zoukankan      html  css  js  c++  java
  • [RxJS] RefCount: automatically starting and stopping an execution

    With the connect() method on a ConnectableObservable, the programmer is responsible for avoiding leaked executions of shared RxJS Observables. This lesson will teach you about refCount(), a handy operator that creates an automatically connected Observable, to avoid manually using connect().

    After multicast(new Rx.Subject()), we call refCount(), so it will help us to manage the connections, so we don't need to worry about the memory leak.

    var shared = Rx.Observable.interval(1000)
      .do(x => console.log('source ' + x))
      .multicast(new Rx.Subject())
      .refCount();
    
    var observerA = {
      next: function (x) { console.log('A next ' + x); },
      error: function (err) { console.log('A error ' + err); },
      complete: function () { console.log('A done'); },
    };
    
    var subA = shared.subscribe(observerA); // start
    
    var observerB = {
      next: function (x) { console.log('B next ' + x); },
      error: function (err) { console.log('B error ' + err); },
      complete: function () { console.log('B done'); },
    };
    
    var subB;
    setTimeout(function () {
      subB = shared.subscribe(observerB); // 1 => 2
    }, 2000);
    
    setTimeout(function () {
      subA.unsubscribe(); // 2 => 1
      console.log('unsubscribed A');
    }, 5000);
    
    setTimeout(function () {
      subB.unsubscribe(); // 1 => 0 (stop)
      console.log('unsubscribed B');
    }, 7000);
    
    
    /*
    "source 0"
    "A next 0"
    "source 1"
    "A next 1"
    "source 2"
    "A next 2"
    "B next 2"
    "source 3"
    "A next 3"
    "B next 3"
    "source 4"
    "A next 4"
    "B next 4"
    "unsubscribed A"
    "source 5"
    "B next 5"
    "source 6"
    "B next 6"
    "unsubscribed B"
    */
  • 相关阅读:
    她又在这个星期联系我了 20110422
    用心去做 20110307
    2011年随笔记
    让我有勇气坚持下去 20110427
    2011年随笔记 5月30号以后的日志薄
    因为迷失,所以 201103015
    迷失只是暂时 20110313
    我们做一对好哥们吧 20101228
    3.20号,她恢复了联系 20110320
    FW: Deploy reporting services web parts (RSWebParts) to SharePoint 2010
  • 原文地址:https://www.cnblogs.com/Answer1215/p/5988917.html
Copyright © 2011-2022 走看看