• Building blockchain based on Java language (6) — Merkle tree


    The final content is subject to the original texthttps://wangwei.one/posts/630… introduction At the beginning of this series, we mentioned that blockchain is a distributed database. At that time, we decided to skip distributed and focus on data storage. So far, we have implemented almost all the components of the blockchain. In this article, we will cover […]

  • Profiler of react learning


    ability: measure how often to render a react application and the cost of rendering, in order to identify the slower parts of the application. Usage: can be used anywhere in the react tree to measure the overhead of rendering that part. Demo: render() { return ( <App> <Profiler id=”Navigation” onRender={callback}> <Navigation props={…props} /> </Profiler> <Main […]

  • 20. Nginx performance optimization


    AB performance test yum install httpd-tools ab -n 100 -c 100 #Concurrent quantity Concurrency Level: 100 #Time spent on the whole test Time taken for tests: 0.014 seconds #Number of completed requests Complete requests: 100 #Number of failed requests Failed requests: 0 #Number of write errors Write errors: 0 #Number of non-200 response codes […]

  • Which do you choose, NPM or yarn?


    By Charlie midtlyng Crazy technology house Original: https://javascript.christmas/ No reprinting without permission Every team has to make decisions in the development process. It usually involvesyarn,npmOr other tools for building and packaging JavaScript code. Some developers are eager to move in a certain direction, sometimes they spend a lot of time trying to make decisions that […]

  • Python Foundation (18): preliminary understanding module, re module


    1. Understanding module Common scenario: a module is a file containing Python definitions and declarations. The filename is the module name plus the suffix. Py. However, the modules loaded by import are divided into four general categories: 1. Code written in python (. Py file) 2. C or C + + extensions that have been […]