bittorrent-tracker/lib/swarm.js
Feross Aboukhadijeh 5aa0696a34 fix crash, oops
2015-07-27 15:46:49 -07:00

111 lines
3.1 KiB
JavaScript

module.exports = Swarm
var debug = require('debug')('bittorrent-tracker')
var randomIterate = require('random-iterate')
// Regard this as the default implementation of an interface that you
// need to support when overriding Server.getSwarm()
function Swarm (infoHash, server) {
this.peers = {}
this.complete = 0
this.incomplete = 0
}
Swarm.prototype.announce = function (params, cb) {
var self = this
var peer = self.peers[params.addr || params.peer_id]
if (params.event === 'started') {
self._onAnnounceStarted(params, peer)
} else if (params.event === 'stopped') {
self._onAnnounceStopped(params, peer)
} else if (params.event === 'completed') {
self._onAnnounceCompleted(params, peer)
} else if (params.event === 'update') {
self._onAnnounceUpdate(params, peer)
} else {
cb(new Error('invalid event'))
return
}
cb(null, {
complete: self.complete,
incomplete: self.incomplete,
peers: self._getPeers(params.numwant, !!params.socket)
})
}
Swarm.prototype.scrape = function (params, cb) {
cb(null, {
complete: this.complete,
incomplete: this.incomplete
})
}
Swarm.prototype._onAnnounceStarted = function (params, peer) {
if (peer) {
debug('unexpected `started` event from peer that is already in swarm')
return this._onAnnounceUpdate(params, peer) // treat as an update
}
if (params.left === 0) this.complete += 1
else this.incomplete += 1
peer = this.peers[params.addr || params.peer_id] = {
complete: params.left === 0,
peerId: params.peer_id, // as hex
ip: params.ip, // only http, udp
port: params.port, // only http, udp
socket: params.socket // only websocket
}
}
Swarm.prototype._onAnnounceStopped = function (params, peer) {
if (!peer) {
debug('unexpected `stopped` event from peer that is not in swarm')
return // do nothing
}
if (peer.complete) this.complete -= 1
else this.incomplete -= 1
this.peers[params.addr || params.peer_id] = null
}
Swarm.prototype._onAnnounceCompleted = function (params, peer) {
if (!peer) {
debug('unexpected `completed` event from peer that is not in swarm')
return this._onAnnounceStarted(params, peer) // treat as a start
}
if (peer.complete) {
debug('unexpected `completed` event from peer that is already marked as completed')
return // do nothing
}
this.complete += 1
this.incomplete -= 1
peer.complete = true
}
Swarm.prototype._onAnnounceUpdate = function (params, peer) {
if (!peer) {
debug('unexpected `update` event from peer that is not in swarm')
return this._onAnnounceStarted(params, peer) // treat as a start
}
if (!peer.complete && params.left === 0) {
this.complete += 1
this.incomplete -= 1
peer.complete = true
}
}
Swarm.prototype._getPeers = function (numwant, isWebRTC) {
var peers = []
var ite = randomIterate(Object.keys(this.peers))
var peerId
while ((peerId = ite()) && peers.length < numwant) {
var peer = this.peers[peerId]
if (!peer) continue
if ((isWebRTC && peer.socket) || (!isWebRTC && peer.ip)) peers.push(peer)
}
return peers
}