add support for page-based cursortokens (like goext)

scnserver/db/cursortoken/token.go

@@ -4,21 +4,27 @@ import (
 	"encoding/base32"
 	"encoding/json"
 	"errors"
+	"fmt"
+	"strconv"
 	"strings"
 	"time"
+
+	"git.blackforestbytes.com/BlackForestBytes/goext/langext"
 )
 
 type Mode string //@enum:type
 
 const (
-	CTMStart  = "START"
-	CTMNormal = "NORMAL"
-	CTMEnd    = "END"
+	CTMStart     = "START"
+	CTMNormal    = "NORMAL"
+	CTMPaginated = "PAGINATED"
+	CTMEnd       = "END"
 )
 
 type CursorToken struct {
 	Mode       Mode
-	Timestamp  int64
+	Timestamp  *int64
+	Page       *int
 	Id         string
 	Direction  string
 	FilterHash string
@@ -34,7 +40,8 @@ type cursorTokenSerialize struct {
 func Start() CursorToken {
 	return CursorToken{
 		Mode:       CTMStart,
-		Timestamp:  0,
+		Timestamp:  langext.Ptr[int64](0),
+		Page:       nil,
 		Id:         "",
 		Direction:  "",
 		FilterHash: "",
@@ -44,7 +51,8 @@ func Start() CursorToken {
 func End() CursorToken {
 	return CursorToken{
 		Mode:       CTMEnd,
-		Timestamp:  0,
+		Timestamp:  nil,
+		Page:       nil,
 		Id:         "",
 		Direction:  "",
 		FilterHash: "",
@@ -54,13 +62,22 @@ func End() CursorToken {
 func Normal(ts time.Time, id string, dir string, filter string) CursorToken {
 	return CursorToken{
 		Mode:       CTMNormal,
-		Timestamp:  ts.UnixMilli(),
+		Timestamp:  langext.Ptr(ts.UnixMilli()),
+		Page:       nil,
 		Id:         id,
 		Direction:  dir,
 		FilterHash: filter,
 	}
 }
 
+func Paginated(p int) CursorToken {
+	return CursorToken{
+		Mode:      CTMPaginated,
+		Timestamp: nil,
+		Page:      langext.Ptr(p),
+	}
+}
+
 func (c *CursorToken) Token() string {
 	if c.Mode == CTMStart {
 		return "@start"
@@ -69,6 +86,10 @@ func (c *CursorToken) Token() string {
 		return "@end"
 	}
 
+	if c.Page != nil {
+		return fmt.Sprintf("$%d", *c.Page)
+	}
+
 	// 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
@@ -80,8 +101,8 @@ func (c *CursorToken) Token() string {
 		sertok.Id = &c.Id
 	}
 
-	if c.Timestamp != 0 {
-		sertok.Timestamp = &c.Timestamp
+	if c.Timestamp != nil && *c.Timestamp != 0 {
+		sertok.Timestamp = langext.Ptr(*c.Timestamp)
 	}
 
 	if c.Direction != "" {
@@ -111,6 +132,14 @@ func Decode(tok string) (CursorToken, error) {
 		return End(), nil
 	}
 
+	if strings.HasPrefix(tok, "$") {
+		p, err := strconv.ParseInt(tok[1:], 10, 0)
+		if err != nil {
+			return CursorToken{}, errors.New("could not decode paginated token")
+		}
+		return Paginated(int(p)), nil
+	}
+
 	if !strings.HasPrefix(tok, "tok_") {
 		return CursorToken{}, errors.New("could not decode token, missing prefix")
 	}
@@ -129,7 +158,7 @@ func Decode(tok string) (CursorToken, error) {
 	token := CursorToken{Mode: CTMNormal}
 
 	if tokenDeserialize.Timestamp != nil {
-		token.Timestamp = *tokenDeserialize.Timestamp
+		token.Timestamp = langext.Ptr(*tokenDeserialize.Timestamp)
 	}
 	if tokenDeserialize.Id != nil {
 		token.Id = *tokenDeserialize.Id

scnserver/db/impl/primary/messages.go

@@ -1,12 +1,13 @@
 package primary
 
 import (
+	"errors"
+	"time"
+
 	"blackforestbytes.com/simplecloudnotifier/db"
 	ct "blackforestbytes.com/simplecloudnotifier/db/cursortoken"
 	"blackforestbytes.com/simplecloudnotifier/models"
-	"errors"
 	"git.blackforestbytes.com/BlackForestBytes/goext/sq"
-	"time"
 )
 
 func (db *Database) GetMessageByUserMessageID(ctx db.TxContext, usrMsgId string) (*models.Message, error) {
@@ -87,26 +88,32 @@ func (db *Database) ListMessages(ctx db.TxContext, filter models.MessageFilter,
 		return nil, ct.CursorToken{}, 0, err
 	}
 
-	pageCond := "1=1"
-	if inTok.Mode == ct.CTMNormal {
-		pageCond = "timestamp_real < :tokts OR (timestamp_real = :tokts AND message_id < :tokid )"
-	}
-
 	filterCond, filterJoin, prepParams, err := filter.SQL()
 
-	orderClause := ""
+	pageCond := "1=1"
+
+	limitCond := ""
 	if pageSize != nil {
-		orderClause = "ORDER BY COALESCE(timestamp_client, timestamp_real) DESC, message_id DESC LIMIT :lim"
+		limitCond = "LIMIT :lim"
 		prepParams["lim"] = *pageSize + 1
-	} else {
-		orderClause = "ORDER BY COALESCE(timestamp_client, timestamp_real) DESC, message_id DESC"
 	}
 
-	sqlQueryList := "SELECT " + "messages.*" + " FROM messages " + filterJoin + " WHERE ( " + pageCond + " ) AND ( " + filterCond + " ) " + orderClause
-	sqlQueryCount := "SELECT " + " COUNT(*) AS count FROM messages " + filterJoin + " WHERE  ( " + filterCond + " ) "
+	if inTok.Mode == ct.CTMNormal {
+		pageCond = "timestamp_real < :tokts OR (timestamp_real = :tokts AND message_id < :tokid )"
+		prepParams["tokts"] = inTok.Timestamp
+		prepParams["tokid"] = inTok.Id
+	} else if inTok.Mode == ct.CTMPaginated {
+		if pageSize != nil {
+			limitCond = "LIMIT :lim OFFSET :off"
+			prepParams["lim"] = *pageSize + 1
+			prepParams["off"] = (*pageSize) * (*inTok.Page)
+		}
+	}
 
-	prepParams["tokts"] = inTok.Timestamp
-	prepParams["tokid"] = inTok.Id
+	orderClause := "ORDER BY COALESCE(timestamp_client, timestamp_real) DESC, message_id DESC"
+
+	sqlQueryList := "SELECT " + "messages.*" + " FROM messages " + filterJoin + " WHERE ( " + pageCond + " ) AND ( " + filterCond + " ) " + orderClause + " " + limitCond
+	sqlQueryCount := "SELECT " + " COUNT(*) AS count FROM messages " + filterJoin + " WHERE  ( " + filterCond + " ) "
 
 	if inTok.Mode == ct.CTMEnd {
 
@@ -132,7 +139,12 @@ func (db *Database) ListMessages(ctx db.TxContext, filter models.MessageFilter,
 			return nil, ct.CursorToken{}, 0, err
 		}
 
-		outToken := ct.Normal(dataList[*pageSize-1].Timestamp(), dataList[*pageSize-1].MessageID.String(), "DESC", filter.Hash())
+		var outToken ct.CursorToken
+		if inTok.Mode == ct.CTMPaginated {
+			outToken = ct.Paginated(*inTok.Page + 1)
+		} else {
+			outToken = ct.Normal(dataList[*pageSize-1].Timestamp(), dataList[*pageSize-1].MessageID.String(), "DESC", filter.Hash())
+		}
 
 		return dataList[0:*pageSize], outToken, dataCount.Count, nil
 	}

scnserver/db/impl/requests/requestlogs.go

@@ -52,14 +52,29 @@ func (db *Database) ListRequestLogs(ctx context.Context, filter models.RequestLo
 		return make([]models.RequestLog, 0), ct.End(), nil
 	}
 
-	pageCond := "1=1"
-	if inTok.Mode == ct.CTMNormal {
-		pageCond = "timestamp_created < :tokts OR (timestamp_created = :tokts AND request_id < :tokid )"
-	}
-
 	filterCond, filterJoin, prepParams, err := filter.SQL()
 
-	orderClause := ""
+	pageCond := "1=1"
+
+	limitCond := ""
+	if pageSize != nil {
+		limitCond = "LIMIT :lim"
+		prepParams["lim"] = *pageSize + 1
+	}
+
+	if inTok.Mode == ct.CTMNormal {
+		pageCond = "timestamp_created < :tokts OR (timestamp_created = :tokts AND request_id < :tokid )"
+		prepParams["tokts"] = inTok.Timestamp
+		prepParams["tokid"] = inTok.Id
+	} else if inTok.Mode == ct.CTMPaginated {
+		if pageSize != nil {
+			limitCond = "LIMIT :lim OFFSET :off"
+			prepParams["lim"] = *pageSize + 1
+			prepParams["off"] = (*pageSize) * (*inTok.Page)
+		}
+	}
+
+	orderClause := "ORDER BY timestamp_created DESC, request_id DESC"
 	if pageSize != nil {
 		orderClause = "ORDER BY timestamp_created DESC, request_id DESC LIMIT :lim"
 		prepParams["lim"] = *pageSize + 1
@@ -67,7 +82,7 @@ func (db *Database) ListRequestLogs(ctx context.Context, filter models.RequestLo
 		orderClause = "ORDER BY timestamp_created DESC, request_id DESC"
 	}
 
-	sqlQuery := "SELECT " + "requests.*" + " FROM requests " + filterJoin + " WHERE ( " + pageCond + " ) AND ( " + filterCond + " ) " + orderClause
+	sqlQuery := "SELECT " + "requests.*" + " FROM requests " + filterJoin + " WHERE ( " + pageCond + " ) AND ( " + filterCond + " ) " + orderClause + " " + limitCond
 
 	prepParams["tokts"] = inTok.Timestamp
 	prepParams["tokid"] = inTok.Id