73 lines
2.2 KiB
JavaScript
73 lines
2.2 KiB
JavaScript
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'use strict';
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.Semaphore = undefined;
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exports.ncpAsync = ncpAsync;
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var _ncp;
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function _load_ncp() {
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return _ncp = _interopRequireDefault(require('ncp'));
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}
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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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function _asyncToGenerator(fn) { return function () { var gen = fn.apply(this, arguments); return new Promise(function (resolve, reject) { function step(key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { return Promise.resolve(value).then(function (value) { step("next", value); }, function (err) { step("throw", err); }); } } return step("next"); }); }; }
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function ncpAsync(source, dest, options = {}) {
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return new Promise((resolve, reject) => {
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(0, (_ncp || _load_ncp()).default)(source, dest, options, err => {
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if (err) {
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reject(err);
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} else {
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resolve();
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}
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});
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});
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}
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class Semaphore {
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constructor() {
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this.queue = [];
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this.available = 1;
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}
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acquire() {
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var _this = this;
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return _asyncToGenerator(function* () {
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if (_this.available > 0) {
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_this.available -= 1;
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return Promise.resolve(true);
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}
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// If there is no permit available, we return a promise that resolves once the semaphore gets
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// signaled enough times that "available" is equal to one.
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return new Promise(function (resolver) {
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return _this.queue.push(resolver);
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});
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})();
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}
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release() {
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this.available += 1;
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if (this.available > 1 && this.queue.length > 0) {
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throw new Error('this.available should never be > 0 when there is someone waiting.');
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} else if (this.available === 1 && this.queue.length > 0) {
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// If there is someone else waiting, immediately consume the permit that was released
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// at the beginning of this function and let the waiting function resume.
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this.available -= 1;
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const nextResolver = this.queue.shift();
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if (nextResolver) {
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nextResolver(true);
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}
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}
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}
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}
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exports.Semaphore = Semaphore;
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//# sourceMappingURL=__sourcemaps__/Utils.js.map
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