server swarm: split out announce events

Author: astro

lib/swarm.js

@@ -15,82 +15,84 @@ Swarm.prototype.announce = function (params, cb) {
   var self = this
   var peer = self.peers[params.addr]
 
-  var start = function () {
-    if (peer) {
-      debug('unexpected `started` event from peer that is already in swarm')
-      return update() // treat as an update
-    }
-    if (params.left === 0) self.complete += 1
-    else self.incomplete += 1
-    peer = self.peers[params.addr] = {
-      ip: params.ip,
-      port: params.port,
-      peerId: params.peer_id
-    }
-    self.emit('start', params.addr)
-  }
+  // Dispatch announce event
+  if (!params.event || params.event === 'empty') params.event = 'update'
+  var fn = '_onAnnounce_' + params.event
+  if (self[fn]) {
+    self[fn](params, peer, function (err) {
+      // event processed, prepare response:
+
+      if (params.left === 0 && peer) peer.complete = true
 
-  var stop = function () {
-    if (!peer) {
-      debug('unexpected `stopped` event from peer that is not in swarm')
-      return // do nothing
-    }
-    if (peer.complete) self.complete -= 1
-    else self.incomplete -= 1
-    self.peers[params.addr] = null
-    self.emit('stop', params.addr)
+      // send peers
+      var peers = self._getPeers(params.numwant)
+
+      cb(null, {
+        complete: self.complete,
+        incomplete: self.incomplete,
+        peers: peers
+      })
+    })
+  } else {
+    cb(new Error('invalid event'))
   }
+}
 
-  var complete = function () {
-    if (!peer) {
-      debug('unexpected `completed` event from peer that is not in swarm')
-      return start() // treat as a start
-    }
-    if (peer.complete) {
-      debug('unexpected `completed` event from peer that is already marked as completed')
-      return // do nothing
-    }
-    self.complete += 1
-    self.incomplete -= 1
-    peer.complete = true
-    self.emit('complete', params.addr)
+Swarm.prototype._onAnnounce_started = function (params, peer, cb) {
+  if (peer) {
+    debug('unexpected `started` event from peer that is already in swarm')
+    return this._onAnnounce_update() // treat as an update
+  }
+  if (params.left === 0) this.complete += 1
+  else this.incomplete += 1
+  peer = this.peers[params.addr] = {
+    ip: params.ip,
+    port: params.port,
+    peerId: params.peer_id
   }
+  this.emit('start', params.addr)
+
+  cb()
+}
 
-  var update = function () {
-    if (!peer) {
-      debug('unexpected `update` event from peer that is not in swarm')
-      return start() // treat as a start
-    }
-    self.emit('update', params.addr)
+Swarm.prototype._onAnnounce_stopped = function (params, peer, cb) {
+  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] = null
+  this.emit('stop', params.addr)
 
-  switch (params.event) {
-  case 'started':
-    start()
-    break
-  case 'stopped':
-    stop()
-    break
-  case 'completed':
-    complete()
-    break
-  case '': case undefined: case 'empty': case 'update': // update
-    update()
-    break
-  default:
-    return cb(new Error('invalid event')) // early return
+  cb()
+}
+
+Swarm.prototype._onAnnounce_completed = function (params, peer, cb) {
+  if (!peer) {
+    debug('unexpected `completed` event from peer that is not in swarm')
+    return start() // 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
+  this.emit('complete', params.addr)
 
-  if (params.left === 0 && peer) peer.complete = true
+  cb()
+}
 
-  // send peers
-  var peers = self._getPeers(params.numwant)
+Swarm.prototype._onAnnounce_update = function (params, peer, cb) {
+  if (!peer) {
+    debug('unexpected `update` event from peer that is not in swarm')
+    return start() // treat as a start
+  }
+  this.emit('update', params.addr)
 
-  cb(null, {
-    complete: this.complete,
-    incomplete: this.incomplete,
-    peers: peers
-  })
+  cb()
 }
 
 Swarm.prototype._getPeers = function (numwant) {