_parallel.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = parallel;

var _AsynccError = _interopRequireDefault(require("./AsynccError"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

function parallel(limit, length, run) {
  var opts = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : {};
  var callback = arguments.length > 4 ? arguments[4] : undefined;

  if (typeof opts === 'function') {
    callback = opts;
    opts = {};
  }

  limit = Math.abs(limit || length);
  var errpos = [];
  var errors = new Array(length).fill();
  var results = new Array(length).fill();
  var i = 0;
  var l = length;
  var done = 0;

  if (l === 0) {
    _final();

    return;
  }

  if (opts.timeout) {
    setTimeout(function () {
      /* istanbul ignore else */
      if (l) _final('err_timeout');
    }, opts.timeout);
  }

  limit = limit < length ? limit : length;

  while (i < limit) {
    run(i++, cb);
  }

  function _final(errMsg) {
    if (done++) return;
    var err = null;

    if (errpos.length || errMsg) {
      err = new _AsynccError["default"](errMsg || 'err', errors, errpos);
    }

    callback && callback(err, results);
  }

  function cb(j, err, res) {
    results[j] = res;
    errors[j] = err;

    if (err) {
      errpos.push(j);

      if (opts.bail) {
        _final('err_bail');

        return;
      }
    }

    l--;

    if (i < length) {
      run(i++, cb);
    } else if (!l) {
      _final();
    }
  }
}