Merge pull request #3 from remerge/CbBmFu37/69-race-condition-in-reme…

…rge-gzip-causing-bidder-to-crash

Return gzip writer back to pool when everything is flushed only

go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/ugorji/go/codec v1.1.7 // indirect
 	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 // indirect
-	golang.org/x/sys v0.0.0-20200116001909-b77594299b42 // indirect
+	golang.org/x/sys v0.0.0-20221010170243-090e33056c14 // indirect
 	gopkg.in/yaml.v2 v2.2.8 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
 )

go.sum

@@ -46,6 +46,8 @@ golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42 h1:vEOn+mP2zCOVzKckCZy6YsCtDblrpj/w7B9nxGNELpg=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20221010170243-090e33056c14 h1:k5II8e6QD8mITdi+okbbmR/cIyEbeXLBhy5Ha4nevyc=
+golang.org/x/sys v0.0.0-20221010170243-090e33056c14/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

handler.go

@@ -6,29 +6,20 @@ import (
 	"net/http"
 	"path/filepath"
 	"strings"
-	"sync"
 
 	"github.com/gin-gonic/gin"
 	"github.com/klauspost/compress/gzip"
 )
 
 type gzipHandler struct {
 	*Options
-	gzPool sync.Pool
+	gzipLevel int
 }
 
 func newGzipHandler(level int, options ...Option) *gzipHandler {
 	handler := &gzipHandler{
-		Options: DefaultOptions,
-		gzPool: sync.Pool{
-			New: func() interface{} {
-				gz, err := gzip.NewWriterLevel(ioutil.Discard, level)
-				if err != nil {
-					panic(err)
-				}
-				return gz
-			},
-		},
+		Options:   DefaultOptions,
+		gzipLevel: level,
 	}
 	for _, setter := range options {
 		setter(handler.Options)
@@ -45,14 +36,13 @@ func (g *gzipHandler) Handle(c *gin.Context) {
 		return
 	}
 
-	gz := g.gzPool.Get().(*gzip.Writer)
-	defer g.gzPool.Put(gz)
-	defer gz.Reset(ioutil.Discard)
+	gz := g.mustNewGzipWriter()
 	gz.Reset(c.Writer)
 
 	c.Header("Content-Encoding", "gzip")
 	c.Header("Vary", "Accept-Encoding")
-	c.Writer = &gzipWriter{c.Writer, gz}
+	c.Writer = &gzipWriter{ResponseWriter: c.Writer, writer: gz}
+
 	defer func() {
 		gz.Close()
 		c.Header("Content-Length", fmt.Sprint(c.Writer.Size()))
@@ -82,3 +72,11 @@ func (g *gzipHandler) isPathExcluded(path string) bool {
 		g.ExcludedPaths.Contains(path) ||
 		g.ExcludedPathesRegexs.Contains(path)
 }
+
+func (g *gzipHandler) mustNewGzipWriter() *gzip.Writer {
+	gz, err := gzip.NewWriterLevel(ioutil.Discard, g.gzipLevel)
+	if err != nil {
+		panic(err)
+	}
+	return gz
+}