From cb62365f5737d8c6a803b0737b3f34a64e526b6b Mon Sep 17 00:00:00 2001
From: Alexey Borzenkov <snaury@gmail.com>
Date: Mon, 28 May 2012 10:46:51 -0700
Subject: [PATCH] net/http: reuse http proxy connections for different http
 requests

Comment on cache keys above connectMethod says "http to proxy, http
anywhere after that", however in reality target address was always
included, which prevented http requests to different target
addresses to reuse the same http proxy connection.

R=golang-dev, r, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/5901064
---
 src/pkg/net/http/proxy_test.go | 30 ++++++++++++++++++++++++++++++
 src/pkg/net/http/transport.go  |  6 +++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/pkg/net/http/proxy_test.go b/src/pkg/net/http/proxy_test.go
index 9b320b3aa5..5ecffaface 100644
--- a/src/pkg/net/http/proxy_test.go
+++ b/src/pkg/net/http/proxy_test.go
@@ -5,6 +5,7 @@
 package http
 
 import (
+	"net/url"
 	"os"
 	"testing"
 )
@@ -46,3 +47,32 @@ func TestUseProxy(t *testing.T) {
 		}
 	}
 }
+
+var cacheKeysTests = []struct {
+	proxy  string
+	scheme string
+	addr   string
+	key    string
+}{
+	{"", "http", "foo.com", "|http|foo.com"},
+	{"", "https", "foo.com", "|https|foo.com"},
+	{"http://foo.com", "http", "foo.com", "http://foo.com|http|"},
+	{"http://foo.com", "https", "foo.com", "http://foo.com|https|foo.com"},
+}
+
+func TestCacheKeys(t *testing.T) {
+	for _, tt := range cacheKeysTests {
+		var proxy *url.URL
+		if tt.proxy != "" {
+			u, err := url.Parse(tt.proxy)
+			if err != nil {
+				t.Fatal(err)
+			}
+			proxy = u
+		}
+		cm := connectMethod{proxy, tt.scheme, tt.addr}
+		if cm.String() != tt.key {
+			t.Fatalf("{%q, %q, %q} cache key %q; want %q", tt.proxy, tt.scheme, tt.addr, cm.String(), tt.key)
+		}
+	}
+}
diff --git a/src/pkg/net/http/transport.go b/src/pkg/net/http/transport.go
index 483af556e4..dd514386ac 100644
--- a/src/pkg/net/http/transport.go
+++ b/src/pkg/net/http/transport.go
@@ -450,10 +450,14 @@ type connectMethod struct {
 
 func (ck *connectMethod) String() string {
 	proxyStr := ""
+	targetAddr := ck.targetAddr
 	if ck.proxyURL != nil {
 		proxyStr = ck.proxyURL.String()
+		if ck.targetScheme == "http" {
+			targetAddr = ""
+		}
 	}
-	return strings.Join([]string{proxyStr, ck.targetScheme, ck.targetAddr}, "|")
+	return strings.Join([]string{proxyStr, ck.targetScheme, targetAddr}, "|")
 }
 
 // addr returns the first hop "host:port" to which we need to TCP connect.
-- 
2.48.1