You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
183 lines
4.9 KiB
183 lines
4.9 KiB
# fastq [![build status](https://secure.travis-ci.org/mcollina/fastq.png)](http://travis-ci.org/mcollina/fastq) |
|
|
|
Fast, in memory work queue. `fastq` is API compatible with |
|
[`async.queue`](https://github.com/caolan/async#queueworker-concurrency) |
|
|
|
Benchmarks (1 million tasks): |
|
|
|
* setImmediate: 1359ms |
|
* fastq: 1492ms |
|
* async.queue: 4039ms |
|
* neoAsync.queue: 4476ms |
|
|
|
Obtained on node 4.2.2, on a MacBook Pro 2014 (i7, 16GB of RAM). |
|
|
|
If you need zero-overhead series function call, check out |
|
[fastseries](http://npm.im/fastseries). For zero-overhead parallel |
|
function call, check out [fastparallel](http://npm.im/fastparallel). |
|
|
|
[![js-standard-style](https://raw.githubusercontent.com/feross/standard/master/badge.png)](https://github.com/feross/standard) |
|
|
|
* <a href="#install">Installation</a> |
|
* <a href="#basic">Basic Example</a> |
|
* <a href="#api">API</a> |
|
* <a href="#licence">Licence & copyright</a> |
|
|
|
## Install |
|
|
|
`npm i fastq --save` |
|
|
|
## Usage |
|
|
|
```js |
|
'use strict' |
|
|
|
var queue = require('fastq')(worker, 1) |
|
|
|
queue.push(42, function (err, result) { |
|
if (err) { throw err } |
|
console.log('the result is', result) |
|
}) |
|
|
|
function worker (arg, cb) { |
|
cb(null, 42 * 2) |
|
} |
|
``` |
|
|
|
### Setting this |
|
|
|
```js |
|
'use strict' |
|
|
|
var that = { hello: 'world' } |
|
var queue = require('fastq')(that, worker, 1) |
|
|
|
queue.push(42, function (err, result) { |
|
if (err) { throw err } |
|
console.log(this) |
|
console.log('the result is', result) |
|
}) |
|
|
|
function worker (arg, cb) { |
|
console.log(this) |
|
cb(null, 42 * 2) |
|
} |
|
``` |
|
|
|
## API |
|
|
|
* <a href="#fastqueue"><code>fastqueue()</code></a> |
|
* <a href="#push"><code>queue#<b>push()</b></code></a> |
|
* <a href="#unshift"><code>queue#<b>unshift()</b></code></a> |
|
* <a href="#pause"><code>queue#<b>pause()</b></code></a> |
|
* <a href="#resume"><code>queue#<b>resume()</b></code></a> |
|
* <a href="#idle"><code>queue#<b>idle()</b></code></a> |
|
* <a href="#length"><code>queue#<b>length()</b></code></a> |
|
* <a href="#kill"><code>queue#<b>kill()</b></code></a> |
|
* <a href="#killAndDrain"><code>queue#<b>killAndDrain()</b></code></a> |
|
* <a href="#concurrency"><code>queue#<b>concurrency</b></code></a> |
|
* <a href="#drain"><code>queue#<b>drain</b></code></a> |
|
* <a href="#empty"><code>queue#<b>empty</b></code></a> |
|
* <a href="#saturated"><code>queue#<b>saturated</b></code></a> |
|
|
|
------------------------------------------------------- |
|
<a name="fastqueue"></a> |
|
### fastqueue([that], worker, concurrency) |
|
|
|
Creates a new queue. |
|
|
|
Arguments: |
|
|
|
* `that`, optional context of the `worker` function. |
|
* `worker`, worker function, it would be called with `that` as `this`, |
|
if that is specified. |
|
* `concurrency`, number of concurrent tasks that could be executed in |
|
parallel. |
|
|
|
------------------------------------------------------- |
|
<a name="push"></a> |
|
### queue.push(task, done) |
|
|
|
Add a task at the end of the queue. `done(err, result)` will be called |
|
when the task was processed. |
|
|
|
------------------------------------------------------- |
|
<a name="unshift"></a> |
|
### queue.unshift(task, done) |
|
|
|
Add a task at the beginning of the queue. `done(err, result)` will be called |
|
when the task was processed. |
|
|
|
------------------------------------------------------- |
|
<a name="pause"></a> |
|
### queue.pause() |
|
|
|
Pause the processing of tasks. Currently worked tasks are not |
|
stopped. |
|
|
|
------------------------------------------------------- |
|
<a name="resume"></a> |
|
### queue.resume() |
|
|
|
Resume the processing of tasks. |
|
|
|
------------------------------------------------------- |
|
<a name="idle"></a> |
|
### queue.idle() |
|
|
|
Returns `false` if there are tasks being processed or waiting to be processed. |
|
`true` otherwise. |
|
|
|
------------------------------------------------------- |
|
<a name="length"></a> |
|
### queue.length() |
|
|
|
Returns the number of tasks waiting to be processed (in the queue). |
|
|
|
------------------------------------------------------- |
|
<a name="kill"></a> |
|
### queue.kill() |
|
|
|
Removes all tasks waiting to be processed, and reset `drain` to an empty |
|
function. |
|
|
|
------------------------------------------------------- |
|
<a name="killAndDrain"></a> |
|
### queue.killAndDrain() |
|
|
|
Same than `kill` but the `drain` function will be called before reset to empty. |
|
|
|
------------------------------------------------------- |
|
<a name="concurrency"></a> |
|
### queue.concurrency |
|
|
|
Property that returns the number of concurrent tasks that could be executed in |
|
parallel. It can be altered at runtime. |
|
|
|
------------------------------------------------------- |
|
<a name="drain"></a> |
|
### queue.drain |
|
|
|
Function that will be called when the last |
|
item from the queue has been processed by a worker. |
|
It can be altered at runtime. |
|
|
|
------------------------------------------------------- |
|
<a name="empty"></a> |
|
### queue.empty |
|
|
|
Function that will be called when the last |
|
item from the queue has been assigned to a worker. |
|
It can be altered at runtime. |
|
|
|
------------------------------------------------------- |
|
<a name="saturated"></a> |
|
### queue.saturated |
|
|
|
Function that will be called when the queue hits the concurrency |
|
limit. |
|
It can be altered at runtime. |
|
|
|
## License |
|
|
|
ISC
|
|
|