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Diffstat (limited to 'lib/cargoQueue.js')
-rw-r--r-- | lib/cargoQueue.js | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/lib/cargoQueue.js b/lib/cargoQueue.js new file mode 100644 index 0000000..381195a --- /dev/null +++ b/lib/cargoQueue.js @@ -0,0 +1,59 @@ +import queue from './internal/queue'; + +/** + * Creates a `cargoQueue` object with the specified payload. Tasks added to the + * cargoQueue will be processed together (up to the `payload` limit) in `concurrency` parallel workers. + * If the all `workers` are in progress, the task is queued until one becomes available. Once + * a `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, and [`cargo`]{@link module:ControlFlow.cargo} passes an array of tasks to a single worker, + * the cargoQueue passes an array of tasks to multiple parallel workers. + * + * @name cargoQueue + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.queue]{@link module:ControlFlow.queue} + * @see [async.cargo]{@link module:ControlFLow.cargo} + * @category Control Flow + * @param {AsyncFunction} worker - An asynchronous function for processing an array + * of queued tasks. Invoked with `(tasks, 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. + * @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 cargoQueue object to manage the tasks. Callbacks can + * attached as certain properties to listen for specific events during the + * lifecycle of the cargoQueue and inner queue. + * @example + * + * // create a cargoQueue object with payload 2 and concurrency 2 + * var cargoQueue = async.cargoQueue(function(tasks, callback) { + * for (var i=0; i<tasks.length; i++) { + * console.log('hello ' + tasks[i].name); + * } + * callback(); + * }, 2, 2); + * + * // add some items + * cargoQueue.push({name: 'foo'}, function(err) { + * console.log('finished processing foo'); + * }); + * cargoQueue.push({name: 'bar'}, function(err) { + * console.log('finished processing bar'); + * }); + * cargoQueue.push({name: 'baz'}, function(err) { + * console.log('finished processing baz'); + * }); + * cargoQueue.push({name: 'boo'}, function(err) { + * console.log('finished processing boo'); + * }); + */ +export default function cargo(worker, concurrency, payload) { + return queue(worker, concurrency, payload); +} |