如何测量用PHP编写的代码的速度? [英] How can I measure the speed of code written in PHP?

问题描述

我如何说很多(哪一个都执行相同的工作)中的哪一个执行得更快?有软件可以测量吗?

How can I say which class of many (which all do the same job) execute faster? is there a software to measure that?

推荐答案

您有(至少)两个解决方案:

一个相当幼稚"的方法是在一部分代码之前和之后使用microtime(true)，以获取在其执行过程中经过了多少时间；其他答案已经说过了，并且已经给出了例子，所以我就不多说了.

The quite "naïve" one is using microtime(true) tobefore and after a portion of code, to get how much time has passed during its execution ; other answers said that and gave examples already, so I won"t say much more.

如果您想对一些指令进行基准测试，这是一个不错的解决方案；例如，比较两种类型的函数-最好执行数千次，以确保对任何扰动元素"进行平均.

This is a nice solution if you want to benchmark a couple of instructions ; like compare two types of functions, for instance -- it's better if done thousands of times, to make sure any "perturbating element" is averaged.

类似的事情，所以，如果您想知道序列化数组需要多长时间:

Something like this, so, if you want to know how long it take to serialize an array :

$before = microtime(true);

for ($i=0 ; $i<100000 ; $i++) {
    serialize($list);
}

$after = microtime(true);
echo ($after-$before)/$i . " sec/serialize\n";

并不完美，但很有用，并且不需要花费很多时间进行设置.

Not perfect, but useful, and it doesn't take much time to set up.

如果要确定整个脚本中哪个函数需要花费大量时间，另一种解决方案效果很好:

The other solution, that works quite nice if you want to identify which function takes lots of time in an entire script, is to use :

• Xdebug 扩展名，以生成脚本的分析数据
• 读取概要分析数据并为您呈现可读性的软件.我知道其中三个:
  • Webgrind ；网络界面;应该可以在任何Apache + PHP服务器上运行
  • WinCacheGrind ；仅在Windows上
  • KCacheGrind ；大概只有Linux和类似linux的;我喜欢的就是那个，顺便说一句
  • The Xdebug extension, to generate profiling data for the script
  • Software that read the profiling data, and presents you something readable. I know three of those :
    • Webgrind ; web interface ; should work on any Apache+PHP server
    • WinCacheGrind ; only on windows
    • KCacheGrind ; probably only Linux and linux-like ; That's the one I prefer, btw

    要获取配置文件，您必须安装和配置Xdebug；看看文档的剖析PHP脚本页面.

    To get profiling files, you have to install and configure Xdebug ; take a look at the Profiling PHP Scripts page of the documentation.

    我通常所做的是默认情况下不启用分析器(它会生成很大的文件，并降低速度)，但会使用可能性将名为XDEBUG_PROFILE的参数作为GET数据发送，仅为我需要的页面激活分析.
    我的php.ini中与分析相关的部分看起来像这样:

    What I generally do is not enable the profiler by default (it generates quite big files, and slows things down), but use the possibility to send a parameter called XDEBUG_PROFILE as GET data, to activate profiling just for the page I need.
    The profiling-related part of my php.ini looks like this :

    xdebug.profiler_enable = 0              ; Profiling not activated by default
    xdebug.profiler_enable_trigger = 1      ; Profiling activated when requested by the GET parameter
    xdebug.profiler_output_dir = /tmp/ouput_directory
    xdebug.profiler_output_name = files_names
    

    (有关更多信息，请阅读文档)

    此屏幕快照来自KcacheGrind中的C ++程序:
    _{(来源: sourceforge.net )}
    
    使用PHP脚本，您将获得完全相同的结果；-)
    (对于KCacheGrind，我的意思是； WinCacheGrind不如KCacheGrind ...)

    This screenshot is from a C++ program in KcacheGrind :
    _{(source: sourceforge.net)}
    
    You'll get exactly the same kind of thing with PHP scripts ;-)
    (With KCacheGrind, I mean ; WinCacheGrind is not as good as KCacheGrind...)

    这使您可以很好地了解应用程序中所花的时间-有时可以明确地帮助定位 函数，该函数会使所有操作变慢^^

    This allows you to get a nice view of what takes time in your application -- and it sometimes definitly helps to locate the function that is slowing everything down ^^

    请注意，Xdebug会计算PHP花费的CPU时间；当PHP在等待数据库的答案时(例如)，它不起作用；只等着.因此Xdebug会认为数据库请求不会花费很多时间！
    这应该在SQL服务器而不是PHP上进行概要分析，所以...

    Note that Xdebug counts the CPU time spent by PHP ; when PHP is waiting for an answer from a Database (for instance), it is not working ; only waiting. So Xdebug will think the DB request doesn't take much time !
    This should be profiled on the SQL server, not PHP, so...

    
    希望这会有所帮助:-)
    玩得开心！

    
    Hope this is helpful :-)
    Have fun !

    这篇关于如何测量用PHP编写的代码的速度?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！