zoukankan      html  css  js  c++  java
  • [RxJS] Hot Observable, by .share()

    .share() is an alias for .publish().refCount().

    So if the source is not yet completed, no matter how many subscribers subscribe to the source, they share the same source. 

    const clock$ = Rx.Observable.interval(500).share().take(6);
    
    const randomNum$ = clock$
      .map(i => Math.random() * 100).share();
    
    const smallNum$ = randomNum$
      .filter(x => x <= 50)
      .toArray();
    
    const largeNum$ = randomNum$
      .filter(x => x > 50)
      .toArray();
    
    randomNum$.subscribe(x => console.log('random: ' + x));
    smallNum$.subscribe(x => console.log('small:', x));
    largeNum$.subscribe(x => console.log('large:', x));
    
    /*
    
    Console Run  Clear
    "random: 49.87840398986816"
    "random: 75.01024609865293"
    "random: 32.59613439667008"
    "random: 63.4234109489461"
    "random: 35.58020574147034"
    "random: 74.94599860014348"
    "small:"
    [49.87840398986816, 32.59613439667008, 35.58020574147034]
    "large:"
    [75.01024609865293, 63.4234109489461, 74.94599860014348]
    */

    It is important to know share the same source is only before the source stream completed, if it is already completed, then the new subscribers will trigger another source running.

    For example, in the code, we change largeNum$ happens after 4s of first subscriber.

    setTimeout(() => largeNum$.subscribe(x => console.log('large:', x)), 4000)

    Because source will complete after 3s, therefor it will trigger a new source:

    /*
    "random: 74.91154828671043"
    "random: 10.964684522348733"
    "random: 29.076967396825903"
    "random: 20.070493440627235"
    "random: 22.44421045844409"
    "random: 14.233614544120798"
    "small:"
    [10.964684522348733, 29.076967396825903, 20.070493440627235, 22.44421045844409, 14.233614544120798]
    "large:"
    [93.04544926644354, 65.4090612653734, 67.15475480984114]
    */

    As we can see, in the large array, all the numbers are not from random we log out before.

  • 相关阅读:
    6.1成果(冲刺2.10)
    5.31成果(冲刺2.9)
    5.30成果(冲刺2.8)
    5.29成果(冲刺2.7)
    5.28成果(冲刺2.6)
    5.27成果(冲刺2.5)
    5.26成果(冲刺2.4)
    5.25成果(冲刺2.3)
    Nginx location匹配后 跳转问题
    记一次centos上发布core,访问502的bug
  • 原文地址:https://www.cnblogs.com/Answer1215/p/6925452.html
Copyright © 2011-2022 走看看