facets 示例源码

{
  "name": "facets",
  "main": "index.js",
  "compatibility_date": "2026-01-01",
  "worker_loaders": [{ "binding": "LOADER" }],
  "durable_objects": {
    "bindings": [{ "name": "SUPERVISOR", "class_name": "Supervisor" }]
  },
  "migrations": [{ "tag": "v1", "new_sqlite_classes": ["Supervisor"] }]
}

import { DurableObject, WorkerEntrypoint } from "cloudflare:workers";

// facet 的代码。实际应用可以从打包文件、数据库或请求中加载；
// 这里用字符串保存，让整个示例位于同一个文件中。
const CODE = `
  import { DurableObject } from "cloudflare:workers";
  export class App extends DurableObject {
    async fetch() {
      const n = this.ctx.storage.kv.get("n") ?? 0;
      this.ctx.storage.kv.put("n", n + 1);
      const greeting = await this.env.GREETER.greet("facet");
      return new Response(String(n) + ":" + greeting);
    }
  }
`;

export class Greeter extends WorkerEntrypoint {
  greet(name) {
    return `${this.ctx.props.greeting}, ${name}`;
  }
}

export class Supervisor extends DurableObject {
  fetch(request) {
    const worker = this.env.LOADER.get("app-v1", () => ({
      compatibilityDate: "2025-01-01",
      mainModule: "app.js",
      modules: { "app.js": CODE },
      env: {
        GREETER: this.ctx.exports.Greeter({
          props: { greeting: "hello" },
        }),
      },
    }));
    const facet = this.ctx.facets.get("app", () => ({
      class: worker.getDurableObjectClass("App"),
    }));
    return facet.fetch(request);
  }
}

export default {
  fetch(request, env) {
    return env.SUPERVISOR.getByName("only").fetch(request);
  },
};