Use multiple DB connections but retry failed requests

server/common/ginresp/wrapper.go

@@ -1,25 +1,80 @@
 package ginresp
 
-import "github.com/gin-gonic/gin"
+import (
+	scn "blackforestbytes.com/simplecloudnotifier"
+	"github.com/gin-gonic/gin"
+	"github.com/mattn/go-sqlite3"
+	"github.com/rs/zerolog/log"
+	"gogs.mikescher.com/BlackForestBytes/goext/dataext"
+	"time"
+)
 
 type WHandlerFunc func(*gin.Context) HTTPResponse
 
 func Wrap(fn WHandlerFunc) gin.HandlerFunc {
 
+	maxRetry := scn.Conf.RequestMaxRetry
+	retrySleep := scn.Conf.RequestRetrySleep
+
 	return func(g *gin.Context) {
 
 		reqctx := g.Request.Context()
 
-		wrap := fn(g)
-
-		if g.Writer.Written() {
-			panic("Writing in WrapperFunc is not supported")
+		if g.Request.Body != nil {
+			g.Request.Body = dataext.NewBufferedReadCloser(g.Request.Body)
 		}
 
-		if reqctx.Err() == nil {
-			wrap.Write(g)
+		for ctr := 1; ; ctr++ {
+
+			wrap := fn(g)
+
+			if g.Writer.Written() {
+				panic("Writing in WrapperFunc is not supported")
+			}
+
+			if ctr < maxRetry && isSqlite3Busy(wrap) {
+				log.Warn().Int("counter", ctr).Str("url", g.Request.URL.String()).Msg("Retry request (ErrBusy)")
+
+				err := resetBody(g)
+				if err != nil {
+					panic(err)
+				}
+
+				time.Sleep(retrySleep)
+				continue
+			}
+
+			if reqctx.Err() == nil {
+				wrap.Write(g)
+			}
+
+			return
 		}
 
 	}
 
 }
+
+func resetBody(g *gin.Context) error {
+	if g.Request.Body == nil {
+		return nil
+	}
+
+	err := g.Request.Body.(dataext.BufferedReadCloser).Reset()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func isSqlite3Busy(r HTTPResponse) bool {
+	if errwrap, ok := r.(*errorHTTPResponse); ok && errwrap != nil {
+		if s3err, ok := (errwrap.error).(sqlite3.Error); ok {
+			if s3err.Code == sqlite3.ErrBusy {
+				return true
+			}
+		}
+	}
+	return false
+}