From 4f3335aac752ce779d8485299d187e23f75ae11a Mon Sep 17 00:00:00 2001
From: Tyler Bunnell <tylerbunnell@gmail.com>
Date: Fri, 11 Sep 2015 16:23:57 -0600
Subject: [PATCH] Add sync.Pool to gzip middleware

---
 middleware/compress.go      | 16 ++++++++++++++--
 middleware/compress_test.go | 22 ++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/middleware/compress.go b/middleware/compress.go
index eba2c7c4..8c009555 100644
--- a/middleware/compress.go
+++ b/middleware/compress.go
@@ -4,9 +4,11 @@ import (
 	"bufio"
 	"compress/gzip"
 	"io"
+	"io/ioutil"
 	"net"
 	"net/http"
 	"strings"
+	"sync"
 
 	"github.com/labstack/echo"
 )
@@ -37,6 +39,12 @@ func (w *gzipWriter) CloseNotify() <-chan bool {
 	return w.ResponseWriter.(http.CloseNotifier).CloseNotify()
 }
 
+var writerPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(ioutil.Discard)
+	},
+}
+
 // Gzip returns a middleware which compresses HTTP response using gzip compression
 // scheme.
 func Gzip() echo.MiddlewareFunc {
@@ -46,8 +54,12 @@ func Gzip() echo.MiddlewareFunc {
 		return func(c *echo.Context) error {
 			c.Response().Header().Add(echo.Vary, echo.AcceptEncoding)
 			if strings.Contains(c.Request().Header.Get(echo.AcceptEncoding), scheme) {
-				w := gzip.NewWriter(c.Response().Writer())
-				defer w.Close()
+				w := writerPool.Get().(*gzip.Writer)
+				w.Reset(c.Response().Writer())
+				defer func() {
+					w.Close()
+					writerPool.Put(w)
+				}()
 				gw := gzipWriter{Writer: w, ResponseWriter: c.Response().Writer()}
 				c.Response().Header().Set(echo.ContentEncoding, scheme)
 				c.Response().SetWriter(gw)
diff --git a/middleware/compress_test.go b/middleware/compress_test.go
index 85cc9ca2..fc727068 100644
--- a/middleware/compress_test.go
+++ b/middleware/compress_test.go
@@ -119,3 +119,25 @@ func TestGzipCloseNotify(t *testing.T) {
 
 	assert.Equal(t, closed, true)
 }
+
+func BenchmarkGzip(b *testing.B) {
+
+	b.StopTimer()
+	b.ReportAllocs()
+
+	h := func(c *echo.Context) error {
+		c.Response().Write([]byte("test")) // For Content-Type sniffing
+		return nil
+	}
+	req, _ := http.NewRequest(echo.GET, "/", nil)
+	req.Header.Set(echo.AcceptEncoding, "gzip")
+
+	b.StartTimer()
+
+	for i := 0; i < b.N; i++ {
+		rec := httptest.NewRecorder()
+		c := echo.NewContext(req, echo.NewResponse(rec), echo.New())
+		Gzip()(h)(c)
+	}
+
+}