


php performance optimization php language-level performance optimization 1
For this problem, first we need to know what is the reason that affects the performance of php? That is
1 Under what circumstances will PHP performance problems occur?
1php Improper use of syntax (including some businesses that can be processed using PHP’s own functions)
2 Use php language to do things it is not good at
3 The server connected using php language is not powerful (of course, if it is localhost, your local configuration is relatively poor, it is recommended to change it, haha)
4php’s own shortcomings (PHP itself can’t do it)
5 Questions We Don’t Know (囧)
2 Introduction to PHP performance issues and solutions to PHP performance issues
From the least difficult to the most difficult are:
1 Php language level performance optimization
2 Performance optimization of Php peripheral issues (such as mysql nginx|apache)
3 Php language senior analysis and optimization (ps mainly refers to the underlying c code)
The following is an example discussion of PHP language-level performance optimization, and a test of the content mentioned in the title. Next, we need to write two files bad.php, goods.php
What we want to test is the operation of merging two arrays (test tool apache ab test)
bad.php
Things:
First add array 1 to the target array one by one;
After, traverse array 2 and compare whether the elements of array 2 appear in array 1. If not, insert them into the target array, otherwise ignore
<span style="font-size:14px;"><?php //准备两个内容随机的数组 $arr1 = $arr2 = $arr_merged = array(); //接下来随机给两个数组赋值 for ( $i=0; $i<rand(1000,2000); $i++) { $arr1[] = rand(); } for ( $i=0; $i<rand(1000,2000); $i++) { $arr2[] = rand(); } //开始循环比较 foreach ( $arr1 as $v ) { $arr_merged[] = $v; } foreach ( $arr2 as $v ) { if(!in_array($v, $arr_merged)){ $arr_merged[] = $v; } } var_dump($arr_merged);</span>
goods.php
Things:
Randomly generate two arrays and shuffle them in order
After that, use array_merge to merge
<span style="font-size:14px;"><?php //准备两个内容随机的数组 $arr1 = $arr2 = range(1000, 2000); $arr_merged = array(); //接下来随机给两个数组赋值 shuffle($arr1); shuffle($arr2); $arr_merged = array_merge($arr1, $arr2); var_dump($arr_merged); </span>
3 Use ab to test the speed of two php scripts: (ps: the amazing moment begins)
bad.php
goods.php喎?http://www.Bkjia.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+PGltZyBzcmM9"http://www.2cto.com/uploadfile/Collfiles/20141205/20141205084010231.png" alt="">
For these two tests, we can clearly see that the difference is not a little bit different. When executing bad.php, I obviously felt the computer fan blowing. You know!
bad.php responds to 174 requests per second, processing 572ms per request
goods.php responds to 4050 requests per second, processing 24ms per request
ps: If you still use the bad wording, change it as soon as possible, and be careful not to let your boss know!
4 The reasonI am also surprised by this result, but the facts are right in front of me and there is nothing we can do about it. So why is there such an effect? Let’s continue to find out:
*.php (php code) -----Scanner (zend engine scans line by line into syntax that zend can recognize) ----> exprs
-----parser(parse to opcode)-----> opcodes ------exec(execute final output)-------> output
You can know that a PHP file needs to be scanned first to execute zend, and then parsed into opcode for execution output. The problem lies here. When we use PHP’s own functions, it actually belongs to the zend engine, so zend is relatively easy to parse. It's smooth and fast (goods.php), but when bad.php is executed, it will be slower, because reading code written by others is definitely not as fast as reading code written by yourself, right? So I still use the original one. It’s better not to make your own wheels!
To tell you a little more, this is why many Php extensions (such as apc) now cache opcodes because this eliminates the need for scanning and parsing, which is definitely faster!
5 Summary
Optimization points: write less code and use more capabilities provided by PHP itself
Performance issues:
The code I wrote is redundant, not readable, and has low performance
Why is the performance low?
The PHP code needs to be compiled and parsed into the underlying language. This process will be processed for each request, which is very expensive.
Good method:
Use more PHP built-in variables, constants, and functions (spl can bring you useful functions)

如何优化Java开发中的文件压缩解压性能随着互联网技术的不断发展,文件传输和存储成为我们日常开发中经常遇到的需求。为了减小网络传输的带宽消耗和文件存储的空间占用,我们通常需要对文件进行压缩。在Java开发中,常用的文件压缩格式有ZIP和GZIP。本文将介绍如何优化Java开发中的文件压缩解压性能,帮助提高效率。一、合理选择压缩算法在Java开发中,进行文件压

电脑性能看如下几个方面:1、电脑安装的操作系统的版本;2、电脑所配置的处理器类型;3、电脑安装的内存大小;4、操作系统是32位的还是64位的。

在Java开发中,字符串查找是一个常见且关键的操作。无论是在文本处理、数据分析还是系统日志分析等应用场景中,字符串的查找性能都对程序的整体性能有着重要影响。因此,如何优化字符串查找性能成为了Java开发中不可忽视的问题。一、使用indexOf()方法代替contains()方法在字符串查找中,Java提供了两个常用的方法:indexOf()和contains

如何优化Java开发中的随机数生成性能随机数在计算机科学中有广泛的应用,特别是在密码学、模拟、游戏等领域。在Java开发中,我们常常需要生成随机数来满足各种需求。然而,随机数生成的性能通常是开发者关注的问题之一。本文将探讨如何优化Java开发中的随机数生成性能。使用ThreadLocalRandom类在Java7中引入了ThreadLocalRandom类

Vue3是一款流行的JavaScript框架,它具有易学易用、高效稳定的特点,尤其擅长构建单页应用程序(SPA)。Vue3中的lazy函数,作为懒加载组件的利器之一,可以很大程度上提高应用程序的性能。本文将详解Vue3中的lazy函数的使用方法与原理,以及它在实际开发中的应用场景和优点。什么是懒加载?在传统的前后端分离的开发中,前端开发人员往往需要处理大量的

MySQL是一种常用的关系型数据库管理系统(RDBMS),在各种应用场景下都得到广泛的应用。然而,在高并发、大数据量的情况下,MySQL数据库的性能受到挑战,特别是在读写操作频繁的场景下,容易出现性能瓶颈。为了提高MySQL数据库的性能,可以通过设置MySQL缓存来减少数据库的IO操作,从而提高MySQL的查询效率。在本文中,我们将介绍如何通过设置MySQL

随着深度强化学习技术的快速发展,越来越多的研究团队开始将其应用于自动驾驶决策规划中,将行为决策与运动规划模块相融合,直接学习得到行驶轨迹。 自动驾驶中的决策规划模块是衡量和评价自动驾驶能力最核心的指标之一,它的主要任务是在接收到传感器的各种感知信息之后,对当前环境作出分析,然后对底层控制模块下达指令。典型的决策规划模块可以分为三个层次:全局路径规划、行为决策、运动规划。01 引言在一套完整的自动驾驶系统中,如果将感知模块比作人的眼睛和耳朵,那么决策规划就是自动驾驶的大脑。大脑在接收到传感器的各种

昨天一个跑了220个小时的微调训练完成了,主要任务是想在CHATGLM-6B上微调出一个能够较为精确的诊断数据库错误信息的对话模型来。不过这个等了将近十天的训练最后的结果令人失望,比起我之前做的一个样本覆盖更小的训练来,差的还是挺大的。这样的结果还是有点令人失望的,这个模型基本上是没有实用价值的。看样子需要重新调整参数与训练集,再做一次训练。大语言模型的训练是一场军备竞赛,没有好的装备是玩不起来的。看样子我们也必须要升级一下实验室的装备了,否则没有几个十天可以浪费。从最近的几次失败的微调训练来看


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Linux new version
SublimeText3 Linux latest version

Notepad++7.3.1
Easy-to-use and free code editor

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

Dreamweaver CS6
Visual web development tools
