@eggjs/cluster/dist/utils/messenger.js

cluster manager for egg

import { debuglog } from "node:util";
import workerThreads from "node:worker_threads";

//#region src/utils/messenger.ts
const debug = debuglog("egg/cluster/messenger");
/**
* master messenger, provide communication between parent, master, agent and app.
*
*             ┌────────┐
*             │ parent │
*            /└────────┘\
*           /     |      \
*          /  ┌────────┐  \
*         /   │ master │   \
*        /    └────────┘    \
*       /     /         \    \
*     ┌───────┐         ┌───────┐
*     │ agent │ ------- │  app  │
*     └───────┘         └───────┘
*
*
* in app worker
*
* ```js
* process.send({
*   action: 'xxx',
*   data: '',
*   to: 'agent/master/parent', // default to agent
* });
* ```
*
* in agent worker
*
* ```js
* process.send({
*   action: 'xxx',
*   data: '',
*   to: 'app/master/parent', // default to app
* });
* ```
*
* in parent
*
* ```js
* process.send({
*   action: 'xxx',
*   data: '',
*   to: 'app/agent/master', // default to master
* });
* ```
*/
var Messenger = class {
	#master;
	#workerManager;
	#hasParent;
	constructor(master, workerManager) {
		this.#master = master;
		this.#workerManager = workerManager;
		this.#hasParent = !!workerThreads.parentPort || !!process.send;
		process.on("message", (msg) => {
			msg.from = "parent";
			this.send(msg);
		});
		process.once("disconnect", () => {
			this.#hasParent = false;
		});
	}
	/**
	* send message
	* @param {Object} data message body
	*  - {String} from from who
	*  - {String} to to who
	*/
	send(data) {
		if (!data.from) data.from = "master";
		const receiverWorkerId = data.receiverWorkerId ?? data.receiverPid;
		if (receiverWorkerId) if (receiverWorkerId === String(process.pid)) data.to = "master";
		else if (receiverWorkerId === String(this.#workerManager.getAgent().workerId)) data.to = "agent";
		else data.to = "app";
		if (!data.to) {
			if (data.from === "agent") data.to = "app";
			if (data.from === "app") data.to = "agent";
			if (data.from === "parent") data.to = "master";
		}
		if (data.to === "master") {
			debug("%s -> master, data: %j", data.from, data);
			this.sendToMaster(data);
			return;
		}
		if (data.to === "parent") {
			debug("%s -> parent, data: %j", data.from, data);
			this.sendToParent(data);
			return;
		}
		if (data.to === "app") {
			debug("%s -> %s, data: %j", data.from, data.to, data);
			this.sendToAppWorker(data);
			return;
		}
		if (data.to === "agent") {
			debug("%s -> %s, data: %j", data.from, data.to, data);
			this.sendToAgentWorker(data);
			return;
		}
	}
	/**
	* send message to master self
	* @param {Object} data message body
	*/
	sendToMaster(data) {
		this.#master.emit(data.action, data.data);
	}
	/**
	* send message to parent process
	* @param {Object} data message body
	*/
	sendToParent(data) {
		if (!this.#hasParent) return;
		process.send(data);
	}
	/**
	* send message to app worker
	* @param {Object} data message body
	*/
	sendToAppWorker(data) {
		for (const worker of this.#workerManager.listWorkers()) {
			if (worker.state === "disconnected") continue;
			const receiverWorkerId = data.receiverWorkerId ?? data.receiverPid;
			if (receiverWorkerId && receiverWorkerId !== String(worker.workerId)) continue;
			worker.send(data);
		}
	}
	/**
	* send message to agent worker
	* @param {Object} data message body
	*/
	sendToAgentWorker(data) {
		const agent = this.#workerManager.getAgent();
		if (agent) agent.send(data);
	}
};

//#endregion
export { Messenger };