Purge peers that have not announced for twice the announce interval

config/config.go

@@ -50,6 +50,8 @@ type Config struct {
 	Freeleech bool `json:"freeleech"`
 	Whitelist bool `json:"whitelist"`
 
+	PurgeInactiveTorrents bool `json:"purge_inactive_torrents"`
+
 	Announce        Duration `json:"announce"`
 	MinAnnounce     Duration `json:"min_announce"`
 	RequestTimeout  Duration `json:"request_timeout"`
@@ -59,15 +61,21 @@ type Config struct {
 // DefaultConfig is a configuration that can be used as a fallback value.
 var DefaultConfig = Config{
 	Addr: "127.0.0.1:6881",
+
 	Tracker: DriverConfig{
 		Name: "memory",
 	},
+
 	Backend: DriverConfig{
 		Name: "noop",
 	},
-	Private:         false,
-	Freeleech:       false,
-	Whitelist:       false,
+
+	Private:   false,
+	Freeleech: false,
+	Whitelist: false,
+
+	PurgeInactiveTorrents: true,
+
 	Announce:        Duration{30 * time.Minute},
 	MinAnnounce:     Duration{15 * time.Minute},
 	RequestTimeout:  Duration{10 * time.Second},

drivers/tracker/memory/conn.go

@@ -5,6 +5,7 @@
 package memory
 
 import (
+	"runtime"
 	"time"
 
 	"github.com/chihaya/chihaya/drivers/tracker"
@@ -223,3 +224,47 @@ func (c *Conn) DeleteClient(peerID string) error {
 	return nil
 }
 
+func (c *Conn) PurgeInactivePeers(purgeEmptyTorrents bool, before time.Time) error {
+	unixtime := before.Unix()
+
+	// Build array of map keys to operate on.
+	c.torrentsM.RLock()
+	index := 0
+	keys := make([]string, len(c.torrents))
+
+	for infohash, _ := range c.torrents {
+		keys[index] = infohash
+		index++
+	}
+
+	c.torrentsM.RUnlock()
+
+	// Process keys.
+	for _, infohash := range keys {
+		runtime.Gosched() // Let other goroutines run, since this is low priority.
+
+		c.torrentsM.Lock()
+		torrent := c.torrents[infohash]
+
+		for key, peer := range torrent.Seeders {
+			if peer.LastAnnounce < unixtime {
+				delete(torrent.Seeders, key)
+			}
+		}
+
+		for key, peer := range torrent.Leechers {
+			if peer.LastAnnounce < unixtime {
+				delete(torrent.Leechers, key)
+			}
+		}
+
+		peers := torrent.PeerCount()
+		c.torrentsM.Unlock()
+
+		if purgeEmptyTorrents && peers == 0 {
+			c.PurgeInactiveTorrent(infohash)
+		}
+	}
+
+	return nil
+}

drivers/tracker/routines.go

@@ -0,0 +1,30 @@
+// Copyright 2014 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
+package tracker
+
+import (
+	"time"
+
+	"github.com/golang/glog"
+)
+
+func PurgeInactivePeers(p Pool, purgeEmptyTorrents bool, threshold, interval time.Duration) {
+	for _ = range time.NewTicker(interval).C {
+		before := time.Now().Add(-threshold)
+		glog.V(0).Infof("Purging peers with no announces since %s", before)
+
+		conn, err := p.Get()
+
+		if err != nil {
+			glog.Error("Unable to get connection for a routine")
+			continue
+		}
+
+		err = conn.PurgeInactivePeers(purgeEmptyTorrents, before)
+		if err != nil {
+			glog.Errorf("Error purging torrents: %s", err)
+		}
+	}
+}

drivers/tracker/tracker.go

@@ -9,6 +9,7 @@ package tracker
 import (
 	"errors"
 	"fmt"
+	"time"
 
 	"github.com/chihaya/chihaya/config"
 	"github.com/chihaya/chihaya/models"
@@ -79,7 +80,9 @@ type Conn interface {
 	DeleteLeecher(infohash, peerkey string) error
 	PutSeeder(infohash string, p *models.Peer) error
 	DeleteSeeder(infohash, peerkey string) error
+
 	PurgeInactiveTorrent(infohash string) error
+	PurgeInactivePeers(purgeEmptyTorrents bool, before time.Time) error
 
 	// User interactions
 	FindUser(passkey string) (*models.User, error)

http/announce.go

@@ -91,7 +91,7 @@ func (t *Tracker) ServeAnnounce(w http.ResponseWriter, r *http.Request, p httpro
 		if err != nil {
 			return http.StatusInternalServerError, err
 		}
-	} else if torrent.PeerCount() == 0 {
+	} else if t.cfg.PurgeInactiveTorrents && torrent.PeerCount() == 0 {
 		// Rather than deleting the torrent explicitly, let the tracker driver
 		// ensure there are no race conditions.
 		conn.PurgeInactiveTorrent(torrent.Infohash)

http/http.go

@@ -99,6 +99,13 @@ func Serve(cfg *config.Config) {
 		glog.Fatal("New: ", err)
 	}
 
+	go tracker.PurgeInactivePeers(
+		t.pool,
+		cfg.PurgeInactiveTorrents,
+		cfg.Announce.Duration*2,
+		cfg.Announce.Duration,
+	)
+
 	glog.V(0).Info("Starting on ", cfg.Addr)
 	graceful.Run(cfg.Addr, cfg.RequestTimeout.Duration, NewRouter(t, cfg))
 }