httpクライアントBodyの読み残し問題

main.go

package main

import (
	"crypto/tls"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"time"
)

func withDrain(client *http.Client, url string) interface{} {
	resp, err := client.Get(url)
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		io.Copy(ioutil.Discard, resp.Body)
		resp.Body.Close()
	}()
	fmt.Println(url, resp.Status)
	var v interface{}
	if err := json.NewDecoder(resp.Body).Decode(&v); err != nil {
		log.Fatal(err)
	}
	return v
}

func withoutDrain(client *http.Client, url string) interface{} {
	resp, err := client.Get(url)
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		resp.Body.Close()
	}()
	fmt.Println(url, resp.Status)
	var v interface{}
	if err := json.NewDecoder(resp.Body).Decode(&v); err != nil {
		log.Fatal(err)
	}
	return v
}

func run(url string) {
	client := &http.Client{
		CheckRedirect: func(req *http.Request, via []*http.Request) error {
			log.Println(via)
			return nil
		},
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		},
	}
	for i := 0; i < 2; i++ {
		begin := time.Now()
		withDrain(client, url)
		fmt.Println("with-dorain:", i+1, time.Since(begin))
	}
	client = &http.Client{
		CheckRedirect: func(req *http.Request, via []*http.Request) error {
			log.Println(via)
			return nil
		},
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
		},
	}
	for i := 0; i < 2; i++ {
		begin := time.Now()
		withoutDrain(client, url)
		fmt.Println("without-dorain:", i+1, time.Since(begin))
	}
}

func main() {
	run("https://api.github.com/repos/nobonobo/jsonrpc")
}

それで https://go-review.googlesource.com/#/c/21290/ このパッチというわけか。

そして上記は取りやめになって https://go-review.googlesource.com/#/c/21291/3/src/net/http/transport.go httpのtransportが修正・マージされましたと。

結果は golang/go@18072ad これ。