sc-codec-pbf

Minimal binary codec for SC based on pbf.
This codec helps reduce bandwidth usage and is ideal for games and other high-throughput applications.

This module is designed to be hooked up on both the client and server.

This codec also assumes you're using one proto message type per SocketCluster client/worker instance for maximum efficiency, and that you're either sending objects that can be encoded with that message, or strings.

To install, use:

npm install --save sc-codec-pbf

Install pbf and compile a JavaScript module from a .proto file:

# example.proto
message Example {
  int64 x = 1;
  int64 y = 2;
  string playerID = 3;
  PlayerState playerState = 4;
  enum PlayerState {
    MOVING = 0;
    TALKING = 1;
    IN_COMBAT = 2;
  }
}

$ npm install -g pbf
$ pbf example.proto > example.js

On the server, inside worker.js, you should use:

var scCodecPbf = require('sc-codec-pbf');
 
// ...pbf
// This needs to go inside the run function - Near the top.
var Example = require('./example.js').Example;
worker.scServer.setCodecEngine(new scCodecPbf(Example));

On the client-side, you can either include the sc-codec-pbf module using your favorite bundler such as Browserify or Webpack or you can include the sc-codec-pbf.js file using a script tag; this will expose the scCodecPbf object globally. To use it, you just need to add it on connect:

var socket = socketCluster.connect({
  // ...
  codecEngine: new scCodecPbf(Example)
});
 
socket.emit('playerUpdate', {
  x: 500,
  y: 204,
  playerID: 'sdshu8ijodln',
  playerState: 0
})

Note that the codec used on the client and on the server always need to match.

Early Benchmarks

This hasn't been extensively battle tested yet, but early comparisons show a reduction of around half from sc-codec-min-bin. With the example above, Chrome WS frame inspector showed:

• JSON Stringify/Parse: 87 bytes
• sc-codec-min-bin: 54 bytes
• sc-codec-pbf: 27 bytes

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Contributing

To build the global script for the browser:

browserify -s scCodecPbf index.js > sc-codec-pbf.js