info/php-the-right-way
1
0
Fork 0
mirror of https://github.com/codeguy/php-the-right-way.git synced 2025-08-09 23:46:37 +02:00
Code Issues Projects Releases Wiki Activity

Merge pull request #692 from wturrell/patch-10

Browse Source 
Clarify opcodes, cache names, PHP versions
This commit is contained in:
Phil Sturgeon
2016-10-10 17:38:28 +03:00
committed by GitHub
parent 1b975e3e12 ce95ad0ee9
commit a5dec4ae40
1 changed files with 7 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
_posts/14-02-01-Opcode-Cache.md
View File

@@ -5,23 +5,18 @@ anchor: opcode_cache
## Opcode Cache {#opcode_cache_title} ## Opcode Cache {#opcode_cache_title}
When a PHP file is executed, under the hood it is first compiled to opcodes and, only then, the opcodes are executed. When a PHP file is executed, it must first be compiled into [opcodes](http://php.net/manual/en/internals2.opcodes.php) (machine language instructions for the CPU). If the source code is unchanged, the opcodes will be the same, so this compilation step becomes a waste of CPU resources.
If a PHP file is not modified, the opcodes will always be the same. This means that the compilation step is a waste of
CPU resources.
This is where opcode caches come in. They prevent redundant compilation by storing opcodes in memory and reusing it on An opcode cache prevents redundant compilation by storing opcodes in memory and reusing them on successive calls. It will typically check signature or modification time of the file first, in case there have been any changes.
successive calls. Setting up an opcode cache takes a matter of minutes, and your application will speed up
significantly. There's really no reason not to use it.
As of PHP 5.5, there is a built-in opcode cache called [OPcache][opcache-book]. It is also available for earlier It's likely an opcode cache will make a significant speed improvement to your application. Since PHP 5.5 there is one built in - [Zend OPcache][opcache-book]. Depending on your PHP package/distribution, it's usually turned on by default - check [opcache.enable](http://php.net/manual/en/opcache.configuration.php#ini.opcache.enable) and the output of `phpinfo()` to make sure. For earlier versions there's a PECL extension.
versions.
Read more about opcode caches: Read more about opcode caches:
* [OPcache][opcache-book] (built-in since PHP 5.5) * [Zend OPcache][opcache-book] (bunded with PHP since 5.5)
* [APC] (PHP 5.4 and earlier) * Zend OPcache (formerly known as Zend Optimizer+) is now [open source][Zend Optimizer+]
* [APC] - PHP 5.4 and earlier
* [XCache] * [XCache]
* [Zend Optimizer+] (part of Zend Server package)
* [WinCache] (extension for MS Windows Server) * [WinCache] (extension for MS Windows Server)
* [list of PHP accelerators on Wikipedia][PHP_accelerators] * [list of PHP accelerators on Wikipedia][PHP_accelerators]
@@ -29,6 +24,6 @@ Read more about opcode caches:
[opcache-book]: http://php.net/book.opcache [opcache-book]: http://php.net/book.opcache
[APC]: http://php.net/book.apc [APC]: http://php.net/book.apc
[XCache]: http://xcache.lighttpd.net/ [XCache]: http://xcache.lighttpd.net/
[Zend Optimizer+]: http://www.zend.com/en/products/zend_server [Zend Optimizer+]: https://github.com/zendtech/ZendOptimizerPlus
[WinCache]: http://www.iis.net/download/wincacheforphp [WinCache]: http://www.iis.net/download/wincacheforphp
[PHP_accelerators]: http://en.wikipedia.org/wiki/List_of_PHP_accelerators [PHP_accelerators]: http://en.wikipedia.org/wiki/List_of_PHP_accelerators