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Diffstat (limited to 'node_modules/async/internal/queue.js')
| -rw-r--r-- | node_modules/async/internal/queue.js | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/node_modules/async/internal/queue.js b/node_modules/async/internal/queue.js new file mode 100644 index 0000000..cbc590d --- /dev/null +++ b/node_modules/async/internal/queue.js @@ -0,0 +1,294 @@ +'use strict'; + +Object.defineProperty(exports, "__esModule", { + value: true +}); +exports.default = queue; + +var _onlyOnce = require('./onlyOnce.js'); + +var _onlyOnce2 = _interopRequireDefault(_onlyOnce); + +var _setImmediate = require('./setImmediate.js'); + +var _setImmediate2 = _interopRequireDefault(_setImmediate); + +var _DoublyLinkedList = require('./DoublyLinkedList.js'); + +var _DoublyLinkedList2 = _interopRequireDefault(_DoublyLinkedList); + +var _wrapAsync = require('./wrapAsync.js'); + +var _wrapAsync2 = _interopRequireDefault(_wrapAsync); + +function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } + +function queue(worker, concurrency, payload) { + if (concurrency == null) { + concurrency = 1; + } else if (concurrency === 0) { + throw new RangeError('Concurrency must not be zero'); + } + + var _worker = (0, _wrapAsync2.default)(worker); + var numRunning = 0; + var workersList = []; + const events = { + error: [], + drain: [], + saturated: [], + unsaturated: [], + empty: [] + }; + + function on(event, handler) { + events[event].push(handler); + } + + function once(event, handler) { + const handleAndRemove = (...args) => { + off(event, handleAndRemove); + handler(...args); + }; + events[event].push(handleAndRemove); + } + + function off(event, handler) { + if (!event) return Object.keys(events).forEach(ev => events[ev] = []); + if (!handler) return events[event] = []; + events[event] = events[event].filter(ev => ev !== handler); + } + + function trigger(event, ...args) { + events[event].forEach(handler => handler(...args)); + } + + var processingScheduled = false; + function _insert(data, insertAtFront, rejectOnError, callback) { + if (callback != null && typeof callback !== 'function') { + throw new Error('task callback must be a function'); + } + q.started = true; + + var res, rej; + function promiseCallback(err, ...args) { + // we don't care about the error, let the global error handler + // deal with it + if (err) return rejectOnError ? rej(err) : res(); + if (args.length <= 1) return res(args[0]); + res(args); + } + + var item = q._createTaskItem(data, rejectOnError ? promiseCallback : callback || promiseCallback); + + if (insertAtFront) { + q._tasks.unshift(item); + } else { + q._tasks.push(item); + } + + if (!processingScheduled) { + processingScheduled = true; + (0, _setImmediate2.default)(() => { + processingScheduled = false; + q.process(); + }); + } + + if (rejectOnError || !callback) { + return new Promise((resolve, reject) => { + res = resolve; + rej = reject; + }); + } + } + + function _createCB(tasks) { + return function (err, ...args) { + numRunning -= 1; + + for (var i = 0, l = tasks.length; i < l; i++) { + var task = tasks[i]; + + var index = workersList.indexOf(task); + if (index === 0) { + workersList.shift(); + } else if (index > 0) { + workersList.splice(index, 1); + } + + task.callback(err, ...args); + + if (err != null) { + trigger('error', err, task.data); + } + } + + if (numRunning <= q.concurrency - q.buffer) { + trigger('unsaturated'); + } + + if (q.idle()) { + trigger('drain'); + } + q.process(); + }; + } + + function _maybeDrain(data) { + if (data.length === 0 && q.idle()) { + // call drain immediately if there are no tasks + (0, _setImmediate2.default)(() => trigger('drain')); + return true; + } + return false; + } + + const eventMethod = name => handler => { + if (!handler) { + return new Promise((resolve, reject) => { + once(name, (err, data) => { + if (err) return reject(err); + resolve(data); + }); + }); + } + off(name); + on(name, handler); + }; + + var isProcessing = false; + var q = { + _tasks: new _DoublyLinkedList2.default(), + _createTaskItem(data, callback) { + return { + data, + callback + }; + }, + *[Symbol.iterator]() { + yield* q._tasks[Symbol.iterator](); + }, + concurrency, + payload, + buffer: concurrency / 4, + started: false, + paused: false, + push(data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return; + return data.map(datum => _insert(datum, false, false, callback)); + } + return _insert(data, false, false, callback); + }, + pushAsync(data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return; + return data.map(datum => _insert(datum, false, true, callback)); + } + return _insert(data, false, true, callback); + }, + kill() { + off(); + q._tasks.empty(); + }, + unshift(data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return; + return data.map(datum => _insert(datum, true, false, callback)); + } + return _insert(data, true, false, callback); + }, + unshiftAsync(data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return; + return data.map(datum => _insert(datum, true, true, callback)); + } + return _insert(data, true, true, callback); + }, + remove(testFn) { + q._tasks.remove(testFn); + }, + process() { + // Avoid trying to start too many processing operations. This can occur + // when callbacks resolve synchronously (#1267). + if (isProcessing) { + return; + } + isProcessing = true; + while (!q.paused && numRunning < q.concurrency && q._tasks.length) { + var tasks = [], + data = []; + var l = q._tasks.length; + if (q.payload) l = Math.min(l, q.payload); + for (var i = 0; i < l; i++) { + var node = q._tasks.shift(); + tasks.push(node); + workersList.push(node); + data.push(node.data); + } + + numRunning += 1; + + if (q._tasks.length === 0) { + trigger('empty'); + } + + if (numRunning === q.concurrency) { + trigger('saturated'); + } + + var cb = (0, _onlyOnce2.default)(_createCB(tasks)); + _worker(data, cb); + } + isProcessing = false; + }, + length() { + return q._tasks.length; + }, + running() { + return numRunning; + }, + workersList() { + return workersList; + }, + idle() { + return q._tasks.length + numRunning === 0; + }, + pause() { + q.paused = true; + }, + resume() { + if (q.paused === false) { + return; + } + q.paused = false; + (0, _setImmediate2.default)(q.process); + } + }; + // define these as fixed properties, so people get useful errors when updating + Object.defineProperties(q, { + saturated: { + writable: false, + value: eventMethod('saturated') + }, + unsaturated: { + writable: false, + value: eventMethod('unsaturated') + }, + empty: { + writable: false, + value: eventMethod('empty') + }, + drain: { + writable: false, + value: eventMethod('drain') + }, + error: { + writable: false, + value: eventMethod('error') + } + }); + return q; +} +module.exports = exports['default'];
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