node-insim/dist/esm/protocols/TCP.js

An InSim library for NodeJS with TypeScript support

import net from 'net';
import { copyBuffer } from '../lfspack';
import { log as baseLog } from '../log';
import { Protocol } from './Protocol';
const log = baseLog.extend('tcp');
/** @internal */
export class TCP extends Protocol {
    constructor(host, port, packetSizeMultiplier = 1) {
        super({ host, port, packetSizeMultiplier });
        this.stream = null;
        this.tempBuf = null;
        this.connect = () => {
            this.stream = net.connect(this.port, this.host);
            this.stream.on('connect', () => {
                this.emit('connect');
            });
            this.stream.on('close', () => {
                log('Disconnected');
                this.emit('disconnect');
            });
            this.stream.on('error', (error) => {
                this.emit('error', error);
            });
            this.stream.on('data', (data) => {
                log('Data received:', data.join());
                // Set or append to temp buffer
                if (this.tempBuf === null) {
                    this.tempBuf = data;
                }
                else {
                    this.tempBuf = Buffer.concat([this.tempBuf, data]);
                }
                this.processBuf();
            });
        };
        this.send = (data) => {
            if (this.stream === null) {
                log('Cannot send data - not connected');
                return;
            }
            log('Send data:', data.join());
            this.stream.write(data);
        };
        this.disconnect = () => {
            if (this.stream === null) {
                log('Cannot disconnect - not connected');
                return;
            }
            this.stream.end();
        };
    }
    processBuf() {
        if (this.tempBuf === null) {
            log('No buffer to process');
            return;
        }
        // Haven't got a full 32 bit header
        if (this.tempBuf.length < 4) {
            log('Got packet with <4 bytes');
            return;
        }
        const size = this.tempBuf[0] * this.packetSizeMultiplier;
        if (this.tempBuf.length === size) {
            // We have at least one full packet
            this.emit('data', copyBuffer(this.tempBuf));
            this.tempBuf = null;
        }
        else if (this.tempBuf.length > size) {
            // Process first packet...
            this.emit('data', copyBuffer(this.tempBuf.slice(0, size)));
            this.tempBuf = this.tempBuf.slice(size, this.tempBuf.length);
            // Recurse on remaining buffer
            this.processBuf();
        }
        else {
            log('Got incomplete packet');
        }
    }
}