@cf-wasm/og/dist/esm/core/cache.js

Generate Open Graph Images dynamically from HTML/CSS without a browser.

// src/core/cache.ts
var CACHE_INSTANCE_MAP = /* @__PURE__ */ new Map();
var CACHE_INTERFACE = {
  add: () => Promise.resolve(),
  addAll: () => Promise.resolve(),
  delete: () => Promise.resolve(false),
  keys: () => Promise.resolve([]),
  match: () => Promise.resolve(void 0),
  matchAll: () => Promise.resolve([]),
  put: () => Promise.resolve()
};
var CacheUtils = class {
  constructor() {
    /** Indicates whether cache is enabled */
    this._enabled = true;
    /**
     * The {@link Cache} instance or a
     * string representing the name of {@link Cache} to be opened
     */
    this.store = "cf-wasm-og-cache";
    /**
     * The `Cache-Control` header to set for asset responses for caching
     *
     * @default 'public, max-age=604800, s-maxage=43200'
     */
    this.cacheControlHeader = "public, max-age=604800, s-maxage=43200";
  }
  /**
   * Indicates whether {@link Cache} api is supported
   * in current environment or not
   */
  get supported() {
    return typeof caches !== "undefined";
  }
  /** Enables cache */
  enable() {
    this._enabled = true;
  }
  /** Disables cache */
  disable() {
    this._enabled = false;
  }
  /**
   * Sets execution context
   *
   * Example for Cloudflare workers:
   *
   * ```ts
   * import { cache } from "@cf-wasm/og";
   *
   * export interface Env {}
   *
   * export default {
   *   fetch(req: Request, env: Env, ctx: ExecutionContext) {
   *     cache.setExecutionContext(ctx);
   *
   *     // ...
   *   }
   * }
   * ```
   */
  setExecutionContext(ctx) {
    if (typeof ctx?.waitUntil !== "function") {
      throw new TypeError("Provided object is not an execution context object.");
    }
    this._waitUntil = (promise) => ctx.waitUntil(promise);
  }
  /**
   * Opens a cache
   *
   * @param cacheName If provided, the name of cache to be opened
   *
   * @returns A promise which resolves to {@link Cache}
   */
  async open(cacheName) {
    if (typeof this.store === "object") {
      return this.store;
    }
    const name = typeof cacheName === "string" ? cacheName : this.store;
    const store = this.supported ? CACHE_INSTANCE_MAP.get(name) ?? await caches.open(name) : CACHE_INTERFACE;
    CACHE_INSTANCE_MAP.set(name, store);
    return store;
  }
  /**
   * Serve cached assets
   *
   * @param key The cache key
   * @param fallback The fallback function which provides the {@link Response} when cache key is not matched
   * @param param2 Options
   *
   * @returns A promise which resolves to {@link Response}
   */
  async serve(key, fallback, { cache: cacheStore, preserveHeaders, overwriteCacheControl = true } = {}) {
    const store = cacheStore ?? await this.open();
    let response;
    if (!this._enabled || !this.supported || !this._waitUntil) {
      const fallbackResponse = await fallback(key, store);
      if (fallbackResponse instanceof Response) {
        response = new Response(fallbackResponse.body, fallbackResponse);
      }
    } else {
      response = await store.match(key).then((res) => res?.ok ? res : void 0);
      if (!response) {
        const fallbackResponse = await fallback(key, store);
        if (fallbackResponse instanceof Response) {
          response = new Response(fallbackResponse.body, fallbackResponse);
          if (preserveHeaders !== true) {
            response.headers.forEach((value, _key) => {
              if (preserveHeaders === false) {
                response?.headers.delete(_key);
              } else if (typeof preserveHeaders === "function" && !preserveHeaders(_key, value, response, store, key)) {
                response?.headers.delete(_key);
              } else {
                const preservedHeaders = (Array.isArray(preserveHeaders) ? preserveHeaders : ["content-type", "cache-control"]).map(
                  (e) => e.toLowerCase()
                );
                if (!preservedHeaders.includes(_key.toLowerCase())) {
                  response?.headers.delete(_key);
                }
              }
            });
          }
          if (overwriteCacheControl === true || typeof overwriteCacheControl === "string" || !response.headers.has("Cache-Control")) {
            response.headers.set("Cache-Control", typeof overwriteCacheControl === "string" ? overwriteCacheControl : this.cacheControlHeader);
          }
          const promise = store.put(key, response.clone());
          this._waitUntil(promise);
        }
      } else {
        response = new Response(response.body, response);
      }
    }
    return response;
  }
};
var cache = new CacheUtils();
export {
  CACHE_INSTANCE_MAP,
  CACHE_INTERFACE,
  cache
};