TCPocket

A request response communication wrapper around a tcp server/client.

API

tcpocket.createServer(options, handler)

The handler will execute with a request and response argument.

request

A request will have command (a number between 2 and 255), and optionally some data (a buffer).

response

A response has two commands (reply, send). You can reply only once, and that will resolve the promise on the client. You can send many times, but the server will not correlate this with the request.

Example usage

Insecure

const tcpocket = require('tcpocket');

// A command must be a number between 2 and 255
const TEST1 = 123;
const TEST2 = 125;
const TEST3 = 128;

async function main () {
  const server = tcpocket.createServer({ port: 8000 }, function (request, response) {
    console.log(request.command) // === TEST1 || 123
    console.log(request.data) // === <Buffer>'some data'

    // You can reply only once
    response.reply(TEST2, Buffer.from('some reply'));

    // Sending happens outside of a reply and can be called multiple times
    response.send(TEST3, Buffer.from('some extra data'));
  });
  server.open();

  const client = tcpocket.createClient({ host: '0.0.0.0', port: 8000 });
  client.on('message', ({ command, data }) => {
    console.log(command) // === TEST3
    console.log(data) // === 'some extra data'
  });

  await client.waitUntilReady();
  const { command, data} = await client.send(TEST1, Buffer.from('some data'));
  console.log(command) // === TEST2
  console.log(data) // === 'some reply''
}

main();

Using TLS

There is a file ./makeCerts.sh that will create the certs used in the example below.

const fs = require('fs');
const tcpocket = require('tcpocket');

const tls = {
  key: fs.readFileSync('./certs/localhost.privkey.pem'),
  cert: fs.readFileSync('./certs/localhost.cert.pem'),
  ca: [fs.readFileSync('./certs/ca.cert.pem')]
};

async function main () {
  const server = tcpocket.createServer({ port: 8000, ...tls }, function (request, response) {
    console.log(request.command) // === TEST1 || 123
    console.log(request.data) // === <Buffer> 'some data'

    // You can reply only once
    response.reply(TEST2, Buffer.from('some reply'));

    // Sending happens outside of a reply and can be called multiple times
    response.send(TEST3, Buffer.from('some extra data'));
  });
  server.open();

  const client = tcpocket.createClient({ host: '0.0.0.0', port: 8000 });
  client.on('message', ({ command, data }) => {
    console.log(command) // === TEST3
    console.log(data) // === 'some extra data'
  });

  await client.waitUntilReady();
  const { command, data} = await client.send(TEST1, Buffer.from('some data'));
  console.log(command) // === TEST2
  console.log(data) // === 'some reply''
}

main();

License

This project is licensed under the terms of the MIT license.