| import { Subscriber } from '../Subscriber'; |
| import { ArgumentOutOfRangeError } from '../util/ArgumentOutOfRangeError'; |
| import { empty } from '../observable/empty'; |
| export function takeLast(count) { |
| return function takeLastOperatorFunction(source) { |
| if (count === 0) { |
| return empty(); |
| } |
| else { |
| return source.lift(new TakeLastOperator(count)); |
| } |
| }; |
| } |
| class TakeLastOperator { |
| constructor(total) { |
| this.total = total; |
| if (this.total < 0) { |
| throw new ArgumentOutOfRangeError; |
| } |
| } |
| call(subscriber, source) { |
| return source.subscribe(new TakeLastSubscriber(subscriber, this.total)); |
| } |
| } |
| class TakeLastSubscriber extends Subscriber { |
| constructor(destination, total) { |
| super(destination); |
| this.total = total; |
| this.ring = new Array(); |
| this.count = 0; |
| } |
| _next(value) { |
| const ring = this.ring; |
| const total = this.total; |
| const count = this.count++; |
| if (ring.length < total) { |
| ring.push(value); |
| } |
| else { |
| const index = count % total; |
| ring[index] = value; |
| } |
| } |
| _complete() { |
| const destination = this.destination; |
| let count = this.count; |
| if (count > 0) { |
| const total = this.count >= this.total ? this.total : this.count; |
| const ring = this.ring; |
| for (let i = 0; i < total; i++) { |
| const idx = (count++) % total; |
| destination.next(ring[idx]); |
| } |
| } |
| destination.complete(); |
| } |
| } |
| //# sourceMappingURL=takeLast.js.map |