tcp-bridge

Description

This is a small framework for connecting 2 or more servers to each other by tcp.

The framework has the function of automatic reconnection to each server, the sending queue, the lifetime of the tasks for sending.

Installation

With yarn:

yarn add tcp-bridge

or with npm:

npm install tcp-bridge

Usage

For a simple connection of two servers on localhost, you can do this:

const BridgeClass = require('tcp-bridge');
const Bridge = new BridgeClass();
Bridge.addPoint({
    port: 2020
});
Bridge.addPoint({
    port: 3030
});

If possible, connections will be established to servers localhost:2020 and localhost:3030.

All data from server 1 will be sent to server 2. All data from server 2 will be sent to server 1.

Servers may be more

require('tcp-bridge') returns constructor of Bridge class. To create new instance of Bridge you can do this:

const BridgeClass = require('tcp-bridge');
const Bridge = new BridgeClass();

For debugging you can use debug npm package or with same functionality. Example debugging: Install debug package:

yarn add debug

or:

npm install debug

then code:

const BridgeClass = require('tcp-bridge');
const debug = require('debug');
const Bridge = new BridgeClass(debug);

and run script with debug env variable, ex.:

DEBUG=* node index.js

---

BridgeInstance functions

#addPoint(params) -> point uuid identifier

Adds a new server, initiates a connection and returns a unique identifier.

Signature:

BridgeInstance.addPoint({
    port,
    host,
    reconnectOnClose,
    reconnectOnHasSendData,
    checkTime,
    taskTimeout,
    enabledRedirect,
    encoding,
})

Parameter	Required	Description	Default value
port	true	Port of server
host		Hostname (or ip) of server	'127.0.0.1'
reconnectOnClose		auto reconnect on close connection	true
reconnectOnHasSendData		auto reconnect if connection is closed and clinet has data to send	false
checkTime		time to check new data for sending	300 ms
taskTimeout		task lifetime (in ms), 0 for disable	60000
enabledRedirect		if false - data from this point will not be redirected	true
encoding		Set the encoding for the socket as a Readable Stream. See readable.setEncoding() for more information.	null

#removePoint(identifier)

Disconnects and removes server by identifier.

Parameter	Required	Description	Default value
identifier	true	Identifier of point (server)

#sendDataToPoint(identifier, data)

Send data to one point.

Parameter	Required	Description	Default value
identifier	true	Identifier of point (server)
data	true	Bytes (as in net library in socket.send function)

#getPoint(identifier) -> point instance

Getting one point instance.

Parameter	Required	Description	Default value
identifier	true	Identifier of point (server)

Client (Point) functions and properties

#enableRedirect()

Data from this point will be redirected.

#disableRedirect()

Data from this point will not be redirected.

#on('data', callback) – event, triggered if data will be received

#on('ready') – event, triggered if connection is activated

property .connected – true, if connection to server is active

More examples

4 servers with debug and encoding UTF8

const debug = require('debug');
const BridgeClass = require('tcp-bridge');
const Bridge = new BridgeClass(debug);
 
const firstUid = Bridge.addPoint({
    port: 2020,
    encoding: 'utf8',
});
Bridge.addPoint({
    port: 3030,
    reconnectOnClose: false,
    reconnectOnHasSendData: true,
    encoding: 'utf8',
});
Bridge.addPoint({
    port: 4040,
    encoding: 'utf8',
});
Bridge.addPoint({
    port: 5050,
    encoding: 'utf8',
});
 
Bridge.removePoint(firstUid);
 
const lastUid = Bridge.addPoint({
    port: 6060,
    encoding: 'utf8',
});
 
const point = Bridge.getPoint(lastUid);
point.on('ready', data => {
    console.log('READY');
});
point.on('data', data => {
    console.log('DATA', data);
});