@reactivex/rxjs
Version:
Reactive Extensions for modern JavaScript
115 lines • 4.93 kB
JavaScript
var __extends = (this && this.__extends) || function (d, b) {
for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
define(["require", "exports", '../Subscriber'], function (require, exports, Subscriber_1) {
"use strict";
/**
* Buffers the source Observable values until the size hits the maximum
* `bufferSize` given.
*
* <span class="informal">Collects values from the past as an array, and emits
* that array only when its size reaches `bufferSize`.</span>
*
* <img src="./img/bufferCount.png" width="100%">
*
* Buffers a number of values from the source Observable by `bufferSize` then
* emits the buffer and clears it, and starts a new buffer each
* `startBufferEvery` values. If `startBufferEvery` is not provided or is
* `null`, then new buffers are started immediately at the start of the source
* and when each buffer closes and is emitted.
*
* @example <caption>Emit the last two click events as an array</caption>
* var clicks = Rx.Observable.fromEvent(document, 'click');
* var buffered = clicks.bufferCount(2);
* buffered.subscribe(x => console.log(x));
*
* @example <caption>On every click, emit the last two click events as an array</caption>
* var clicks = Rx.Observable.fromEvent(document, 'click');
* var buffered = clicks.bufferCount(2, 1);
* buffered.subscribe(x => console.log(x));
*
* @see {@link buffer}
* @see {@link bufferTime}
* @see {@link bufferToggle}
* @see {@link bufferWhen}
* @see {@link pairwise}
* @see {@link windowCount}
*
* @param {number} bufferSize The maximum size of the buffer emitted.
* @param {number} [startBufferEvery] Interval at which to start a new buffer.
* For example if `startBufferEvery` is `2`, then a new buffer will be started
* on every other value from the source. A new buffer is started at the
* beginning of the source by default.
* @return {Observable<T[]>} An Observable of arrays of buffered values.
* @method bufferCount
* @owner Observable
*/
function bufferCount(bufferSize, startBufferEvery) {
if (startBufferEvery === void 0) { startBufferEvery = null; }
return this.lift(new BufferCountOperator(bufferSize, startBufferEvery));
}
exports.bufferCount = bufferCount;
var BufferCountOperator = (function () {
function BufferCountOperator(bufferSize, startBufferEvery) {
this.bufferSize = bufferSize;
this.startBufferEvery = startBufferEvery;
}
BufferCountOperator.prototype.call = function (subscriber, source) {
return source._subscribe(new BufferCountSubscriber(subscriber, this.bufferSize, this.startBufferEvery));
};
return BufferCountOperator;
}());
/**
* We need this JSDoc comment for affecting ESDoc.
* @ignore
* @extends {Ignored}
*/
var BufferCountSubscriber = (function (_super) {
__extends(BufferCountSubscriber, _super);
function BufferCountSubscriber(destination, bufferSize, startBufferEvery) {
_super.call(this, destination);
this.bufferSize = bufferSize;
this.startBufferEvery = startBufferEvery;
this.buffers = [[]];
this.count = 0;
}
BufferCountSubscriber.prototype._next = function (value) {
var count = (this.count += 1);
var destination = this.destination;
var bufferSize = this.bufferSize;
var startBufferEvery = (this.startBufferEvery == null) ? bufferSize : this.startBufferEvery;
var buffers = this.buffers;
var len = buffers.length;
var remove = -1;
if (count % startBufferEvery === 0) {
buffers.push([]);
}
for (var i = 0; i < len; i++) {
var buffer = buffers[i];
buffer.push(value);
if (buffer.length === bufferSize) {
remove = i;
destination.next(buffer);
}
}
if (remove !== -1) {
buffers.splice(remove, 1);
}
};
BufferCountSubscriber.prototype._complete = function () {
var destination = this.destination;
var buffers = this.buffers;
while (buffers.length > 0) {
var buffer = buffers.shift();
if (buffer.length > 0) {
destination.next(buffer);
}
}
_super.prototype._complete.call(this);
};
return BufferCountSubscriber;
}(Subscriber_1.Subscriber));
});
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