chore: monorepo setup (#7175)

packages/voice/src/receive/AudioReceiveStream.ts

@@ -0,0 +1,89 @@
+import { Readable, ReadableOptions } from 'node:stream';
+import { SILENCE_FRAME } from '../audio/AudioPlayer';
+
+/**
+ * The different behaviors an audio receive stream can have for deciding when to end.
+ */
+export enum EndBehaviorType {
+	/**
+	 * The stream will only end when manually destroyed.
+	 */
+	Manual,
+
+	/**
+	 * The stream will end after a given time period of silence/no audio packets.
+	 */
+	AfterSilence,
+
+	/**
+	 * The stream will end after a given time period of no audio packets.
+	 */
+	AfterInactivity,
+}
+
+export type EndBehavior =
+	| {
+			behavior: EndBehaviorType.Manual;
+	  }
+	| {
+			behavior: EndBehaviorType.AfterSilence | EndBehaviorType.AfterInactivity;
+			duration: number;
+	  };
+
+export interface AudioReceiveStreamOptions extends ReadableOptions {
+	end: EndBehavior;
+}
+
+export function createDefaultAudioReceiveStreamOptions(): AudioReceiveStreamOptions {
+	return {
+		end: {
+			behavior: EndBehaviorType.Manual,
+		},
+	};
+}
+
+/**
+ * A readable stream of Opus packets received from a specific entity
+ * in a Discord voice connection.
+ */
+export class AudioReceiveStream extends Readable {
+	/**
+	 * The end behavior of the receive stream.
+	 */
+	public readonly end: EndBehavior;
+
+	private endTimeout?: NodeJS.Timeout;
+
+	public constructor({ end, ...options }: AudioReceiveStreamOptions) {
+		super({
+			...options,
+			objectMode: true,
+		});
+
+		this.end = end;
+	}
+
+	public override push(buffer: Buffer | null) {
+		if (buffer) {
+			if (
+				this.end.behavior === EndBehaviorType.AfterInactivity ||
+				(this.end.behavior === EndBehaviorType.AfterSilence &&
+					(buffer.compare(SILENCE_FRAME) !== 0 || typeof this.endTimeout === 'undefined'))
+			) {
+				this.renewEndTimeout(this.end);
+			}
+		}
+
+		return super.push(buffer);
+	}
+
+	private renewEndTimeout(end: EndBehavior & { duration: number }) {
+		if (this.endTimeout) {
+			clearTimeout(this.endTimeout);
+		}
+		this.endTimeout = setTimeout(() => this.push(null), end.duration);
+	}
+
+	// eslint-disable-next-line @typescript-eslint/no-empty-function
+	public override _read() {}
+}