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