Linda Socket.IO

Coordinatioin Launguage "Linda" implementation for Node.js and Socket.IO

• https://github.com/shokai/linda-socket.io
• https://npmjs.org/package/linda-socket.io

Install

% npm install linda-socket.io

Requirements

• Node.js
• Socket.IO

Linda

Linda is a coordination launguage for parallel programming.

• http://en.wikipedia.org/wiki/Linda_(coordination_language)
• http://ja.wikipedia.org/wiki/Linda

TupleSpace

Shared memory on Node.js server.

Tuple Operations

• write( tuple , options )
  • put a Tuple into the TupleSpace
  • options = {expire : 300} # => expire after 300 sec
• take( tuple, callback(err, tuple) )
  • get a matched Tuple from the TupleSpace and delete
• read( tuple, callback(err, tuple) )
  • get a matched Tuple from the TupleSpace
• watch( tuple, callback(err, tuple) )
  • overwatch written Tuples in the TupleSpace

Samples

• https://github.com/shokai/linda-socket.io/tree/master/samples
• https://github.com/shokai/linda-job-queue-sample

Install Dependencies

% git clone https://github.com/shokai/linda-socket.io.git
% cd linda-socket.io
% npm install
% npm install -g grunt-cli coffee-script

Chat

% coffee samples/chat/server.coffee 3000

=> http://localhost:3000

Job-Queue

% coffee samples/job-queue/server.coffee 3000

=> http://localhost:3000

Usage

Setup

Server Side (node.js)

var http = require('http');

var app_handler = function(req, res){
  // your web app code
};

var app = http.createServer(app_handler);

var io = require('socket.io').listen(app);

var linda = require('linda-socket.io').Linda.listen({io: io, server: app});

app.listen(3000);
console.log("server start - http://localhost:3000");

Client Side (web browser)

<script src="/socket.io/socket.io.js"></script>
<script src="/linda/linda-socket.io.js"></script>

var socket = io.connect("http://localhost:3000");
var linda = new Linda().connect(socket);

Client Side (node.js)

var LindaClient = require('linda-socket.io').Client;
var socket = require('socket.io-client').connect('http://localhost:3000');
var linda = new LindaClient().connect(socket);

Job-Queue Sample

job client

// connect to tuplespace (shared memory)
var ts = linda.tuplespace("calc");

// request
$("#btn_request").click(function(){
  ts.write({type: "request", query: "1-2+3*4"});
});

// wait result
socket.on('connect', function(){
  // overwatch Tuple
  ts.watch({type: 'result'}, function(err, tuple){
    if(err) return;
    console.log(tuple.data.result); // => "1-2+3*4 = 11"
  });
});

job worker

// connect to tuplespace (shared memory)
var ts = linda.tuplespace("calc");

// calculate
var work = function(){
  ts.take({type: 'request'}, function(err, tuple){
    if(!err){
      var result = eval(tuple.data.query); // => "1-2+3*4"
      console.log(tuple.data.query+" = "+result); // => "1-2+3*4 = 11"
      ts.write({type: 'result', result: result}); // return to 'client' side
    }
    work(); // recursive call
  });
};

socket.on('connect', function(){ // Socket.IO's "connect" event
  work();
});

see more samples

Test

% npm install
% npm install -g grunt-cli coffee-script
% grunt test

watch

% grunt

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request