SEARCH KEYWORD -- Reference counting



  Why using + to concatenate string in Java loop is not a good option

String concatenation is a common operation in Java programming. It is to concatenate multiple strings into a single string. Java provides a String class which is an immutable class which means the object cannot be mutated once instantiated. Once a String object is instantiated, its properties cannot be changed anymore, so when concatenating strings, it's actually create a new String instance to store the concatenated string values. For example, below is a simple string concatenation example. Str...

   JAVA,STRING,JAVA 8     2019-01-18 22:07:12

  Cripple Pachebel's Canon on Matlab

What can Matlab do? What the following Matlab code does is playing the piano music of Cripple Pachebel's Canon. You can have a try if you have Matlab installed on your computer. % Cripple Pachebel's Canon on Matlab % Have fun fs = 44100; % sample rate dt = 1/fs; T16 = 0.125; t16 = [0:dt:T16]; [temp k] = size(t16); t4 = linspace(0,4*T16,4*k); t8 = linspace(0,2*T16,2*k); [temp i] = size(t4); [temp j] = size(t8); % Modification functions mod4 =...

   Matlab,Programming,Canon,Music     2012-05-16 11:55:13

  Write Your Own R Packages

Introduction A set of user-defined functions (UDF) or utility functions are helpful to simplify our code and avoid repeating the same typing for daily analysis work. Previously, I saved all my R functions to a single R file. Whenever I want to use them, I can simply source the R file to import all functions. This is a simple but not perfect approach, especially when I want to check the documentation of certain functions. It was quite annoying that you can’t just type ?func&n...

   DATA SCIENCE,R PROGRAMMING,DATA ENGINEERING     2019-10-19 07:20:52

  Service discovery with etcd

In previous post, we have talked about etcd and its usage. This post we will cover how to implement server discovery with etcd. Service discovery is to solve one of the most commonly seen scenarios in distributed system where how to find the corresponding target service to talk to. In short, it is to find some server which one can talk to based on some service name. A complete service discovery system include below three key functions: Service registration: A service must register itself to so...

   ETCD,SERVICE DISCOVERY,DEMO,TUTORIAL     2021-03-08 05:36:29

  Data as code

What is a good command line parser API? A good command line parser should consider below 5 aspects: Support convenient help information generation Support sub commands, for example, git has push,pull,commit sub commands. Support single character option, word option, flag option and option with parameter. Support default option, for example, if no -port is set, set it as 5037 Support usage model, for example, tar's -c and -x is mutually exclusive, they belong to different usage models. Here are...

   Command line,API     2013-08-08 22:40:36

  The Pitfall of WebSocket Disconnections Caused by Browser Power-Saving Mechanisms

Preface Recently, while using WebSocket (WS) connections, we encountered frequent disconnection issues, occurring hundreds of times per day for a single user. Although using the auto-reconnect feature of socket.io allowed us to quickly restore connections after disconnections, it did not guarantee that every reconnection would successfully receive WS messages. Therefore, we conducted several investigations and tests. Ultimately, we identified the root cause of the issue: the browser's power-savi...

   WEBSOCKET,JAVASCRIPT,POWER SAVING,TROUBLESHOOTING     2024-06-23 01:19:39

  Simplify Cloud Data Security: A Deep Dive Into Protecting Sensitive Data in Java

Featuring encryption, anonymization, hashing, and access control Network security incidents occur now and then, mostly caused by data leakage. Data security has aroused widespread concern, and the community keeps working hard on approaches to simplify data security, especially in sensitive data protection. Sensitive data includes but is not limited to personally identifiable information (PII) like names, ID numbers, passport numbers, driver’s license numbers, contact information like addre...

   JAVA,SECURITY,ENCRYPTION,DECRYPTION,TOKENIZATION     2023-04-28 21:22:10

  Why accessing Java HashMap may cause infinite loop in concurrent environment

HashMap in Java is frequently used to handle key/value pairs. But it is not a good candidate to be used in concurrent environment where ConcurrentHashMap should be used instead. If used in concurrent environment, it may cause lots of unexpected behavior even including make the program getting into an infinite loop situation. To understand how this can happen, let's first discuss how HaspMap works internally. In this post we will use implementation of HashMap before Java 8 as example, Java 8 prov...

   JAVA,HASHMAP,INFINITE LOOP     2020-03-29 01:47:00

  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

  Responsive Web Design

With the popularity of 3G, more and more people are surfing the Internet using mobile phones. Mobile devices are becoming common devices for accessing internet. So web design faces a big challenge which is how to display the same webpage on different devices with different screen  resolutions.Screen resolution of mobile device are usually not very large, the width is below 600px, while PC usually has a resolution over 1000px. It is not an easy task to display the same content with satisfyin...

   CSS,Web design,Layout,Response web design     2012-05-03 06:59:40