Comparison between APC constant definition and PHP define _ PHP Tutorial

Source: Internet
Author: User
Tags constant definition define function php define
The definition of APC constant is compared with define of PHP. Recently, when I was working on the preliminary code architecture of the cloud platform, I encountered a constant definition speed comparison problem, so I would like to make a comparison. Php apc extension, which is described in the following section in the PHP Manual: h recently encountered a constant definition speed comparison problem when working on the preliminary code architecture of the cloud platform.
The APC extension of PHP is described in the following section in the PHP manual:
Http://cn.php.net/manual/zh/function.apc-define-constants.php
Define () is notoriously slow. Since the main benefit of APC is to increase the performance of scripts/applications, this mechanism is provided to streamline the process of mass constant definition.
This means that PHP's define function is relatively slow. in the PHP environment where apc is enabled, the constant definition method using apc is much faster than define.
The apc constant definition uses the apc_define_constants () and apc_load_constants () functions.
Here we have prepared two programs to test their running time respectively:
Code of the define function:
$ Stime = microtime (true );

Define ('tmp _ path', '/TMP ');
//... Other definitions, 20 in total

Echo API_MAIL;
Echo'
';

$ Etime = microtime (true );
Echo $ etime-$ stime;
?>
The constant definition code of apc:
$ Stime = microtime (true );
If (! Apc_load_constants ('api ')){
Apc_define_constants ('api ', array (
'Tmp _ path' => '/TMP ',
//... Other definitions, 20 in total
));
}

Echo API_MAIL;
Echo'
';

$ Etime = microtime (true );
Echo $ etime-$ stime;
?>
Execution result:
Define function:
0.000098943710327148
0.00010895729064941
0.00010585784912109
0.00010395050048828
...
Apc constant definition:
0.00010991096496582
0.000039100646972656
0.000042915344238281
0.000041961669921875
...
From the results, we can see that the apc constant definition takes almost the same time as define during the first execution, but after the first execution, the execution time is very small, only 1/3 of define. The execution time of define is very average every time, and there is not much ups and downs.
From code analysis, the definition of apc constant is to get a constant through the apc_load_constants () function, and then execute apc_define_constants () to define a constant when the constant does not exist. The advantage is that constants are imported to the PHP execution space at a time, so they do not need to be define once, so the efficiency is higher.
Note: In this test, the apc cache is enabled in the PHP environment, so the test of the define function is also executed in memory.


This article is from the "Zhenzhong Technical Notebook" blog

Bytes. Php apc extension, which is described in the following section in the PHP Manual: h...

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.