ncpu
multi-threaded library that node.js run function worker
Installation
npm install ncpuncpu for the node.js environment,use ncpu-web for the browser environment.
require:Node.js version>=12
Attention
Because it is multithreaded, context information cannot be received and parameter passing can only be achieved by cloning( The cloning will occur as described in the HTML structured clone algorithm, and an error will be thrown if the object cannot be cloned (e.g. because it contains functions)).
Quick Start
import {NCPU} from 'ncpu' // or const {NCPU} = require('ncpu')
async function main () {
// ### run
await NCPU.run((a,b)=>a+b,[1,2]) // result: 3
await NCPU.run((list)=>{
return list.reduce((total,value)=>{return total+value;});
},[[1,2,3]]) // result: 6
// ### pick
const workerFibo = await NCPU.pick((num)=>{
const fibo = (value)=>{
if(value<=2){return 1;}
return fibo(value-2)+fibo(value-1);
}
return fibo(num);
});
// slef time to run
await workerFibo(38)+await workerFibo(39) // result: 102334155 //fibo(40)
// ### getWorker // reuse a thread
const ncpuWorker = NCPU.getWorker();
const multiplexingWorkerFibo = await NCPU.pick((num)=>{
const fibo = (value)=>{
if(value<=2){return 1;}
return fibo(value-2)+fibo(value-1);
}
return fibo(num);
}, {ncpuWorker}); // reuse a thread
const res = await Promise.all([multiplexingWorkerFibo(38), NCPU.run((num)=>{
const fibo = (value)=>{
if(value<=2){return 1;}
return fibo(value-2)+fibo(value-1);
}
return fibo(num);
}, [39] ,{ncpuWorker})]); // reuse a thread
// ### inject globalData
await NCPU.run(()=>{
return require('fs') === require('fs');
},[],{injectList:['require']}) // result: true
}
main()The above example spawns a Worker thread for each callback function when runing. In actual practice, use a pool of Workers instead for these kinds of tasks. Otherwise, the overhead of creating Workers would likely exceed their benefit.
Other solutions
License
ncpu is available under the MIT license. See the LICENSE file for details.