Go:CloseNotify, Timeout example

main.go

package main

import (
	"fmt"
	"log"
	"net/http"
	"time"
)

func outln(w http.ResponseWriter, mes string) {
	w.Write([]byte(mes))
	w.Write([]byte("\n"))
	w.(http.Flusher).Flush()
	log.Println(mes)
}

func handler(w http.ResponseWriter, r *http.Request) {

	// Transfer-Encoding: chunked
	w.WriteHeader(http.StatusOK)

	outln(w, "start")

	// for over
	times := 5
	// for TimeOut
	//times := 10

	// メッセージを送る人
	ch := make(chan string)
	go func() {
		for i := 0; i < times; i++ {
			time.Sleep(time.Second * 1)
			ch <- fmt.Sprintf("hoge:%d", i)
		}
		close(ch)
	}()

	// 時間制限は10秒
	timeout := time.After(time.Second * 10)

	// 通信切断されたら抜ける
	closeNotify := w.(http.CloseNotifier).CloseNotify()

	// 何かしら結果が出るまでループする
Loop:
	for {
		select {
		case mes, ok := <-ch:
			if ok {
				outln(w, mes)
			} else {
				outln(w, "message is over")
				break Loop
			}
		case <-closeNotify:
			log.Println("session closed")
			break Loop
		case <-timeout:
			outln(w, "process timeout")
			break Loop
		}
	}

	outln(w, "bye")
}

func main() {
	http.HandleFunc("/", handler)
	http.ListenAndServe(":8085", nil)
}