Node-Threads-Pool

Node-Threads-Pool is a Node.js library that provides a simple and efficient way to execute tasks in child threads. It creates a pool of threads that can be used to parallelize the execution of CPU-intensive tasks, making it possible to take advantage of multi-core processors.

The library is designed to be easy to use and to integrate with existing projects. It provides a simple API that allows you to create a thread pool and run tasks in child threads, and it also supports passing data between threads.

[![node version][node-image]][node-url]
[![npm download][download-image]][download-url]
[![npm license][license-image]][download-url]

[david-url]: https://david-dm.org/pengxigua/node-threads-pool
[node-image]: https://img.shields.io/badge/node.js-%3E=_12-green.svg?style=flat-square
[node-url]: http://nodejs.org/download/
[download-image]: https://img.shields.io/npm/dm/node-threads-pool.svg?style=flat-square
[download-url]: https://npmjs.org/package/node-threads-pool
[license-image]: https://img.shields.io/npm/l/node-threads-pool.svg

Installation
------------

You can install Node-Threads-Pool using NPM:

``
npm install node-threads-pool
`

Usage
-----

To use Node-Threads-Pool, you need to create an instance of the Eve class, which represents the thread pool.

`javascript
// main.js

const { Eve } = require('node-threads-pool');

const tp = new Eve(filename, threadCount);

`

The Eve constructor takes two arguments: the path to the worker script and the number of threads to create. The run method takes one argument, which is the data to be passed to the worker script.


* filename: The path to the worker's main script or module. See the Node.js documentation for more details.
* threadCount: The number of threads in the thread pool.

To run a task in a worker thread, use the run method:

`javascript
// main.js

tp.run(workerData)
.then(result => {
// handle the result
})
.catch(err => {
// handle the error
})
`

When you no longer need the pool, call destroy() to immediately terminate all workers, reject any pending tasks, and release references so the instance can be garbage collected:

`javascript
// main.js

tp.destroy();
`

You can create a new thread directly using the Thread class:

`javascript
// thread.js

const {Thread} = require('node-threads-pool');

new Thread(async (data) => {
// Do some work with data
const result = await doSomething(data);
return result;
});
`

The Thread constructor takes a single argument, which is the function to be executed in the child thread. The function should return a Promise that resolves with the result of the computation.

Example
-------

Here are some examples of how to use Node Threads Pool.

$3

This example shows how to create a pool of 20 worker threads to perform some calculations:

`javascript
// main.js
const os = require('os');
const { Eve } = require('node-threads-pool');

const tp = new Eve('thread.js', os.cpus().length);

module.exports = async (data) => {
return await tp.run(data);
};


// thread.js
const { Thread } = require('node-threads-pool');

const thread = new Thread(async (data) => {
return await doSomething(data);
});

`

Alternatively, you can write to the same JS file:


`javascript
// main.js
const { Eve, Thread, isMainThread } = require('node-threads-pool');
const os = require('os');

if(isMainThread) {

const tp = new Eve('thread.js', os.cpus().length);

module.exports = async (data) => {
return await tp.run(data);
};

} else {

new Thread(async (data) => {
return await doSomething(data);
});

}
`

$3

This example shows how to use Node Threads Pool to render Pug templates to HTML:
`javascript
const pug = require('pug');
const os = require('os');
const {Eve, Thread, isMainThread} = require('node-threads-pool');

if(!isMainThread) {
const options = {};
new Thread(_data => {
const {template, data} = _data;
options.data = data;
return pug.renderFile(template, options);
});
} else {
const tp = new Eve(__filename, os.cpus().length);
module.exports = async (template, data) => {
return await tp.run({
template, data
});
};
}
`

Test
-----
`
npm run eve
``

License
-------

Node-Threads-Pool is licensed under the MIT License. (see LICENSE)