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1"use strict";2/*3 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.4 * SPDX-License-Identifier: Apache-2.0.5 */6Object.defineProperty(exports, "__esModule", { value: true });7exports.BufferedEventEmitter = void 0;8/**9 * Module for base types related to event emission10 *11 * @packageDocumentation12 * @module event13 */14const events_1 = require("events");15/**16 * @internal17 */18class BufferedEvent {19    constructor(event, args) {20        this.event = event;21        this.args = args;22    }23    static newWithEmissionCallback(key, callback, args) {24        let bufferedEvent = new BufferedEvent(key, args);25        bufferedEvent.callback = callback;26        return bufferedEvent;27    }28}29/**30 * Provides buffered event emitting semantics, similar to many Node-style streams.31 * Subclasses will override EventEmitter.on() and trigger uncorking.32 * NOTE: It is HIGHLY recommended that uncorking should always be done via33 * ```process.nextTick()```, not during the EventEmitter.on() call.34 *35 * See also: [Node writable streams](https://nodejs.org/api/stream.html#stream_writable_cork)36 *37 * @category Events38 */39class BufferedEventEmitter extends events_1.EventEmitter {40    constructor() {41        super();42        this.corked = false;43    }44    /**45     * Forces all written events to be buffered in memory. The buffered data will be46     * flushed when {@link BufferedEventEmitter.uncork} is called.47     */48    cork() {49        this.corked = true;50    }51    /**52     * Flushes all data buffered since {@link BufferedEventEmitter.cork} was called.53     *54     * NOTE: It is HIGHLY recommended that uncorking should always be done via55     * ``` process.nextTick```, not during the ```EventEmitter.on()``` call.56     */57    uncork() {58        this.corked = false;59        while (this.eventQueue) {60            const event = this.eventQueue;61            super.emit(event.event, ...event.args);62            if (event.callback) {63                event.callback();64            }65            this.eventQueue = this.eventQueue.next;66        }67    }68    /**69     * Synchronously calls each of the listeners registered for the event key supplied70     * in registration order. If the {@link BufferedEventEmitter} is currently corked,71     * the event will be buffered until {@link BufferedEventEmitter.uncork} is called.72     * @param event The name of the event73     * @param args Event payload74     */75    emit(event, ...args) {76        if (this.corked) {77            // queue requests in order78            let last = this.lastQueuedEvent;79            this.lastQueuedEvent = new BufferedEvent(event, args);80            if (last) {81                last.next = this.lastQueuedEvent;82            }83            else {84                this.eventQueue = this.lastQueuedEvent;85            }86            return this.listeners(event).length > 0;87        }88        return super.emit(event, ...args);89    }90    emitWithCallback(event, emissionCallback, ...args) {91        if (this.corked) {92            // queue requests in order93            let last = this.lastQueuedEvent;94            this.lastQueuedEvent = BufferedEvent.newWithEmissionCallback(event, emissionCallback, args);95            if (last) {96                last.next = this.lastQueuedEvent;97            }98            else {99                this.eventQueue = this.lastQueuedEvent;100            }101            return this.listeners(event).length > 0;102        }103        let result = super.emit(event, ...args);104        emissionCallback();105        return result;106    }107}108exports.BufferedEventEmitter = BufferedEventEmitter;109//# sourceMappingURL=event.js.map