From 9f55dea1620b3a61c811c00d9616d144f737b4b0 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Fri, 5 Jun 2020 21:37:10 +0300
Subject: [PATCH] lib/httpserver: do not flush and do not close gzip writer if
 response compression is disabled

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/535
---
 lib/httpserver/httpserver.go | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/httpserver/httpserver.go b/lib/httpserver/httpserver.go
index 3ee057d28..c4930c809 100644
--- a/lib/httpserver/httpserver.go
+++ b/lib/httpserver/httpserver.go
@@ -336,11 +336,13 @@ func (zrw *gzipResponseWriter) writeHeader() {
 
 // Implements http.Flusher
 func (zrw *gzipResponseWriter) Flush() {
-	if err := zrw.bw.Flush(); err != nil && !isTrivialNetworkError(err) {
-		logger.Warnf("gzipResponseWriter.Flush (buffer): %s", err)
-	}
-	if err := zrw.zw.Flush(); err != nil && !isTrivialNetworkError(err) {
-		logger.Warnf("gzipResponseWriter.Flush (gzip): %s", err)
+	if !zrw.disableCompression {
+		if err := zrw.bw.Flush(); err != nil && !isTrivialNetworkError(err) {
+			logger.Warnf("gzipResponseWriter.Flush (buffer): %s", err)
+		}
+		if err := zrw.zw.Flush(); err != nil && !isTrivialNetworkError(err) {
+			logger.Warnf("gzipResponseWriter.Flush (gzip): %s", err)
+		}
 	}
 	if fw, ok := zrw.ResponseWriter.(http.Flusher); ok {
 		fw.Flush()
@@ -353,7 +355,10 @@ func (zrw *gzipResponseWriter) Close() error {
 		return nil
 	}
 	zrw.Flush()
-	err := zrw.zw.Close()
+	var err error
+	if !zrw.disableCompression {
+		err = zrw.zw.Close()
+	}
 	putGzipWriter(zrw.zw)
 	zrw.zw = nil
 	putBufioWriter(zrw.bw)