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import CachePolicy from "https://cdn.skypack.dev/http-cache-semantics?dts";
function cacheRequest(req: Request): CachePolicy.Request {  return {    url: req.url,    headers: Object.fromEntries(req.headers.entries()),    method: req.method,  };}
export interface CachedResponse {  body: Uint8Array;  policy: CachePolicy.CachePolicyObject;}
export interface CacheStorage {  get(url: string): Promise<CachedResponse | undefined>;  set(url: string, resp: CachedResponse): Promise<void>;  delete(url: string): Promise<void>;  close(): void;}
export class Cache {  #storage: CacheStorage;
  constructor(storage: CacheStorage) {    this.#storage = storage;  }
  close() {    this.#storage.close();  }
  async match(request: RequestInfo): Promise<Response | undefined> {    const req = request instanceof Request ? request : new Request(request);
    const cached = await this.#storage.get(req.url);    if (cached === undefined) return Promise.resolve(undefined);
    const policy = CachePolicy.fromObject(cached.policy);
    const usable = policy.satisfiesWithoutRevalidation(cacheRequest(req));    if (!usable) return Promise.resolve(undefined);
    const resp = new Response(cached.body, {      headers: policy.responseHeaders() as Record<string, string>,      status: cached.policy.st,    });
    return Promise.resolve(resp);  }
  async put(request: RequestInfo, response: Response): Promise<void> {    const req = request instanceof Request ? request : new Request(request);    response = response.clone();
    const status = response.status;    const headers = Object.fromEntries(response.headers.entries());
    const policy = new CachePolicy(cacheRequest(req), { status, headers }, {      shared: true,    });
    if (!policy.storable()) return;
    const body = await response.arrayBuffer();
    await this.#storage.set(req.url, {      body: new Uint8Array(body),      policy: policy.toObject(),    });  }
  async delete(request: RequestInfo): Promise<void> {    const req = request instanceof Request ? request : new Request(request);    await this.#storage.delete(req.url);    return Promise.resolve();  }}