| import { Subscriber } from '../Subscriber'; |
| import { Subject } from '../Subject'; |
| /** |
| * Branch out the source Observable values as a nested Observable with each |
| * nested Observable emitting at most `windowSize` values. |
| * |
| * <span class="informal">It's like {@link bufferCount}, but emits a nested |
| * Observable instead of an array.</span> |
| * |
| * <img src="./img/windowCount.png" width="100%"> |
| * |
| * Returns an Observable that emits windows of items it collects from the source |
| * Observable. The output Observable emits windows every `startWindowEvery` |
| * items, each containing no more than `windowSize` items. 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 `startWindowEvery` is not provided, then new windows are |
| * started immediately at the start of the source and when each window completes |
| * with size `windowSize`. |
| * |
| * @example <caption>Ignore every 3rd click event, starting from the first one</caption> |
| * var clicks = Rx.Observable.fromEvent(document, 'click'); |
| * var result = clicks.windowCount(3) |
| * .map(win => win.skip(1)) // skip first of every 3 clicks |
| * .mergeAll(); // flatten the Observable-of-Observables |
| * result.subscribe(x => console.log(x)); |
| * |
| * @example <caption>Ignore every 3rd click event, starting from the third one</caption> |
| * var clicks = Rx.Observable.fromEvent(document, 'click'); |
| * var result = clicks.windowCount(2, 3) |
| * .mergeAll(); // flatten the Observable-of-Observables |
| * result.subscribe(x => console.log(x)); |
| * |
| * @see {@link window} |
| * @see {@link windowTime} |
| * @see {@link windowToggle} |
| * @see {@link windowWhen} |
| * @see {@link bufferCount} |
| * |
| * @param {number} windowSize The maximum number of values emitted by each |
| * window. |
| * @param {number} [startWindowEvery] Interval at which to start a new window. |
| * For example if `startWindowEvery` is `2`, then a new window will be started |
| * on every other value from the source. A new window is started at the |
| * beginning of the source by default. |
| * @return {Observable<Observable<T>>} An Observable of windows, which in turn |
| * are Observable of values. |
| * @method windowCount |
| * @owner Observable |
| */ |
| export function windowCount(windowSize, startWindowEvery = 0) { |
| return function windowCountOperatorFunction(source) { |
| return source.lift(new WindowCountOperator(windowSize, startWindowEvery)); |
| }; |
| } |
| class WindowCountOperator { |
| constructor(windowSize, startWindowEvery) { |
| this.windowSize = windowSize; |
| this.startWindowEvery = startWindowEvery; |
| } |
| call(subscriber, source) { |
| return source.subscribe(new WindowCountSubscriber(subscriber, this.windowSize, this.startWindowEvery)); |
| } |
| } |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| class WindowCountSubscriber extends Subscriber { |
| constructor(destination, windowSize, startWindowEvery) { |
| super(destination); |
| this.destination = destination; |
| this.windowSize = windowSize; |
| this.startWindowEvery = startWindowEvery; |
| this.windows = [new Subject()]; |
| this.count = 0; |
| destination.next(this.windows[0]); |
| } |
| _next(value) { |
| const startWindowEvery = (this.startWindowEvery > 0) ? this.startWindowEvery : this.windowSize; |
| const destination = this.destination; |
| const windowSize = this.windowSize; |
| const windows = this.windows; |
| const len = windows.length; |
| for (let i = 0; i < len && !this.closed; i++) { |
| windows[i].next(value); |
| } |
| const c = this.count - windowSize + 1; |
| if (c >= 0 && c % startWindowEvery === 0 && !this.closed) { |
| windows.shift().complete(); |
| } |
| if (++this.count % startWindowEvery === 0 && !this.closed) { |
| const window = new Subject(); |
| windows.push(window); |
| destination.next(window); |
| } |
| } |
| _error(err) { |
| const windows = this.windows; |
| if (windows) { |
| while (windows.length > 0 && !this.closed) { |
| windows.shift().error(err); |
| } |
| } |
| this.destination.error(err); |
| } |
| _complete() { |
| const windows = this.windows; |
| if (windows) { |
| while (windows.length > 0 && !this.closed) { |
| windows.shift().complete(); |
| } |
| } |
| this.destination.complete(); |
| } |
| _unsubscribe() { |
| this.count = 0; |
| this.windows = null; |
| } |
| } |
| //# sourceMappingURL=windowCount.js.map |