qpp
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Promises Augmentation & Patterns
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Promises Augmentation & Patterns
[](https://travis-ci.org/mprinc/qpp)
[](https://david-dm.org/mprinc/qpp)
[](https://coveralls.io/r/mprinc/qpp)
[](https://www.gittip.com/mprinc/)
[](https://nodei.co/npm/qpp/)
npm install qpp --save
* 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](http://mprinc.github.io/qpp/ "QPP Documentation") for detailed documentation and basic examples.
For more detailed and complex examples, please check the ***test*** folder in the repository
npm test
* 1.0.0 Initial release