feat: @discordjs/ws (#8260)

Co-authored-by: Parbez <imranbarbhuiya.fsd@gmail.com>

packages/ws/src/strategies/context/IContextFetchingStrategy.ts

@@ -0,0 +1,31 @@
+import type { Awaitable } from '@vladfrangu/async_event_emitter';
+import type { APIGatewayBotInfo } from 'discord-api-types/v10';
+import type { SessionInfo, WebSocketManager, WebSocketManagerOptions } from '../../ws/WebSocketManager';
+
+export interface FetchingStrategyOptions
+	extends Omit<
+		WebSocketManagerOptions,
+		'retrieveSessionInfo' | 'updateSessionInfo' | 'shardCount' | 'shardIds' | 'rest'
+	> {
+	readonly gatewayInformation: APIGatewayBotInfo;
+	readonly shardCount: number;
+}
+
+/**
+ * Strategies responsible solely for making manager information accessible
+ */
+export interface IContextFetchingStrategy {
+	readonly options: FetchingStrategyOptions;
+	retrieveSessionInfo: (shardId: number) => Awaitable<SessionInfo | null>;
+	updateSessionInfo: (shardId: number, sessionInfo: SessionInfo | null) => Awaitable<void>;
+}
+
+export async function managerToFetchingStrategyOptions(manager: WebSocketManager): Promise<FetchingStrategyOptions> {
+	const { retrieveSessionInfo, updateSessionInfo, shardCount, shardIds, rest, ...managerOptions } = manager.options;
+
+	return {
+		...managerOptions,
+		gatewayInformation: await manager.fetchGatewayInformation(),
+		shardCount: await manager.getShardCount(),
+	};
+}

packages/ws/src/strategies/context/SimpleContextFetchingStrategy.ts

@@ -0,0 +1,14 @@
+import type { FetchingStrategyOptions, IContextFetchingStrategy } from './IContextFetchingStrategy';
+import type { SessionInfo, WebSocketManager } from '../../ws/WebSocketManager';
+
+export class SimpleContextFetchingStrategy implements IContextFetchingStrategy {
+	public constructor(private readonly manager: WebSocketManager, public readonly options: FetchingStrategyOptions) {}
+
+	public async retrieveSessionInfo(shardId: number): Promise<SessionInfo | null> {
+		return this.manager.options.retrieveSessionInfo(shardId);
+	}
+
+	public updateSessionInfo(shardId: number, sessionInfo: SessionInfo | null) {
+		return this.manager.options.updateSessionInfo(shardId, sessionInfo);
+	}
+}

packages/ws/src/strategies/context/WorkerContextFetchingStrategy.ts

@@ -0,0 +1,49 @@
+import { isMainThread, parentPort } from 'node:worker_threads';
+import { Collection } from '@discordjs/collection';
+import type { FetchingStrategyOptions, IContextFetchingStrategy } from './IContextFetchingStrategy';
+import type { SessionInfo } from '../../ws/WebSocketManager';
+import {
+	WorkerRecievePayload,
+	WorkerRecievePayloadOp,
+	WorkerSendPayload,
+	WorkerSendPayloadOp,
+} from '../sharding/WorkerShardingStrategy';
+
+export class WorkerContextFetchingStrategy implements IContextFetchingStrategy {
+	private readonly sessionPromises = new Collection<number, (session: SessionInfo | null) => void>();
+
+	public constructor(public readonly options: FetchingStrategyOptions) {
+		if (isMainThread) {
+			throw new Error('Cannot instantiate WorkerContextFetchingStrategy on the main thread');
+		}
+
+		parentPort!.on('message', (payload: WorkerSendPayload) => {
+			if (payload.op === WorkerSendPayloadOp.SessionInfoResponse) {
+				const resolve = this.sessionPromises.get(payload.nonce);
+				resolve?.(payload.session);
+				this.sessionPromises.delete(payload.nonce);
+			}
+		});
+	}
+
+	public async retrieveSessionInfo(shardId: number): Promise<SessionInfo | null> {
+		const nonce = Math.random();
+		const payload: WorkerRecievePayload = {
+			op: WorkerRecievePayloadOp.RetrieveSessionInfo,
+			shardId,
+			nonce,
+		};
+		const promise = new Promise<SessionInfo | null>((resolve) => this.sessionPromises.set(nonce, resolve));
+		parentPort!.postMessage(payload);
+		return promise;
+	}
+
+	public updateSessionInfo(shardId: number, sessionInfo: SessionInfo | null) {
+		const payload: WorkerRecievePayload = {
+			op: WorkerRecievePayloadOp.UpdateSessionInfo,
+			shardId,
+			session: sessionInfo,
+		};
+		parentPort!.postMessage(payload);
+	}
+}