feed_fetch.go

type feedResult struct {
	feed *Feed
	err error
}

func fetchFeeds(urls []string) ([]*Feed) {
	// Create a channel to process the feeds
	feedc := make(chan feedResult, len(urls))

	// Start a goroutine for each feed url
	for _, u := range urls {
		go fetchFeed(u, feedc)
	}

	// Wait for the goroutines to write their results to the channel
	feeds := []*Feed{}
	for i := 0; i < len(urls); i++ {
		res := <-feedc
		// If the goroutine errors out, we'll just wait for others
		if res.err != nil {
			continue
		}
		feeds = append(feeds, res.feed)
	}

	return feeds
}

func fetchFeed(url string, feedc chan feedResult) {
	// Create a client with a default timeout
	net := &http.Client{
		Timeout: time.Second * 10,
	}
	// Issue a GET request for the feed
	res, err := net.Get(url)
	// If there was an error write that to the channel and return immediately
	if err != nil {
		feedc <- feedResult{nil, err}
		return
	}
	defer res.Body.Close()
	// Read the body of the request and parse the feed
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		feedc <- feedResult{nil, err}
		return
	}
	feed, err := parseFeed(body)
	if err != nil {
		feedc <- feedResult{nil, err}
		return
	}
	feedc <- feedResult{feed, nil}
}