186 lines
6.2 KiB
Markdown
186 lines
6.2 KiB
Markdown
[](http://badge.fury.io/js/mini-queue)
|
|
[](https://travis-ci.org/alykoshin/mini-queue)
|
|
[](https://coveralls.io/github/alykoshin/mini-queue?branch=master)
|
|
[](https://codeclimate.com/github/alykoshin/mini-queue)
|
|
[](https://inch-ci.org/github/alykoshin/mini-queue)
|
|
|
|
[](https://david-dm.org/alykoshin/mini-queue#info=dependencies)
|
|
[](https://david-dm.org/alykoshin/mini-queue#info=devDependencies)
|
|
|
|
|
|
# mini-queue
|
|
|
|
Job queue
|
|
|
|
|
|
If you have different needs regarding the functionality, please add a [feature request](https://github.com/alykoshin/mini-queue/issues).
|
|
|
|
|
|
## Installation
|
|
|
|
```sh
|
|
npm install --save mini-queue
|
|
```
|
|
|
|
## Usage
|
|
|
|
```
|
|
QueueJob State Diagram (methods of JobQueue object)
|
|
======================
|
|
|
|
|
|
|
createJob |
|
|
+------V-----+
|
|
| new |
|
|
| |
|
|
+---+--+--+--+
|
|
| | | _rejectJob +------------+
|
|
| | +--------------------------------> reject |
|
|
| | | |
|
|
_startJob | | _queueJob +------------+
|
|
| +------------+
|
|
| |
|
|
| +-----v------+ _cancelJob
|
|
| | queue +-----------------+
|
|
| | | |
|
|
| +---+----^---+ |
|
|
| _dequeueJob | | |
|
|
| | | |
|
|
| | | _queueJob |
|
|
| +---v----+---+ +-V----------+
|
|
| | dequeue +---------------> cancel |
|
|
| | | _cancelJob | |
|
|
| +-----+------+ +------------+
|
|
| _startJob |
|
|
| |
|
|
| +----------+
|
|
| |
|
|
+---v----v---+ _terminateJob +------------+
|
|
| process +----------------------> terminate |
|
|
| | |(not implem)|
|
|
+-----+------+ +------------+
|
|
|
|
|
|
|
|
|
|
|
+-----v------+
|
|
| complete |
|
|
| |
|
|
+------------+
|
|
|
|
```
|
|
|
|
`job.journalEntry` for each state (`queue`, `dequeue`, `process`, `complete`, `reject`, `cancel`) stores the time when transition to state occured. If several changes has occured, only the last time is stored(`id` is job identifier `job.id`):
|
|
|
|
```json
|
|
{ id: 4,
|
|
new: 2017-11-10T08:37:17.428Z,
|
|
queue: 2017-11-10T08:37:17.428Z,
|
|
dequeue: 2017-11-10T08:37:17.941Z,
|
|
process: 2017-11-10T08:37:17.941Z,
|
|
complete: 2017-11-10T08:37:18.943Z },
|
|
|
|
```
|
|
|
|
For each `group` and `name` as provided in `option` for `createJob()`, `journalEntries` are kept ar array in `queue.journal` (newest is the first, oldest is the last).
|
|
|
|
Example (`group` and `name` not set, `default` value is used):
|
|
|
|
```json
|
|
journal: { group:
|
|
{ name:
|
|
[ { id: 5,
|
|
new: 2017-11-10T08:37:17.929Z,
|
|
reject: 2017-11-10T08:37:17.929Z },
|
|
. . .
|
|
{ id: 2,
|
|
new: 2017-11-10T08:37:16.426Z,
|
|
queue: 2017-11-10T08:37:16.427Z,
|
|
dequeue: 2017-11-10T08:37:16.937Z,
|
|
process: 2017-11-10T08:37:16.937Z,
|
|
complete: 2017-11-10T08:37:17.941Z } ] } } +2s
|
|
|
|
```
|
|
|
|
Up to `maxJournalLength` option for `createJob()` records are kept.
|
|
|
|
|
|
## Example
|
|
|
|
You may find this example in `demo` subdirectory of the package.
|
|
|
|
```js
|
|
"use strict";
|
|
|
|
process.env.DEBUG = 'queue,app';// + (process.env.DEBUG || '');
|
|
var util = require('util');
|
|
var debug = require('debug')('app');
|
|
|
|
|
|
//var Queue = require('express-queue');
|
|
var Queue = require('../');
|
|
var queue = new Queue({ activeLimit: 1, queuedLimit: 1, maxJournalLength: 4 });
|
|
|
|
// create jobs
|
|
var maxCount = 5,
|
|
count = 0;
|
|
|
|
var interval = setInterval(function() {
|
|
var jobData = {};
|
|
// Create new job for the queue
|
|
// If number of active job is less than `activeLimit`, the job will be started on Node's next tick.
|
|
// Otherwise it will be queued.
|
|
var job = queue.createJob(
|
|
jobData, // we may pass some data to job when calling queue.createJob() function
|
|
{ group: 'group', name: 'name' } // group/name to be used for journal
|
|
);
|
|
|
|
if (++count >= maxCount) {
|
|
clearInterval(interval);
|
|
|
|
setTimeout(()=> { // after last job has finished
|
|
debug('journal:', util.inspect(queue.journal, {depth:3}));
|
|
}, 1500);
|
|
}
|
|
}, 500);
|
|
|
|
|
|
// execute jobs
|
|
|
|
queue.on('process', function(job, jobDone) {
|
|
debug(`queue.on('process'): [${job.id}]: status: ${job.status}, journalEntry: ${JSON.stringify(job.journalEntry)}`);
|
|
// Here the job starts
|
|
//
|
|
// It is also possible to do the processing inside job.on('process'), just be careful
|
|
// to call jobDone() callback once and only once.
|
|
//
|
|
// Value of job.data is set to value passed to queue.createJob()
|
|
//
|
|
// Imitate job processing which takes 1 second to be finished
|
|
setTimeout(function() {
|
|
// Call the callback to signal to the queue that the job has finished
|
|
// and the next one may be started
|
|
jobDone();
|
|
// Now on Node's next tick the next job (if any) will be started
|
|
}, 1000);
|
|
});
|
|
|
|
// Signal about jobs rejected due to queueLimit
|
|
|
|
queue.on('reject', function(job) {
|
|
debug(`queue.on('reject'): [${job.id}]: status: ${job.status}, journalEntry: ${JSON.stringify(job.journalEntry)}`);
|
|
});
|
|
```
|
|
|
|
## Credits
|
|
[Alexander](https://github.com/alykoshin/)
|
|
|
|
|
|
# Links to package pages:
|
|
|
|
[github.com](https://github.com/alykoshin/mini-queue) [npmjs.com](https://www.npmjs.com/package/mini-queue) [travis-ci.org](https://travis-ci.org/alykoshin/mini-queue) [coveralls.io](https://coveralls.io/github/alykoshin/mini-queue) [inch-ci.org](https://inch-ci.org/github/alykoshin/mini-queue)
|
|
|
|
|
|
## License
|
|
|
|
MIT
|