add stats package; it is not yet integrated

tracker/stats/stats.go

@@ -0,0 +1,92 @@
+// 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 stats implements a means of tracking processing statistics for a
+// BitTorrent tracker.
+package stats
+
+import "time"
+
+const (
+	Announce = iota
+	Scrape
+	Completed
+	NewPeer
+	DeletedPeer
+	NewSeeder
+	DeletedSeeder
+	NewTorrent
+	DeletedTorrent
+)
+
+type Stats struct {
+	Start     time.Time
+	Announces uint64
+	Scrapes   uint64
+	Completed uint64
+	Peers     uint64
+	Seeders   uint64
+	Torrents  uint64
+
+	events chan int
+}
+
+func New(chanSize int) *Stats {
+	s := &Stats{
+		Start:  time.Now(),
+		events: make(chan int, chanSize),
+	}
+
+	go s.handleEvents()
+
+	return s
+}
+
+func (s *Stats) Close() {
+	close(s.events)
+}
+
+func (s *Stats) Uptime() time.Duration {
+	return time.Since(s.Start)
+}
+
+func (s *Stats) RecordEvent(event int) {
+	s.events <- event
+}
+
+func (s *Stats) handleEvents() {
+	for event := range s.events {
+		switch event {
+		case Announce:
+			s.Announces++
+
+		case Scrape:
+			s.Scrapes++
+
+		case Completed:
+			s.Completed++
+
+		case NewPeer:
+			s.Peers++
+
+		case DeletedPeer:
+			s.Peers--
+
+		case NewSeeder:
+			s.Seeders++
+
+		case DeletedSeeder:
+			s.Seeders--
+
+		case NewTorrent:
+			s.Torrents++
+
+		case DeletedTorrent:
+			s.Torrents--
+
+		default:
+			panic("stats: RecordEvent called with an unknown event")
+		}
+	}
+}