net/http: use copyBufPool in transferWriter.doBodyCopy()

This is a followup to CL 14177. It applies copyBufPool optimization to transferWriter.doBodyCopy(). The function is used every time Request or Response is written. Without this patch for every Request and Response processed, if there is a body, we need to allocate and GC a 32k buffer. This is quickly causing GC pressure. Fixes #57202 Change-Id: I4c30e1737726ac8d9937846106efd02effbae300 GitHub-Last-Rev: 908573c GitHub-Pull-Request: #57205 Reviewed-on: https://go-review.googlesource.com/c/go/+/456435 Reviewed-by: Damien Neil <[email protected]> Reviewed-by: Bryan Mills <[email protected]> TryBot-Result: Gopher Robot <[email protected]> LUCI-TryBot-Result: Go LUCI <[email protected]> Reviewed-by: qiulaidongfeng <[email protected]>
golang · Nov 9, 2023 · 96eeb45 · 96eeb45
1 parent 3128aee
commit 96eeb45
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/src/net/http/transfer.go b/src/net/http/transfer.go
@@ -410,7 +410,11 @@ func (t *transferWriter) writeBody(w io.Writer) (err error) {
 //
 // This function is only intended for use in writeBody.
 func (t *transferWriter) doBodyCopy(dst io.Writer, src io.Reader) (n int64, err error) {
-	n, err = io.Copy(dst, src)
+	bufp := copyBufPool.Get().(*[]byte)
+	buf := *bufp
+	defer copyBufPool.Put(bufp)
+
+	n, err = io.CopyBuffer(dst, src, buf)
 	if err != nil && err != io.EOF {
 		t.bodyReadError = err
 	}