import { Operator } from '../Operator';
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import { Subscriber } from '../Subscriber';
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import { Observable } from '../Observable';
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import { OperatorFunction } from '../types';
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import { SimpleOuterSubscriber, innerSubscribe, SimpleInnerSubscriber } from '../innerSubscribe';
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/**
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* Buffers the source Observable values until `closingNotifier` emits.
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*
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* <span class="informal">Collects values from the past as an array, and emits
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* that array only when another Observable emits.</span>
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*
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* 
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*
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* Buffers the incoming Observable values until the given `closingNotifier`
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* Observable emits a value, at which point it emits the buffer on the output
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* Observable and starts a new buffer internally, awaiting the next time
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* `closingNotifier` emits.
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*
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* ## Example
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*
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* On every click, emit array of most recent interval events
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*
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* ```ts
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* import { fromEvent, interval } from 'rxjs';
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* import { buffer } from 'rxjs/operators';
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*
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* const clicks = fromEvent(document, 'click');
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* const intervalEvents = interval(1000);
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* const buffered = intervalEvents.pipe(buffer(clicks));
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* buffered.subscribe(x => console.log(x));
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* ```
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*
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* @see {@link bufferCount}
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* @see {@link bufferTime}
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* @see {@link bufferToggle}
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* @see {@link bufferWhen}
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* @see {@link window}
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*
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* @param {Observable<any>} closingNotifier An Observable that signals the
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* buffer to be emitted on the output Observable.
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* @return {Observable<T[]>} An Observable of buffers, which are arrays of
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* values.
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* @method buffer
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* @owner Observable
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*/
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export function buffer<T>(closingNotifier: Observable<any>): OperatorFunction<T, T[]> {
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return function bufferOperatorFunction(source: Observable<T>) {
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return source.lift(new BufferOperator<T>(closingNotifier));
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};
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}
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class BufferOperator<T> implements Operator<T, T[]> {
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constructor(private closingNotifier: Observable<any>) {
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}
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call(subscriber: Subscriber<T[]>, source: any): any {
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return source.subscribe(new BufferSubscriber(subscriber, this.closingNotifier));
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}
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}
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/**
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* We need this JSDoc comment for affecting ESDoc.
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* @ignore
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* @extends {Ignored}
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*/
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class BufferSubscriber<T> extends SimpleOuterSubscriber<T, any> {
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private buffer: T[] = [];
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constructor(destination: Subscriber<T[]>, closingNotifier: Observable<any>) {
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super(destination);
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this.add(innerSubscribe(closingNotifier, new SimpleInnerSubscriber(this)));
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}
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protected _next(value: T) {
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this.buffer.push(value);
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}
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notifyNext(): void {
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const buffer = this.buffer;
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this.buffer = [];
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this.destination.next!(buffer);
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}
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}
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