kefir/src/one-source/buffer-with-time-or-count.js

Reactive Programming library for JavaScript inspired by Bacon.js and RxJS with focus on high performance and low memory usage

import {createStream, createProperty} from '../patterns/one-source'

const mixin = {
  _init({wait, count, flushOnEnd}) {
    this._wait = wait
    this._count = count
    this._flushOnEnd = flushOnEnd
    this._intervalId = null
    this._$onTick = () => this._flush()
    this._buff = []
  },

  _free() {
    this._$onTick = null
    this._buff = null
  },

  _flush() {
    if (this._buff !== null) {
      this._emitValue(this._buff)
      this._buff = []
    }
  },

  _handleValue(x) {
    this._buff.push(x)
    if (this._buff.length >= this._count) {
      clearInterval(this._intervalId)
      this._flush()
      this._intervalId = setInterval(this._$onTick, this._wait)
    }
  },

  _handleEnd() {
    if (this._flushOnEnd && this._buff.length !== 0) {
      this._flush()
    }
    this._emitEnd()
  },

  _onActivation() {
    this._intervalId = setInterval(this._$onTick, this._wait)
    this._source.onAny(this._$handleAny) // copied from patterns/one-source
  },

  _onDeactivation() {
    if (this._intervalId !== null) {
      clearInterval(this._intervalId)
      this._intervalId = null
    }
    this._source.offAny(this._$handleAny) // copied from patterns/one-source
  },
}

const S = createStream('bufferWithTimeOrCount', mixin)
const P = createProperty('bufferWithTimeOrCount', mixin)

export default function bufferWithTimeOrCount(obs, wait, count, {flushOnEnd = true} = {}) {
  return new (obs._ofSameType(S, P))(obs, {wait, count, flushOnEnd})
}