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- 'use strict';
- Object.defineProperty(exports, "__esModule", {
- value: true
- });
- exports.default = function (worker, concurrency) {
- var _worker = (0, _wrapAsync2.default)(worker);
- return (0, _queue2.default)((items, cb) => {
- _worker(items[0], cb);
- }, concurrency, 1);
- };
- var _queue = require('./internal/queue.js');
- var _queue2 = _interopRequireDefault(_queue);
- var _wrapAsync = require('./internal/wrapAsync.js');
- var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
- function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
- module.exports = exports['default'];
- /**
- * A queue of tasks for the worker function to complete.
- * @typedef {Iterable} 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 {number} payload - an integer that specifies how many items are
- * passed to the worker function at a time. only applies if this is a
- * [cargo]{@link module:ControlFlow.cargo} object
- * @property {AsyncFunction} 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 {AsyncFunction} unshift - add a new task to the front of the `queue`.
- * Invoke with `queue.unshift(task, [callback])`.
- * @property {AsyncFunction} pushAsync - the same as `q.push`, except this returns
- * a promise that rejects if an error occurs.
- * @property {AsyncFunction} unshiftAsync - the same as `q.unshift`, except this returns
- * a promise that rejects if an error occurs.
- * @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 function that sets a callback that is
- * called when the number of running workers hits the `concurrency` limit, and
- * further tasks will be queued. If the callback is omitted, `q.saturated()`
- * returns a promise for the next occurrence.
- * @property {Function} unsaturated - a function that sets a callback that is
- * called when the number of running workers is less than the `concurrency` &
- * `buffer` limits, and further tasks will not be queued. If the callback is
- * omitted, `q.unsaturated()` returns a promise for the next occurrence.
- * @property {number} buffer - A minimum threshold buffer in order to say that
- * the `queue` is `unsaturated`.
- * @property {Function} empty - a function that sets a callback that is called
- * when the last item from the `queue` is given to a `worker`. If the callback
- * is omitted, `q.empty()` returns a promise for the next occurrence.
- * @property {Function} drain - a function that sets a callback that is called
- * when the last item from the `queue` has returned from the `worker`. If the
- * callback is omitted, `q.drain()` returns a promise for the next occurrence.
- * @property {Function} error - a function that sets a callback that is called
- * when a task errors. Has the signature `function(error, task)`. If the
- * callback is omitted, `error()` returns a promise that rejects on the next
- * error.
- * @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()`.
- *
- * @example
- * const q = async.queue(worker, 2)
- * q.push(item1)
- * q.push(item2)
- * q.push(item3)
- * // queues are iterable, spread into an array to inspect
- * const items = [...q] // [item1, item2, item3]
- * // or use for of
- * for (let item of q) {
- * console.log(item)
- * }
- *
- * q.drain(() => {
- * console.log('all done')
- * })
- * // or
- * await q.drain()
- */
- /**
- * 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`'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 be
- * 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('hello ' + task.name);
- * callback();
- * }, 2);
- *
- * // assign a callback
- * q.drain(function() {
- * console.log('all items have been processed');
- * });
- * // or await the end
- * await q.drain()
- *
- * // assign an error callback
- * q.error(function(err, task) {
- * console.error('task experienced an error');
- * });
- *
- * // add some items to the queue
- * q.push({name: 'foo'}, function(err) {
- * console.log('finished processing foo');
- * });
- * // callback is optional
- * q.push({name: 'bar'});
- *
- * // add some items to the queue (batch-wise)
- * q.push([{name: 'baz'},{name: 'bay'},{name: 'bax'}], function(err) {
- * console.log('finished processing item');
- * });
- *
- * // add some items to the front of the queue
- * q.unshift({name: 'bar'}, function (err) {
- * console.log('finished processing bar');
- * });
- */
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