summaryrefslogtreecommitdiff
path: root/v2/queue.js.html
blob: 34bdebc2ed32e80428c4e731fb6b184e9dbf7040 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
<!DOCTYPE html>
<html lang="en">
<head>

    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>queue.js - Documentation</title>


    <link rel="icon" href="favicon.ico?v=2">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/bootstrap/3.3.6/css/bootstrap.min.css">

    <link rel="stylesheet" href="styles/prettify-tomorrow.css">

    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Montserrat:400,700">
    <link rel="stylesheet" href="styles/jsdoc-default.css">

    <!--[if lt IE 9]>
      <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
    <![endif]-->
    <link type="text/css" rel="stylesheet" href="https://cdn.jsdelivr.net/ionicons/2.0.1/css/ionicons.min.css">
</head>
<body>

<div class="navbar navbar-default navbar-fixed-top">
  <div class="navbar-header">
    <a class="navbar-brand" href="#">
        <img src="img/async-logo.svg" alt="Async.js">
    </a>
  </div>
  <ul class="nav navbar-nav">
    <li id="version-dropdown" class="dropdown">
      <a href="#" class="dropdown-toggle vertically-centered" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">v2.6.2 <span class="caret"></span>
      </a>
      <ul class="dropdown-menu">
        <li><a href="docs.html">v2.6.2</a></li>
        <li>
          <a href="https://github.com/caolan/async/blob/v1.5.2/README.md">v1.5.x</a>
        </li>
      </ul>
    </li>
    <li><a href="./index.html">Home</a></li>
    <li><a href="./docs.html">Docs</a></li>
    <li><a href="https://github.com/caolan/async/blob/master/CHANGELOG.md">Changelog</a></li>
    <li><a href="https://github.com/caolan/async"><i class="ion-social-github" aria-hidden="true"></i></a></li>
  </ul>
  <ul class="nav navbar-nav navbar-right">
    <form class="navbar-form navbar-left" role="search">
      <div class="form-group">
        <input type="text" class="form-control typeahead" id="doc-search" placeholder="Search" autofocus>
      </div>
    </form>
  </ul>
</div>


<input type="checkbox" id="nav-trigger" class="nav-trigger">
<label for="nav-trigger" class="navicon-button x">
  <div class="navicon"></div>
</label>

<label for="nav-trigger" class="overlay"></label>

<div id="main">
    <div id="main-container" data-spy="scroll" data-target="#toc" data-offset="50">
        
        <h1 class="page-title">queue.js</h1>
        

        



    
    <section>
        <article>
            <pre class="prettyprint source linenums"><code>import queue from &apos;./internal/queue&apos;;
import wrapAsync from &apos;./internal/wrapAsync&apos;;

/**
 * A queue of tasks for the worker function to complete.
 * @typedef {Object} QueueObject
 * @memberOf module:ControlFlow
 * @property {Function} length - a function returning the number of items
 * waiting to be processed. Invoke with `queue.length()`.
 * @property {boolean} started - a boolean indicating whether or not any
 * items have been pushed and processed by the queue.
 * @property {Function} running - a function returning the number of items
 * currently being processed. Invoke with `queue.running()`.
 * @property {Function} workersList - a function returning the array of items
 * currently being processed. Invoke with `queue.workersList()`.
 * @property {Function} idle - a function returning false if there are items
 * waiting or being processed, or true if not. Invoke with `queue.idle()`.
 * @property {number} concurrency - an integer for determining how many `worker`
 * functions should be run in parallel. This property can be changed after a
 * `queue` is created to alter the concurrency on-the-fly.
 * @property {Function} push - add a new task to the `queue`. Calls `callback`
 * once the `worker` has finished processing the task. Instead of a single task,
 * a `tasks` array can be submitted. The respective callback is used for every
 * task in the list. Invoke with `queue.push(task, [callback])`,
 * @property {Function} unshift - add a new task to the front of the `queue`.
 * Invoke with `queue.unshift(task, [callback])`.
 * @property {Function} remove - remove items from the queue that match a test
 * function.  The test function will be passed an object with a `data` property,
 * and a `priority` property, if this is a
 * [priorityQueue]{@link module:ControlFlow.priorityQueue} object.
 * Invoked with `queue.remove(testFn)`, where `testFn` is of the form
 * `function ({data, priority}) {}` and returns a Boolean.
 * @property {Function} saturated - a callback that is called when the number of
 * running workers hits the `concurrency` limit, and further tasks will be
 * queued.
 * @property {Function} unsaturated - a callback that is called when the number
 * of running workers is less than the `concurrency` &amp; `buffer` limits, and
 * further tasks will not be queued.
 * @property {number} buffer - A minimum threshold buffer in order to say that
 * the `queue` is `unsaturated`.
 * @property {Function} empty - a callback that is called when the last item
 * from the `queue` is given to a `worker`.
 * @property {Function} drain - a callback that is called when the last item
 * from the `queue` has returned from the `worker`.
 * @property {Function} error - a callback that is called when a task errors.
 * Has the signature `function(error, task)`.
 * @property {boolean} paused - a boolean for determining whether the queue is
 * in a paused state.
 * @property {Function} pause - a function that pauses the processing of tasks
 * until `resume()` is called. Invoke with `queue.pause()`.
 * @property {Function} resume - a function that resumes the processing of
 * queued tasks when the queue is paused. Invoke with `queue.resume()`.
 * @property {Function} kill - a function that removes the `drain` callback and
 * empties remaining tasks from the queue forcing it to go idle. No more tasks
 * should be pushed to the queue after calling this function. Invoke with `queue.kill()`.
 */

/**
 * Creates a `queue` object with the specified `concurrency`. Tasks added to the
 * `queue` are processed in parallel (up to the `concurrency` limit). If all
 * `worker`s are in progress, the task is queued until one becomes available.
 * Once a `worker` completes a `task`, that `task`&apos;s callback is called.
 *
 * @name queue
 * @static
 * @memberOf module:ControlFlow
 * @method
 * @category Control Flow
 * @param {AsyncFunction} worker - An async function for processing a queued task.
 * If you want to handle errors from an individual task, pass a callback to
 * `q.push()`. Invoked with (task, callback).
 * @param {number} [concurrency=1] - An `integer` for determining how many
 * `worker` functions should be run in parallel.  If omitted, the concurrency
 * defaults to `1`.  If the concurrency is `0`, an error is thrown.
 * @returns {module:ControlFlow.QueueObject} A queue object to manage the tasks. Callbacks can
 * attached as certain properties to listen for specific events during the
 * lifecycle of the queue.
 * @example
 *
 * // create a queue object with concurrency 2
 * var q = async.queue(function(task, callback) {
 *     console.log(&apos;hello &apos; + task.name);
 *     callback();
 * }, 2);
 *
 * // assign a callback
 * q.drain = function() {
 *     console.log(&apos;all items have been processed&apos;);
 * };
 *
 * // add some items to the queue
 * q.push({name: &apos;foo&apos;}, function(err) {
 *     console.log(&apos;finished processing foo&apos;);
 * });
 * q.push({name: &apos;bar&apos;}, function (err) {
 *     console.log(&apos;finished processing bar&apos;);
 * });
 *
 * // add some items to the queue (batch-wise)
 * q.push([{name: &apos;baz&apos;},{name: &apos;bay&apos;},{name: &apos;bax&apos;}], function(err) {
 *     console.log(&apos;finished processing item&apos;);
 * });
 *
 * // add some items to the front of the queue
 * q.unshift({name: &apos;bar&apos;}, function (err) {
 *     console.log(&apos;finished processing bar&apos;);
 * });
 */
export default function (worker, concurrency) {
    var _worker = wrapAsync(worker);
    return queue(function (items, cb) {
        _worker(items[0], cb);
    }, concurrency, 1);
}
</code></pre>
        </article>
    </section>




    <footer>
    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Sun May 26 2019 15:21:49 GMT-0700 (Pacific Daylight Time) using the Minami theme.
 Documentation has been modified from the original.  For more information, please see the <a href="https://github.com/caolan/async">async</a> repository.</footer></div>
</div>

<nav id="toc">
    <h3>Methods:</h3><ul class="nav methods"><li class="toc-header"><a href="docs.html#collections">Collections</a></li><li data-type="method" class="toc-method"><a href="docs.html#concat">concat</a></li><li data-type="method" class="toc-method"><a href="docs.html#concatLimit">concatLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#concatSeries">concatSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#detect">detect</a></li><li data-type="method" class="toc-method"><a href="docs.html#detectLimit">detectLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#detectSeries">detectSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#each">each</a></li><li data-type="method" class="toc-method"><a href="docs.html#eachLimit">eachLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#eachOf">eachOf</a></li><li data-type="method" class="toc-method"><a href="docs.html#eachOfLimit">eachOfLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#eachOfSeries">eachOfSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#eachSeries">eachSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#every">every</a></li><li data-type="method" class="toc-method"><a href="docs.html#everyLimit">everyLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#everySeries">everySeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#filter">filter</a></li><li data-type="method" class="toc-method"><a href="docs.html#filterLimit">filterLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#filterSeries">filterSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#groupBy">groupBy</a></li><li data-type="method" class="toc-method"><a href="docs.html#groupByLimit">groupByLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#groupBySeries">groupBySeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#map">map</a></li><li data-type="method" class="toc-method"><a href="docs.html#mapLimit">mapLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#mapSeries">mapSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#mapValues">mapValues</a></li><li data-type="method" class="toc-method"><a href="docs.html#mapValuesLimit">mapValuesLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#mapValuesSeries">mapValuesSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#reduce">reduce</a></li><li data-type="method" class="toc-method"><a href="docs.html#reduceRight">reduceRight</a></li><li data-type="method" class="toc-method"><a href="docs.html#reject">reject</a></li><li data-type="method" class="toc-method"><a href="docs.html#rejectLimit">rejectLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#rejectSeries">rejectSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#some">some</a></li><li data-type="method" class="toc-method"><a href="docs.html#someLimit">someLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#someSeries">someSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#sortBy">sortBy</a></li><li data-type="method" class="toc-method"><a href="docs.html#transform">transform</a></li><li class="toc-header"><a href="docs.html#controlflow">Control Flow</a></li><li data-type="method" class="toc-method"><a href="docs.html#applyEach">applyEach</a></li><li data-type="method" class="toc-method"><a href="docs.html#applyEachSeries">applyEachSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#auto">auto</a></li><li data-type="method" class="toc-method"><a href="docs.html#autoInject">autoInject</a></li><li data-type="method" class="toc-method"><a href="docs.html#cargo">cargo</a></li><li data-type="method" class="toc-method"><a href="docs.html#compose">compose</a></li><li data-type="method" class="toc-method"><a href="docs.html#doDuring">doDuring</a></li><li data-type="method" class="toc-method"><a href="docs.html#doUntil">doUntil</a></li><li data-type="method" class="toc-method"><a href="docs.html#doWhilst">doWhilst</a></li><li data-type="method" class="toc-method"><a href="docs.html#during">during</a></li><li data-type="method" class="toc-method"><a href="docs.html#forever">forever</a></li><li data-type="method" class="toc-method"><a href="docs.html#parallel">parallel</a></li><li data-type="method" class="toc-method"><a href="docs.html#parallelLimit">parallelLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#priorityQueue">priorityQueue</a></li><li data-type="method" class="toc-method active"><a href="docs.html#queue">queue</a></li><li data-type="method" class="toc-method"><a href="docs.html#race">race</a></li><li data-type="method" class="toc-method"><a href="docs.html#retry">retry</a></li><li data-type="method" class="toc-method"><a href="docs.html#retryable">retryable</a></li><li data-type="method" class="toc-method"><a href="docs.html#seq">seq</a></li><li data-type="method" class="toc-method"><a href="docs.html#series">series</a></li><li data-type="method" class="toc-method"><a href="docs.html#times">times</a></li><li data-type="method" class="toc-method"><a href="docs.html#timesLimit">timesLimit</a></li><li data-type="method" class="toc-method"><a href="docs.html#timesSeries">timesSeries</a></li><li data-type="method" class="toc-method"><a href="docs.html#tryEach">tryEach</a></li><li data-type="method" class="toc-method"><a href="docs.html#until">until</a></li><li data-type="method" class="toc-method"><a href="docs.html#waterfall">waterfall</a></li><li data-type="method" class="toc-method"><a href="docs.html#whilst">whilst</a></li><li class="toc-header"><a href="docs.html#utils">Utils</a></li><li data-type="method" class="toc-method"><a href="docs.html#apply">apply</a></li><li data-type="method" class="toc-method"><a href="docs.html#asyncify">asyncify</a></li><li data-type="method" class="toc-method"><a href="docs.html#constant">constant</a></li><li data-type="method" class="toc-method"><a href="docs.html#dir">dir</a></li><li data-type="method" class="toc-method"><a href="docs.html#ensureAsync">ensureAsync</a></li><li data-type="method" class="toc-method"><a href="docs.html#log">log</a></li><li data-type="method" class="toc-method"><a href="docs.html#memoize">memoize</a></li><li data-type="method" class="toc-method"><a href="docs.html#nextTick">nextTick</a></li><li data-type="method" class="toc-method"><a href="docs.html#reflect">reflect</a></li><li data-type="method" class="toc-method"><a href="docs.html#reflectAll">reflectAll</a></li><li data-type="method" class="toc-method"><a href="docs.html#setImmediate">setImmediate</a></li><li data-type="method" class="toc-method"><a href="docs.html#timeout">timeout</a></li><li data-type="method" class="toc-method"><a href="docs.html#unmemoize">unmemoize</a></li></ul><h3>Methods:</h3>
</nav>

<br class="clear">




<script src="https://cdn.jsdelivr.net/prettify/0.1/prettify.js"></script>

<script src="https://cdn.jsdelivr.net/jquery/2.2.4/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="https://cdn.jsdelivr.net/typeahead.js/0.11.1/typeahead.bundle.min.js"></script>
<script>prettyPrint();</script>
<script src="scripts/async.js"></script>

<script src="scripts/linenumber.js" async></script>
<script src="scripts/jsdoc-custom.js" async></script>
</body>