internet-programming/lab3/node_modules/async/priorityQueue.js

98 lines
3.0 KiB
JavaScript

'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = function (worker, concurrency) {
// Start with a normal queue
var q = (0, _queue2.default)(worker, concurrency);
// Override push to accept second parameter representing priority
q.push = function (data, priority, callback) {
if (callback == null) callback = _noop2.default;
if (typeof callback !== 'function') {
throw new Error('task callback must be a function');
}
q.started = true;
if (!(0, _isArray2.default)(data)) {
data = [data];
}
if (data.length === 0) {
// call drain immediately if there are no tasks
return (0, _setImmediate2.default)(function () {
q.drain();
});
}
priority = priority || 0;
var nextNode = q._tasks.head;
while (nextNode && priority >= nextNode.priority) {
nextNode = nextNode.next;
}
for (var i = 0, l = data.length; i < l; i++) {
var item = {
data: data[i],
priority: priority,
callback: callback
};
if (nextNode) {
q._tasks.insertBefore(nextNode, item);
} else {
q._tasks.push(item);
}
}
(0, _setImmediate2.default)(q.process);
};
// Remove unshift function
delete q.unshift;
return q;
};
var _isArray = require('lodash/isArray');
var _isArray2 = _interopRequireDefault(_isArray);
var _noop = require('lodash/noop');
var _noop2 = _interopRequireDefault(_noop);
var _setImmediate = require('./setImmediate');
var _setImmediate2 = _interopRequireDefault(_setImmediate);
var _queue = require('./queue');
var _queue2 = _interopRequireDefault(_queue);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
module.exports = exports['default'];
/**
* The same as [async.queue]{@link module:ControlFlow.queue} only tasks are assigned a priority and
* completed in ascending priority order.
*
* @name priorityQueue
* @static
* @memberOf module:ControlFlow
* @method
* @see [async.queue]{@link module:ControlFlow.queue}
* @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 - 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 priorityQueue object to manage the tasks. There are two
* differences between `queue` and `priorityQueue` objects:
* * `push(task, priority, [callback])` - `priority` should be a number. If an
* array of `tasks` is given, all tasks will be assigned the same priority.
* * The `unshift` method was removed.
*/