SEARCH KEYWORD -- Memory


  How to check whether a struct implements an interface in GoLang

Unlike other programming languages like Java, when implementing an interface in GoLang, there is no syntax like below to explicit tell the relationship: type I interface { } type A struct implements I { } When looking at the code or running the code in GoLang, it might lead to a case one doesn't know whether a struct implements interface before trying to use it as some interface. According to GoLang spec, as long as a struct implements all functions of an interface, it is considered as having i...

   GOLANG,INTERFACE,IMPLEMENTATION,CHECK     2020-05-03 00:05:54

  Using MemoryMappedBuffer to handle large file in Java

When handling large files, it will largely affect the process speed while using traditional FileInputStream, FileOutputStream or RandomAccessFile since they trigger lots of read and write operations. In Java NIO, a new way of handling large file is introduced which is to use MmeoryMappedBuffer to create memory mapped file. Memory-mapped I/O uses the filesystem to establish a virtual memory mapping from user space directly to the applicable filesystem pages. With a memory-mapped file, you can pre...

   JAVA,IO,NIO     2015-11-13 01:58:08

  HeartBleed: Should C be blamed for the HeartBleed bug?

There is a discussion about the security of applications written in C on Hacker News recently after the report of HeartBleed bug in OpenSSL. In this discussion, some people are saying that the applications written in C are unsafe. It seems all or most of the faults should be laid on C. I think this is biased. The language itself should not be blamed.Safety is a relative term for programming languages. No language is absolutely safe. We claim some languages like Java and C# are safer than C/C++ b...

   C,HeartBleed,Analysis,Code review     2014-04-14 03:52:55

  Nokia unveils Lumia 820

Just finishing introducing the latest flagship model Lumia 920 Nokia introduced mid-range Lumia 820 which is equipped with Windows Phone 8The Lumia 820 is equipped with a Qualcomm Snapdragon S4 1.5GHz dual-core CPU, but the screen is 4.3 inch WVGA screen with 800 x 480 pixels, at the same time it is equipped with 8GB memory space and a 8-megapixel rear camera. In addition, users can extend 8 GB more memory space through Windows Phone 8's extension function.Lumia 820's screen adopts Super S...

   Nokia,Lumia 820,Window Phone 8     2012-09-05 19:10:14

  new expression vs operator new in C++

In C++, there is a new mechanism for memory allocation and management. When we want to initialize an object, we can use new expression to get enough memory for storing an object and also initialize the object. When we want to create a new object, we can use new expression, for example: Obj *obj=new Obj; Basically, what the new expression does is to allocate enough memory for storing the obj object, in addition, it will initialize the object with some intial values. Also, there is an operator new...

   C++, new expression, operator new     2012-08-12 11:42:39

  new() and make() in GoLang

GoLang is a modern, statically typed, compiled programming language designed for building scalable, concurrent, and efficient software. It provides various built-in functions and features that help developers write concise and efficient code. Among them are the new() and make() functions, which may appear similar at first glance but serve different purposes in GoLang and are crucial for memory allocation and data initialization. In this blog article, we will explore the differences between the n...

   NEW,MAKE,GOLANG     2023-11-18 13:43:25

  Output control functions in PHP

The Output Control functions in PHP allow you to control when output is sent from the script. This can be useful in several different situations, especially if you need to send headers to the browser after your script has began outputting data. The Output Control functions do not affect headers sent using header() or setcookie(), only functions such as echo and data between blocks of PHP code. These output control functions include ob_start(0, ob_clean(),ob_get_contents(), etc. To be honest, I a...

   PHP,output buffer,relationship,ob     2012-06-15 10:11:58

  Simple explanation about process and thread

Process and thread are two basic concepts of operating system, but they are a bit abstract which cannot be  mastered easily. There is an analogy which explains these concepts very well. 1. The kernel of the computer is CPU, it handles all the computing tasks, it's like a factory and will run all the time. 2. Assume there is power limitation for the factory, it can only supply to one unit once,i.e, when one unit is working, other units must stop and wait. The meaning behind this is that eac...

   Process,Thread,CPU,Operating system     2013-04-24 11:33:10

  Use Java ThreadLocal with caution

According to Oracle documentation, ThreadLocal is a class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal instances are typically private static fields in classes that wish to associate state with a thread. In short, ThreadLocal variables are variables belong to a thread, not a class or an instance of a class. One common...

   JAVA,MEMORY LEAK, THREADLOCAL     2015-11-03 07:31:57

  How Kafka achieves high throughput low latency

Kafka is a message streaming system with high throughput and low latency. It is widely adopted in lots of big companies. A well configured Kafka cluster can achieve super high throughput with millions of concurrent writes. How Kafka can achieve this? This post will try to explain some technologies used by Kafka. Page cache + Disk sequential write Every time when Kafka receives a record, it will write it to disk file eventually. But if it writes to disk every time it receives a record, it would ...

   BIG DATA,KAFKA     2019-03-08 09:42:57

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