package torrent import ( "bytes" "errors" "fmt" "time" "github.com/anacrolix/missinggo" "github.com/anacrolix/torrent/tracker" ) // Announces a torrent to a tracker at regular intervals, when peers are // required. type trackerScraper struct { url string // Causes the trackerScraper to stop running. stop missinggo.Event t *Torrent lastAnnounce trackerAnnounceResult } func (ts *trackerScraper) statusLine() string { var w bytes.Buffer fmt.Fprintf(&w, "%q\t%s\t%s", ts.url, func() string { // return ts.lastAnnounce.Completed.Add(ts.lastAnnounce.Interval).Format("2006-01-02 15:04:05 -0700 MST") na := ts.lastAnnounce.Completed.Add(ts.lastAnnounce.Interval).Sub(time.Now()) na /= time.Second na *= time.Second if na > 0 { return na.String() } else { return "anytime" } }(), func() string { if ts.lastAnnounce.Err != nil { return ts.lastAnnounce.Err.Error() } if ts.lastAnnounce.Completed.IsZero() { return "never" } return fmt.Sprintf("%d peers", ts.lastAnnounce.NumPeers) }()) return w.String() } type trackerAnnounceResult struct { Err error NumPeers int Interval time.Duration Completed time.Time } func trackerToTorrentPeers(ps []tracker.Peer) (ret []Peer) { ret = make([]Peer, 0, len(ps)) for _, p := range ps { ret = append(ret, Peer{ IP: p.IP, Port: p.Port, Source: peerSourceTracker, }) } return } // Return how long to wait before trying again. For most errors, we return 5 // minutes, a relatively quick turn around for DNS changes. func (me *trackerScraper) announce() (ret trackerAnnounceResult) { defer func() { ret.Completed = time.Now() }() ret.Interval = 5 * time.Minute blocked, urlToUse, host, err := me.t.cl.prepareTrackerAnnounceUnlocked(me.url) if err != nil { ret.Err = err return } if blocked { ret.Err = errors.New("blocked by IP") return } me.t.cl.mu.Lock() req := me.t.announceRequest() me.t.cl.mu.Unlock() res, err := tracker.AnnounceHost(urlToUse, &req, host) if err != nil { ret.Err = err return } me.t.AddPeers(trackerToTorrentPeers(res.Peers)) ret.NumPeers = len(res.Peers) ret.Interval = time.Duration(res.Interval) * time.Second return } func (me *trackerScraper) Run() { for { select { case <-me.t.closed.LockedChan(&me.t.cl.mu): return case <-me.stop.LockedChan(&me.t.cl.mu): return case <-me.t.wantPeersEvent.LockedChan(&me.t.cl.mu): } ar := me.announce() me.t.cl.mu.Lock() me.lastAnnounce = ar me.t.cl.mu.Unlock() intervalChan := time.After(ar.Completed.Add(ar.Interval).Sub(time.Now())) select { case <-me.t.closed.LockedChan(&me.t.cl.mu): return case <-me.stop.LockedChan(&me.t.cl.mu): return case <-intervalChan: } } }