fixed_server.go

package main

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

func newProducer(readTimeout time.Duration, products ...string) <-chan string {
	results := make(chan string)
	go func() {
		defer close(results)
		for _, product := range products {
			select {
			case results <- product:
				// didn't time out
			case <-time.After(readTimeout):
				return
			}
		}
	}()
	return results
}

var timeout = 1 * time.Second

func exampleEndpoint(w http.ResponseWriter, req *http.Request) {
	var counter = 0
	for result := range newProducer(timeout, "A", "B", "C", "E", "F", "G") {
		counter++
		fmt.Fprintln(w, result)
		if counter == 3 {
			return
		}
	}
}

func main() {
	http.HandleFunc("/example", exampleEndpoint)
	log.Fatal(http.ListenAndServe(":8080", nil))
}