@iprokit/service/lib/sdp/server.d.ts

Powering distributed systems with simplicity and speed.

/**
 * @iProKit/Service
 * Copyright (c) 2019-2025 Rutvik Katuri / iProTechs
 * SPDX-License-Identifier: Apache-2.0
 */
/// <reference types="node" />
/// <reference types="node" />
import { EventEmitter } from 'events';
import { Attributes } from './pod';
declare const socket: unique symbol;
/**
 * `Server` binds to a multicast address and port number, listening for incoming SDP client connections.
 * Tracks pods' availability and emits events when their states change.
 *
 * @emits `listening` when the server is bound after calling `listen()`.
 * @emits `available` when a pod becomes available.
 * @emits `unavailable` when a pod becomes unavailable.
 * @emits `error` when an error occurs.
 * @emits `close` when the server is fully closed.
 */
export default class Server extends EventEmitter {
    #private;
    /**
     * Pods discovered.
     */
    readonly pods: Map<string, IPod>;
    /**
     * Underlying UDP Socket.
     */
    private readonly [socket];
    /**
     * Creates an instance of SDP `Server`.
     *
     * @param identifier unique identifier of the server.
     */
    constructor(identifier: string);
    /**
     * Unique identifier of the server.
     */
    get identifier(): string;
    /**
     * Attributes of the server.
     */
    get attributes(): Attributes;
    /**
     * Multicast group that have been joined.
     */
    get membership(): string | null;
    /**
     * Local port of the server.
     */
    get localPort(): number | null;
    /**
     * Local address of the server.
     */
    get localAddress(): string | null;
    /**
     * `true` when the server is listening for connections, `false` otherwise.
     */
    get listening(): boolean;
    /**
     * Retrieves the bound address, family, and port of the server as reported by operating system.
     */
    address(): import("net").AddressInfo | null;
    /**
     * @emits `available` when a pod is available.
     * @emits `unavailable` when a pod is unavailable.
     */
    private onMessage;
    /**
     * Encodes and multicasts `this.#pod` on the network.
     *
     * @param callback called once the pod is multicast.
     */
    private send;
    /**
     * Encodes and multicasts `this.#pod` on the network, then waits for an echo.
     *
     * @param callback called once the echo is received.
     */
    private echo;
    /**
     * Starts listening for pods on the network and emits `listening` event.
     *
     * @param port local port.
     * @param address address of the multicast group.
     * @param callback optional callback added as a one-time listener for the `listening` event.
     */
    listen(port: number, address: string, callback?: () => void): this;
    /**
     * Closes the underlying UDP socket and stops listening for pods, emitting the `close` event.
     *
     * @param callback optional callback added as a one-time listener for the `close` event.
     */
    close(callback?: () => void): this;
    /**
     * References the socket, preventing it from closing automatically.
     * Calling `ref` again has no effect if already referenced.
     */
    ref(): this;
    /**
     * Unreferences the socket, allowing it to close automatically when no other event loop activity is present.
     * Calling `unref` again has no effect if already unreferenced.
     */
    unref(): this;
    /**
     * Returns a new session token for an available pod.
     */
    private static createToken;
    /**
     * Session token representing an unavailable pod.
     */
    static readonly UNAVAILABLE_TOKEN = "00000";
}
/**
 * Interface of `Pod`.
 */
export interface IPod {
    /**
     * Session token of the pod.
     */
    session: string;
    /**
     * Attributes of the Pod.
     */
    attributes: Attributes | null;
    /**
     * Host address of the Pod.
     */
    host: string | null;
}
export {};