"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.ncpAsync = ncpAsync;
exports.Semaphore = void 0;

function _ncp() {
  const data = require("ncp");

  _ncp = function () {
    return data;
  };

  return data;
}

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

function ncpAsync(source, dest, options = {}) {
  return new Promise((resolve, reject) => {
    (0, _ncp().ncp)(source, dest, options, err => {
      if (err) {
        reject(err);
      } else {
        resolve();
      }
    });
  });
}

class Semaphore {
  constructor() {
    _defineProperty(this, "queue", []);

    _defineProperty(this, "available", 1);
  }

  async acquire() {
    if (this.available > 0) {
      this.available -= 1;
      return Promise.resolve(true);
    } // If there is no permit available, we return a promise that resolves once the semaphore gets
    // signaled enough times that "available" is equal to one.


    return new Promise(resolver => this.queue.push(resolver));
  }

  release() {
    this.available += 1;

    if (this.available > 1 && this.queue.length > 0) {
      throw new Error('this.available should never be > 0 when there is someone waiting.');
    } else if (this.available === 1 && this.queue.length > 0) {
      // If there is someone else waiting, immediately consume the permit that was released
      // at the beginning of this function and let the waiting function resume.
      this.available -= 1;
      const nextResolver = this.queue.shift();

      if (nextResolver) {
        nextResolver(true);
      }
    }
  }

}

exports.Semaphore = Semaphore;
//# sourceMappingURL=__sourcemaps__/Utils.js.map