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  Fastjson just fixed a bug which might cause out of memory issue

Fastjson just fixed a bug which might cause service down a few days ago. This bug is caused by some mishandling of special character \x which is an escaped character to indicate hexdecimal number. The impact of this bug would be big if the attacker constructs a malicious data which would cause the service down.  The code which causes the issue is in com.alibaba.fastjson.parser.JSONLexerBase#scanString, when a JSON string is passed in, fastjson would parse the string character by c...

   FASTJSON,ALIBABA,BUG,NEWS     2019-09-07 06:03:49

  In-memory key-value store in C, Go and Python

Subtitle: Wow Go’s net library is fast On paternity leave for my second child, I found myself writing an in-memory hashmap (a poor-man’s memcached), in Go, Python and C. I was wondering how hard it would be to replace memcached, if we wanted to do something unusual with our key-value store. I also wanted to compare the languages, and, well, I get bored easily! The code is on github as Key-Value-Polyglot. Each version implements enough of the get and set commands from the mem...

   key-value,Memory,C,Python,Go     2012-03-21 09:21:51

  memcpy() vs memmove() in C

memcpy() copies the bytes of data between memory blocks. If the block of memory overlaps, the function might not work properly. Use memmove() to deal with overlapping memory blocks. memmove() is very much like memcpy() but very flexible as it handles overlapping of memory blocks. example : char msg[50] = "abcdefghijklmnopqrstuvwxyz"; char temp[50]; main() { strcpy(temp, msg); printf("Original Msg = %s\n",temp); memcpy(temp+4, temp+16, 10); printf...

   Memory,memcpy,memmove,C,comparison,diffe     2011-04-14 09:05:10

  Don't. Waste. Time.

Stuff we startups do that doesn't delight users:Office spaceLaunch partiesHealth insurance plansSalary negotiationsFounder equity splitsSeries F stockOffice Food Team-building activitiesCRM systemsBookkeepingHead countWorking in SOMAConvertible debt capsValuationsTechCrunchKarma scoresISOsPowerpointBusiness CardsBanksLawyersDesks1099sBug TrackersAgile ProcessesAdvisory BoardsHiringCap TablesPayrollMeetupsMeetingsOf course, much of this stuff still needs to get done.  At some point.&nbs...

   Time management,Work,Startup,How to     2011-11-21 09:55:06

  Tips for improving PHP efficiency

0. Using single quote to replace double quote to enclose string literal, this will be a bit faster. Because PHP engine will search variables in double quoted string. 1. If a method in class can be declared as static, then make it static, this will be 4 times faster. 2. $row["id"] is 7 times faster than $row[id] 3. echo is faster than print, and you should use multiple parameters instead of string concatenation, i.e use comma(,) instead of dot(.) to concatenate string. For example echo $str1,$str...

   PHP, efficiency, tips     2012-10-01 19:39:06

  Install and setup Kafka on Windows

Kafka has become a very popular distributed message delivery service which decouples different services while making message delivery between service easy, fast and reliable. In this post, we will walk through how to install and set up Kafka on Windows. Pre-requisite Java Apache ZooKeeper Installation Go to Kafka's download link and download the latest stable release, we downloaded 2.2.0 as of this writing. After downloading, copy the installation file to some folder and unzip it.  Sinc...

   KAFKA,STREAM,USER GUIDE     2019-06-01 02:12:07

  Be careful about printing error as string in GoLang

In GoLang, we can format and produce string using fmt.Printf(), just like C, GoLang also supports format verbs like %s, %d which can be placeholder for different types of values. But please pay attention when printing error as string so that you will not fall into some trap. Let's first take an example code snippet and see what trap we are talking about. package main import "fmt" type A string func (a A) Error() string { return fmt.Sprintf("%s is an error", a) } func main() { a := A("hello...

   STACKOVERFLOW,GOLANG,FMT     2019-01-23 09:17:15

   Move.Me Writing Your Own WebSocket Server

The WebSocket protocol has applications beyond plain vanilla web development.  I will explain how the protocol works, how to implement your own server and share some insights I had along the way. Before we get down and dirty, I will explain what I’ve been doing with it. At this point I expect many of you are saying “I’m not working on a web game this doesn’t seem relevant to me.” Well, neither am I. I embed a WebSocket server into my game engine and wit...

   Socket,NetWorking,WebSocket,Server development     2012-01-28 07:06:43

  GitHub launches a separate training page

Code hosting community Github has much proud data: 55 employees, Andreessen Horowitz promised a $100 million investment, $750 million valuation, a place developers stay longest since its launch in 2008 ... Github announced the official launch of a separate teaching page, to teach developers collaborative programming through various forms. Github announces the detail about the training program on its official blog, the entire training project has two modes : free and paid. The content of their t...

   GitHub,Training,Open source     2012-10-07 05:45:47

  People Detection Radar [IoT] : Build a Raspberry PI Xandar Kardian IoT People Count Radar

Program Design Purpose: People detection sensors and radars are utilized in various applications across multiple fields such as security and surveillance, healthcare, building automation, smart cities, transportation and autonomous manufacturing systems. This project aims to develop a prototype IoT device for an indoor people counting using the Xandar Kardian people detection radar and a Raspberry Pi. The device will be network-ready and easily integrated with other systems. The Python-based I...

       2024-07-21 08:19:57

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