了解运行时

import { DurableObject, RpcTarget } from "cloudflare:workers";
import { routeAgentRequest } from "agents";
import { Lifecycle } from "agents/lifecycle";
import { State } from "agents/state";
import { WebSockets } from "agents/websockets";

export class Counter extends DurableObject {
	// Durable state, stored in the object's SQLite database
	state = new State({
		initialState: { count: 0 },
		onChanged: (_state, source) => this.webSockets.broadcastState(source),
	});

	// WebSocket connections. Each client receives the state, and can
	// call the methods on CounterMethods.
	webSockets = new WebSockets({
		state: this.state,
		callables: new CounterMethods(this),
	});

	// The lifecycle starts each capability inside the Durable Object
	lifecycle = Lifecycle.install(this).use(this.state).use(this.webSockets);

	increment() {
		const count = (this.state.get()?.count ?? 0) + 1;
		this.state.set({ count });
		return count;
	}

	onRequest(request) {
		if (request.method === "POST") {
			return Response.json({ count: this.increment() });
		}
		return Response.json(this.state.get());
	}
}

// The methods that clients can call over a WebSocket
class CounterMethods extends RpcTarget {
	#counter;

	constructor(counter) {
		super();
		this.#counter = counter;
	}

	increment() {
		return this.#counter.increment();
	}

	reset() {
		this.#counter.state.set({ count: 0 });
	}
}

export default {
	async fetch(request, env) {
		return (
			(await routeAgentRequest(request, env)) ??
			new Response("Not found", { status: 404 })
		);
	},
};

import { DurableObject, RpcTarget } from "cloudflare:workers";
import { routeAgentRequest } from "agents";
import { Lifecycle } from "agents/lifecycle";
import { State } from "agents/state";
import { WebSockets } from "agents/websockets";

export type CounterState = { count: number };

export class Counter extends DurableObject<Env> {
	// Durable state, stored in the object's SQLite database
	readonly state: State<CounterState> = new State({
		initialState: { count: 0 },
		onChanged: (_state, source) => this.webSockets.broadcastState(source),
	});

	// WebSocket connections. Each client receives the state, and can
	// call the methods on CounterMethods.
	readonly webSockets: WebSockets = new WebSockets({
		state: this.state,
		callables: new CounterMethods(this),
	});

	// The lifecycle starts each capability inside the Durable Object
	readonly lifecycle = Lifecycle.install(this)
		.use(this.state)
		.use(this.webSockets);

	increment(): number {
		const count = (this.state.get()?.count ?? 0) + 1;
		this.state.set({ count });
		return count;
	}

	onRequest(request: Request): Response {
		if (request.method === "POST") {
			return Response.json({ count: this.increment() });
		}
		return Response.json(this.state.get());
	}
}

// The methods that clients can call over a WebSocket
class CounterMethods extends RpcTarget {
	readonly #counter: Counter;

	constructor(counter: Counter) {
		super();
		this.#counter = counter;
	}

	increment(): number {
		return this.#counter.increment();
	}

	reset(): void {
		this.#counter.state.set({ count: 0 });
	}
}

export default {
	async fetch(request: Request, env: Env): Promise<Response> {
		return (
			(await routeAgentRequest(request, env)) ??
			new Response("Not found", { status: 404 })
		);
	},
} satisfies ExportedHandler<Env>;