Qpp NPM | npm.io

qpp

Promises Augmentation & Patterns

Installation

npm install qpp --save

Features

Works in node and browser
Support for limiting a bandwidth of executing a set of function by the number of concurrent running functions (TODO) by the number of functions running at particular time period
Support for parallelism Semaphores single resource allocation support for naming consumers (great for debugging deadlocks and leaks) every time you call wait you can provide a name, and use it on signal you can also use auto-provided unique consumer id check unit test: file: test/semaphore.spec.js test: 'it should be possible to wait and signal from multiple callbacks' multiple resources allocation Semaphores hash * collection of semaphores, each addressed by unique name

Plans to add (please create new issue to ask for it)

Time bandwidth

Usage

// Example of two consumers
var QPP = require('./..');
var s = new QPP.Semaphore('airstrip', 1);

// airplane (consumer) 1, waits for passengers to board
setTimeout(function(){
	s.wait() // allocating the resource (airstrip), returns a promise
	.then(function(){ // resource is available, consuming resource
		console.log("Pilot 1: Yes! The airstrip is freee! We are the next one!");
		setTimeout(function(){
			console.log("Pilot 1: Ah, view is much better here!")
			s.signal(); // releasing resource (airstrip)
		}, parseInt(Math.random()*1500)+1);
	});
}, parseInt(Math.random()*1500)+1);

setTimeout(function(){ // airplane (consumer) 2
	s.wait() // allocating the resource (airstrip)
	.then(function(){ // resource is available, consuming resource
		console.log("Pilot 2: Great we are ready to departure, no one on the airstrip!");
		setTimeout(function(){
			console.log("Pilot 2: Dear passangers, enjoy our flight!")
			s.signal(); // releasing resource (airstrip)
		}, parseInt(Math.random()*2000)+1);
	});
}, parseInt(Math.random()*1500)+1);

// For more examples, please check unit tests at @see qpp.Semaphore

Please check documentation for detailed documentation and basic examples.

For more detailed and complex examples, please check the test folder in the repository