![Build Status](https://travis-ci.org/adleroliveira/jobQ)

jobQ

Async and parallel execution of jobs, tasks and processes. This library is aimed to solve the problem of having to limit how many parallel tasks you want to perform.
It accepts several kinds of sources including Arrays, Promises, Functions, etc.

Installation

bash
npm install --save jobq


Usage

js
var jobQ = require('jobq')
var queue = new jobQ({
  process: function(x, callback){
    setTimeout(function() {
      callback(null, x)
    }, 3000)
  },
  source: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
  maxProceses: 2
})

queue.start()`

`Options`


* source: required View source section.
* process: required View process section.
* maxProceses:

`` indicates how many jobs will run in parallel. A value of `0` means 'no limit'. Default `1`


* debug:

`` enables or disables debug. Default `false`


* stopOnError:

`` indicates if jobs will stop after first error or continue. If enabled, `processFinish` will be called with status `error` if an error occurs. Default `false`


* pooling:

`` pooling timeout in milliseconds. When enabled, JobQ will continue to try and fetch data from the source (`Function`

 only). Default: No pooling
Events

js
var queue = new jobQ({
  process: myProcess,
  source: mySource,
  maxProceses: 2
})
queue.on('start', function(){})
queue.on('jobFetch', function(){})
queue.on('jobRun', function(){})
queue.on('jobFinish', function(){})
queue.on('processFinish', function(){})
queue.on('pooling', function(){})
queue.on('pause', function(){})
queue.on('resume', function(){})
queue.on('error', function(){})

queue.start()`

#### start Emited once after calling`start()`with an object containing: * startTime:``date when start was called * processed:``jobs processed so far * errors:``jobs errored so far * maxProceses:`` maxProceses passed to constructor. Default `1`* stopOnError:`` stopOnError passed to constructor. Default `false`* sourceType:`` Detected source type (`array`, `function`, `promise` or `stream`). * status:`` queue status. will always be running at this point.

#### jobFetch Emited once for each job before fetching it from the queue with an object containing: * jobsRunning:`` current amount of processing jobs. It will not count the one that triggered the event.

#### jobRun Emited once for each job when it starts running with: *`` job id (autoincrement)

#### jobFinish Emited once after calling`start()`with an object containing: * jobId:``job id * jobStartTime:``date when job started to process * jobEndTime:``date when job finishes to process * result:``job result received * jobsRunning:`` current amount of processing jobs. It will count the one that triggered the event.

#### processFinish Emited once after calling`start()`with an object containing: * startTime:``date when start was called * endTime:``date when queue was fully processed * processed:``total amount of jobs processed * errors:``total amount of errors * maxProceses:`` maxProceses passed to constructor. Default `1`* stopOnError:`` stopOnError passed to constructor. Default `false`* sourceType:`` Detected source type (`array`, `function`, `promise` or `stream`). * status:`` queue status. will always be `finished` or `error`.

#### pooling Emited every time the source function returns`null` as value and JobQ starts waiting to check again. Only emited if `pooling`is enabled, with an object containing: * startTime:``date when start was called * processed:``jobs processed so far * errors:``jobs errored so far * maxProceses:`` maxProceses passed to constructor. Default `1`* stopOnError:`` stopOnError passed to constructor. Default `false`* sourceType:`` Detected source type (`array`, `function`, `promise` or `stream`). * status:`` queue status. will always be pooling at this point.

#### pause Emited once after calling`pause()`with an object containing: * startTime:``date when start was called * processed:``jobs processed so far * errors:``jobs errored so far * maxProceses:`` maxProceses passed to constructor. Default `1`* stopOnError:`` stopOnError passed to constructor. Default `false`* sourceType:`` Detected source type (`array`, `function`, `promise` or `stream`). * status:`` queue status. will always be paused at this point.

#### resume Emited once after calling`resume()`with an object containing: * startTime:``date when start was called * processed:``jobs processed so far * errors:``jobs errored so far * maxProceses:`` maxProceses passed to constructor. Default `1`* stopOnError:`` stopOnError passed to constructor. Default `false`* sourceType:`` Detected source type (`array`, `function`, `promise` or `stream`). * status:`` queue status. will always be running at this point.

#### error Emited once for each job error: *`` error received

`Source`


Source is where data will be fetched in order to be processed. It can be one of the following:
*

`` like `[1, 2, 3]`

.
*

`` of promise like `[promise1, promise2, promise3]`

.
*

 returning a value.
*

 returning a promise.
*

`` returning nothing and passing data to `callback`

 with error as the first parameter and response as the second one.
*

`` that supports `on('readable')` and `read()`

.
*

`` that resolves to any of the previous source types.

IMPORTANT: When using `Function` and `Promise` sources, you must pass `null` as value to stop execution.

`Process`


Process function receives a value from the queue and be anby of the following:
*

 that returns a value
*

 that returns a Promise wich resolves to a value
*

`` that returns nothing and executes a `callback`` with error as the first parameter and response as the second one.

![Build Status](https://travis-ci.org/adleroliveira/jobQ)

jobQ

Installation

bash
npm install --save jobq


Usage

js
var jobQ = require('jobq')
var queue = new jobQ({
  process: function(x, callback){
    setTimeout(function() {
      callback(null, x)
    }, 3000)
  },
  source: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
  maxProceses: 2
})

queue.start()`

`Options`


* source: required View source section.
* process: required View process section.
* maxProceses:

`` indicates how many jobs will run in parallel. A value of `0` means 'no limit'. Default `1`


* debug:

`` enables or disables debug. Default `false`


* stopOnError:

`` indicates if jobs will stop after first error or continue. If enabled, `processFinish` will be called with status `error` if an error occurs. Default `false`


* pooling:

`` pooling timeout in milliseconds. When enabled, JobQ will continue to try and fetch data from the source (`Function`

 only). Default: No pooling
Events

js
var queue = new jobQ({
  process: myProcess,
  source: mySource,
  maxProceses: 2
})
queue.on('start', function(){})
queue.on('jobFetch', function(){})
queue.on('jobRun', function(){})
queue.on('jobFinish', function(){})
queue.on('processFinish', function(){})
queue.on('pooling', function(){})
queue.on('pause', function(){})
queue.on('resume', function(){})
queue.on('error', function(){})

queue.start()`

#### jobRun Emited once for each job when it starts running with: *`` job id (autoincrement)

#### error Emited once for each job error: *`` error received

`Source`


Source is where data will be fetched in order to be processed. It can be one of the following:
*

`` like `[1, 2, 3]`

.
*

`` of promise like `[promise1, promise2, promise3]`

.
*

 returning a value.
*

 returning a promise.
*

`` returning nothing and passing data to `callback`

 with error as the first parameter and response as the second one.
*

`` that supports `on('readable')` and `read()`

.
*

`` that resolves to any of the previous source types.

IMPORTANT: When using `Function` and `Promise` sources, you must pass `null` as value to stop execution.

`Process`


Process function receives a value from the queue and be anby of the following:
*

 that returns a value
*

 that returns a Promise wich resolves to a value
*

`` that returns nothing and executes a `callback`` with error as the first parameter and response as the second one.