status-sharding/src/handlers/message.ts

Welcome to Status Sharding! This package is designed to provide an efficient and flexible solution for sharding Discord bots, allowing you to scale your bot across multiple processes or workers.

import { BaseMessage, DataType, DataTypes, EvalMessage } from '../other/message';
import { ClientRefType, ClusterClient } from '../core/clusterClient';
import { MessageTypes, PackageType, Serializable } from '../types';
import { ShardingUtils } from '../other/shardingUtils';
import { Worker } from '../classes/worker';
import { Cluster } from '../core/cluster';
import { Child } from '../classes/child';

/** Handles messages for the cluster. */
export class ClusterHandler {
	/** Creates an instance of ClusterHandler. */
	constructor (private cluster: Cluster, private ipc: Worker | Child) { }

	/** Handles the message received, and executes the callback. (Not meant to be used by the user.) */
	public async handleMessage<D extends DataType, A = Serializable, P extends object = object>(message: BaseMessage<D, A, P>): Promise<void> {
		switch (message._type) {
			case MessageTypes.ClientReady: {
				if (this.cluster.ready) {
					this.cluster.manager._debug(`[Cluster ${this.cluster.id}] Received duplicate ready signal, ignoring.`);
					return;
				}

				const readyData = message.data as { packageType?: PackageType | null } | undefined;
				if (readyData?.packageType && !this.cluster.manager.options.packageType) {
					this.cluster.manager.options.packageType = readyData.packageType;
					this.cluster.manager._debug(`[Cluster ${this.cluster.id}] Package type set to: ${readyData.packageType}`);
				}

				this.cluster.ready = true;
				this.cluster.exited = false;
				this.cluster.lastHeartbeatReceived = Date.now();

				this.cluster.emit('ready', this.cluster);
				this.cluster.manager._debug(`[Cluster ${this.cluster.id}] Cluster is ready.`);

				const allReady = this.cluster.manager.clusters.every((cluster) => cluster.ready);

				if (!this.cluster.manager.ready && allReady && this.cluster.manager.clusters.size === this.cluster.manager.options.totalClusters) {
					this.cluster.manager.ready = true;

					this.cluster.manager.emit('ready', this.cluster.manager);
					this.cluster.manager._debug('All clusters are ready.');

					for (const cluster of this.cluster.manager.clusters.values()) {
						cluster._sendInstance({ _type: MessageTypes.ManagerReady } as BaseMessage<'readyOrSpawn'>);
					}
				}

				break;
			}
			case MessageTypes.ClientBroadcastRequest: {
				const { script, options } = message.data as EvalMessage;
				const results = await this.cluster.manager.broadcastEval(script, options);

				this.ipc.send({
					_type: MessageTypes.ClientBroadcastResponse,
					_nonce: message._nonce,
					data: results,
				} as BaseMessage<'evalResult'>).catch((err) => {
					this.ipc.send({
						_type: MessageTypes.ClientBroadcastResponseError,
						_nonce: message._nonce,
						data: ShardingUtils.makePlainError(err),
					} as BaseMessage<'error'>);
				});

				break;
			}
			case MessageTypes.ClientBroadcast: {
				const data = message.data as { message: Serializable; ignore?: number; };
				await this.cluster.manager.broadcast(data.message, data.ignore !== undefined ? [data.ignore] : undefined);

				break;
			}
			case MessageTypes.ClientManagerEvalRequest: {
				const { script, options } = message.data as EvalMessage;
				const result = await this.cluster.manager.eval(script, options);

				if (result.error) {
					this.ipc.send({
						_type: MessageTypes.ClientManagerEvalResponseError,
						_nonce: message._nonce,
						data: ShardingUtils.makePlainError(result.error),
					} as BaseMessage<'error'>);
				} else {
					this.ipc.send({
						_type: MessageTypes.ClientManagerEvalResponse,
						_nonce: message._nonce,
						data: result.result,
					} as BaseMessage<'evalResult'>);
				}

				break;
			}
			case MessageTypes.CustomReply:
			case MessageTypes.ClientEvalResponseError:
			case MessageTypes.ClientEvalResponse: {
				this.cluster.manager.promise.resolve(message);
				break;
			}
			case MessageTypes.ClientRespawnAll: {
				const { clusterDelay, respawnDelay, timeout, except } = message.data as DataTypes['respawnAll'];
				this.cluster.manager.respawnAll(clusterDelay, respawnDelay, timeout, except);
				break;
			}
			case MessageTypes.ClientRespawnSpecific: {
				const { clusterDelay, respawnDelay, timeout, clusterIds } = message.data as DataTypes['respawnSome'];
				this.cluster.manager.respawnClusters(clusterIds, clusterDelay, respawnDelay, timeout);
				break;
			}
			case MessageTypes.ClientRespawn: {
				const { respawnDelay, timeout } = message.data as Omit<DataTypes['respawnAll'], 'clusterDelay' | 'except'>;
				this.cluster.respawn(respawnDelay, timeout);
				break;
			}
			case MessageTypes.ClientSpawnNextCluster: {
				this.cluster.manager.clusterQueue.next();
				break;
			}
			case MessageTypes.HeartbeatAck: {
				this.cluster.lastHeartbeatReceived = Date.now();
				this.cluster.manager._debug(`[Cluster ${this.cluster.id}] Received heartbeat.`);
				break;
			}
		}
	}
}

/** Handles messages for the cluster client. */
export class ClusterClientHandler<InternalClient extends ClientRefType = ClientRefType> {
	/** Creates an instance of ClusterClientHandler. */
	constructor (private clusterClient: ClusterClient<InternalClient>) { }

	/** Handles the message received, and executes the callback. (Not meant to be used by the user.) */
	public async handleMessage<D extends DataType, A = Serializable, P extends object = object>(message: BaseMessage<D, A, P>): Promise<void> {
		switch (message._type) {
			case MessageTypes.ClientEvalRequest: {
				const { script } = message.data as EvalMessage;
				try {
					if (!script) return this.clusterClient._respond({
						_type: MessageTypes.ClientEvalResponseError,
						_nonce: message._nonce,
						data: ShardingUtils.makePlainError(new Error('No script provided.')),
					} as BaseMessage<'error'>);

					try {
						const result = await this.clusterClient.evalOnClient(script);
						this.clusterClient._respond({
							_type: MessageTypes.ClientEvalResponse,
							_nonce: message._nonce,
							data: ShardingUtils.isSerializable(result) ? result : {
								...ShardingUtils.makePlainError(new Error('Evaluated script returned an unserializable value.')),
								script: script?.replace(/(\n|\r|\t)/g, '').replace(/( )+/g, ' ').replace(/(\/\/.*)/g, ''),
							},
						} as BaseMessage<'evalResult'>);
					} catch (err) {
						if (err instanceof Error) {
							this.clusterClient._respond({
								_type: MessageTypes.ClientEvalResponseError,
								_nonce: message._nonce,
								data: {
									...ShardingUtils.makePlainError(err),
									script: script?.replace(/(\n|\r|\t)/g, '').replace(/( )+/g, ' ').replace(/(\/\/.*)/g, ''),
								},
							} as BaseMessage<'error'>);
						} else {
							this.clusterClient._respond({
								_type: MessageTypes.ClientEvalResponseError,
								_nonce: message._nonce,
								data: {
									...ShardingUtils.makePlainError(new Error('An error occurred while evaluating the script.')),
									script: script?.replace(/(\n|\r|\t)/g, '').replace(/( )+/g, ' ').replace(/(\/\/.*)/g, ''),
								},
							} as BaseMessage<'error'>);
						}

						throw err;
					}
				} catch (err) {
					this.clusterClient._respond({
						_type: MessageTypes.ClientEvalResponseError,
						_nonce: message._nonce,
						data: ShardingUtils.makePlainError(err as Error),
					} as BaseMessage<'error'>);
				}

				break;
			}
			case MessageTypes.CustomReply:
			case MessageTypes.ClientManagerEvalResponse:
			case MessageTypes.ClientManagerEvalResponseError:
			case MessageTypes.ClientBroadcastResponse:
			case MessageTypes.ClientBroadcastResponseError: {
				this.clusterClient.promise.resolve(message);
				break;
			}
			case MessageTypes.ManagerReady: {
				this.clusterClient.emit('managerReady');
				break;
			}
			case MessageTypes.Heartbeat: {
				this.clusterClient._respond({ _type: MessageTypes.HeartbeatAck } as BaseMessage<'heartbeat'>);
				break;
			}
		}
	}
}