Wait-queue-es5 NPM

wait-queue-es5

A javascript wait queue object handle infinity loop tasks more efficiently (ES5), can run in lower version of Node.js or browsers

Installation

$ npm install wait-queue-es5

ES6 NodeJS version

ES6 version for NodeJS

Benchmark

$ npm run benchmark

Sample data in Macbook Pro MF839/8GB

.push() 1k data speed test x 395,760 ops/sec ±29.88% (33 runs sampled)
.unshift() 1k data speed test x 203,834 ops/sec ±49.09% (25 runs sampled)
.push() 4k data speed test x 48,703 ops/sec ±38.31% (11 runs sampled)
.unshift() 4k data speed test x 37,036 ops/sec ±49.09% (11 runs sampled)
.shift() 106449.58100205069 /s

Changes Log

1.0.3

Fix a bug that set wq.queue to an Array when empty() or terminate() is called, should set wq.queue to an empty LinkList

1.0.2

Add a chinese document, and fix some problem in docs

1.0.1

Replace wq.queue from Array to LinkList, because do shift() operation on Array of 10,000,000 item cost too many time
Add Benchmark

Simple Example

'use strict';

var WaitQueue = require('wait-queue-es5');
var wq = new WaitQueue();

// there's no task here 
wq.shift(function (err, item) {
    console.log(err, item);
});

// task will add after 1s
setTimeout(function () {
    wq.push('any object');
}, 1000);

Example(More Complex)

'use strict';

var WaitQueue = require('wait-queue-es5');
var wq = new WaitQueue();

// do loop while catch a error
function loop() {
    wq.shift(function (err, item) {
        if (err) {
            return console.error('end loop', err);
        }
        console.log(item);
        setTimeout(loop, 0);
    });
}
setTimeout(loop, 0);

var taskID = 0;
var interval;
// add a task every 1s
interval = setInterval(function () {
    wq.push({
        taskid: taskID++
    });
}, 1000);

// terminate after 10s
setTimeout(function () {
    wq.terminate();
}, 10 * 1000);

Methods

wq.push(item)

Add an item to the end of the queue, will return true if item added to the queue, if wait-queue is terminated, it will return false

wq.shift(function(err, item){...})

Get an item at the front of the queue, this is a callback method, if there's no item in the queue, it will wait

err will always be null unless wq.terminate() is called, in this case, err will be an instance of TerminateError you can use err.isTerminateQueue to check if is a TerminateError

wq.unshift(item)

Put an item in front of the queue, will return true if item added to the queue, if wait-queue is terminated, it will return false

wq.pop(function(err, item){...})

Got an item at the end of the queue, this is a callback method, if there's no item in the queue, it will wait

err will always be null unless wq.terminate() is called, in this case, err will be an instance of TerminateError you can use err.isTerminateQueue to check if is a TerminateError

wq.terminate()

Teminate the queue, and if there's any shift() or pop() waited, every method will receive a TerminateError, you can use e.isTerminateQueue to check