🧹 chore: Use sync.Pool for form and multipart binding

binder/form.go

@@ -2,13 +2,27 @@ package binder
 
 import (
 	"mime/multipart"
+	"sync"
 
 	"github.com/gofiber/utils/v2"
 	"github.com/valyala/fasthttp"
 )
 
 const MIMEMultipartForm string = "multipart/form-data"
 
+var (
+	formMapPool = sync.Pool{
+		New: func() any {
+			return make(map[string][]string)
+		},
+	}
+	formFileMapPool = sync.Pool{
+		New: func() any {
+			return make(map[string][]*multipart.FileHeader)
+		},
+	}
+)
+
 // FormBinding is the form binder for form request body.
 type FormBinding struct {
 	EnableSplitting bool
@@ -21,13 +35,14 @@ func (*FormBinding) Name() string {
 
 // Bind parses the request body and returns the result.
 func (b *FormBinding) Bind(req *fasthttp.Request, out any) error {
-	data := make(map[string][]string)
-
 	// Handle multipart form
 	if FilterFlags(utils.UnsafeString(req.Header.ContentType())) == MIMEMultipartForm {
 		return b.bindMultipart(req, out)
 	}
 
+	data := acquireFormMap()
+	defer releaseFormMap(data)
+
 	for key, val := range req.PostArgs().All() {
 		k := utils.UnsafeString(key)
 		v := utils.UnsafeString(val)
@@ -46,15 +61,19 @@ func (b *FormBinding) bindMultipart(req *fasthttp.Request, out any) error {
 		return err
 	}
 
-	data := make(map[string][]string)
+	data := acquireFormMap()
+	defer releaseFormMap(data)
+
 	for key, values := range multipartForm.Value {
 		err = formatBindData(b.Name(), out, data, key, values, b.EnableSplitting, true)
 		if err != nil {
 			return err
 		}
 	}
 
-	files := make(map[string][]*multipart.FileHeader)
+	files := acquireFileHeaderMap()
+	defer releaseFileHeaderMap(files)
+
 	for key, values := range multipartForm.File {
 		err = formatBindData(b.Name(), out, files, key, values, b.EnableSplitting, true)
 		if err != nil {
@@ -69,3 +88,37 @@ func (b *FormBinding) bindMultipart(req *fasthttp.Request, out any) error {
 func (b *FormBinding) Reset() {
 	b.EnableSplitting = false
 }
+
+func acquireFormMap() map[string][]string {
+	m, ok := formMapPool.Get().(map[string][]string)
+	if !ok {
+		m = make(map[string][]string)
+	}
+	return m
+}
+
+func releaseFormMap(m map[string][]string) {
+	clearFormMap(m)
+	formMapPool.Put(m)
+}
+
+func acquireFileHeaderMap() map[string][]*multipart.FileHeader {
+	m, ok := formFileMapPool.Get().(map[string][]*multipart.FileHeader)
+	if !ok {
+		m = make(map[string][]*multipart.FileHeader)
+	}
+	return m
+}
+
+func releaseFileHeaderMap(m map[string][]*multipart.FileHeader) {
+	clearFileHeaderMap(m)
+	formFileMapPool.Put(m)
+}
+
+func clearFormMap(m map[string][]string) {
+	clear(m)
+}
+
+func clearFileHeaderMap(m map[string][]*multipart.FileHeader) {
+	clear(m)
+}

binder/form_test.go

@@ -238,6 +238,89 @@ func Test_FormBinder_BindMultipart_FileError(t *testing.T) {
 	require.Contains(t, err.Error(), "unmatched brackets")
 }
 
+func Test_FormBinder_Bind_MapClearedBetweenRequests(t *testing.T) {
+	t.Parallel()
+
+	b := &FormBinding{}
+
+	type payload struct {
+		Name string `form:"name"`
+		Age  int    `form:"age"`
+	}
+
+	firstReq := fasthttp.AcquireRequest()
+	firstReq.SetBodyString("name=john&age=21")
+	firstReq.Header.SetContentType("application/x-www-form-urlencoded")
+	t.Cleanup(func() { fasthttp.ReleaseRequest(firstReq) })
+
+	var first payload
+	require.NoError(t, b.Bind(firstReq, &first))
+	require.Equal(t, "john", first.Name)
+	require.Equal(t, 21, first.Age)
+
+	secondReq := fasthttp.AcquireRequest()
+	secondReq.SetBodyString("age=42")
+	secondReq.Header.SetContentType("application/x-www-form-urlencoded")
+	t.Cleanup(func() { fasthttp.ReleaseRequest(secondReq) })
+
+	var second payload
+	require.NoError(t, b.Bind(secondReq, &second))
+	require.Empty(t, second.Name)
+	require.Equal(t, 42, second.Age)
+}
+
+func Test_FormBinder_BindMultipart_MapsClearedBetweenRequests(t *testing.T) {
+	t.Parallel()
+
+	b := &FormBinding{}
+
+	type payload struct { // betteralign:ignore - test payload prioritizes readability over alignment
+		Avatar *multipart.FileHeader `form:"avatar"`
+		Name   string                `form:"name"`
+		Age    int                   `form:"age"`
+	}
+
+	firstReq := fasthttp.AcquireRequest()
+	firstBuffer := &bytes.Buffer{}
+	firstWriter := multipart.NewWriter(firstBuffer)
+
+	require.NoError(t, firstWriter.WriteField("name", "john"))
+	require.NoError(t, firstWriter.WriteField("age", "21"))
+
+	firstFile, err := firstWriter.CreateFormFile("avatar", "avatar.txt")
+	require.NoError(t, err)
+	_, err = firstFile.Write([]byte("avatar-content"))
+	require.NoError(t, err)
+	require.NoError(t, firstWriter.Close())
+
+	firstReq.Header.SetContentType(firstWriter.FormDataContentType())
+	firstReq.SetBody(firstBuffer.Bytes())
+	t.Cleanup(func() { fasthttp.ReleaseRequest(firstReq) })
+
+	var first payload
+	require.NoError(t, b.Bind(firstReq, &first))
+	require.Equal(t, "john", first.Name)
+	require.Equal(t, 21, first.Age)
+	require.NotNil(t, first.Avatar)
+	require.Equal(t, "avatar.txt", first.Avatar.Filename)
+
+	secondReq := fasthttp.AcquireRequest()
+	secondBuffer := &bytes.Buffer{}
+	secondWriter := multipart.NewWriter(secondBuffer)
+	require.NoError(t, secondWriter.WriteField("age", "42"))
+	require.NoError(t, secondWriter.Close())
+
+	secondReq.Header.SetContentType(secondWriter.FormDataContentType())
+	secondReq.SetBody(secondBuffer.Bytes())
+	t.Cleanup(func() { fasthttp.ReleaseRequest(secondReq) })
+
+	var second payload
+	require.NoError(t, b.Bind(secondReq, &second))
+	require.Empty(t, second.Name)
+	require.Equal(t, 42, second.Age)
+	require.Nil(t, second.Avatar)
+}
+
 func Benchmark_FormBinder_BindMultipart(b *testing.B) {
 	b.ReportAllocs()