Merge pull request #1640 from imxyb/feature/opt-split

Use IndexAny instead of Split to reduce memory allocation

Author: lammel

context.go

@@ -276,7 +276,11 @@ func (c *context) RealIP() string {
 	}
 	// Fall back to legacy behavior
 	if ip := c.request.Header.Get(HeaderXForwardedFor); ip != "" {
-		return strings.Split(ip, ", ")[0]
+		i := strings.IndexAny(ip, ", ")
+		if i > 0 {
+			return ip[:i]
+		}
+		return ip
 	}
 	if ip := c.request.Header.Get(HeaderXRealIP); ip != "" {
 		return ip

context_test.go

@@ -72,6 +72,15 @@ func BenchmarkAllocXML(b *testing.B) {
 	}
 }
 
+func BenchmarkRealIPForHeaderXForwardFor(b *testing.B) {
+	c := context{request: &http.Request{
+		Header: http.Header{HeaderXForwardedFor: []string{"127.0.0.1, 127.0.1.1, "}},
+	}}
+	for i := 0; i < b.N; i++ {
+		c.RealIP()
+	}
+}
+
 func (t *Template) Render(w io.Writer, name string, data interface{}, c Context) error {
 	return t.templates.ExecuteTemplate(w, name, data)
 }
@@ -847,6 +856,14 @@ func TestContext_RealIP(t *testing.T) {
 			},
 			"127.0.0.1",
 		},
+		{
+			&context{
+				request: &http.Request{
+					Header: http.Header{HeaderXForwardedFor: []string{"127.0.0.1"}},
+				},
+			},
+			"127.0.0.1",
+		},
 		{
 			&context{
 				request: &http.Request{