dograma/gramjs/extensions/PromisedNetSockets.ts

NodeJS/Browser MTProto API Telegram client library,

import * as net from "./net";
import { SocksClient } from "./socks";

import { Mutex } from "async-mutex";
import { ProxyInterface } from "../network/connection/TCPMTProxy";

const mutex = new Mutex();

const closeError = new Error("NetSocket was closed");

export class PromisedNetSockets {
    private client?: net.Socket;
    private closed: boolean;
    private stream: Buffer;
    private canRead?: boolean | Promise<boolean>;
    private resolveRead: ((value?: any) => void) | undefined;
    private proxy?: ProxyInterface;

    constructor(proxy?: ProxyInterface) {
        this.client = undefined;
        this.closed = true;
        this.stream = Buffer.alloc(0);
        if (!proxy?.MTProxy) {
            // we only want to use this when it's not an MTProto proxy.
            if (proxy) {
                if (!proxy.ip || !proxy.port || !proxy.socksType) {
                    throw new Error(
                        `Invalid sockets params. ${proxy.ip}, ${proxy.port}, ${proxy.socksType}`
                    );
                }
            }
            this.proxy = proxy;
        }
    }

    async readExactly(number: number) {
        let readData = Buffer.alloc(0);
        while (true) {
            const thisTime = await this.read(number);
            readData = Buffer.concat([readData, thisTime]);
            number = number - thisTime.length;
            if (!number) {
                return readData;
            }
        }
    }

    async read(number: number) {
        if (this.closed) {
            throw closeError;
        }
        await this.canRead;
        if (this.closed) {
            throw closeError;
        }
        const toReturn = this.stream.slice(0, number);
        this.stream = this.stream.slice(number);
        if (this.stream.length === 0) {
            this.canRead = new Promise((resolve) => {
                this.resolveRead = resolve;
            });
        }

        return toReturn;
    }

    async readAll() {
        if (this.closed || !(await this.canRead)) {
            throw closeError;
        }
        const toReturn = this.stream;
        this.stream = Buffer.alloc(0);
        this.canRead = new Promise((resolve) => {
            this.resolveRead = resolve;
        });
        return toReturn;
    }

    /**
     * Creates a new connection
     * @param port
     * @param ip
     * @returns {Promise<void>}
     */
    async connect(port: number, ip: string) {
        this.stream = Buffer.alloc(0);
        let connected = false;
        if (this.proxy) {
            const info = await SocksClient.createConnection({
                proxy: {
                    host: this.proxy.ip,
                    port: this.proxy.port,
                    type:
                        this.proxy.socksType != undefined
                            ? this.proxy.socksType
                            : 5, // Proxy version (4 or 5)
                    userId: this.proxy.username,
                    password: this.proxy.password,
                },

                command: "connect",
                timeout: (this.proxy.timeout || 5) * 1000,
                destination: {
                    host: ip,
                    port: port,
                },
            });
            this.client = info.socket;
            connected = true;
        } else {
            this.client = new net.Socket();
        }

        this.canRead = new Promise((resolve) => {
            this.resolveRead = resolve;
        });
        this.closed = false;
        return new Promise((resolve, reject) => {
            if (this.client) {
                if (connected) {
                    this.receive();
                    resolve(this);
                } else {
                    this.client.connect(port, ip, () => {
                        this.receive();
                        resolve(this);
                    });
                }
                this.client.on("error", reject);
                this.client.on("close", () => {
                    if (this.client && this.client.destroyed) {
                        if (this.resolveRead) {
                            this.resolveRead(false);
                        }
                        this.closed = true;
                    }
                });
            }
        });
    }

    write(data: Buffer) {
        if (this.closed) {
            throw closeError;
        }
        if (this.client) {
            this.client.write(data);
        }
    }

    async close() {
        if (this.client) {
            await this.client.destroy();
            this.client.unref();
        }
        this.closed = true;
    }

    async receive() {
        if (this.client) {
            this.client.on("data", async (message: Buffer) => {
                const release = await mutex.acquire();
                try {
                    let data;
                    //CONTEST BROWSER
                    this.stream = Buffer.concat([this.stream, message]);
                    if (this.resolveRead) {
                        this.resolveRead(true);
                    }
                } finally {
                    release();
                }
            });
        }
    }
    toString() {
        return "PromisedNetSocket";
    }
}