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  Best practices of front end optimization

1. Use DocumentFragment or innerHTML to replace complex elements insertion DOM operation on browser is expensive. Although browser performance is improved much, multiple DOM elements insertion is still expensive and will affect the page load speed. Assume we have an ul element on our page, we now want to retrieve a JSON list using AJAX and then update the ul using JavaScript. Usually we may write it as : var list = document.querySelector('ul'); ajaxResult.items.forEach(function(item) { // ...

   JavaScript,Front end,Optimization,Tips     2013-07-06 11:26:27

  Content based HTTP Cache

Browsers may cache the webpages we visited, when user types a URL on the address bar, the browser may cache the webpage returned from server while displaying it. If there is no update on the webpage, then next time when the browser requests the same page, it will not download the page again, instead it will load the cached page. If the website explicitly specify that the page is updated, then the browser will download the page again from the server. What's HTTP Cache? You may be familiar with th...

   HTTP Cache,Web crawler     2013-05-24 05:12:59

  Why TCP needs 3 handshakes

Prerequisite Knowledge First, let's look at the control bits and state machine of TCP, which form the basis for understanding the three-way handshake of TCP. TCP Packet Control Bits The control bits in the TCP packet header are used to control the status of the TCP connection and can indicate various control information such as connection establishment, termination, reset, etc. There are six common control bits: SYN (Synchronize Sequence Numbers): Requests to establish a connection (part of the...

   REASON,NETWORK,TCP,EXPLANATION,HANDSHAKE     2024-09-28 08:57:52

  Kubernetes Authentication & Authorization 101

If we want to build a system with user modules, Authentication and Authorization are something that we can never ignore, though they could be fuzzy to understand. Authentication (from Greek: αὐθεντικÏŒς authentikos, “real, genuine”, from αὐθέντης authentes, “author”) is the act of proving an assertion, such as the identity of a computer s...

   RBAC,AUTHORIZATION,AUTHENTICATION,KUBERNETES     2021-06-05 23:19:18

  10 less known but useful PHP functions

PHP has abundant built in functions. As PHP developers, we may have used many of them. But there are still some useful functions we may not be so familiar with. In this post, we will introduce some of them. levenshtein() Have you ever wondered how to check differences between two works? This function just does what you want. It can tell you how much the difference is between two words. <?php $str1 = "carrot"; $str2 = "carrrott"; echo levenshtein($str1, $str2); //Outputs 2 ?> get_defined_va...

   PHP,function     2014-01-20 08:01:31

  New HTTP status code: 451 Unavailable for Legal Reasons

On June 11th,2012, Google proposed a new HTTP status code to indicate webpage contents which are not conform to law. The new HTTP status code is 451 Unavailable for Legal Reasons. Google Android Developer Advocate Tim Bray submitted the draft for the new HTTP status code, it will be used on some webpages which can not be served because of legal reasons. Visitors will know that the page cannot be seen because of the government censorship.According to the draft, responses using this status code sh...

   HTTP status,451,Tim Bray     2012-06-12 09:07:44

  Android socket programming example

Socket is a kind of interface for different sides t communicate, it usually identified by an IP and a port. There are many server side software on a server and they would provide different service. Each server many create some sockets and bind them to some ports so that clients can listen to. Software on the Internet will exchange data though a bidirectional connection established. Each end of the connection has a socket created. In Java, Socket and ServerSocket are in java.net package, ServerSo...

   Android,Socket,Java     2013-05-11 22:17:16

  Alibaba gains spotlight due to female employee alleging sex harassment from supervisor

During the weekend, the Chinese e-commerce giant Alibaba gains spotlight from Chinese general public due to a hot discussion going on on various Chinese social media platforms where a female employee alleges that her supervisor(alias Yi Qu) conducted sex harassment on her during a previous business trip. The case happened a couple of weeks back where the female employee at Alibaba was asked by her direct supervisor to go for a business trip to Shandong province(a northern province in China), sh...

   ALIBABA,SEX HARASSMENT     2021-08-07 22:27:02

  Recursive class initialization in Java

When a Java class is referenced and initialized, it has to go through the loading and linking first. Once the loading and linking complete successfully. The class will be initialized. The static variables and constant variables will be initialized during this process. Once the class is initialized, it is ready for use. If when class A is initialized and it is referencing a class B, the class B will also get initialized. But what will happen if class B is referencing class A as well? This is call...

   Java,JVM,class initialization,static final     2015-04-15 21:04:29

  Keys to increase website conversion rate

In internet marketing, conversion rate is the ratio of visitors who convert casual content views or website visits into desired actions based on subtle or direct requests from marketers, advertisers, and content creators.Successful conversions are interpreted differently by individual marketers, advertisers, and content creators. To online retailers, for example, a successful conversion may constitute the sale of a product to a consumer whose interest in the item was initially sparked by clickin...

   Conversion rate, Website,Sale     2012-07-12 11:04:38

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