esthread
v1.3.0
Published
Simple and modern web worker threading library.
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ESThread
modern worker threading library
Usage
browser
<script src="https://unpkg.com/esthread"></script>
<script>
// any task.
// const thread = new Thread(function(a,b){return a+b})
</script>
or esmodule
<script type="module">
import Thread from 'https://unpkg.com/esthread/dist/thread.mjs'
// any task.
// const thread = new Thread(function(a,b){return a+b})
</script>
or npm module
npm install esthread --save
and
import Thread from 'esthread'
// const thread = new Thread(function(a,b){return a+b})
[Example1] Simple
const thread = new Thread((a,b)=>a+b)
thread.execute(2,3).then(result=>console.log(result))
.then(()=>thread.terminate())
.catch(()=>thread.terminate())
[Example2-a] with progress.
const thread2a = new Thread((async function(v){
let sum = 0
for(let i=v;i>=0;i--){
await new Promise(res=>setTimeout(res,1000))
this.emit('count',i) // <-------------
sum+=i
}
return sum
}))
thread2a.on('count',(n)=>console.info(n))
thread2a.execute(10).then(n=>{
console.log(n)
thread2a.terminate()
})
[Example2-b] with progress. if use arrow function task , can't modify this args. should use scoped emit function.
// if use typescript: declare function emit(type:string,data?:any):void
const thread2b = new Thread((async (v)=>{
let sum = 0
for(let i=v;i>=0;i--){
await new Promise(res=>setTimeout(res,1000))
emit('count',i) // <------------
sum+=i
}
return sum
}))
thread2b.on('count',(n)=>console.info(n))
thread2b.execute(10).then(n=>{
console.log(n)
thread2a.terminate()
})
[Example3] cloned thread.
// blocking slow function.
function fibonacci(n){
return n<2 ? n : ( fibonacci(n-1) + fibonacci(n-2) )
}
const [thread3a,thread3b,thread3c] = new Thread(fibonacci).clone(3)
thread3a.once(40).then(result=>console.log(result))
thread3b.once(42).then(result=>console.log(result))
thread3c.once(44).then(result=>console.log(result))
[Example4] transferable ArrayBuffer. like webworker.postMessage
const thread4 = new Thread(buffer=>{
buffer.set([192,168,10,3])
return buffer
})
const input = new Uint32Array(256)
thread4.execute(input,[input.buffer]).then(output=>{
// input was transfered. ( can not access from sender )
console.log(output)
})
[Example5] transferable OffscreenCanvas [experimental technology]
const canvas = document.createElement('canvas')
document.body.appendChild(canvas)
const renderer = new Thread((canvas)=>{
const ctx = canvas.getContext('2d')
ctx.fillStyle = 'rgb(200, 0, 0)'
ctx.fillRect(20, 30, 60, 40)
ctx.commit()
})
const offscreen = canvas.transferControlToOffscreen() // NOTE: OffscreenCanvas required explicitly enable this feature 2018.3.
renderer.execute( offscreen , [offscreen] )
[Example6] with other libraries
async function learn(){
// foo bar
}
const thread6 = new Thread(learn,['https://cdn.jsdelivr.net/npm/[email protected]/setImmediate.min.js'])
[Example7] NodeJS Worker [experimental technology] ( nodejs > v10.5.0 )
node --experimental-worker examples/nodejs/example3.js
const { Thread } = require('esthread')
function fibonacci(n){
// if need other library. you can use require('some library') here.
return n<2 ? n : ( fibonacci(n-1) + fibonacci(n-2) )
}
const [thread3a,thread3b,thread3c] = new Thread(fibonacci).clone(3)
thread3a.once(37).then(result=>console.log(result))
thread3b.once(39).then(result=>console.log(result))
thread3c.once(41).then(result=>console.log(result))