SEARCH KEYWORD -- REFERENCE


  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

  Do you really understand C? 21st International Obfuscated C Code Contest winning entries

The 21st International Obfuscated C Code Contest(IOCCC) officially launched the winning source code. IOCCC requires contestants to write the most creative and the most obfuscated C codes with the size limited to 4kb and less Work of each participant is impressive. The winners, including one French, one Korean, five Americans, one Belgian, one Israeli, one British, four Japanese and one Chinese. Here we list some codes: Best short program Seonghoon Kang  from Korea- Decodes spelled out ...

   C,Obsfucation contest     2012-10-25 12:26:55

  OT Railway System Development: How to Use PLC to Implement Land Based Railway Track Fixed Block Sign

Figure-00: Railway fixed block signaling system over view diagram, version v1.3 (2024) Project Design Purpose: This project aims to use Programmable Logic Controllers (PLC) with train detection sensors and train control signals to develop an automated OT system for railway track fixed block signaling control. The system will include a digital equivalent simulation to explain the logic of the track fixed block Automatic Train Control (ATC) mechanism for demonstration and training purposes. In th...

       2024-07-27 04:08:41

  What can CSS :has pseudo class be used for?

CSS's :has is a pseudo-class representing an element if any of the selectors passed as parameters matching at least one element. From the name, it's also easy to understand how it matches elements. The syntax is pretty easy as well: :has([some-selector]) With this pseudo class, it can do lots of things which previously would be challenging or need tweaking the DOM elements with JavaScript. This post will demonstrate what :has can be used for. Introduction Below are a few simple ex...

   CSS,:HAS,:NOT,PSEUDO CLASS     2022-09-18 01:40:54

  Using JavaScript to operate clipboard

Browsers allow JavaScript to read and write data on clipboard. Generally script should not modify user's clipboard to avoid impacting user expectation, but there are cases where this can indeed bring convenience to users. For example, for some code snippet, user can copy it to clipboard with one click instead of select and copy manually. There are three options for clipboard operation provided in JavaScript/browser: document.execCommand() Asynchronous Clipboard API copy and paste events This p...

   JAVASCRIPT,CLIPBOARD,NAVIGATOR.CLIPBOARD     2021-01-23 23:23:34

  Why is single threaded Redis so fast

Redis is a high-performance, in-memory key-value database. According to official test reports, it can support around 100,000 QPS (queries per second) on a single machine. However, Redis uses a single-threaded architecture in its design. Why does Redis still have such high performance with a single-threaded design? Wouldn't it be better to use multiple threads for concurrent request processing? In this article, let's explore why Redis has a single-threaded architecture and still maintains its spe...

   REDIS,SINGLE-THREADED,MULTI-THREADING     2023-02-28 05:16:22

RECENT