325 lines
8.1 KiB
JavaScript
325 lines
8.1 KiB
JavaScript
/*
|
|
MIT License http://www.opensource.org/licenses/mit-license.php
|
|
Author Tobias Koppers @sokra
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
const { SyncHook, AsyncSeriesHook } = require("tapable");
|
|
const ArrayQueue = require("./ArrayQueue");
|
|
|
|
const QUEUED_STATE = 0;
|
|
const PROCESSING_STATE = 1;
|
|
const DONE_STATE = 2;
|
|
|
|
let inHandleResult = 0;
|
|
|
|
/**
|
|
* @template T
|
|
* @callback Callback
|
|
* @param {Error=} err
|
|
* @param {T=} result
|
|
*/
|
|
|
|
/**
|
|
* @template T
|
|
* @template K
|
|
* @template R
|
|
*/
|
|
class AsyncQueueEntry {
|
|
/**
|
|
* @param {T} item the item
|
|
* @param {Callback<R>} callback the callback
|
|
*/
|
|
constructor(item, callback) {
|
|
this.item = item;
|
|
/** @type {typeof QUEUED_STATE | typeof PROCESSING_STATE | typeof DONE_STATE} */
|
|
this.state = QUEUED_STATE;
|
|
this.callback = callback;
|
|
/** @type {Callback<R>[] | undefined} */
|
|
this.callbacks = undefined;
|
|
this.result = undefined;
|
|
this.error = undefined;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @template T
|
|
* @template K
|
|
* @template R
|
|
*/
|
|
class AsyncQueue {
|
|
/**
|
|
* @param {Object} options options object
|
|
* @param {string=} options.name name of the queue
|
|
* @param {number=} options.parallelism how many items should be processed at once
|
|
* @param {AsyncQueue<any, any, any>=} options.parent parent queue, which will have priority over this queue and with shared parallelism
|
|
* @param {function(T): K=} options.getKey extract key from item
|
|
* @param {function(T, Callback<R>): void} options.processor async function to process items
|
|
*/
|
|
constructor({ name, parallelism, parent, processor, getKey }) {
|
|
this._name = name;
|
|
this._parallelism = parallelism || 1;
|
|
this._processor = processor;
|
|
this._getKey =
|
|
getKey || /** @type {(T) => K} */ (item => /** @type {any} */ (item));
|
|
/** @type {Map<K, AsyncQueueEntry<T, K, R>>} */
|
|
this._entries = new Map();
|
|
/** @type {ArrayQueue<AsyncQueueEntry<T, K, R>>} */
|
|
this._queued = new ArrayQueue();
|
|
/** @type {AsyncQueue<any, any, any>[]} */
|
|
this._children = undefined;
|
|
this._activeTasks = 0;
|
|
this._willEnsureProcessing = false;
|
|
this._needProcessing = false;
|
|
this._stopped = false;
|
|
this._root = parent ? parent._root : this;
|
|
if (parent) {
|
|
if (this._root._children === undefined) {
|
|
this._root._children = [this];
|
|
} else {
|
|
this._root._children.push(this);
|
|
}
|
|
}
|
|
|
|
this.hooks = {
|
|
/** @type {AsyncSeriesHook<[T]>} */
|
|
beforeAdd: new AsyncSeriesHook(["item"]),
|
|
/** @type {SyncHook<[T]>} */
|
|
added: new SyncHook(["item"]),
|
|
/** @type {AsyncSeriesHook<[T]>} */
|
|
beforeStart: new AsyncSeriesHook(["item"]),
|
|
/** @type {SyncHook<[T]>} */
|
|
started: new SyncHook(["item"]),
|
|
/** @type {SyncHook<[T, Error, R]>} */
|
|
result: new SyncHook(["item", "error", "result"])
|
|
};
|
|
|
|
this._ensureProcessing = this._ensureProcessing.bind(this);
|
|
}
|
|
|
|
/**
|
|
* @param {T} item a item
|
|
* @param {Callback<R>} callback callback function
|
|
* @returns {void}
|
|
*/
|
|
add(item, callback) {
|
|
if (this._stopped) return callback(new Error("Queue was stopped"));
|
|
this.hooks.beforeAdd.callAsync(item, err => {
|
|
if (err) {
|
|
callback(err);
|
|
return;
|
|
}
|
|
const key = this._getKey(item);
|
|
const entry = this._entries.get(key);
|
|
if (entry !== undefined) {
|
|
if (entry.state === DONE_STATE) {
|
|
process.nextTick(() => callback(entry.error, entry.result));
|
|
} else if (entry.callbacks === undefined) {
|
|
entry.callbacks = [callback];
|
|
} else {
|
|
entry.callbacks.push(callback);
|
|
}
|
|
return;
|
|
}
|
|
const newEntry = new AsyncQueueEntry(item, callback);
|
|
if (this._stopped) {
|
|
this.hooks.added.call(item);
|
|
this._root._activeTasks++;
|
|
process.nextTick(() =>
|
|
this._handleResult(newEntry, new Error("Queue was stopped"))
|
|
);
|
|
} else {
|
|
this._entries.set(key, newEntry);
|
|
this._queued.enqueue(newEntry);
|
|
const root = this._root;
|
|
root._needProcessing = true;
|
|
if (root._willEnsureProcessing === false) {
|
|
root._willEnsureProcessing = true;
|
|
setImmediate(root._ensureProcessing);
|
|
}
|
|
this.hooks.added.call(item);
|
|
}
|
|
});
|
|
}
|
|
|
|
/**
|
|
* @param {T} item a item
|
|
* @returns {void}
|
|
*/
|
|
invalidate(item) {
|
|
const key = this._getKey(item);
|
|
const entry = this._entries.get(key);
|
|
this._entries.delete(key);
|
|
if (entry.state === QUEUED_STATE) {
|
|
this._queued.delete(entry);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @returns {void}
|
|
*/
|
|
stop() {
|
|
this._stopped = true;
|
|
const queue = this._queued;
|
|
this._queued = new ArrayQueue();
|
|
const root = this._root;
|
|
for (const entry of queue) {
|
|
this._entries.delete(this._getKey(entry.item));
|
|
root._activeTasks++;
|
|
this._handleResult(entry, new Error("Queue was stopped"));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @returns {void}
|
|
*/
|
|
increaseParallelism() {
|
|
const root = this._root;
|
|
root._parallelism++;
|
|
/* istanbul ignore next */
|
|
if (root._willEnsureProcessing === false && root._needProcessing) {
|
|
root._willEnsureProcessing = true;
|
|
setImmediate(root._ensureProcessing);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @returns {void}
|
|
*/
|
|
decreaseParallelism() {
|
|
const root = this._root;
|
|
root._parallelism--;
|
|
}
|
|
|
|
/**
|
|
* @param {T} item an item
|
|
* @returns {boolean} true, if the item is currently being processed
|
|
*/
|
|
isProcessing(item) {
|
|
const key = this._getKey(item);
|
|
const entry = this._entries.get(key);
|
|
return entry !== undefined && entry.state === PROCESSING_STATE;
|
|
}
|
|
|
|
/**
|
|
* @param {T} item an item
|
|
* @returns {boolean} true, if the item is currently queued
|
|
*/
|
|
isQueued(item) {
|
|
const key = this._getKey(item);
|
|
const entry = this._entries.get(key);
|
|
return entry !== undefined && entry.state === QUEUED_STATE;
|
|
}
|
|
|
|
/**
|
|
* @param {T} item an item
|
|
* @returns {boolean} true, if the item is currently queued
|
|
*/
|
|
isDone(item) {
|
|
const key = this._getKey(item);
|
|
const entry = this._entries.get(key);
|
|
return entry !== undefined && entry.state === DONE_STATE;
|
|
}
|
|
|
|
/**
|
|
* @returns {void}
|
|
*/
|
|
_ensureProcessing() {
|
|
while (this._activeTasks < this._parallelism) {
|
|
const entry = this._queued.dequeue();
|
|
if (entry === undefined) break;
|
|
this._activeTasks++;
|
|
entry.state = PROCESSING_STATE;
|
|
this._startProcessing(entry);
|
|
}
|
|
this._willEnsureProcessing = false;
|
|
if (this._queued.length > 0) return;
|
|
if (this._children !== undefined) {
|
|
for (const child of this._children) {
|
|
while (this._activeTasks < this._parallelism) {
|
|
const entry = child._queued.dequeue();
|
|
if (entry === undefined) break;
|
|
this._activeTasks++;
|
|
entry.state = PROCESSING_STATE;
|
|
child._startProcessing(entry);
|
|
}
|
|
if (child._queued.length > 0) return;
|
|
}
|
|
}
|
|
if (!this._willEnsureProcessing) this._needProcessing = false;
|
|
}
|
|
|
|
/**
|
|
* @param {AsyncQueueEntry<T, K, R>} entry the entry
|
|
* @returns {void}
|
|
*/
|
|
_startProcessing(entry) {
|
|
this.hooks.beforeStart.callAsync(entry.item, err => {
|
|
if (err) {
|
|
this._handleResult(entry, err);
|
|
return;
|
|
}
|
|
let inCallback = false;
|
|
try {
|
|
this._processor(entry.item, (e, r) => {
|
|
inCallback = true;
|
|
this._handleResult(entry, e, r);
|
|
});
|
|
} catch (err) {
|
|
if (inCallback) throw err;
|
|
this._handleResult(entry, err, null);
|
|
}
|
|
this.hooks.started.call(entry.item);
|
|
});
|
|
}
|
|
|
|
/**
|
|
* @param {AsyncQueueEntry<T, K, R>} entry the entry
|
|
* @param {Error=} err error, if any
|
|
* @param {R=} result result, if any
|
|
* @returns {void}
|
|
*/
|
|
_handleResult(entry, err, result) {
|
|
this.hooks.result.callAsync(entry.item, err, result, hookError => {
|
|
const error = hookError || err;
|
|
|
|
const callback = entry.callback;
|
|
const callbacks = entry.callbacks;
|
|
entry.state = DONE_STATE;
|
|
entry.callback = undefined;
|
|
entry.callbacks = undefined;
|
|
entry.result = result;
|
|
entry.error = error;
|
|
|
|
const root = this._root;
|
|
root._activeTasks--;
|
|
if (root._willEnsureProcessing === false && root._needProcessing) {
|
|
root._willEnsureProcessing = true;
|
|
setImmediate(root._ensureProcessing);
|
|
}
|
|
|
|
if (inHandleResult++ > 3) {
|
|
process.nextTick(() => {
|
|
callback(error, result);
|
|
if (callbacks !== undefined) {
|
|
for (const callback of callbacks) {
|
|
callback(error, result);
|
|
}
|
|
}
|
|
});
|
|
} else {
|
|
callback(error, result);
|
|
if (callbacks !== undefined) {
|
|
for (const callback of callbacks) {
|
|
callback(error, result);
|
|
}
|
|
}
|
|
}
|
|
inHandleResult--;
|
|
});
|
|
}
|
|
}
|
|
|
|
module.exports = AsyncQueue;
|