131 lines
4.6 KiB
JavaScript
131 lines
4.6 KiB
JavaScript
"use strict";
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/*
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* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
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* SPDX-License-Identifier: Apache-2.0.
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*/
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var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
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if (k2 === undefined) k2 = k;
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var desc = Object.getOwnPropertyDescriptor(m, k);
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if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
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desc = { enumerable: true, get: function() { return m[k]; } };
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}
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Object.defineProperty(o, k2, desc);
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}) : (function(o, m, k, k2) {
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if (k2 === undefined) k2 = k;
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o[k2] = m[k];
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}));
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var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
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Object.defineProperty(o, "default", { enumerable: true, value: v });
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}) : function(o, v) {
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o["default"] = v;
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});
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var __importStar = (this && this.__importStar) || function (mod) {
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if (mod && mod.__esModule) return mod;
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var result = {};
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if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
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__setModuleDefault(result, mod);
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return result;
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};
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.newCancellablePromiseFromNextEvent = exports.CancelController = exports.EVENT_NAME = void 0;
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/**
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*
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* A module containing support for cancelling asynchronous operations
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*
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* @packageDocumentation
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* @module cancel
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*/
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const events_1 = require("events");
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const promise = __importStar(require("./promise"));
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exports.EVENT_NAME = 'cancelled';
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/**
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* CRT implementation of the ICancelController interface
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*/
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class CancelController {
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constructor(options) {
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this.cancelled = false;
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if (options && options.emitterFactory) {
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this.emitter = options.emitterFactory();
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}
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else {
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this.emitter = new events_1.EventEmitter();
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}
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}
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/**
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* Cancels all asynchronous operations associated with this controller
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*/
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cancel() {
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if (!this.cancelled) {
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this.cancelled = true;
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this.emitter.emit(exports.EVENT_NAME);
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this.emitter.removeAllListeners(exports.EVENT_NAME);
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}
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}
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/**
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* Checks whether or not the controller is in the cancelled state
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*/
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hasBeenCancelled() {
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return this.cancelled;
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}
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/**
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* Registers a callback to be notified when cancel() is invoked externally. In general, the callback
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* will cancel an asynchronous operation by rejecting the associated promise.
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*
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* IMPORTANT: The listener is invoked synchronously if the controller has already been cancelled.
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*
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* @param listener - function to invoke on cancel; invoked synchronously if the controller has been cancelled
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*
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* @return undefined if the controller has already been cancelled, otherwise a function object whose invocation
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* will remove the listener from the controller's event emitter.
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*
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*/
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addListener(listener) {
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if (this.cancelled) {
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listener();
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return undefined;
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}
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this.emitter.on(exports.EVENT_NAME, listener);
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return () => { this.emitter.removeListener(exports.EVENT_NAME, listener); };
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}
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}
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exports.CancelController = CancelController;
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/**
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* Creates a promise that can be rejected by a CancelController and resolved by the receipt of an event from an
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* EventEmitter.
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*
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* @param config promise creation options
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*/
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function newCancellablePromiseFromNextEvent(config) {
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let onEvent = undefined;
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let cancelRemoveListener = undefined;
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let liftedPromise = promise.newLiftedPromise();
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onEvent = (eventData) => {
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try {
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if (config.eventDataTransformer) {
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liftedPromise.resolve(config.eventDataTransformer(eventData));
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}
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else {
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liftedPromise.resolve(eventData);
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}
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}
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catch (err) {
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liftedPromise.reject(err);
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}
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};
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config.emitter.addListener(config.eventName, onEvent);
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if (config.cancelController) {
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cancelRemoveListener = config.cancelController.addListener(() => {
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liftedPromise.reject(config.cancelMessage);
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});
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}
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return promise.makeSelfCleaningPromise(liftedPromise.promise, () => {
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if (onEvent) {
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config.emitter.removeListener(config.eventName, onEvent);
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}
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if (cancelRemoveListener) {
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cancelRemoveListener();
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}
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});
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}
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exports.newCancellablePromiseFromNextEvent = newCancellablePromiseFromNextEvent;
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//# sourceMappingURL=cancel.js.map
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