Cache a Class Loader
Cache a Class Loader¶
Introduction¶
Finding the file for a particular class can be an expensive task. Luckily,
the ClassLoader component comes with two classes to cache the mapping
from a class to its containing file. Both the Symfony\Component\ClassLoader\ApcClassLoader
and the Symfony\Component\ClassLoader\XcacheClassLoader wrap
around an object which implements a findFile() method to find the file
for a class.
Note
Both the ApcClassLoader and the XcacheClassLoader can be used
to cache Composer’s autoloader.
ApcClassLoader¶
ApcClassLoader wraps an existing class loader and caches calls to its
findFile() method using APC:
require_once '/path/to/src/Symfony/Component/ClassLoader/ApcClassLoader.php';
// instance of a class that implements a findFile() method, like the ClassLoader
$loader = ...;
// sha1(__FILE__) generates an APC namespace prefix
$cachedLoader = new ApcClassLoader(sha1(__FILE__), $loader);
// register the cached class loader
$cachedLoader->register();
// deactivate the original, non-cached loader if it was registered previously
$loader->unregister();
XcacheClassLoader¶
XcacheClassLoader uses XCache to cache a class loader. Registering
it is straightforward:
require_once '/path/to/src/Symfony/Component/ClassLoader/XcacheClassLoader.php';
// instance of a class that implements a findFile() method, like the ClassLoader
$loader = ...;
// sha1(__FILE__) generates an XCache namespace prefix
$cachedLoader = new XcacheClassLoader(sha1(__FILE__), $loader);
// register the cached class loader
$cachedLoader->register();
// deactivate the original, non-cached loader if it was registered previously
$loader->unregister();
This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.