Never create Ruby strings longer than 23 characters

Looking at things through a microscopesometimes leads to surprising discoveries Obviously this is an utterly preposterous statement: it’s hard to think of a more ridiculous and esoteric coding requirement. I can just imagine all sorts of amusing conversations with designers and business sponsors: “No… the size of this <input> field should be 23… 24 is just too long!” Or: “We need to explain to users that their subject lines should be les...

   Ruby,Specification,String,Interpreter,Optimization,23     2012-01-05 07:58:07

  Understanding PGO in GoLang 1.20

Background The Go 1.20 version was officially released in February 2023, it introduced the PGO(Profile Guided Optimization) mechanism. The basic principle of PGO can be divided into the following two steps: First, profiling is performed on the program to collect data about the program's runtime and generate a profiling file. When compiling the program, enable the PGO option, and the compiler will optimize the program's performance based on the content in the .pgo file. When compiling a program...

   GO 1.20,PGO,GOLANG     2023-02-28 04:27:46

  Linus Torvalds apologizes for Linux 4.8 kernel bug

On Oct 2, Linus Torvalds proudly announced the release of Linux 4.8. But just days after the release, a bug was found in the kernel and Linus came out and apologized for this bug. I'm really sorry I applied that last series from Andrew just before doing the 4.8 release, because they cause problems, and now it is in 4.8 (and that buggy crap is marked for stable too). In particular, I just got this kernel BUG at ./include/linux/swap.h:276 and the end result was a dea...

   LINUX,LINUX KERNEL,NEWS,LINUS TORVALDS,BUG_ON     2016-10-07 03:46:17

  Hail the return of native code and the resurgence of C++

Programming language trends come and go. First, Java is the hot new language, then it's Python, then Ruby steals the limelight, then it's back to JavaScript. But the latest language darling is probably the last one anyone expected. Believe it or not, 2011 could be the year of C++. Last week, the latest version of the ISO C++ Standard was approved by unanimous vote. It's the first major revision of the language in 13 years. Now officially known as C++11, the new standard introduces features desig...

   C++,Future,Return back,Popular,Local dev     2011-08-24 02:20:24

  What can we do about Facebook?

Around 4 years ago, we have posted an article Is Facebook becoming Tencent like? to analyze the strategy Facebook adopted to build its technology empire at that time. Today, we would continue this discussion since the story seems not end there. Facebook is still on the way of copying others. The latest victim being copied is Snapchat where lots of its new features have been copied by Instagram -- an app owned by Facebook. This has helped Instagram acquired lots of active users, especi...

   FACEBOOK,OPINION,SNAPCHAT,NEWS     2017-08-11 10:39:37

  Signature sign/verification demo in Java

Digital signature is commonly used in areas where data authentication and integrity are required. It is extremely important to have signature while transferring sensitive data from one peer to other peers through network since there might be malicious applications or man-in-the-middle attacks which may alter the data along the way. Java provides some APIs to generate and verify digital signature. One important class is Signature.  When generating the signature, a private key needs to be pa...

   SECURITY,JAVA,SIGNATURE     2015-11-21 09:48:12

  Common usage of ls command in Linux

In Linux, ls might be one of the most frequently used commands. It is used to list files in a specific directory. In most cases, we may just use ls -l to list the files under a directory. But have you explored other usages of this command. In this post, we will summarise some other common usages of ls command Assuming we have below directory structure in our system, let's see them using tree command. List details of the files If we want to list the details of the files in /home/alvin/test_...

   LINUX,SHELL,LS     2018-12-16 03:00:42

  Create namespace in JavaScript

A namespace (sometimes also called a name scope) is an abstract container or environment created to hold a logical grouping of unique identifiers or symbols (i.e., names). An identifier defined in a namespace is associated only with that namespace. The same identifier can be independently defined in multiple namespaces. That is, the meaning associated with an identifier defined in one namespace may or may not have the same meaning as the same identifier defined in another namespace. Languag...

   JavaScript,namespace,example     2012-05-10 04:57:17

  Is programmer really profession for youth only?

- dedicated to the new programmers just into the workplace.

One young Chinese friend asked me: is programmer meant only for less experienced youth? Should I consider transition once if I work on it until 30 years old?

   Programmer,Youth,Product,Project,Career,Analysis     2012-03-18 07:06:44

  Only 4G can resolve the conflicts between China Telecom Carriers and WeChat ?

Why WeChat has made the three big Chinese telecom companies uncomfortable? Let's analyze from both technical and commercial levels. From a technical point of view, Mr. Huang, Dean of China Mobile Research Institute, described the impact of "always online service" applications like WeChat. Instead of using technical terms, we will explain in simple vivid phrases. First, mobile QQ, or WeChat, will have their own "request frequency". These requests are sent to the carrier network, to check the re...

   4G,WeChat,Telecom,China     2013-03-25 08:28:59