refactor crawler

src/server/routes.go

@@ -155,35 +155,32 @@ func (s *Server) handleFeedList(c *router.Context) {
 			return
 		}
 
-		feed, feedUrl, sources, err := worker.DiscoverFeed(form.Url)
-		if err != nil {
-			log.Print(err)
+		result, err := worker.DiscoverFeed(form.Url)
+		switch {
+		case err != nil:
+			log.Printf("Faild to discover feed for %s: %s", form.Url, err)
 			c.JSON(http.StatusOK, map[string]string{"status": "notfound"})
-			return
-		}
-
-		if feed != nil {
-			storedFeed := s.db.CreateFeed(
-				feed.Title,
+		case len(result.Sources) > 0:
+			c.JSON(http.StatusOK, map[string]interface{}{"status": "multiple", "choice": result.Sources})
+		case result.Feed != nil:
+			feed := s.db.CreateFeed(
+				result.Feed.Title,
 				"",
-				feed.SiteURL,
-				feedUrl,
+				result.Feed.SiteURL,
+				result.FeedLink,
 				form.FolderID,
 			)
-			s.db.CreateItems(worker.ConvertItems(feed.Items, *storedFeed))
+			s.db.CreateItems(worker.ConvertItems(result.Feed.Items, *feed))
 
-			icon, err := worker.FindFavicon(storedFeed.Link, storedFeed.FeedLink)
+			icon, err := worker.FindFavicon(feed.Link, feed.FeedLink)
 			if icon != nil {
-				s.db.UpdateFeedIcon(storedFeed.Id, icon)
+				s.db.UpdateFeedIcon(feed.Id, icon)
 			}
 			if err != nil {
-				log.Printf("Failed to find favicon for %s (%d): %s", storedFeed.FeedLink, storedFeed.Id, err)
+				log.Printf("Failed to find favicon for %s (%d): %s", feed.FeedLink, feed.Id, err)
 			}
-
 			c.JSON(http.StatusOK, map[string]string{"status": "success"})
-		} else if sources != nil {
-			c.JSON(http.StatusOK, map[string]interface{}{"status": "multiple", "choice": sources})
-		} else {
+		default:
 			c.JSON(http.StatusOK, map[string]string{"status": "notfound"})
 		}
 	}

src/worker/client.go

@@ -0,0 +1,52 @@
+package worker
+
+import (
+	"net"
+	"net/http"
+	"time"
+)
+
+type Client struct {
+	httpClient *http.Client
+	userAgent  string
+}
+
+func (c *Client) get(url string) (*http.Response, error) {
+	return c.getConditional(url, "", "")
+}
+
+func (c *Client) getConditional(url, lastModified, etag string) (*http.Response, error) {
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("User-Agent", c.userAgent)
+	if lastModified != "" {
+		req.Header.Set("If-Modified-Since", lastModified)
+	}
+	if etag != "" {
+		req.Header.Set("If-None-Match", etag)
+	}
+	return c.httpClient.Do(req)
+}
+
+var client *Client
+
+func init() {
+	transport := &http.Transport{
+		Proxy: http.ProxyFromEnvironment,
+		DialContext: (&net.Dialer{
+			Timeout: 10 * time.Second,
+		}).DialContext,
+		DisableKeepAlives:   true,
+		TLSHandshakeTimeout: time.Second * 10,
+	}
+	httpClient := &http.Client{
+		Timeout:   time.Second * 30,
+		Transport: transport,
+	}
+	client = &Client{
+		httpClient: httpClient,
+		userAgent:  "Yarr/1.0",
+	}
+}

src/worker/crawler.go

@@ -5,11 +5,8 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
-	"log"
-	"net"
 	"net/http"
 	"net/url"
-	"time"
 
 	"github.com/nkanaev/yarr/src/scraper"
 	"github.com/nkanaev/yarr/src/parser"
@@ -22,102 +19,54 @@ type FeedSource struct {
 	Url   string `json:"url"`
 }
 
-type Client struct {
-	httpClient *http.Client
-	userAgent  string
+type DiscoverResult struct {
+	Feed     *parser.Feed
+	FeedLink string
+	Sources  []FeedSource
 }
 
-func (c *Client) get(url string) (*http.Response, error) {
-	req, err := http.NewRequest("GET", url, nil)
-	if err != nil {
-		return nil, err
-	}
-	req.Header.Set("User-Agent", c.userAgent)
-	return c.httpClient.Do(req)
-}
-
-func (c *Client) getConditional(url, lastModified, etag string) (*http.Response, error) {
-	req, err := http.NewRequest("GET", url, nil)
-	if err != nil {
-		return nil, err
-	}
-	req.Header.Set("User-Agent", c.userAgent)
-	if lastModified != "" {
-		req.Header.Set("If-Modified-Since", lastModified)
-	}
-	if etag != "" {
-		req.Header.Set("If-None-Match", etag)
-	}
-	return c.httpClient.Do(req)
-}
-
-var defaultClient *Client
-
-func searchFeedLinks(html []byte, siteurl string) ([]FeedSource, error) {
-	sources := make([]FeedSource, 0, 0)
-	for url, title := range scraper.FindFeeds(string(html), siteurl) {
-		sources = append(sources, FeedSource{Title: title, Url: url})
-	}
-	return sources, nil
-}
-
-func DiscoverFeed(candidateUrl string) (*parser.Feed, string, *[]FeedSource, error) {
+func DiscoverFeed(candidateUrl string) (*DiscoverResult, error) {
+	result := &DiscoverResult{}
 	// Query URL
-	res, err := defaultClient.get(candidateUrl)
+	res, err := client.get(candidateUrl)
 	if err != nil {
-		return nil, "", nil, err
+		return nil, err
 	}
 	defer res.Body.Close()
 	if res.StatusCode != 200 {
-		errmsg := fmt.Sprintf("Failed to fetch feed %s (status: %d)", candidateUrl, res.StatusCode)
-		return nil, "", nil, errors.New(errmsg)
+		return nil, fmt.Errorf("status code %d", res.StatusCode)
 	}
 	content, err := ioutil.ReadAll(res.Body)
 	if err != nil {
-		return nil, "", nil, err
+		return nil, err
 	}
 
 	// Try to feed into parser
 	feed, err := parser.Parse(bytes.NewReader(content))
 	if err == nil {
-		/*
-		// WILD: feeds may not always have link to themselves
-		if len(feed.FeedLink) == 0 {
-			feed.FeedLink = candidateUrl
-		}
-		*/
-
-		// WILD: resolve relative links (path, without host)
-		/*
-		base, _ := url.Parse(candidateUrl)
-		if link, err := url.Parse(feed.Link); err == nil && link.Host == "" {
-			feed.Link = base.ResolveReference(link).String()
-		}
-		if link, err := url.Parse(feed.FeedLink); err == nil && link.Host == "" {
-			feed.FeedLink = base.ResolveReference(link).String()
-		}
-		*/
-		err := feed.TranslateURLs(candidateUrl)
-		if err != nil {
-			log.Printf("Failed to translate feed urls: %s", err)
-		}
-
-		return feed, candidateUrl, nil, nil
+		feed.TranslateURLs(candidateUrl)
+		result.Feed = feed
+		result.FeedLink = candidateUrl
+		return result, nil
 	}
 
 	// Possibly an html link. Search for feed links
-	sources, err := searchFeedLinks(content, candidateUrl)
-	if err != nil {
-		return nil, "", nil, err
-	} else if len(sources) == 0 {
-		return nil, "", nil, errors.New("No feeds found at the given url")
-	} else if len(sources) == 1 {
+	sources := make([]FeedSource, 0)
+	for url, title := range scraper.FindFeeds(string(content), candidateUrl) {
+		sources = append(sources, FeedSource{Title: title, Url: url})
+	}
+	switch {
+	case len(sources) == 0:
+		return nil, errors.New("No feeds found at the given url")
+	case len(sources) == 1:
 		if sources[0].Url == candidateUrl {
-			return nil, "", nil, errors.New("Recursion!")
+			return nil, errors.New("Recursion!")
 		}
 		return DiscoverFeed(sources[0].Url)
 	}
-	return nil, "", &sources, nil
+
+	result.Sources = sources
+	return result, nil
 }
 
 func FindFavicon(websiteUrl, feedUrl string) (*[]byte, error) {
@@ -132,7 +81,7 @@ func FindFavicon(websiteUrl, feedUrl string) (*[]byte, error) {
 	}
 
 	if len(websiteUrl) != 0 {
-		res, err := defaultClient.get(websiteUrl)
+		res, err := client.get(websiteUrl)
 		if err != nil {
 			return nil, err
 		}
@@ -157,7 +106,7 @@ func FindFavicon(websiteUrl, feedUrl string) (*[]byte, error) {
 		"image/gif",
 	}
 	for _, url := range candidateUrls {
-		res, err := defaultClient.get(url)
+		res, err := client.get(url)
 		if err != nil {
 			continue
 		}
@@ -180,18 +129,6 @@ func ConvertItems(items []parser.Item, feed storage.Feed) []storage.Item {
 	result := make([]storage.Item, len(items))
 	for i, item := range items {
 		item := item
-		podcastUrl := item.PodcastURL
-
-		/*
-		var podcastUrl *string
-		if item.Enclosures != nil {
-			for _, enclosure := range item.Enclosures {
-				if strings.ToLower(enclosure.Type) == "audio/mpeg" {
-					podcastUrl = &enclosure.URL
-				}
-			}
-		}
-		*/
 		result[i] = storage.Item{
 			GUID:        item.GUID,
 			FeedId:      feed.Id,
@@ -203,33 +140,30 @@ func ConvertItems(items []parser.Item, feed storage.Feed) []storage.Item {
 			Date:        &item.Date,
 			Status:      storage.UNREAD,
 			Image:       item.ImageURL,
-			PodcastURL:  &podcastUrl,
+			PodcastURL:  nil,
 		}
 	}
 	return result
 }
 
 func listItems(f storage.Feed, db *storage.Storage) ([]storage.Item, error) {
-	var res *http.Response
-	var err error
-
-	httpState := db.GetHTTPState(f.Id)
-	if httpState != nil {
-		res, err = defaultClient.getConditional(f.FeedLink, httpState.LastModified, httpState.Etag)
-	} else {
-		res, err = defaultClient.get(f.FeedLink)
+	lmod := ""
+	etag := ""
+	if state := db.GetHTTPState(f.Id); state != nil {
+		lmod = state.LastModified
+		etag = state.Etag
 	}
 
+	res, err := client.getConditional(f.FeedLink, lmod, etag)
 	if err != nil {
 		return nil, fmt.Errorf("unable to get: %s", err)
 	}
 	defer res.Body.Close()
 
-	if res.StatusCode/100 == 4 || res.StatusCode/100 == 5 {
+	switch {
+	case res.StatusCode < 200 || res.StatusCode > 399:
 		return nil, fmt.Errorf("status code %d", res.StatusCode)
-	}
-
-	if res.StatusCode == 304 {
+	case res.StatusCode == http.StatusNotModified:
 		return nil, nil
 	}
 
@@ -237,34 +171,17 @@ func listItems(f storage.Feed, db *storage.Storage) ([]storage.Item, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to init response body: %s", err)
 	}
+
 	feed, err := parser.Parse(body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse: %s", err)
 	}
 
-	lastModified := res.Header.Get("Last-Modified")
-	etag := res.Header.Get("Etag")
-	if lastModified != "" || etag != "" {
-		db.SetHTTPState(f.Id, lastModified, etag)
-	}
-	return ConvertItems(feed.Items, f), nil
+	lmod = res.Header.Get("Last-Modified")
+	etag = res.Header.Get("Etag")
+	if lmod != "" || etag != "" {
+		db.SetHTTPState(f.Id, lmod, etag)
 	}
 
-func init() {
-	transport := &http.Transport{
-		Proxy: http.ProxyFromEnvironment,
-		DialContext: (&net.Dialer{
-			Timeout: 10 * time.Second,
-		}).DialContext,
-		DisableKeepAlives:   true,
-		TLSHandshakeTimeout: time.Second * 10,
-	}
-	httpClient := &http.Client{
-		Timeout:   time.Second * 30,
-		Transport: transport,
-	}
-	defaultClient = &Client{
-		httpClient: httpClient,
-		userAgent:  "Yarr/1.0",
-	}
+	return ConvertItems(feed.Items, f), nil
 }