fast timeout of tracker scraping, fixes scakemyer/plugin.video.quasar…

…#569

providers/search.go

@@ -3,6 +3,7 @@ package providers
 import (
 	"sort"
 	"sync"
+	"time"
 
 	"github.com/op/go-logging"
 	"github.com/scakemyer/quasar/bittorrent"
@@ -28,6 +29,8 @@ const (
 	Sort480p720p1080p
 )
 
+var trackerTimeout = time.Duration(5) * time.Second
+
 var log = logging.MustGetLogger("linkssearch")
 
 func Search(searchers []Searcher, query string) []*bittorrent.Torrent {
@@ -110,6 +113,20 @@ func SearchEpisode(searchers []EpisodeSearcher, show *tmdb.Show, episode *tmdb.E
 	return processLinks(torrentsChan, SortShows)
 }
 
+func waitTimeout(wg *sync.WaitGroup, timeout time.Duration) bool {
+	c := make(chan struct{})
+	go func() {
+		defer close(c)
+		wg.Wait()
+	}()
+	select {
+	case <-c:
+		return false // completed normally
+	case <-time.After(timeout):
+		return true // timed out
+	}
+}
+
 func processLinks(torrentsChan chan *bittorrent.Torrent, sortType int) []*bittorrent.Torrent {
 	trackers := map[string]*bittorrent.Tracker{}
 	torrentsMap := map[string]*bittorrent.Torrent{}
@@ -182,6 +199,7 @@ func processLinks(torrentsChan chan *bittorrent.Torrent, sortType int) []*bittor
 	}
 
 	log.Infof("Scraping torrent metrics from %d trackers...\n", len(trackers))
+
 	scrapeResults := make(chan []bittorrent.ScrapeResponseEntry)
 	go func() {
 		wg := sync.WaitGroup{}
@@ -190,13 +208,18 @@ func processLinks(torrentsChan chan *bittorrent.Torrent, sortType int) []*bittor
 			go func(tracker *bittorrent.Tracker) {
 				defer wg.Done()
 				if err := tracker.Connect(); err != nil {
-					log.Errorf("Tracker %s is not available because: %s", tracker, err)
+					log.Errorf("Tracker %s failed: %s", tracker, err)
 					return
 				}
 				scrapeResults <- tracker.Scrape(torrents)
 			}(tracker)
 		}
-		wg.Wait()
+		// wg.Wait()
+		if waitTimeout(&wg, trackerTimeout) {
+			log.Error("Timed out waiting for trackers.")
+		} else {
+			log.Notice("Finished scraping trackers.")
+		}
 		close(scrapeResults)
 	}()
 
@@ -210,6 +233,7 @@ func processLinks(torrentsChan chan *bittorrent.Torrent, sortType int) []*bittor
 			}
 		}
 	}
+	log.Notice("Finished comparing seeds/peers of results to trackers...")
 
 	conf := config.Get()
 	sortMode := conf.SortingModeMovies