Adding sync.Pool to Decompress middleware

middleware/compress.go

@@ -59,7 +59,7 @@ func GzipWithConfig(config GzipConfig) echo.MiddlewareFunc {
 		config.Level = DefaultGzipConfig.Level
 	}
 
-	pool := gzipPool(config)
+	pool := gzipCompressPool(config)
 
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
@@ -133,7 +133,7 @@ func (w *gzipResponseWriter) Push(target string, opts *http.PushOptions) error {
 	return http.ErrNotSupported
 }
 
-func gzipPool(config GzipConfig) sync.Pool {
+func gzipCompressPool(config GzipConfig) sync.Pool {
 	return sync.Pool{
 		New: func() interface{} {
 			w, err := gzip.NewWriterLevel(ioutil.Discard, config.Level)

middleware/decompress.go

@@ -3,53 +3,115 @@ package middleware
 import (
 	"bytes"
 	"compress/gzip"
-	"github.com/labstack/echo/v4"
 	"io"
 	"io/ioutil"
+	"net/http"
+	"sync"
+
+	"github.com/labstack/echo/v4"
 )
 
 type (
 	// DecompressConfig defines the config for Decompress middleware.
 	DecompressConfig struct {
 		// Skipper defines a function to skip middleware.
 		Skipper Skipper
+
+		// GzipDecompressPool defines an interface to provide the sync.Pool used to create/store Gzip readers
+		GzipDecompressPool Decompressor
 	}
 )
 
 //GZIPEncoding content-encoding header if set to "gzip", decompress body contents.
 const GZIPEncoding string = "gzip"
 
+// Decompressor is used to get the sync.Pool used by the middleware to get Gzip readers
+type Decompressor interface {
+	gzipDecompressPool() sync.Pool
+}
+
 var (
 	//DefaultDecompressConfig defines the config for decompress middleware
-	DefaultDecompressConfig = DecompressConfig{Skipper: DefaultSkipper}
+	DefaultDecompressConfig = DecompressConfig{
+		Skipper:            DefaultSkipper,
+		GzipDecompressPool: &DefaultGzipDecompressPool{},
+	}
 )
 
+// DefaultGzipDecompressPool is the default implementation of Decompressor interface
+type DefaultGzipDecompressPool struct {
+}
+
+func (d *DefaultGzipDecompressPool) gzipDecompressPool() sync.Pool {
+	return sync.Pool{
+		New: func() interface{} {
+			// create with an empty reader (but with GZIP header)
+			w, err := gzip.NewWriterLevel(ioutil.Discard, gzip.BestSpeed)
+			if err != nil {
+				return err
+			}
+
+			b := new(bytes.Buffer)
+			w.Reset(b)
+			w.Flush()
+			w.Close()
+
+			r, err := gzip.NewReader(bytes.NewReader(b.Bytes()))
+			if err != nil {
+				return err
+			}
+			return r
+		},
+	}
+}
+
 //Decompress decompresses request body based if content encoding type is set to "gzip" with default config
 func Decompress() echo.MiddlewareFunc {
 	return DecompressWithConfig(DefaultDecompressConfig)
 }
 
 //DecompressWithConfig decompresses request body based if content encoding type is set to "gzip" with config
 func DecompressWithConfig(config DecompressConfig) echo.MiddlewareFunc {
+	// Defaults
+	if config.Skipper == nil {
+		config.Skipper = DefaultGzipConfig.Skipper
+	}
+	if config.GzipDecompressPool == nil {
+		config.GzipDecompressPool = DefaultDecompressConfig.GzipDecompressPool
+	}
+
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		pool := config.GzipDecompressPool.gzipDecompressPool()
 		return func(c echo.Context) error {
 			if config.Skipper(c) {
 				return next(c)
 			}
 			switch c.Request().Header.Get(echo.HeaderContentEncoding) {
 			case GZIPEncoding:
-				gr, err := gzip.NewReader(c.Request().Body)
-				if err != nil {
+				b := c.Request().Body
+
+				i := pool.Get()
+				gr, ok := i.(*gzip.Reader)
+				if !ok {
+					return echo.NewHTTPError(http.StatusInternalServerError, i.(error).Error())
+				}
+
+				if err := gr.Reset(b); err != nil {
+					pool.Put(gr)
 					if err == io.EOF { //ignore if body is empty
 						return next(c)
 					}
 					return err
 				}
-				defer gr.Close()
 				var buf bytes.Buffer
 				io.Copy(&buf, gr)
+
+				gr.Close()
+				pool.Put(gr)
+
+				b.Close() // http.Request.Body is closed by the Server, but because we are replacing it, it must be closed here
+
 				r := ioutil.NopCloser(&buf)
-				defer r.Close()
 				c.Request().Body = r
 			}
 			return next(c)

middleware/decompress_test.go

@@ -3,10 +3,12 @@ package middleware
 import (
 	"bytes"
 	"compress/gzip"
+	"errors"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"strings"
+	"sync"
 	"testing"
 
 	"github.com/labstack/echo/v4"
@@ -43,6 +45,35 @@ func TestDecompress(t *testing.T) {
 	assert.Equal(body, string(b))
 }
 
+func TestDecompressDefaultConfig(t *testing.T) {
+	e := echo.New()
+	req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader("test"))
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+
+	h := DecompressWithConfig(DecompressConfig{})(func(c echo.Context) error {
+		c.Response().Write([]byte("test")) // For Content-Type sniffing
+		return nil
+	})
+	h(c)
+
+	assert := assert.New(t)
+	assert.Equal("test", rec.Body.String())
+
+	// Decompress
+	body := `{"name": "echo"}`
+	gz, _ := gzipString(body)
+	req = httptest.NewRequest(http.MethodPost, "/", strings.NewReader(string(gz)))
+	req.Header.Set(echo.HeaderContentEncoding, GZIPEncoding)
+	rec = httptest.NewRecorder()
+	c = e.NewContext(req, rec)
+	h(c)
+	assert.Equal(GZIPEncoding, req.Header.Get(echo.HeaderContentEncoding))
+	b, err := ioutil.ReadAll(req.Body)
+	assert.NoError(err)
+	assert.Equal(body, string(b))
+}
+
 func TestCompressRequestWithoutDecompressMiddleware(t *testing.T) {
 	e := echo.New()
 	body := `{"name":"echo"}`
@@ -108,6 +139,36 @@ func TestDecompressSkipper(t *testing.T) {
 	assert.Equal(t, body, string(reqBody))
 }
 
+type TestDecompressPoolWithError struct {
+}
+
+func (d *TestDecompressPoolWithError) gzipDecompressPool() sync.Pool {
+	return sync.Pool{
+		New: func() interface{} {
+			return errors.New("pool error")
+		},
+	}
+}
+
+func TestDecompressPoolError(t *testing.T) {
+	e := echo.New()
+	e.Use(DecompressWithConfig(DecompressConfig{
+		Skipper:            DefaultSkipper,
+		GzipDecompressPool: &TestDecompressPoolWithError{},
+	}))
+	body := `{"name": "echo"}`
+	req := httptest.NewRequest(http.MethodPost, "/echo", strings.NewReader(body))
+	req.Header.Set(echo.HeaderContentEncoding, GZIPEncoding)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+	e.ServeHTTP(rec, req)
+	assert.Equal(t, GZIPEncoding, req.Header.Get(echo.HeaderContentEncoding))
+	reqBody, err := ioutil.ReadAll(c.Request().Body)
+	assert.NoError(t, err)
+	assert.Equal(t, body, string(reqBody))
+	assert.Equal(t, rec.Code, http.StatusInternalServerError)
+}
+
 func BenchmarkDecompress(b *testing.B) {
 	e := echo.New()
 	body := `{"name": "echo"}`