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SEARCH KEYWORD -- set theory

  What will the value of Integer.valueOf(127) == Integer.valueOf(127) be in Java?

Do you really understand how Java does the integer comparison? OK, ignore the statements in the post title. What we are interested in is another set of comparison statements. Let's first see below code snippet. public class IntegerComparison { public static void main(String[] args) { Integer a = 127, b = 127; Integer c = 128, d = 128; System.out.println(a == b); System.out.println(c == d); } } What do you think the output will be? Are they both displaying true? You will find out t...

   JAVA,==,EQUALSTO     2018-01-13 22:18:15

  UIWebView Secrets - Part1 - Memory Leaks on Xmlhttprequest

My first blog post on iphone subject reveal a big memory bug when using UIWebView component. This is the (only one) component to display some HTML content in an iphone interface. UIWebView object has a lot of differents issues and I’m going to highlight the biggest of them. Actually, all XMLHttpRequests used in javascript code are fully leaking!!! I mean when you do a request that retrieve 100ko of data, your memory used grow up for 100ko! This bug is not always active, but almost always....

   XMLHttpRequest,Memory leak,Mobile device,UIWebView     2011-11-25 13:46:30

  Mark Zuckerbeg's hacker way

According to TechCrunch, Facebook CEO Mark Zuckerberg wrote codes for the latest mobile IM application : Poke, the tone played when receiving push notifications is from the mouth of Zuckerberg. This approach reflects the way pursued by Zuckerberg : hacker way.As one of the earliest features of Facebook the "Poking" is invented by Zuckerberg, it is not surprising that Zuckerberg involves in Poke's development.Zuckerberg recorded his own voice on the phone initially just for fun. But he was later ...

   Poke,Facebook,Snapchat, Mark Zuckerberg     2012-12-24 12:01:52

  Why Software Projects are Terrible and How Not To Fix Them

If you are a good developer and you’ve worked in bad organizations, you often have ideas to improve the process.  The famous Joel Test is a collection of 12 such ideas.  Some of these ideas have universal acceptance within the software industry (say, using source control), while others might be slightly more controversial (TDD).  But for any particular methodology, whether it is universally accepted or only “mostly” accepted, there are a multitude of o...

   Software,Development,Debug,Design     2011-11-21 10:27:05

  Writing robust shellling scripts

Many people hack together shell scripts quickly to do simple tasks, but these soon take on a life of their own. Unfortunately shell scripts are full of subtle effects which result in scripts failing in unusual ways. It's possible to write scripts which minimise these problems. In this article, I explain several techniques for writing robust bash scripts. Use set -u ...

   Robust,Shell script,Set,Commands     2012-03-19 13:25:26

  Generate certificate in Java -- Certificate chain

In previous post, we have introduced the use of Certificate and how to generate self signed certificate using Java. In this post, we will show you how to generate a certificate chain. Sometimes we may only have a certificate request or we don't have a trusted certificate which can be used for business. Now we need to have a trusted CA to sign our certificate so that it can be used on SSL communications. To generate a certificate chain, we may first have our own certificate(A), then we may use ot...

   Java,Certificate chain,Creation, Pure Java     2014-07-30 08:24:52

  Smuggling data in pointers

While reading up on The ABA Problem I came across a fantastic hack.  The ABA problem, in a nutshell, results from the inability to atomically access both a pointer and a "marked" bit at the same time (read the wikipedia page).  One fun, but very hackish solution is to "smuggle" data in a pointer.  Example:#include "stdio.h"void * smuggle(void * ptr, int value){  return (void *)( (long long)ptr | (value & 3) );}int recoverData(void * ptr){  return (long long)ptr &...

   C,Pointer,Bit,Data,Atomic,Smuggle     2011-11-14 08:15:59

  How to handle ES6 modules in NodeJS

In modern JavaScript, there are two types of modules: ES6 module and CommonJS module used by NodeJS. These two types of module are not compatible. Many people would wonder how to load ES6 modules in their NodeJS project. This post will show how this can be done. Difference The syntax of the module being loaded is different. CommonJS modules are loaded with require() and exported with module.exports. ES6 modules are loaded and exported using import and export respectively. Merchanismwise require(...

   NODEJS,COMMONJS,ES6     2020-08-28 22:01:33

  Restore mocked variables in GoLang unit test

One of the guarding principles of writing unit test is that there should be no real external calls for dependant services. Unit test should run by its own and can run without issues on any environment including local, build, test environment. This indicates there should be some mock responses whenever an external call is needed so that different unit test scenarios can be covered. How can this be done in GoLang? In GoLang, anything can be assigned to a variable even including functions. A variab...

   GOLANG,UNIT TEST,MOCK FUNCTION,RESTORE MOCK     2021-12-10 20:43:00

  Cool HTML5 matrix effect

Do you still remember the movie The Matrix? Do you still remember the cool matrix effect in that movie? How is that effect achieved? Shaun Dunne shared a piece of HTML5 code which displays a cool matrix effect. The matrix demo can be found here. Below is the code which he achieves this effect: with var s = window.screen; var width = q.width = s.width; var height = q.height = s.height; var letters = Array(256).join(1).split(''); var draw = function () { q.getContext('2d').fillStyle='rgba(0,0,...

   Matrix,HTML5     2013-08-14 08:03:34

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