import { Subject } from '../Subject';
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import { Operator } from '../Operator';
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import { async } from '../scheduler/async';
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import { Subscriber } from '../Subscriber';
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import { Observable } from '../Observable';
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import { Subscription } from '../Subscription';
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import { isNumeric } from '../util/isNumeric';
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import { isScheduler } from '../util/isScheduler';
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import { OperatorFunction, SchedulerLike, SchedulerAction } from '../types';
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/**
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* Branch out the source Observable values as a nested Observable periodically
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* in time.
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*
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* <span class="informal">It's like {@link bufferTime}, but emits a nested
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* Observable instead of an array.</span>
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*
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* 
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*
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* Returns an Observable that emits windows of items it collects from the source
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* Observable. The output Observable starts a new window periodically, as
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* determined by the `windowCreationInterval` argument. It emits each window
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* after a fixed timespan, specified by the `windowTimeSpan` argument. When the
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* source Observable completes or encounters an error, the output Observable
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* emits the current window and propagates the notification from the source
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* Observable. If `windowCreationInterval` is not provided, the output
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* Observable starts a new window when the previous window of duration
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* `windowTimeSpan` completes. If `maxWindowCount` is provided, each window
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* will emit at most fixed number of values. Window will complete immediately
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* after emitting last value and next one still will open as specified by
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* `windowTimeSpan` and `windowCreationInterval` arguments.
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*
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* ## Examples
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* In every window of 1 second each, emit at most 2 click events
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* ```ts
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* import { fromEvent } from 'rxjs';
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* import { windowTime, map, mergeAll, take } from 'rxjs/operators';
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*
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* const clicks = fromEvent(document, 'click');
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* const result = clicks.pipe(
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* windowTime(1000),
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* map(win => win.pipe(take(2))), // each window has at most 2 emissions
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* mergeAll(), // flatten the Observable-of-Observables
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* );
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* result.subscribe(x => console.log(x));
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* ```
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*
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* Every 5 seconds start a window 1 second long, and emit at most 2 click events per window
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* ```ts
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* import { fromEvent } from 'rxjs';
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* import { windowTime, map, mergeAll, take } from 'rxjs/operators';
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*
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* const clicks = fromEvent(document, 'click');
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* const result = clicks.pipe(
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* windowTime(1000, 5000),
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* map(win => win.pipe(take(2))), // each window has at most 2 emissions
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* mergeAll(), // flatten the Observable-of-Observables
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* );
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* result.subscribe(x => console.log(x));
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* ```
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*
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* Same as example above but with maxWindowCount instead of take
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* ```ts
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* import { fromEvent } from 'rxjs';
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* import { windowTime, mergeAll } from 'rxjs/operators';
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*
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* const clicks = fromEvent(document, 'click');
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* const result = clicks.pipe(
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* windowTime(1000, 5000, 2), // each window has still at most 2 emissions
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* mergeAll(), // flatten the Observable-of-Observables
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* );
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* result.subscribe(x => console.log(x));
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* ```
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*
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* @see {@link window}
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* @see {@link windowCount}
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* @see {@link windowToggle}
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* @see {@link windowWhen}
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* @see {@link bufferTime}
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*
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* @param {number} windowTimeSpan The amount of time to fill each window.
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* @param {number} [windowCreationInterval] The interval at which to start new
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* windows.
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* @param {number} [maxWindowSize=Number.POSITIVE_INFINITY] Max number of
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* values each window can emit before completion.
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* @param {SchedulerLike} [scheduler=async] The scheduler on which to schedule the
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* intervals that determine window boundaries.
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* @return {Observable<Observable<T>>} An observable of windows, which in turn
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* are Observables.
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* @method windowTime
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* @owner Observable
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*/
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export function windowTime<T>(windowTimeSpan: number,
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scheduler?: SchedulerLike): OperatorFunction<T, Observable<T>>;
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export function windowTime<T>(windowTimeSpan: number,
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windowCreationInterval: number,
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scheduler?: SchedulerLike): OperatorFunction<T, Observable<T>>;
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export function windowTime<T>(windowTimeSpan: number,
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windowCreationInterval: number,
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maxWindowSize: number,
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scheduler?: SchedulerLike): OperatorFunction<T, Observable<T>>;
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export function windowTime<T>(windowTimeSpan: number): OperatorFunction<T, Observable<T>> {
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let scheduler: SchedulerLike = async;
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let windowCreationInterval: number = null;
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let maxWindowSize: number = Number.POSITIVE_INFINITY;
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if (isScheduler(arguments[3])) {
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scheduler = arguments[3];
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}
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if (isScheduler(arguments[2])) {
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scheduler = arguments[2];
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} else if (isNumeric(arguments[2])) {
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maxWindowSize = Number(arguments[2]);
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}
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if (isScheduler(arguments[1])) {
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scheduler = arguments[1];
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} else if (isNumeric(arguments[1])) {
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windowCreationInterval = Number(arguments[1]);
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}
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return function windowTimeOperatorFunction(source: Observable<T>) {
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return source.lift(new WindowTimeOperator<T>(windowTimeSpan, windowCreationInterval, maxWindowSize, scheduler));
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};
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}
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class WindowTimeOperator<T> implements Operator<T, Observable<T>> {
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constructor(private windowTimeSpan: number,
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private windowCreationInterval: number | null,
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private maxWindowSize: number,
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private scheduler: SchedulerLike) {
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}
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call(subscriber: Subscriber<Observable<T>>, source: any): any {
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return source.subscribe(new WindowTimeSubscriber(
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subscriber, this.windowTimeSpan, this.windowCreationInterval, this.maxWindowSize, this.scheduler
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));
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}
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}
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interface CreationState<T> {
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windowTimeSpan: number;
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windowCreationInterval: number;
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subscriber: WindowTimeSubscriber<T>;
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scheduler: SchedulerLike;
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}
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interface TimeSpanOnlyState<T> {
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window: CountedSubject<T>;
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windowTimeSpan: number;
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subscriber: WindowTimeSubscriber<T>;
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}
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interface CloseWindowContext<T> {
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action: SchedulerAction<CreationState<T>>;
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subscription: Subscription;
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}
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interface CloseState<T> {
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subscriber: WindowTimeSubscriber<T>;
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window: CountedSubject<T>;
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context: CloseWindowContext<T>;
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}
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class CountedSubject<T> extends Subject<T> {
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private _numberOfNextedValues: number = 0;
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next(value?: T): void {
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this._numberOfNextedValues++;
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super.next(value);
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}
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get numberOfNextedValues(): number {
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return this._numberOfNextedValues;
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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 WindowTimeSubscriber<T> extends Subscriber<T> {
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private windows: CountedSubject<T>[] = [];
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constructor(protected destination: Subscriber<Observable<T>>,
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private windowTimeSpan: number,
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private windowCreationInterval: number | null,
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private maxWindowSize: number,
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private scheduler: SchedulerLike) {
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super(destination);
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const window = this.openWindow();
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if (windowCreationInterval !== null && windowCreationInterval >= 0) {
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const closeState: CloseState<T> = { subscriber: this, window, context: <any>null };
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const creationState: CreationState<T> = { windowTimeSpan, windowCreationInterval, subscriber: this, scheduler };
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this.add(scheduler.schedule<CloseState<T>>(dispatchWindowClose, windowTimeSpan, closeState));
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this.add(scheduler.schedule<CreationState<T>>(dispatchWindowCreation, windowCreationInterval, creationState));
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} else {
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const timeSpanOnlyState: TimeSpanOnlyState<T> = { subscriber: this, window, windowTimeSpan };
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this.add(scheduler.schedule<TimeSpanOnlyState<T>>(dispatchWindowTimeSpanOnly, windowTimeSpan, timeSpanOnlyState));
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}
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}
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protected _next(value: T): void {
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const windows = this.windows;
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const len = windows.length;
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for (let i = 0; i < len; i++) {
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const window = windows[i];
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if (!window.closed) {
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window.next(value);
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if (window.numberOfNextedValues >= this.maxWindowSize) {
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this.closeWindow(window);
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}
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}
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}
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}
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protected _error(err: any): void {
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const windows = this.windows;
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while (windows.length > 0) {
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windows.shift().error(err);
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}
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this.destination.error(err);
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}
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protected _complete(): void {
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const windows = this.windows;
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while (windows.length > 0) {
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const window = windows.shift();
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if (!window.closed) {
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window.complete();
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}
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}
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this.destination.complete();
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}
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public openWindow(): CountedSubject<T> {
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const window = new CountedSubject<T>();
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this.windows.push(window);
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const destination = this.destination;
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destination.next(window);
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return window;
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}
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public closeWindow(window: CountedSubject<T>): void {
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window.complete();
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const windows = this.windows;
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windows.splice(windows.indexOf(window), 1);
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}
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}
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function dispatchWindowTimeSpanOnly<T>(this: SchedulerAction<TimeSpanOnlyState<T>>, state: TimeSpanOnlyState<T>): void {
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const { subscriber, windowTimeSpan, window } = state;
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if (window) {
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subscriber.closeWindow(window);
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}
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state.window = subscriber.openWindow();
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this.schedule(state, windowTimeSpan);
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}
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function dispatchWindowCreation<T>(this: SchedulerAction<CreationState<T>>, state: CreationState<T>): void {
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const { windowTimeSpan, subscriber, scheduler, windowCreationInterval } = state;
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const window = subscriber.openWindow();
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const action = this;
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let context: CloseWindowContext<T> = { action, subscription: <any>null };
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const timeSpanState: CloseState<T> = { subscriber, window, context };
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context.subscription = scheduler.schedule<CloseState<T>>(dispatchWindowClose, windowTimeSpan, timeSpanState);
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action.add(context.subscription);
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action.schedule(state, windowCreationInterval);
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}
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function dispatchWindowClose<T>(state: CloseState<T>): void {
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const { subscriber, window, context } = state;
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if (context && context.action && context.subscription) {
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context.action.remove(context.subscription);
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}
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subscriber.closeWindow(window);
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}
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