• Source code analysis of liteos kernel: bit operation module


    Abstract:This article leads you to analyze the source code of the bit operation module of liteos. The code is very simple. Refer to the official sample program code, compile and run it, and deepen your understanding. This article is shared from Huawei cloud community《Source code analysis of liteos kernel — bit operation module》Author: zhushy. Before […]

  • JS can also be so romantic, using JS to write down a world (VR)


    Let’s first feel the above image, taking Disney castle as an example. Are you excited? Do you think it’s going to be complicated to implement this cool special effect? No, there are only two steps to achieve this effect We need a panoramic view Configure with photo-sphere-viewer.js (a JavaScript library for panoramic image display) You […]

  • Garbage collector for beginners to learn java performance


    preface Garbage collection algorithm is the methodology of memory recovery; Garbage collector is the concrete implementation of memory recovery. Java virtual machine specification has no rules on how to implement the garbage collector, so different vendors and different versions of virtual machines provide different garbage collectors, and generally provide parameters for users to combine the […]

  • Android basic series (2) Java annotation


    sketch Starting from jdk5, Java adds support for metadata, that is, annotations. Annotations are different from annotations. Annotations can be understood as special tags in code. These tags can be read and processed during compilation, class loading and runtime. Through annotation, developers can embed supplementary information in the source code without changing the original code […]

  • Video element of HTML5


    The markup syntax format is as follows. Alternative text attribute value explain src url The URL to play the video controls controls Add controls such as play, pause and volume           Your browser does not support video tags play() When playing the media, the value of the used property is automatically […]

  • Django security configuration (setting. Py)


    Django security configuration (setting. Py) Tags (space separated): Python Django Web Security — 1. It must be configured with: 0x01. PASSWORD_HASHER This configuration is in useDjangoThe list of encryption algorithms that will be used when using the built-in password encryption function. The default is as follows: PASSWORD_HASHERS = ( ‘django.contrib.auth.hashers.PBKDF2PasswordHasher’, ‘django.contrib.auth.hashers.PBKDF2SHA1PasswordHasher’, ‘django.contrib.auth.hashers.BCryptSHA256PasswordHasher’, ‘django.contrib.auth.hashers.BCryptPasswordHasher’, ‘django.contrib.auth.hashers.SHA1PasswordHasher’, ‘django.contrib.auth.hashers.MD5PasswordHasher’, […]

  • Why TCP shakes hands three times instead of two


    According to my understanding, why TCP shakes hands three times instead of two.Step by step. 1. TCP is reliable TCP is a reliable transmission. Handshake refers to TCP establishing link. How can we establish link reliably? 2. The simplest way is to establish a reliable transmission channel A——–>BA wants to send data to B. if […]

  • JavaScript is a scripting language


    1. Computer languageAt present, it is mainly divided into three categories: machine, assembly and advancedThe programming languages include: assembly and advanced programmingNote: computer CPU and memory hard disk storage only know the binary of machine language, so it is often necessary to pass the high-level languageinterpreter[conversion] 2. ProgrammingWrite a series of instructive codes to control […]

  • Depth first search


    The process of depth first search is similar to the prior traversal of tree First, arbitrarily find a vertex that has not been traversed. For example, starting from V1, because V1 has been visited first, it is necessary to mark V1 as visited; Then traverse the adjacency points of V1, for example, visit V2 and […]

  • Long substring without repeating


    Title: Given a string, find the length of the longest substring without repeating characters. Example 1: Input: “abcabcbb” Output: 3 Explanation: The answer is “abc”, with the length of 3. Example 2: Input: “bbbbb” Output: 1 Explanation: The answer is “b”, with the length of 1. Example 3: Input: “pwwkew” Output: 3 Explanation: The answer […]

  • Data structure questions in front end interview


    1、 Single linked list flipping (leetcode 206) 1. Iterative method var reverseList = function(head) { if(!head || !head.next){ return head; }else{ //Initialize prev and curr first var prev = null; var curr = head; //Continuously point the next pointer of the latter node to the precursor node until the node is null, which means the […]

  • Eureka is a service


    1、 Demand When our project is released, if our registry useseurekaWhen we have multiple service instances, we want to publish a service smoothly and do not make mistakes in the process of calling the service. eg: For example, we have two goods and services. When we publish, we first send instance a and then send […]