SEARCH KEYWORD -- drop test



  Deep clone of JavaScript object

In JavaScript world, it's frequently seen object clone. Normally when creating a clone of an object, it's only the reference being cloned but not all contents. In some scenarioes, it's desired to clone all the content instead of just the reference such that any change made to the cloned object will not change the original object. Differences between shallow clone and deep clone can be as simple as: Shallow clone : Only the object reference is cloned but not the content Deep clone : Clone all co...

   JAAVSCRIPT,DEEP CLONE,DEEP COPY,SHALLOW CLONE,SHALLOW COPY     2016-10-31 00:27:24

  Are college students learning?

In his State of the Union address last Tuesday, President Obama proposed several measures to lower college tuition. University leaders responded cautiously, warning that cost-cutting reforms might also cut into instructional quality. But here's the big open secret in American higher education: Most institutions have no meaningful way to measure the quality...

   College students,Learning,Survey     2012-02-02 07:10:02

  How to prevent next HeartBleed bug?

How to ensure the security of open source projects is a concern for many open source users including individual users and companies. But it's not an easy task to ensure the security of open source projects. Because everyone can see the source code, there is much higher possibility that a bug may be found by someone. Once a bug is disclosed, people may exploit it and do evil things, this may cause loss of money either for individuals or companies, some of the bugs may even have big impact to the...

   Open source,HeartBleed,Security     2014-04-24 09:07:05

  4 asynchronous programming methods in JavaScript

You may know the execution environment of JavaScript is single threaded. The so called single thread means only one task can be running at any time, if there are many tasks, they need to be in a queue and wait for the previous task to be completed. The advantage of this mode is it's easy to implement and the execution environment is relative simple; the disadvantage is that if one task takes long time, the tasks following it must wait in the queue and this will delay other tasks consequently. Th...

   JAVASCRIPT,ASYNCHRONOUS PROGRAMMING, EVENT MODEL,PROMISE     2012-12-25 00:55:47

  Java Sequential IO Performance

Many applications record a series of events to file-based storage for later use.  This can be anything from logging and auditing, through to keeping a transaction redo log in an event sourced design or its close relative CQRS.  Java has a number of means by which a file can be sequentially written to, or read back again.  This article explores some of these mechanisms to understand their performance characteristics.  For the scope of this article I will be using pre-a...

   Java,IO,Sequential,Blocking     2012-02-23 07:09:10

  Select top 3 values from each group in a table with SQL

Yesterday, my friend Liu Bing asked me a question about how to select top 3 values for each person in a database table using SQL. I think this question is interesting and it deserves some thoughts. Here I record down how to solve this issue. Assume we have a table which has two columns, one column contains the names of some people and the other column contains some values related to each person. One person can have more than one value. Each value has a numeric type. The question is we want to se...

   SQL,Correlated query,top 3     2013-05-23 03:21:25

  Preprocessor magic:Default Arguments in C

This post is for programmers who like C or for one reason or another can't use anything else but C in one of their projects. The advantages of having default arguments is not something that needs convincing. It's just very nice and convenient to have them. C++ offers the ability to define them but C under the C99 standard has no way to allow it. In this post I will detail two ways I know of implementing default arguments in C. If a reader happens to know additional ways please share in ...

   C,Preprocessor,Default arguments     2012-02-19 06:17:04

  Android and Security

The last year has been a phenomenal one for the Android ecosystem. Device activations grew 250% year-on-year, and the total number of app downloads from Android Market topped 11 billion. As the platform continues to grow, we’re focused on bringing you the best new features and innovations - including in security.Adding a new layer to Android securityToday we’re revealing a service we’ve developed, codenamed Bouncer, which provides automated scanning of Android Market ...

   Android,Security,Android Apps,App market,Bouncer     2012-02-03 08:03:51

  Launch Java process programmatically in Java

In some cases while working on some automation testcase, developers would like to launch Java process programmatically so that the tests can be ran without manual intervention. Java provides such methods to achieve this. ProcessBuilder can be used to build a Java process which can be launched when everything is ready. Basically it can take a list of parameters which are similar to the command line options/arguments.  For example, if you want to launch a Java process, you can do followi...

   JAVA,PROCESSBUILDER,COMMAND LINE     2016-04-27 04:03:30

  Understand Virtual DOM

With the popularity of React, the internals and implementation of Virtual DOM has becoming top discussed topic in tech communities and interviews. This post will give an introduction of Virtual DOM and how to implement a simple Virtual DOM logic. How to understand Virtual DOM In early days, front end developers would update a webpage view based on the data status change(usually after making AJAX call). But it brings performance penalties when there is frequent update as it would cause page reflo...

   JAVASCRIPT,DOM,VIRTUAL DOM     2019-12-07 23:43:04