message-oriented socket library for node.js heavily inspired by zeromq
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Readme.md

Super Sockets

Super Sockets is a message-oriented socket library for node.js heavily inspired by zeromq.

Installation

$ npm install super-sockets

Features

  • message oriented
  • automated reconnection
  • light-weight wire protocol
  • light-weight implementation (~300 SLOC)
  • supports arbitrary binary message (msgpack, json, BLOBS, etc)
  • supports JSON messages out of the box
  • push / pull pattern
  • pub / sub pattern
  • event emitter pattern

Push / Pull

PushSockets distribute messages round-robin:

var ss = require('super-sockets')
  , sock = ss.socket('push');

sock.bind(3000);
console.log('push server started');

setInterval(function(){
  sock.send('hello');
}, 150);

Receiver of PushSocket messages:

var ss = require('super-sockets')
  , sock = ss.socket('pull');

sock.connect(3000);

sock.on('message', function(msg){
  console.log(msg.toString());
});

Both PushSockets and PullSockets may .bind() or .connect(). In the following configuration the push socket is bound and pull "workers" connect to it to receive work:

push bind

This configuration shows the inverse, where workers connect to a "sink" to push results:

pull bind

Pub / Sub

PubSockets send messages to all subscribers without queueing:

var ss = require('super-sockets')
  , sock = ss.socket('pub');

sock.bind(3000);
console.log('pub server started');

setInterval(function(){
  sock.send('hello');
}, 500);

SubSocket provides selective reception of messages from a PubSocket:

var ss = require('super-sockets')
  , sock = ss.socket('sub');

sock.connect(3000);

sock.on('message', function(msg){
  console.log(msg.toString());
});

EmitterSocket

EmitterSocket's send and receive messages behaving like regular node EventEmitters. This is achieved by using pub / sub sockets behind the scenes, automatically assigned the "json" codec. Currently we simply choose define the EmitterSocket as a PubSocket if you .bind(), and SubSocket if you .connect(), providing the natural API you're used to:

server.js:

var ss = require('super-sockets')
  , sock = ss.socket('emitter');

sock.bind(3000);
console.log('pub server started');

setInterval(function(){
  sock.emit('login', { name: 'tobi' });
}, 500);

client.js:

var ss = require('super-sockets')
  , sock = ss.socket('emitter');

sock.connect(3000);
console.log('sub client connected');

sock.on('login', function(user){
  console.log('%s signed in', user.name);
});

Protocol

The wire protocol is simple and very much zeromq-like, where <length> is a BE 24 bit unsigned integer representing a maximum length of roughly ~16mb. The <meta> data byte is currently only used to store the codec, for example "json" is simply 1, in turn JSON messages received on the client end will then be automatically decoded for you by selecting this same codec.

 octet:     0      1      2      3      <length>
        +------+------+------+------+------------------...
        | meta | <length>           | data ...
        +------+------+------+------+------------------...

Thus 5 bytes is the smallest message super sockets supports at the moment. Later if necessary we can use the meta to indicate a small message and ditch octet 2 and 3 allowing for 3 byte messages.

Codecs

To define a codec simply invoke the ss.codec.define() method, for example here is the JSON codec:

var ss = require('super-sockets');

ss.codec.define('json', {
  encode: JSON.stringify,
  decode: JSON.parse
});

Note: codecs must be defined on both the sending and receiving ends, otherwise super sockets cannot properly decode the messages. You may of course ignore this feature all together and simply pass encoded data to .send().

Performance

I haven't profiled or tuned anything yet but so far for on my macbook pro.

64 byte messages:


      min: 22,085 ops/s
     mean: 585,944 ops/s
   median: 606,176 ops/s
    total: 326,7126 ops in 6.5s
  through: 35.76318359375 mb/s

1k messages:


      min: 1,851 ops/s
     mean: 34,0156 ops/s
   median: 449,660 ops/s
    total: 329,831 ops in 4.241s
  through: 332.18359375 mb/s

What's it good for?

Super sockets are not meant to combat zeromq nor provide feature parity, but provide a nice solution when you don't need the insane nanosecond latency or language interoperability that zeromq provides as super sockets do not rely on any third-party compiled libraries.

Running tests

$ npm install
$ make test

Links

Todo

  • more tests
  • code cov
  • acks
  • make socket options configurable
  • clean up queue / sock
  • emitter style on top of pubsub with multipart
  • weighted fair queuing
  • use mocha for tests
  • multipart frames
  • cap batch size
  • zero-copy for batches...
  • make batching configurable... disable for lower latency
  • binary support for EmitterSocket (requires multipart)
  • subscriptions
  • ...

License

(The MIT License)

Copyright (c) 2012 TJ Holowaychuk <tj@vision-media.ca>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.