source: trip-planner-front/node_modules/async/queue.js@ 6a3a178

Last change on this file since 6a3a178 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

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1'use strict';
2
3Object.defineProperty(exports, "__esModule", {
4 value: true
5});
6
7exports.default = function (worker, concurrency) {
8 var _worker = (0, _wrapAsync2.default)(worker);
9 return (0, _queue2.default)(function (items, cb) {
10 _worker(items[0], cb);
11 }, concurrency, 1);
12};
13
14var _queue = require('./internal/queue');
15
16var _queue2 = _interopRequireDefault(_queue);
17
18var _wrapAsync = require('./internal/wrapAsync');
19
20var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
21
22function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
23
24module.exports = exports['default'];
25
26/**
27 * A queue of tasks for the worker function to complete.
28 * @typedef {Object} QueueObject
29 * @memberOf module:ControlFlow
30 * @property {Function} length - a function returning the number of items
31 * waiting to be processed. Invoke with `queue.length()`.
32 * @property {boolean} started - a boolean indicating whether or not any
33 * items have been pushed and processed by the queue.
34 * @property {Function} running - a function returning the number of items
35 * currently being processed. Invoke with `queue.running()`.
36 * @property {Function} workersList - a function returning the array of items
37 * currently being processed. Invoke with `queue.workersList()`.
38 * @property {Function} idle - a function returning false if there are items
39 * waiting or being processed, or true if not. Invoke with `queue.idle()`.
40 * @property {number} concurrency - an integer for determining how many `worker`
41 * functions should be run in parallel. This property can be changed after a
42 * `queue` is created to alter the concurrency on-the-fly.
43 * @property {Function} push - add a new task to the `queue`. Calls `callback`
44 * once the `worker` has finished processing the task. Instead of a single task,
45 * a `tasks` array can be submitted. The respective callback is used for every
46 * task in the list. Invoke with `queue.push(task, [callback])`,
47 * @property {Function} unshift - add a new task to the front of the `queue`.
48 * Invoke with `queue.unshift(task, [callback])`.
49 * @property {Function} remove - remove items from the queue that match a test
50 * function. The test function will be passed an object with a `data` property,
51 * and a `priority` property, if this is a
52 * [priorityQueue]{@link module:ControlFlow.priorityQueue} object.
53 * Invoked with `queue.remove(testFn)`, where `testFn` is of the form
54 * `function ({data, priority}) {}` and returns a Boolean.
55 * @property {Function} saturated - a callback that is called when the number of
56 * running workers hits the `concurrency` limit, and further tasks will be
57 * queued.
58 * @property {Function} unsaturated - a callback that is called when the number
59 * of running workers is less than the `concurrency` & `buffer` limits, and
60 * further tasks will not be queued.
61 * @property {number} buffer - A minimum threshold buffer in order to say that
62 * the `queue` is `unsaturated`.
63 * @property {Function} empty - a callback that is called when the last item
64 * from the `queue` is given to a `worker`.
65 * @property {Function} drain - a callback that is called when the last item
66 * from the `queue` has returned from the `worker`.
67 * @property {Function} error - a callback that is called when a task errors.
68 * Has the signature `function(error, task)`.
69 * @property {boolean} paused - a boolean for determining whether the queue is
70 * in a paused state.
71 * @property {Function} pause - a function that pauses the processing of tasks
72 * until `resume()` is called. Invoke with `queue.pause()`.
73 * @property {Function} resume - a function that resumes the processing of
74 * queued tasks when the queue is paused. Invoke with `queue.resume()`.
75 * @property {Function} kill - a function that removes the `drain` callback and
76 * empties remaining tasks from the queue forcing it to go idle. No more tasks
77 * should be pushed to the queue after calling this function. Invoke with `queue.kill()`.
78 */
79
80/**
81 * Creates a `queue` object with the specified `concurrency`. Tasks added to the
82 * `queue` are processed in parallel (up to the `concurrency` limit). If all
83 * `worker`s are in progress, the task is queued until one becomes available.
84 * Once a `worker` completes a `task`, that `task`'s callback is called.
85 *
86 * @name queue
87 * @static
88 * @memberOf module:ControlFlow
89 * @method
90 * @category Control Flow
91 * @param {AsyncFunction} worker - An async function for processing a queued task.
92 * If you want to handle errors from an individual task, pass a callback to
93 * `q.push()`. Invoked with (task, callback).
94 * @param {number} [concurrency=1] - An `integer` for determining how many
95 * `worker` functions should be run in parallel. If omitted, the concurrency
96 * defaults to `1`. If the concurrency is `0`, an error is thrown.
97 * @returns {module:ControlFlow.QueueObject} A queue object to manage the tasks. Callbacks can
98 * attached as certain properties to listen for specific events during the
99 * lifecycle of the queue.
100 * @example
101 *
102 * // create a queue object with concurrency 2
103 * var q = async.queue(function(task, callback) {
104 * console.log('hello ' + task.name);
105 * callback();
106 * }, 2);
107 *
108 * // assign a callback
109 * q.drain = function() {
110 * console.log('all items have been processed');
111 * };
112 *
113 * // add some items to the queue
114 * q.push({name: 'foo'}, function(err) {
115 * console.log('finished processing foo');
116 * });
117 * q.push({name: 'bar'}, function (err) {
118 * console.log('finished processing bar');
119 * });
120 *
121 * // add some items to the queue (batch-wise)
122 * q.push([{name: 'baz'},{name: 'bay'},{name: 'bax'}], function(err) {
123 * console.log('finished processing item');
124 * });
125 *
126 * // add some items to the front of the queue
127 * q.unshift({name: 'bar'}, function (err) {
128 * console.log('finished processing bar');
129 * });
130 */
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