https://github.com/flarestart/wait-queue
WaitQueue is an async implement of Array
https://github.com/flarestart/wait-queue
await-promises loop-task queue
Last synced: about 1 month ago
JSON representation
WaitQueue is an async implement of Array
- Host: GitHub
- URL: https://github.com/flarestart/wait-queue
- Owner: flarestart
- License: mit
- Created: 2017-01-17T12:28:06.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2023-12-30T20:51:22.000Z (almost 2 years ago)
- Last Synced: 2025-08-25T03:41:49.820Z (about 1 month ago)
- Topics: await-promises, loop-task, queue
- Language: TypeScript
- Homepage:
- Size: 78.1 KB
- Stars: 18
- Watchers: 3
- Forks: 4
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# wait-queue
[![Travis CI][ci-image]][ci-url]
[![Coveralls][coverage-image]][coverage-url]
[![NPM version][npm-image]][npm-url]
[![Downloads][downloads-image]][downloads-url]
A javascript wait queue object handle infinity loop tasks more efficiently
WaitQueue is an async implements of Array
## Table of Contents
- [How to use](#how-to-use)
- [Requirements](#requirements)
- [Change Log](./CHANGELOG.md)
- [Properties](#properties)
- [Methods](#methods)
- [Benchmark](#benchmark)
Examples
- [Iterator](#iterator)
- [Multi Worker](#example-multi-worker)
- [Push a function](#example-push-a-function)
- [Loop Tasks](#example-loop-tasks)
- [Using with co](#using-with-co)
## How to use
```shell
$ npm install wait-queue
```
### TypeScript
```typescript
import WaitQueue from 'wait-queue';
const wq = new WaitQueue();
async function run() {
const item = await wq.shift();
console.log(item);
}
setTimeout(() => {
wq.push('foo');
}, 1000);
run();
```
### JS
```js
const WaitQueue = require('wait-queue');
const wq = new WaitQueue();
wq.shift().then(function(item) {
// will wait until got value
console.log(item);
// "foo"
});
setTimeout(function() {
wq.push('foo');
}, 1000);
```
## Requirements
**Build**: Node.js >= 8.x
## Properties
### wq.length
Length of the WaitQueue(readonly)
### wq.queue
A LinkedList, used to store the queue items, Do not modify it directly
### wq.listeners
If no elements in queue yet, listener will add here, Don't modify it
## Methods
### wq.push(item1, [item2])
Add items to the end of the queue, will return length of the queue
### wq.shift().then( item => )
Got an item from front of the queue, this is a Promise method, if there's no item
in the queue, it will wait
### wq.unshift(item)
Put an item in front of the queue, will return length of the queue
### wq.pop().then( item => )
Got an item at the end of the queue, this is a Promise method, if there's no item
in the queue, it will wait
### wq.empty() alias of wq.clearQueue()
Clear the queue, Won't clear listeners
### wq.clearListeners()
Clear waited listeners of the queue
## Benchmark
```
$ git clone https://github.com/flarestart/wait-queue.git
$ cd wait-queue
$ npm install
$ npm run benchmark
```
Sample data in Macbook Pro MF839/8GB
### 1.1.0(Improve benchmark code)
Array.push(1k data) speed test x 629,538 ops/sec ±22.90% (26 runs sampled)
Array.push(1k data) 1000000 times then Array.shift() speed test x 492 ops/sec ±1.02% (89 runs sampled)
WaitQueue.push(1k data) speed test x 501,581 ops/sec ±23.45% (14 runs sampled)
WaitQueue.unshift(1k data) speed test x 447,272 ops/sec ±24.80% (14 runs sampled)
WaitQueue.shift() speed test x 315,356 ops/sec ±14.30% (52 runs sampled)
WaitQueue.pop() speed test x 240,568 ops/sec ±51.35% (39 runs sampled)
WaitQueue.push(1k data) 1000000 times then WaitQueue.shift() speed test x 476,918 ops/sec ±26.68% (29 runs sampled)
WaitQueue.push(1k data) 1000000 times then WaitQueue.pop() speed test x 471,668 ops/sec ±25.08% (31 runs sampled)
Array.push(4k data) speed test x 119,981 ops/sec ±61.52% (14 runs sampled)
Array.push(4k data) 1000000 times then Array.shift() speed test x 479 ops/sec ±1.41% (86 runs sampled)
WaitQueue.push(4k data) speed test x 147,153 ops/sec ±46.03% (14 runs sampled)
WaitQueue.unshift(4k data) speed test x 157,694 ops/sec ±37.29% (16 runs sampled)
WaitQueue.push(4k data) 1000000 times then WaitQueue.shift() speed test x 447,783 ops/sec ±28.01% (31 runs sampled)
WaitQueue.push(4k data) 1000000 times then WaitQueue.pop() speed test x 409,826 ops/sec ±30.73% (28 runs sampled)
### 1.0.3(Use LinkedList)
.push() 1k data speed test x 511,367 ops/sec ±31.07% (27 runs sampled)
.unshift() 1k data speed test x 269,995 ops/sec ±39.60% (14 runs sampled)
.push() 4k data speed test x 41,531 ops/sec ±12.20% (7 runs sampled)
.unshift() 4k data speed test x 35,928 ops/sec ±5.11% (8 runs sampled)
.shift() 69614.33093950555 /s
### 1.0.2(Use Array)
.push() 1k data speed test x 554,552 ops/sec ±26.09% (25 runs sampled)
.unshift() 1k data speed test x 132 ops/sec ±2.96% (72 runs sampled)
.push() 4k data speed test x 75,107 ops/sec ±22.32% (9 runs sampled)
.unshift() 4k data speed test x 115 ops/sec ±2.15% (71 runs sampled)
.shift() `wait too long, I didn't wait for the result, I guess is about 110/s`
## Example: Iterator
use for ... of to get all values
```js
'use strict';
const WaitQueue = require('wait-queue');
const wq = new WaitQueue();
wq.push(1, 2, 3, 4, 5);
console.log('length', wq.length);
for (var n of wq) {
console.log(n);
}
```
## Example: Multi Worker
```js
'use strict';
const WaitQueue = require('wait-queue');
const wq = new WaitQueue();
// worker loop
function run_worker(id, time) {
var loop = function() {
// get item at the front of the queue
wq.shift().then(item => {
console.log('worker-' + id);
console.log(' queue-len', wq.queue.length, 'item', item);
setTimeout(loop, time);
});
};
loop();
}
// worker-a use 1s every task
run_worker('a', 1000);
// worker-b use 2s every task
run_worker('b', 2000);
// worker-c use 5s every task
run_worker('c', 5000);
// add a task every 500ms
for (var n = 0; n < 20; n++) {
wq.push(n);
}
```
## Example: Push a function
```js
'use strict';
const WaitQueue = require('wait-queue');
const wq = new WaitQueue();
// there's no task here
wq.shift().then(item => {
item.call();
});
// add a function as item
wq.push(function() {
console.log('a function');
});
```
## Example: Loop Tasks
```js
'use strict';
const WaitQueue = require('wait-queue');
const wq = new WaitQueue();
function loop() {
// put first element out of queue
wq.shift()
.then(function(item) {
// do some job on item
console.log(item);
// do next loop
setImmediate(loop);
})
.catch(function(e) {
console.error('error', e);
setImmediate(loop);
});
}
setImmediate(loop);
var taskID = 0;
var interval;
// add a task every 1s
interval = setInterval(function() {
wq.push({
taskid: taskID++,
});
}, 1000);
```
## Using with co
```js
'use strict';
const WaitQueue = require('wait-queue');
const co = require('co');
const wq = new WaitQueue();
co(function*() {
while (true) {
let item = yield wq.shift();
// catch errors from runTask, so that it won't stop the task loop
try {
yield runTask(item);
} catch (e) {
// output errors
console.error('error', item);
// you can re do task from here
wq.push(item);
console.log('add error item to end of queue');
}
}
});
function runTask(item) {
return new Promise(function(resolve, reject) {
// a task will run 2s
setTimeout(function() {
if (Math.random() > 0.8) {
return reject(new Error('some unknown error'));
}
console.log('done', item);
resolve();
}, 1000);
});
}
// add a task every 1s
var taskID = 0;
setInterval(function() {
wq.push({
taskid: taskID++,
});
}, 1000);
```
## License
MIT
[coverage-image]: https://img.shields.io/coveralls/flarestart/wait-queue.svg
[coverage-url]: https://coveralls.io/github/flarestart/wait-queue
[ci-image]: https://img.shields.io/travis/flarestart/wait-queue.svg?branch=master
[ci-url]: https://travis-ci.org/flarestart/wait-queue
[npm-image]: https://img.shields.io/npm/v/wait-queue.svg
[npm-url]: https://npmjs.org/package/wait-queue
[downloads-image]: http://img.shields.io/npm/dm/wait-queue.svg
[downloads-url]: https://npmjs.org/package/wait-queue