Programmer Think

Linux as a general hardware kernel, how to achieve general and efficient memory management. In the previous article on Linux memory segmentation and paging, we mainly explain that the Linux kernel carries out the abstract mapping of physical address, logical address and linear address, which is like dividing territory for families in a wilderne ...

Basic concepts in hash table Hash table definition: Hash table (also known as hash table) is a data structure that performs insertion, deletion and lookup in constant time. It is a data structure that is accessed directly according to the key value. That is, it accesses records by mapping key values to a location in the table to speed up t ...

This paper continues to study network programming (I) 1, Development steps of Socket server and client Create SocketAdd information (IP address and port number) to the socketMonitor network connectionsListen for client access and accept a connectionData interactionClose socket 2, Main API s of network programming 1. Specify to speak &quot ...

1, Element positioning: positioning of id and name attributes Open Baidu, search Selenium self-study, then click the search button, press F12 in the search page results, click the check button and click the search box Find the attribute id, attribute value "kw", attribute name and attribute value "wd" Next, check to find b ...

We will use a series to explain the complete practice of microservices from requirements to online, from code to k8s deployment, from logging to monitoring. The whole project uses the micro services developed by go zero, which basically includes go zero and some middleware developed by relevant go zero authors. The technology stack used is bas ...

Reference link 1 Reference link 2 The code comes from link 2 and has been modified by yourself. The level is limited. I hope to point out some mistakes. hadoop3. 2.1 write code under centos 7 window, package and submit it to Hadoop cluster on centos for operation.   ideas:   put the picture on hdfs, and then write the path of each im ...

1, shell variables and other related introduction 1. Compiled language and interpreted language Compiled language: compiled language is written before program execution. It needs a special compilation process to compile the program into machine language. For example, the exe format package of Windows. Interpretive language: interpretive la ...

Msgpack / Jason performance data comparison MsgPack is an efficient binary serialization format. Like Jason, it can exchange data between languages and is used to serialize and store data. The advantage is that when the data scale is large, it is more efficient and occupies less resources than Jason; The disadvantage is that it is not easy to ...

1 Concept Foreign key constraints are used to establish links between two table data. One field of one table is constrained by the corresponding field in the other table. In other words, there must be at least two kinds of tables for setting foreign key constraints. The constrained table is called a slave table (child table) and the other ...

Pattern definition Define a series of algorithms, encapsulate them one by one, and make them replaceable (changeable) with each other. This pattern allows the algorithm to change (expand, subclass) independently of the client program using it. Application scenario In the process of software construction, the algorithms used by some objec ...