Reuse compression writers

pkg/middlewares/compress/compress_test.go

@@ -670,39 +670,32 @@ func Test1xxResponses(t *testing.T) {
 	assert.NotEqualValues(t, body, fakeBody)
 }
 
-func BenchmarkCompress(b *testing.B) {
+func BenchmarkCompressGzip(b *testing.B) {
+	runCompressionBenchmark(b, gzipName)
+}
+
+func BenchmarkCompressBrotli(b *testing.B) {
+	runCompressionBenchmark(b, brotliName)
+}
+
+func BenchmarkCompressZstandard(b *testing.B) {
+	runCompressionBenchmark(b, zstdName)
+}
+
+func runCompressionBenchmark(b *testing.B, algorithm string) {
+	b.Helper()
+
 	testCases := []struct {
 		name     string
 		parallel bool
 		size     int
 	}{
-		{
-			name: "2k",
-			size: 2048,
-		},
-		{
-			name: "20k",
-			size: 20480,
-		},
-		{
-			name: "100k",
-			size: 102400,
-		},
-		{
-			name:     "2k parallel",
-			parallel: true,
-			size:     2048,
-		},
-		{
-			name:     "20k parallel",
-			parallel: true,
-			size:     20480,
-		},
-		{
-			name:     "100k parallel",
-			parallel: true,
-			size:     102400,
-		},
+		{"2k", false, 2048},
+		{"20k", false, 20480},
+		{"100k", false, 102400},
+		{"2k parallel", true, 2048},
+		{"20k parallel", true, 20480},
+		{"100k parallel", true, 102400},
 	}
 
 	for _, test := range testCases {
@@ -716,7 +709,7 @@ func BenchmarkCompress(b *testing.B) {
 			handler, _ := New(context.Background(), next, dynamic.Compress{}, "testing")
 
 			req, _ := http.NewRequest(http.MethodGet, "/whatever", nil)
-			req.Header.Set("Accept-Encoding", "gzip")
+			req.Header.Set("Accept-Encoding", algorithm)
 
 			b.ReportAllocs()
 			b.SetBytes(int64(test.size))
@@ -724,7 +717,7 @@ func BenchmarkCompress(b *testing.B) {
 				b.ResetTimer()
 				b.RunParallel(func(pb *testing.PB) {
 					for pb.Next() {
-						runBenchmark(b, req, handler)
+						runBenchmark(b, req, handler, algorithm)
 					}
 				})
 				return
@@ -732,13 +725,13 @@ func BenchmarkCompress(b *testing.B) {
 
 			b.ResetTimer()
 			for range b.N {
-				runBenchmark(b, req, handler)
+				runBenchmark(b, req, handler, algorithm)
 			}
 		})
 	}
 }
 
-func runBenchmark(b *testing.B, req *http.Request, handler http.Handler) {
+func runBenchmark(b *testing.B, req *http.Request, handler http.Handler, algorithm string) {
 	b.Helper()
 
 	res := httptest.NewRecorder()
@@ -747,7 +740,7 @@ func runBenchmark(b *testing.B, req *http.Request, handler http.Handler) {
 		b.Fatalf("Expected 200 but got %d", code)
 	}
 
-	assert.Equal(b, gzipName, res.Header().Get(contentEncodingHeader))
+	assert.Equal(b, algorithm, res.Header().Get(contentEncodingHeader))
 }
 
 func generateBytes(length int) []byte {

pkg/middlewares/compress/compression_handler.go

@@ -8,6 +8,7 @@ import (
 	"mime"
 	"net"
 	"net/http"
+	"sync"
 
 	"github.com/andybalholm/brotli"
 	"github.com/klauspost/compress/zstd"
@@ -45,6 +46,7 @@ type CompressionHandler struct {
 	excludedContentTypes []parsedContentType
 	includedContentTypes []parsedContentType
 	next                 http.Handler
+	writerPool           sync.Pool
 }
 
 // NewCompressionHandler returns a new compressing handler.
@@ -92,7 +94,7 @@ func NewCompressionHandler(cfg Config, next http.Handler) (http.Handler, error)
 func (c *CompressionHandler) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
 	rw.Header().Add(vary, acceptEncoding)
 
-	compressionWriter, err := newCompressionWriter(c.cfg.Algorithm, rw)
+	compressionWriter, err := c.getCompressionWriter(rw)
 	if err != nil {
 		logger := middlewares.GetLogger(r.Context(), c.cfg.MiddlewareName, typeName)
 		logger.Debug().Msgf("Create compression handler: %v", err)
@@ -100,6 +102,7 @@ func (c *CompressionHandler) ServeHTTP(rw http.ResponseWriter, r *http.Request)
 		rw.WriteHeader(http.StatusInternalServerError)
 		return
 	}
+	defer c.putCompressionWriter(compressionWriter)
 
 	responseWriter := &responseWriter{
 		rw:                   rw,
@@ -130,6 +133,8 @@ type compression interface {
 	// as it would otherwise send some extra "end of compression" bytes.
 	// Close also makes sure to flush whatever was left to write from the buffer.
 	Close() error
+	// Reset reinitializes the state of the encoder, allowing it to be reused.
+	Reset(w io.Writer)
 }
 
 type compressionWriter struct {
@@ -137,6 +142,19 @@ type compressionWriter struct {
 	alg string
 }
 
+func (c *CompressionHandler) getCompressionWriter(rw io.Writer) (*compressionWriter, error) {
+	if writer, ok := c.writerPool.Get().(*compressionWriter); ok {
+		writer.compression.Reset(rw)
+		return writer, nil
+	}
+	return newCompressionWriter(c.cfg.Algorithm, rw)
+}
+
+func (c *CompressionHandler) putCompressionWriter(writer *compressionWriter) {
+	writer.Reset(nil)
+	c.writerPool.Put(writer)
+}
+
 func newCompressionWriter(algo string, in io.Writer) (*compressionWriter, error) {
 	switch algo {
 	case brotliName: