Class DurableObjectRawFileSystem

packages/worker-bundler/src/file-system.ts:161–205

 * batches all writes into a single flush.
 */
export class DurableObjectRawFileSystem implements FileSystem {
  /**
   * @param storage The Durable Object storage instance to persist files to.
   * @param prefix  An optional path prefix prepended to every key stored in KV.
   *                Defaults to `"bundle/"`, which namespaces bundle files away
   *                from any other keys the Durable Object may store.
   */
  constructor(
    private readonly storage: DurableObjectStorage,
    private readonly prefix: string = "bundle/"
  ) {}

  read(path: string): string | null {
    return this.storage.kv.get<string>(this.formatPath(path)) ?? null;
  }

  write(path: string, content: string): void {
    this.storage.kv.put(this.formatPath(path), content);
  }

  delete(path: string): void {
    this.storage.kv.delete(this.formatPath(path));
  }

  list(prefix?: string): string[] {
    const formattedPrefix =
      prefix !== undefined ? this.formatPath(prefix) : this.prefix;
    // kv.list() returns Iterable<[key, value]>. Strip the storage prefix from
    // each key so callers always receive logical paths, consistent with
    // InMemoryFileSystem.list().
    const result: string[] = [];
    for (const [key] of this.storage.kv.list({ prefix: formattedPrefix })) {
      result.push(key.slice(this.prefix.length));
    }
    return result;
  }

  flush(): Promise<void> {
    return Promise.resolve();
  }

  private formatPath(path: string): string {
    return `${this.prefix}${path}`;
  }
}

/**
 * A filesystem backed by Durable Object KV storage with a write-overlay.