: %v", keyType)
+		}
+	}
+	return keyVal, err
+}