[perf] Use pattern matching at the namespace level (#217)

This follows #46. Each node will now listen to only three channels:

- `socket.io#<namespace>#*`: used when broadcasting
- `socket.io-request#<namespace>#`: used for requesting information (ex: get every room in the cluster)
- `socket.io-response#<namespace>#`: used for responding to requests

We keep the benefits of #46 since:

- messages from other namespaces are ignored
- when emitting to a single room, the message is sent to
  `socket.io#<namespace>#<my-room>`, so listeners can check whether they
  have the room before unpacking the message (which is CPU consuming).

But there is no need to subscribe / unsubscribe every time a socket
joins or leaves a room (which is also CPU consuming when there are
thousands of subscriptions).

Author: darrachequesne

.travis.yml

@@ -1,8 +1,6 @@
 language: node_js
 sudo: false
 node_js:
-  - "0.10"
-  - "0.12"
   - "4"
   - "6"
   - "node"

README.md

@@ -32,11 +32,9 @@ The following options are allowed:
 - `key`: the name of the key to pub/sub events on as prefix (`socket.io`)
 - `host`: host to connect to redis on (`localhost`)
 - `port`: port to connect to redis on (`6379`)
-- `subEvent`: optional, the redis client event name to subscribe to (`messageBuffer`)
 - `pubClient`: optional, the redis client to publish events on
 - `subClient`: optional, the redis client to subscribe to events on
 - `requestsTimeout`: optional, after this timeout the adapter will stop waiting from responses to request (`1000ms`)
-- `withChannelMultiplexing`: optional, whether channel multiplexing is enabled (a new subscription will be trigggered for each room) (`true`)
 
 If you decide to supply `pubClient` and `subClient`, make sure you use
 [node_redis](https://github.com/mranney/node_redis) as a client or one

index.js

@@ -8,7 +8,6 @@ var redis = require('redis').createClient;
 var msgpack = require('msgpack-lite');
 var Adapter = require('socket.io-adapter');
 var debug = require('debug')('socket.io-redis');
-var async = require('async');
 
 /**
  * Module exports.
@@ -50,11 +49,8 @@ function adapter(uri, opts) {
   // opts
   var pub = opts.pubClient;
   var sub = opts.subClient;
-
   var prefix = opts.key || 'socket.io';
-  var subEvent = opts.subEvent || 'messageBuffer';
   var requestsTimeout = opts.requestsTimeout || 1000;
-  var withChannelMultiplexing = false !== opts.withChannelMultiplexing;
 
   // init clients if needed
   function createClient() {
@@ -85,7 +81,6 @@ function adapter(uri, opts) {
     this.uid = uid;
     this.prefix = prefix;
     this.requestsTimeout = requestsTimeout;
-    this.withChannelMultiplexing = withChannelMultiplexing;
 
     this.channel = prefix + '#' + nsp.name + '#';
     this.requestChannel = prefix + '-request#' + this.nsp.name + '#';
@@ -107,11 +102,17 @@ function adapter(uri, opts) {
 
     var self = this;
 
-    sub.subscribe([this.channel, this.requestChannel, this.responseChannel], function(err){
+    sub.psubscribe(this.channel + '*', function(err){
+      if (err) self.emit('error', err);
+    });
+
+    sub.on('pmessageBuffer', this.onmessage.bind(this));
+
+    sub.subscribe([this.requestChannel, this.responseChannel], function(err){
       if (err) self.emit('error', err);
     });
 
-    sub.on(subEvent, this.onmessage.bind(this));
+    sub.on('messageBuffer', this.onrequest.bind(this));
 
     function onError(err) {
       self.emit('error', err);
@@ -132,21 +133,22 @@ function adapter(uri, opts) {
    * @api private
    */
 
-  Redis.prototype.onmessage = function(channel, msg){
+  Redis.prototype.onmessage = function(pattern, channel, msg){
     channel = channel.toString();
 
-    if (this.channelMatches(channel, this.requestChannel)) {
-      return this.onrequest(channel, msg);
-    } else if (this.channelMatches(channel, this.responseChannel)) {
-      return this.onresponse(channel, msg);
-    } else if (!this.channelMatches(channel, this.channel)) {
+    if (!this.channelMatches(channel, this.channel)) {
       return debug('ignore different channel');
     }
 
+    var room = channel.substring(this.channel.length);
+    if (room !== '' && !this.rooms.hasOwnProperty(room)) {
+      return debug('ignore unknown room %s', room);
+    }
+
     var args = msgpack.decode(msg);
     var packet;
 
-    if (uid == args.shift()) return debug('ignore same uid');
+    if (uid === args.shift()) return debug('ignore same uid');
 
     packet = args[0];
 
@@ -170,6 +172,14 @@ function adapter(uri, opts) {
    */
 
   Redis.prototype.onrequest = function(channel, msg){
+    channel = channel.toString();
+
+    if (this.channelMatches(channel, this.responseChannel)) {
+      return this.onresponse(channel, msg);
+    } else if (!this.channelMatches(channel, this.requestChannel)) {
+      return debug('ignore different channel');
+    }
+
     var self = this;
     var request;
 
@@ -394,116 +404,15 @@ function adapter(uri, opts) {
     packet.nsp = this.nsp.name;
     if (!(remote || (opts && opts.flags && opts.flags.local))) {
       var msg = msgpack.encode([uid, packet, opts]);
-      if (this.withChannelMultiplexing && opts.rooms && opts.rooms.length === 1) {
-        pub.publish(this.channel + opts.rooms[0] + '#', msg);
+      if (opts.rooms && opts.rooms.length === 1) {
+        pub.publish(this.channel + opts.rooms[0], msg);
       } else {
         pub.publish(this.channel, msg);
       }
     }
     Adapter.prototype.broadcast.call(this, packet, opts);
   };
 
-  /**
-   * Subscribe client to room messages.
-   *
-   * @param {String} client id
-   * @param {String} room
-   * @param {Function} callback (optional)
-   * @api public
-   */
-
-  Redis.prototype.add = function(id, room, fn){
-    debug('adding %s to %s ', id, room);
-    var self = this;
-    // subscribe only once per room
-    var alreadyHasRoom = this.rooms.hasOwnProperty(room);
-    Adapter.prototype.add.call(this, id, room);
-
-    if (!this.withChannelMultiplexing || alreadyHasRoom) {
-      if (fn) fn(null);
-      return;
-    }
-
-    var channel = this.channel + room + '#';
-
-    function onSubscribe(err) {
-      if (err) {
-        self.emit('error', err);
-        if (fn) fn(err);
-        return;
-      }
-      if (fn) fn(null);
-    }
-
-    sub.subscribe(channel, onSubscribe);
-  };
-
-  /**
-   * Unsubscribe client from room messages.
-   *
-   * @param {String} session id
-   * @param {String} room id
-   * @param {Function} callback (optional)
-   * @api public
-   */
-
-  Redis.prototype.del = function(id, room, fn){
-    debug('removing %s from %s', id, room);
-
-    var self = this;
-    var hasRoom = this.rooms.hasOwnProperty(room);
-    Adapter.prototype.del.call(this, id, room);
-
-    if (this.withChannelMultiplexing && hasRoom && !this.rooms[room]) {
-      var channel = this.channel + room + '#';
-
-      function onUnsubscribe(err) {
-        if (err) {
-          self.emit('error', err);
-          if (fn) fn(err);
-          return;
-        }
-        if (fn) fn(null);
-      }
-
-      sub.unsubscribe(channel, onUnsubscribe);
-    } else {
-      if (fn) process.nextTick(fn.bind(null, null));
-    }
-  };
-
-  /**
-   * Unsubscribe client completely.
-   *
-   * @param {String} client id
-   * @param {Function} callback (optional)
-   * @api public
-   */
-
-  Redis.prototype.delAll = function(id, fn){
-    debug('removing %s from all rooms', id);
-
-    var self = this;
-    var rooms = this.sids[id];
-
-    if (!rooms) {
-      if (fn) process.nextTick(fn.bind(null, null));
-      return;
-    }
-
-    async.each(Object.keys(rooms), function(room, next){
-      self.del(id, room, next);
-    }, function(err){
-      if (err) {
-        self.emit('error', err);
-        if (fn) fn(err);
-        return;
-      }
-      delete self.sids[id];
-      if (fn) fn(null);
-    });
-  };
-
   /**
    * Gets a list of clients by sid.
    *
@@ -531,6 +440,7 @@ function adapter(uri, opts) {
       }
 
       numsub = parseInt(numsub[1], 10);
+      debug('waiting for %d responses to "clients" request', numsub);
 
       var request = JSON.stringify({
         requestid : requestid,
@@ -619,6 +529,7 @@ function adapter(uri, opts) {
       }
 
       numsub = parseInt(numsub[1], 10);
+      debug('waiting for %d responses to "allRooms" request', numsub);
 
       var request = JSON.stringify({
         requestid : requestid,
@@ -794,6 +705,7 @@ function adapter(uri, opts) {
       }
 
       numsub = parseInt(numsub[1], 10);
+      debug('waiting for %d responses to "customRequest" request', numsub);
 
       var request = JSON.stringify({
         requestid : requestid,

package.json

@@ -14,18 +14,17 @@
     "test": "mocha"
   },
   "dependencies": {
-    "async": "2.1.4",
     "debug": "2.3.3",
     "msgpack-lite": "0.1.26",
     "redis": "2.6.3",
-    "socket.io-adapter": "0.5.0",
+    "socket.io-adapter": "~1.1.0",
     "uid2": "0.0.3"
   },
   "devDependencies": {
     "expect.js": "0.3.1",
     "ioredis": "2.5.0",
     "mocha": "3.2.0",
-    "socket.io": "1.7.x",
-    "socket.io-client": "1.7.x"
+    "socket.io": "latest",
+    "socket.io-client": "latest"
   }
 }

test/index.js

@@ -15,12 +15,6 @@ var socket1, socket2, socket3;
   {
     name: 'socket.io-redis'
   },
-  {
-    name: 'socket.io-redis without channel multiplexing',
-    options: {
-      withChannelMultiplexing: false
-    }
-  },
   {
     name: 'socket.io-redis with ioredis',
     options: function () {
@@ -152,7 +146,7 @@ var socket1, socket2, socket3;
     it('deletes rooms upon disconnection', function(done){
       socket1.join('woot');
       socket1.on('disconnect', function() {
-        expect(socket1.adapter.sids[socket1.id]).to.be.empty();
+        expect(socket1.adapter.sids[socket1.id]).to.be(undefined);
         expect(socket1.adapter.rooms).to.be.empty();
         client1.disconnect();
         done();
@@ -175,6 +169,26 @@ var socket1, socket2, socket3;
       });
     });
 
+    it('ignores messages from unknown channels', function(done){
+      namespace1.adapter.subClient.psubscribe('f?o', function () {
+        namespace3.adapter.pubClient.publish('foo', 'bar');
+      });
+
+      namespace1.adapter.subClient.on('pmessageBuffer', function () {
+        setTimeout(done, 50);
+      });
+    });
+
+    it('ignores messages from unknown channels (2)', function(done){
+      namespace1.adapter.subClient.subscribe('woot', function () {
+        namespace3.adapter.pubClient.publish('woot', 'toow');
+      });
+
+      namespace1.adapter.subClient.on('messageBuffer', function () {
+        setTimeout(done, 50);
+      });
+    });
+
     describe('rooms', function () {
       it('returns rooms of a given client', function(done){
         socket1.join('woot1', function () {
@@ -200,6 +214,7 @@ var socket1, socket2, socket3;
       it('returns all rooms accross several nodes', function(done){
         socket1.join('woot1', function () {
           namespace1.adapter.allRooms(function(err, rooms){
+            expect(err).to.be(null);
             expect(rooms).to.have.length(4);
             expect(rooms).to.contain(socket1.id);
             expect(rooms).to.contain(socket2.id);
@@ -212,6 +227,7 @@ var socket1, socket2, socket3;
 
       it('makes a given socket join a room', function(done){
         namespace3.adapter.remoteJoin(socket1.id, 'woot3', function(err){
+          expect(err).to.be(null);
           var rooms = Object.keys(socket1.rooms);
           expect(rooms).to.have.length(2);
           expect(rooms).to.contain('woot3');
@@ -222,6 +238,7 @@ var socket1, socket2, socket3;
       it('makes a given socket leave a room', function(done){
         socket1.join('woot3', function(){
           namespace3.adapter.remoteLeave(socket1.id, 'woot3', function(err){
+            expect(err).to.be(null);
             var rooms = Object.keys(socket1.rooms);
             expect(rooms).to.have.length(1);
             expect(rooms).not.to.contain('woot3');
@@ -237,6 +254,7 @@ var socket1, socket2, socket3;
         }
 
         namespace3.adapter.customRequest('hello', function(err, replies){
+          expect(err).to.be(null);
           expect(replies).to.have.length(3);
           expect(replies).to.contain(namespace1.adapter.uid);
           done();
@@ -297,7 +315,7 @@ function init(options){
           socket1 = _socket1;
           socket2 = _socket2;
           socket3 = _socket3;
-          done();
+          setTimeout(done, 100);
         });
       });
     });