A javascript wait queue object handle infinity loop tasks more efficiently
WaitQueue is an async implements of Array
Examples
$ npm install wait-queueimport WaitQueue from 'wait-queue';
const wq = new WaitQueue<string>();
async function run() {
const item = await wq.shift();
console.log(item);
}
setTimeout(() => {
wq.push('foo');
}, 1000);
run();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);Build: Node.js >= 8.x
Length of the WaitQueue(readonly)
A LinkedList, used to store the queue items, Do not modify it directly
If no elements in queue yet, listener will add here, Don't modify it
Add items to the end of the queue, will return length of the queue
Got an item from front of the queue, this is a Promise method, if there's no item in the queue, it will wait
Put an item in front of the queue, will return length of the queue
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
Clear the queue, Won't clear listeners
Clear waited listeners of the queue
$ git clone https://github.com/flarestart/wait-queue.git
$ cd wait-queue
$ npm install
$ npm run benchmark
Sample data in Macbook Pro MF839/8GB
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)
.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
.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`
use for ... of to get all values
'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);
}'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);
}'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');
});'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);'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);MIT