Articles
android

Chrome browser architecture

background \ This article was included in the column of browser working principle in my series of articles on front-end technology. As the first article of this column, let s start with the most common problem of how the page is displayed in the browser. At the beginning, an overall introduction to the working principle of the browser. This article is based on Mariko Kosaka 's Inside look at modern web browser series of articles published in the Chrome developer documentation in September 2018,

... Steven
schedule 30 min read
android

Knowledge points of "Flutter" that you may not know will continue to be updated...

The past and present of this article I picked up this article from the draft box. It's a bit historical. Let's talk about some of the "relationships" between me and Flutter . First contactFlutterAt the beginning of 2019, when the company s product App useduni-appThis framework was developed at that timeuni-appThere are still relatively few users, the community is not complete enough, and the nature of the web itself, resulting in some performance problems in the long list of App , due to the ins

... Lincoln
schedule 12 min read
android

A Preliminary Study of Compose

Preparation before use android studio Arctic FoxVersion or newer If it is a new project, you can create a new one when creatingEmpty Compose Activity In the modulebuild.gradleAdd in file android { buildFeatures { compose true } composeOptions { kotlinCompilerExtensionVersion compose_version kotlinCompilerVersion '1.4.32' } } dependencies { implementation'androidx.core :core-ktx:1.3.2' implementation'androidx.appcompat :appcompat:1.2.0' implementation'com.google.android.material :material:1.3.0'

... Bentley
schedule 8 min read
android

50 classic SQL interview questions (part 1)

Click and follow "SQL database development" above, Set as "top or star ", dry goods will be delivered as soon as possible. I recently found this set of classic SQL interview questions when I was collecting SQL daily questions. \ I sorted it out based on the questions, including the table structure, the relationship between the tables, test data, questions, reference answers, etc. Most of the reference answers are common on various database platforms. \ Due to the large number of questions (full

... Jude
schedule 15 min read
android

Briefly describe the treeShaking of rollup

1. Basic use of rollup import {babel} from '@rollup/plugin-babel' ; import resolve from '@rollup/plugin-node-resolve' ; import commonjs from '@rollup/plugin-commonjs' ; import typescript from '@rollup/plugin-typescript ' ; Import {terser} from ' ROLLUP-plugin-terser ' ; Import postcss from ' ROLLUP-plugin-postcss' ; Import serve from 'ROLLUP-plugin-serve' ; Export default { INPUT:"src/main.js" , output : { file : "dist/rollup_bundle_1.js" , format : "es" , // Many Chinese models amd/es/iife/umd/

... Cora
schedule 19 min read
coder_life

Sokoban games

# include <stdio.h> # include <math.h> # include <string.h> # include <stdlib.h> # include <time.h> int main () { begin: int i,j; char p[ 16 ][ 16 ]; for (i= 0 ; i< 16 ; i++) { for (j = 0 ; j< 16 ; j++) p[i][j]= '' ; } for (i = 0 ; i< 16 ; i++) { p[i][ 15 ] = '#' ; p[i][ 0 ] = '#' ; } for (j = 0 ; j< 16 ; j++) { p[ 0 ][j]= '#' ; p[ 15 ][j]= '#' ; } p[ 5 ][ 3 ] = '#' ; p[ 6 ][ 8 ] = '#' ; p[ 2 ][ 3 ] = '#' ; p[ 8 ][ 12 ] = '#' ; p[ 2 ][ 12 ] = '#' ; p[ 11

... Natalie
schedule 7 min read
coder_life

LLVM IR to Asm Part 4

9 IR Memory Representation: 9.1 Value class Reference /// LLVM Value Representation /// This is a very important LLVM class. It is the base class of all values /// computed by a program that may be used as operands to other values. Value is /// the super class of other important classes such as Instruction and Function. /// All Values have a Type. Type is not a subclass of Value. Some values can /// have a name and they belong to some Module. Setting the name on the Value /// automatically upda

... Bryce
schedule 9 min read
coder_life

Android platform RTMP streaming or lightweight RTSP service (camera or same screen) data access type summary before encoding

Many developers always feel that the interface is not enough when doing RTMP streaming or lightweight RTSP services (camera or same screen) on the Android platform. Take the Daniel Live SDK as an example ( Github ). Let s summarize, what we usually need to support What are the types of audio and video data before encoding: 1. The data interface of the Android camera before and after the camera through OnPreviewFrame() callback: @Override public void onPreviewFrame(byte[] data, Camera camera) { f

... Silas
schedule 11 min read
coder_life

Create a department review Scope (Qt XML) on Ubuntu OS

In the previous articles, we have introduced some how to use Qt and C++ API to create a Scope. They are all basic scopes. In this article, we will introduce department Scope and master the methods of developing it. Department Scope will perform classification searches in many Scopes. More information about Scope can be found at developer.ubuntu.com/scopes/ . The interface of our final Scope is as follows: \       \ \ 1) What is department Scope \ First of all, frankly, i

... Hannah
schedule 26 min read
coder_life

Cross-platform low-latency RTMP/RTSP live broadcast player design and implementation

Development background In 2015, when we tried to find a low-latency player specifically for live broadcast on the market to test our RTMP push module, we actually found that there was no useful one on the market, such as VLC or Vitamio, to put it bluntly, is based on FFMPEG. There are many formats and excellent support for on-demand. However, the live broadcast, especially RTMP, has a delay of a few seconds. For example, pure audio and pure video playback, fast start broadcast, network Abnormal

... Adrian
schedule 35 min read
dev_tools

Java language basics-flow control statements

Branch structure The concept of branch structure When you need to make conditional judgments and make choices, use the branch structure. if branch structure if (conditional expression) { Statement block; } Copy code Determine whether the conditional expression is true => If it is true, execute the statement block => If not true, skip the statement block Case topic Prompt the user to enter two integers, use the if branch structure to find the maximum value and print it out. /* Process contr

... Liam
schedule 17 min read
dev_tools

The ARIMA model, SARIMA model and SARIMAX model in Python for time series forecasting

Original link: tecdat.cn/?p=12272 Original source: Tuoduan Data Tribe Official Account   Using the ARIMA model, you can use the past values of the series to predict a time series. In this article, we built an optimal ARIMA model from scratch and extended it to Seasonal ARIMA (SARIMA) and SARIMAX models.   1. Introduction to time series forecasting A time series is a sequence of recording metrics at regular intervals. According to the frequency, the time series can be yearly (for exampl

... Grayson
schedule 23 min read
dev_tools

The magical python pickle module

background Persistence refers to keeping objects, even between multiple executions of the same program. Through this article, you will have a general understanding of the various persistence mechanisms of Python objects (from relational databases to Python's pickle and other mechanisms). In addition, it will give you a deeper understanding of Python's object serialization capabilities. What is persistence? The basic idea of persistence is simple. Suppose there is a Python program. It may be a pr

... Nolan
schedule 19 min read
dev_tools

Inheritance of Object-Oriented Programming II

The sun is shining today, and the cloudy day turns to sunny. My mood has been cloudy since the sunny day. Why is this because I found my grandfather.... Duck eggs are not bad for the classic quotes on money, I still enter the venue with a cheerful sentence. I have been talking about object-oriented in these two chapters, and I don t know what it is facing. In the end, you can only face yourself without facing the object. Hahaha, although in reality you may not be able to grasp the goal around y

... Madison
schedule 13 min read
dev_tools

Interview in 2021, sort out common Java interview questions with answers for the beginning, middle and advanced levels of the whole network

This is part of the interview questions. For more information, see the WeChat applet "Java Selected Interview Questions", 3000+ interview questions. The content is continuously updated including basics, collections, concurrency, JVM, Spring, Spring MVC, Spring Boot, Spring Cloud, Dubbo, MySQL, Redis, MyBaits, Zookeeper, Linux, data structures and algorithms, project management tools, message queues, design patterns , Nginx, common BUG issues, network programming, etc. What are the characteristic

... Nolan
schedule 78 min read
programming

Vue3.0

Vue3.0 Performance Vue 2.x 1.2~2 Tree shaking support , Vue2.x Composition API: API( React Hooks) Better TypeScript support Ts Custom Renderer API API Fragment, Teleport(Protal), Suspense Vue3.0 diff https://vue-next-template-explorer.netlify.app/ + Vue2 dom dom + Vue3 (PatchFlag) patch flag flag _toDisplayString PatchFlag // diff <div> <p> </p> <p>{{msg}}}</p> </div> export function render(_ctx, _cache, $props, $setup, $data, $options) { return (_openBlock(),

... Benjamin
schedule 10 min read
programming

[Image denoising] Image denoising based on matlab GUI median + mean + Wiener + wavelet filtering [including Matlab source code 753]

1. Introduction Image denoising based on matlab GUI median + mean + Wiener + wavelet filtering Second, the source code function varargout = dsp1(varargin) % DSP1 MATLAB code for dsp1.fig % DSP1, by itself, creates a new DSP1 or raises the existing % singleton*. % % H = DSP1 returns the handle to a new DSP1 or the handle to % the existing singleton*. % % DSP1( 'CALLBACK' ,hObject,eventData,handles,...) calls the local % function named CALLBACK in DSP1.M with the given input arguments. % % DSP1( '

... Ezekiel
schedule 9 min read
programming

js-design patterns in a nutshell

The design pattern is a kind of thought, the code is clean, easy to understand, maintain, expand, and optimize Singleton mode Singleton mode: manage the content of a certain module based on a separate instance to achieve independent division of modules and mutual calling Class has only one instance The instance can be accessed globally (we use closure and function scope here) When the project starts, divide the modules, one module per person var A = ( function () { var data = []; function change

... Jayla
schedule 9 min read
programming

DockerFile

Preface Docker series articles: This article is the fifth article in the Docker series. You must follow the demo I made and type it out. The impression will be even more profound. Come on! Why learn Docker Basic concepts of Docker Basic principles of Docker mirroring Docker container data volume What is DockerFile Dockfile is a script interpreted by the Docker program. The Dockerfile consists of instructions one by one, and each instruction corresponds to a command under Linux. The Docker progra

... Makayla
schedule 11 min read
programming

Analysis of the principle of converting Vue2 code to Vue3-eventHub

Preface A few days ago, we released "Alimama has made a new tool to help you change the Vue2 code to Vue3" . This article shares one of the conversion rules: eventHub (or eventBus) conversion ideas. Vue's official migration plan: v3.cn.vuejs.org/guide/migra... 1. First introduce eventHub 1.1 eventHub of Vue2 eventHub is an event center shared between components. It is used in Vue as a bridge for component communication, sending messages to eventHub, and other modules obtain corresponding data by

... Adrian
schedule 6 min read
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