lean-mq

Lean and customizable in-memory message queue. Main motivation is to provide grouping based message / job queue functionality.

In future - a plan is to provide different persistence options.

Quick start

Simple queue

var leanmq = require('lean-mq');
var q = leanmq.Queue('test');

// function to handle tasks
q.handle(function(obj){
	
	console.log('handle - obj = ', obj );
	return Promise.resolve(true);
	
});

// add tasks
q.add( { key: "1", data:"abc" } );

//
// Prints: handle - obj = { key: "1", data:"abc" }
//

Chain (groupped queue)

var leanmq = require('lean-mq');

var opts = {window:5000};
// window -> time-window (ms) to use for groupping, default is 5 seconds
var c = leanmq.Chain('test', opts); 


// function to attach one or more workers
q.attach(function(obj){
	
	console.log('worker 1 - obj = ', obj );
	return Promise.resolve(true);
	
});
q.attach(function(obj){
	
	console.log('worker 2 - obj = ', obj );
	return Promise.resolve(true);
	
});

// add tasks
q.add( "a", { id: 1 } );
q.add( "b", { id: 2 } );
q.add( "a", { id: 3 } );
q.add( "b", { id: 4 } );

//
// Prints: 
// worker 1 - obj = { key: "a", data:[{ id: 1 }, { id: 3 }] }
// worker 2 - obj = { key: "b", data:[{ id: 2 }, { id: 4 }] }
//

Chain [persistent]

var leanmq = require('lean-mq');
var opts = {window: 5000, storage: 'redis', connection: {host: "localhost" }};

var c = leanmq.Chain('test', opts); 

// everything else is the same
// for all connection options, see:
// https://github.com/NodeRedis/node-redis#options-object-properties
/*
{
    host: '127.0.0.1',
    port: 6379,
    db: 0,
    options: {},
}
*/

API

Queue

constructor(name, opts)

Constructor for the simple queue object, opts are optional

// DEFAULT_OPTIONS
{
	storage: 'memory', // memory, redis
	connection: null,
	attempts: 3,
	retry_delay: 1000
}

.handle(function)

Sets a handler function. Function should accept an object as argument and return promise.resolve / reject

.add(msg)

Adds a task to the simple queue, that is then processed by function

.on(eventName, function)

Listens to event emitter - new

Chain

constructor(name, opts)

Constructor for the chain (groupped queue) object, opts are optional

// DEFAULT_OPTIONS
{
	window: 5000 // 5 seconds
}

.attach(function)

Sets a worker function. Function should accept an object as argument and return promise.resolve / reject Round-robin is used to balance the load.

.add(key, msg)

Adds a task to the chain, that is then processed by one of functions after time. Key is used for groupping

.on(eventName, function)

Listens to event emitter - error

Broker

constructor(opts)

// DEFAULT_OPTIONS
{
	port: 2525 // to accept Socket connection
}

Client (requires running broker)

constructor(opts)

// DEFAULT_OPTIONS
{
	name: 'none',
	url: 'localhost:2525' // broker address and port
}

.send / .connect / .subsribe / .close

Performance

lean-mq performance

comparision

name	add	feature 1	feature 2	feature 3
lean-mq	0 ms	+	+	-
some other	0 ms	+	-	+

Other projects

• lean-cache - https://www.npmjs.com/package/lean-cache