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import { Deferred, deferred } from "./deps.ts";import { MessageId, ResponseMessage } from "./message.ts";
const DEFAULT_RESPONSE_TIMEOUT = 10000; // milliseconds
type Waiter = {  timer: number;  response: Deferred<ResponseMessage>;};
export class TimeoutError extends Error {  constructor() {    super("the process didn't complete in time");    this.name = "TimeoutError";  }}
/** * ResponseWaiter is for waiting a response messages for 'msgid' */export class ResponseWaiter {  #waiters: Map<MessageId, Waiter>;  #timeout: number;
  constructor(timeout = DEFAULT_RESPONSE_TIMEOUT) {    this.#waiters = new Map();    this.#timeout = timeout;  }
  /**   * The number of internal waiters   */  get waiterCount(): number {    return this.#waiters.size;  }
  /**   * Wait a response message of 'msgid'   */  wait(msgid: MessageId, timeout?: number): Promise<ResponseMessage> {    let response = this.#waiters.get(msgid)?.response;    if (!response) {      response = deferred();      const timer = setTimeout(() => {        const response = this.#waiters.get(msgid)?.response;        if (!response) {          return;        }        response.reject(new TimeoutError());        this.#waiters.delete(msgid);      }, timeout ?? this.#timeout);      this.#waiters.set(msgid, {        timer,        response,      });    }    return response;  }
  /**   * Provide a response message   *   * It returns false if no one seems to wait the message.   * Otherwise it returns true.   */  provide(message: ResponseMessage): boolean {    const [_type, msgid, _error, _result] = message;    const waiter = this.#waiters.get(msgid);    if (!waiter) {      return false;    }    this.#waiters.delete(msgid);    const { timer, response } = waiter;    clearTimeout(timer);    response.resolve(message);    return true;  }}