Edit File: cargo.js
'use strict'; Object.defineProperty(exports, "__esModule", { value: true }); exports.default = cargo; var _queue = require('./internal/queue'); var _queue2 = _interopRequireDefault(_queue); function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } /** * A cargo of tasks for the worker function to complete. Cargo inherits all of * the same methods and event callbacks as [`queue`]{@link module:ControlFlow.queue}. * @typedef {Object} CargoObject * @memberOf module:ControlFlow * @property {Function} length - A function returning the number of items * waiting to be processed. Invoke like `cargo.length()`. * @property {number} payload - An `integer` for determining how many tasks * should be process per round. This property can be changed after a `cargo` is * created to alter the payload on-the-fly. * @property {Function} push - Adds `task` to the `queue`. The callback is * called once the `worker` has finished processing the task. Instead of a * single task, an array of `tasks` can be submitted. The respective callback is * used for every task in the list. Invoke like `cargo.push(task, [callback])`. * @property {Function} saturated - A callback that is called when the * `queue.length()` hits the concurrency and further tasks will be queued. * @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} idle - a function returning false if there are items * waiting or being processed, or true if not. Invoke like `cargo.idle()`. * @property {Function} pause - a function that pauses the processing of tasks * until `resume()` is called. Invoke like `cargo.pause()`. * @property {Function} resume - a function that resumes the processing of * queued tasks when the queue is paused. Invoke like `cargo.resume()`. * @property {Function} kill - a function that removes the `drain` callback and * empties remaining tasks from the queue forcing it to go idle. Invoke like `cargo.kill()`. */ /** * Creates a `cargo` object with the specified payload. Tasks added to the * cargo will be processed altogether (up to the `payload` limit). If the * `worker` is in progress, the task is queued until it becomes available. Once * the `worker` has completed some tasks, each callback of those tasks is * called. Check out [these](https://camo.githubusercontent.com/6bbd36f4cf5b35a0f11a96dcd2e97711ffc2fb37/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130382f62626330636662302d356632392d313165322d393734662d3333393763363464633835382e676966) [animations](https://camo.githubusercontent.com/f4810e00e1c5f5f8addbe3e9f49064fd5d102699/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130312f38346339323036362d356632392d313165322d383134662d3964336430323431336266642e676966) * for how `cargo` and `queue` work. * * While [`queue`]{@link module:ControlFlow.queue} passes only one task to one of a group of workers * at a time, cargo passes an array of tasks to a single worker, repeating * when the worker is finished. * * @name cargo * @static * @memberOf module:ControlFlow * @method * @see [async.queue]{@link module:ControlFlow.queue} * @category Control Flow * @param {AsyncFunction} worker - An asynchronous function for processing an array * of queued tasks. Invoked with `(tasks, callback)`. * @param {number} [payload=Infinity] - An optional `integer` for determining * how many tasks should be processed per round; if omitted, the default is * unlimited. * @returns {module:ControlFlow.CargoObject} A cargo object to manage the tasks. Callbacks can * attached as certain properties to listen for specific events during the * lifecycle of the cargo and inner queue. * @example * * // create a cargo object with payload 2 * var cargo = async.cargo(function(tasks, callback) { * for (var i=0; i<tasks.length; i++) { * console.log('hello ' + tasks[i].name); * } * callback(); * }, 2); * * // add some items * cargo.push({name: 'foo'}, function(err) { * console.log('finished processing foo'); * }); * cargo.push({name: 'bar'}, function(err) { * console.log('finished processing bar'); * }); * cargo.push({name: 'baz'}, function(err) { * console.log('finished processing baz'); * }); */ function cargo(worker, payload) { return (0, _queue2.default)(worker, 1, payload); } module.exports = exports['default'];
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