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.

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.

// 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:

// main.js

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

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

// 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.

Example 1: Running calculations in 20 threads

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

// 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:

// 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);
  });

}

Example 2: Rendering Pug to HTML

This example shows how to use Node Threads Pool to render Pug templates to HTML:

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)