Execute an async function per stream data event, pausing the stream when a concurrency limit is saturated
npm install stream-workerstream-worker 
=============
Execute an async function per stream data event, pausing the stream when a concurrency limit is saturated. Inspired by async.queue, optimized for streams.
Supports promises and callbacks.
The Basics
----------
```
npm install stream-worker
Requiring:
`js`
var streamWorker = require('stream-worker');
Promise style:
`js`
function doWork(data){
/ ... do some work with data ... /
return Promise.resolve();
}
streamWorker(stream, doWork, {promises : true, concurrency : 10})
.then(function() {
/ ... the stream is exhausted and all workers are finished ... /
}, function(err) {
/ ... there was an error processing the stream ... /
})
Callback style:
`js
function doWork(data, done){
/ ... do some work with data ... /
return done(err);;
}
streamWorker(stream, doWork, {promises : false, concurrency :10},
function(err) {
/ ... the stream is exhauseted and all workers are finished ... /
}
);
``
Signature
---------
streamWorker(stream, work, options, done)
Where options is an object with 2 optional parameters:
| Parameter | Default | Description|
|------------- |-------------| -----|
| promises |false| true if you want to use the above promises style|
| concurrency| 10|specifies how many concurrent workers you want doing work in the stream |
And done is a callback function if you use the callback workflow.