チャンクで返すサーバと、それを受けるクライアント

chanked_client.go

package main

import (
	"bufio"
	"fmt"
	"log"
	"net/http"
	"net/http/httputil"
	"os"
)

func main() {
	client := http.Client{}

	res, err := client.Get("http://127.0.0.1:12345/")
	if err != nil {
		log.Fatal(err)
	}
	defer res.Body.Close()

	ret, _ := httputil.DumpResponse(res, false)
	fmt.Println(string(ret))

	scanner := bufio.NewScanner(res.Body)
	for scanner.Scan() {
		fmt.Println(scanner.Text())
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "reading standard input:", err)
	}
}

chanked_server.go

package main

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

func ChankedServer(w http.ResponseWriter, req *http.Request) {
	closed := false
	closedCh := make(chan struct{})

	go func() {
		notify := w.(http.CloseNotifier).CloseNotify()
		closed = <-notify
	}()

	go func() {
		for {
			switch {
			case closed:
				closedCh <- struct{}{}
				return
			default:
				fmt.Fprintf(w, "%v\n", time.Now())
				w.(http.Flusher).Flush()
				time.Sleep(time.Second * 1)
			}
		}
	}()

	<-closedCh
}

func main() {
	http.HandleFunc("/", ChankedServer)
	err := http.ListenAndServe(":12345", nil)
	if err != nil {
		log.Fatal("ListenAndServe: ", err)
	}
}

$ go run chanked_client.go

HTTP/1.1 200 OK
Transfer-Encoding: chunked
Content-Type: text/plain; charset=utf-8
Date: Tue, 06 Jan 2015 14:29:31 GMT


2015-01-06 23:29:31.286051635 +0900 JST
2015-01-06 23:29:32.289838937 +0900 JST
2015-01-06 23:29:33.291992267 +0900 JST
2015-01-06 23:29:34.296553015 +0900 JST
2015-01-06 23:29:35.300829516 +0900 JST
.
.
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