[thrift] branch master updated: go: Use sync.Pool for gzip in HTTP transport

[dc...@apache.org]

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dcelasun pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/thrift.git


The following commit(s) were added to refs/heads/master by this push:
     new 077b5fc  go: Use sync.Pool for gzip in HTTP transport
077b5fc is described below

commit 077b5fce825e79d84592fff893639b92b637eec7
Author: Duru Can Celasun <dc...@apache.org>
AuthorDate: Wed Sep 30 07:25:51 2020 +0100

    go: Use sync.Pool for gzip in HTTP transport
    
    b67cad4 introduced transparent gzip support for the HTTP transport but
    calling gzip.NewWriter() with every request causes a large number of
    memory allocations [1] and can create GC pressure.
    
    Avoid this by using a sync.Pool for gzip writers.
    
    [1] https://old.reddit.com/r/golang/comments/9uejp4/usage_of_syncpool_for_gzipwriter_in_http_handlers/e94jh8c/
---
 lib/go/thrift/http_transport.go | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/go/thrift/http_transport.go b/lib/go/thrift/http_transport.go
index 66f0f38..bc69227 100644
--- a/lib/go/thrift/http_transport.go
+++ b/lib/go/thrift/http_transport.go
@@ -24,6 +24,7 @@ import (
 	"io"
 	"net/http"
 	"strings"
+	"sync"
 )
 
 // NewThriftHandlerFunc is a function that create a ready to use Apache Thrift Handler function
@@ -40,14 +41,24 @@ func NewThriftHandlerFunc(processor TProcessor,
 
 // gz transparently compresses the HTTP response if the client supports it.
 func gz(handler http.HandlerFunc) http.HandlerFunc {
+	sp := &sync.Pool{
+		New: func() interface{} {
+			return gzip.NewWriter(nil)
+		},
+	}
+
 	return func(w http.ResponseWriter, r *http.Request) {
 		if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
 			handler(w, r)
 			return
 		}
 		w.Header().Set("Content-Encoding", "gzip")
-		gz := gzip.NewWriter(w)
-		defer gz.Close()
+		gz := sp.Get().(*gzip.Writer)
+		gz.Reset(w)
+		defer func() {
+			_ = gz.Close()
+			sp.Put(gz)
+		}()
 		gzw := gzipResponseWriter{Writer: gz, ResponseWriter: w}
 		handler(gzw, r)
 	}