PHP Caching Technology Implementation

A PHP cache implementation, the implementation of APC and file caching, inheritance Cache_abstract can be implemented to invoke a Third-party caching tool.

Refer to the Shindig cache class and APC.

PHP code

<?php

Class Cacheexception extends Exception {}

/**

* Cache abstract Class

*/

Abstract class Cache_abstract {

/**

* Read Cache variable

*

* @param string $key cache subscript

* @return Mixed

*/

Abstract public Function fetch ($KEY);

/**

* Cache Variables

*

* @param string $key cache variable Subscript

* @param string $value The value of the cached variable

* @return BOOL

*/

Abstract Public function Store ($key, $value);

/**

* Delete Cache variable

*

* @param string $key cache subscript

* @return Cache_abstract

*/

Abstract Public Function Delete ($key);

/**

* Clear (delete) except for all caches

*

* @return Cache_abstract

*/

Abstract public Function clear ();

/**

* Lock Cache variable

*

* @param string $key cache subscript

* @return Cache_abstract

*/

Abstract Public Function lock ($key);

/**

* Cache variable Unlock

*

* @param string $key cache subscript

* @return Cache_abstract

*/

Abstract public Function unlock ($key);

/**

* Get the cache variable locked

*

* @param string $key cache subscript

* @return BOOL

*/

Abstract public Function islocked ($key);

/**

* Make sure it's not locked

* Up to do $tries sleep waiting to unlock, timeout is skipped and unlocked

*

* @param string $key cache subscript

*/

Public Function Checklock ($key) {

if (! $this->islocked ($key)) {

return $this;

}

$tries = 10;

$count = 0;

do {

Usleep (200);

$count + +;

while ($count <= $tries && $this->islocked ($key)); Do up to 10 times sleep wait for unlock, timeout to skip and unlock

$this->islocked ($key) && $this->unlock ($key);

return $this;

}

}

/**

* APC Extended Cache implementation

*

*

* @category Mjie

* @package Cache

* @author Water Mengchun

* @copyright Copyright (c) 2008-

* @license New BSD License

* @version $Id: cache/apc.php version number 2010-04-18 23:02 Cmpan $

*/

Class Cache_apc extends Cache_abstract {

protected $_prefix = ' cache.mjie.net ';

Public Function __construct () {

if (!function_exists (' Apc_cache_info ')) {

throw new Cacheexception (' APC extension didn\ ' t installed ');

}

}

/**

* Save Cache variables

*

* @param string $key

* @param mixed $value

* @return BOOL

*/

Public function Store ($key, $value) {

Return Apc_store ($this->_storagekey ($key), $value);

}

/**

* Read Cache

*

* @param string $key

* @return Mixed

*/

Public function Fetch ($key) {

Return Apc_fetch ($this->_storagekey ($key));

}

/**

* Clear Cache

*

* @return CACHE_APC

*/

Public Function Clear () {

Apc_clear_cache ();

return $this;

}

/**

* Delete Cache unit

*

* @return CACHE_APC

*/

Public Function Delete ($key) {

Apc_delete ($this->_storagekey ($key));

return $this;

}

/**

* Whether the cache unit is locked

*

* @param string $key

* @return BOOL

*/

Public Function islocked ($key) {

if (Apc_fetch ($this->_storagekey ($key). '. Lock ') = = = False) {

return false;

}

return true;

}

/**

* Lock Cache Unit

*

* @param string $key

* @return CACHE_APC

*/

Public function Lock ($key) {

Apc_store ($this->_storagekey ($key). '. Lock ', ', 5 ';

return $this;

}

/**

* Buffer Unit Unlock

*

* @param string $key

* @return CACHE_APC

*/

Public function Unlock ($key) {

Apc_delete ($this->_storagekey ($key). '. Lock ');

return $this;

}

/**

* Full Cache Name

*

* @param string $key

* @return String

*/

Private Function _storagekey ($key) {

Return $this->_prefix. '_' . $key;

}

}

/**

* File Cache implementation

*

*

* @category Mjie

* @package Cache

* @author Water Mengchun

* @copyright Copyright (c) 2008-

* @license New BSD License

* @version $Id: cache/file.php version number 2010-04-18 16:46 Cmpan $

*/

Class Cache_file extends Cache_abstract {

Public $useSubdir = false;

Protected $_cachesdir = ' cache ';

Public Function __construct () {

if (defined (' Data_dir ')) {

$this->_setcachedir (Data_dir. '/cache ');

}

}

/**

* Get cached files

*

* @param string $key

* @return String

*/

protected function _getcachefile ($key) {

$subdir = $this->usesubdir? substr ($key, 0, 2). '/' : '';

Return $this->_cachesdir. '/' . $subdir. $key. '. php ';

}

/**

* Read Cache variables

* To prevent information disclosure, cache file format for PHP files, and "" to the beginning

*

* @param string $key cache subscript

* @return Mixed

*/

Public function Fetch ($key) {

$cacheFile = Self::_getcachefile ($key);

if (file_exists ($cacheFile) && is_readable ($cacheFile)) {

Include method

return include $cacheFile;

Serialization mode

Return Unserialize (@file_get_contents ($cacheFile, False, NULL, 13));

}

return false;

}

/**

* Cache Variables

* To prevent information disclosure, cache file format for PHP files, and "" to the beginning

*

* @param string $key cache variable Subscript

* @param string $value The value of the cached variable

* @return BOOL

*/

Public function Store ($key, $value) {

$cacheFile = Self::_getcachefile ($key);

$cacheDir = DirName ($cacheFile);

if (!is_dir ($cacheDir)) {

if (! @mkdir ($cacheDir, 0755, True)) {

throw new Cacheexception ("Could not make cache directory");

}

}

Use the Include method

Return @file_put_contents ($cacheFile, '

Return @file_put_contents ($cacheFile, '. Serialize ($value));

}

/**

* Delete Cache variable

*

* @param string $key cache subscript

* @return Cache_file

*/

Public Function Delete ($key) {

if (Emptyempty ($key)) {

throw new Cacheexception ("Missing argument 1 for Cache_file::d elete ()");

}

$cacheFile = Self::_getcachefile ($key);

if (! @unlink ($cacheFile)) {

throw new Cacheexception ("Cache file could not to be deleted");

}

return $this;

}

/**

* Whether the cache unit is locked

*

* @param string $key

* @return BOOL

*/

Public Function islocked ($key) {

$cacheFile = Self::_getcachefile ($key);

Clearstatcache ();

Return File_exists ($cacheFile. '. Lock ');

}

/**

* Lock

*

* @param string $key

* @return Cache_file

*/

Public function Lock ($key) {

$cacheFile = Self::_getcachefile ($key);

$cacheDir = DirName ($cacheFile);

if (!is_dir ($cacheDir)) {

if (! @mkdir ($cacheDir, 0755, True)) {

if (!is_dir ($cacheDir)) {

throw new Cacheexception ("Could not make cache directory");

}

}

}

To set the access and modification time of a cache lock file

@touch ($cacheFile. '. Lock ');

return $this;

}

/**

* Unlock

*

* @param string $key

* @return Cache_file

*/

Public function Unlock ($key) {

$cacheFile = Self::_getcachefile ($key);

@unlink ($cacheFile. '. Lock ');

Return