/**
* Calculates the cache identifier for read and write operations.
*
* @param CacheKey $cacheKey The applied cache key.
*
* @return string The cache identifier with respect for the given cache key (simple and advanced).
*
* @author Christian Achatz
* @version
* Version 0.1, 08.01.2013<br />
*/
protected function getCacheIdentifier(CacheKey $cacheKey)
{
$identifier = $this->getConfigAttribute('Namespace');
$identifier .= self::CACHE_KEY_DELIMITER . $cacheKey->getKey();
if ($cacheKey instanceof AdvancedCacheKey) {
$identifier .= self::CACHE_KEY_DELIMITER . $cacheKey->getSubKey();
}
return $identifier;
}
public function clear(CacheKey $cacheKey = null)
{
$baseFolder = $this->getConfigAttribute('BaseFolder');
$namespace = str_replace('\\', '/', $this->getConfigAttribute('Namespace'));
// in case we do not have a cache key, remove the entire cache
if ($cacheKey === null) {
try {
FilesystemManager::deleteFolder($baseFolder . '/' . $namespace, true);
return true;
} catch (FileException $e) {
return false;
// indicate, that nothing was to delete (e.g. cache not active or empty)
}
}
/* @var $cacheKey AdvancedCacheKey */
$key = $cacheKey->getKey();
$subKey = $cacheKey->getSubKey();
if ($key == null && $subKey == null) {
FilesystemManager::deleteFolder($baseFolder . '/' . $namespace, true);
} elseif ($key != null && $subKey == null) {
// in case we have the cache key only, delete the entire structure
// including all sub cache entries
$key = md5($key);
$folder = $baseFolder . '/' . $namespace . '/' . substr($key, 0, 2) . '/' . $key;
FilesystemManager::deleteFolder($folder, true);
return true;
} else {
// in case we have both cache key and cache sub key, delete the local
// cache entry structure
$file = $this->getCacheFile($cacheKey);
try {
FilesystemManager::removeFile($file);
return true;
} catch (FileException $e) {
return false;
}
}
return false;
}
/**
* Returns the complete cache file name. Due to filesystem performance reasons,
* the cache key folder is separated into several parts:
* <ul>
* <li>base folder</li>
* <li>namespace</li>
* <li>2 letters of the cache key</li>
* <li>cache key</li>
* <li>2 letters of cache sub key (in case of an AdvancedCacheKey)</li>
* <li>cache sub key as file name (in case of an AdvancedCacheKey)</li>
* <li>apfc as file extension</li>
* </ul>
*
* @param CacheKey $cacheKey the application's cache key.
*
* @return string The cache file name.
*
* @author Christian Achatz
* @version
* Version 0.1, 21.11.2008<br />
* Version 0.2, 05.08.2010 (Enhanced cache file structure)<br />
*/
protected function getCacheFile(CacheKey $cacheKey)
{
$baseFolder = $this->getConfigAttribute('BaseFolder');
$namespace = str_replace('\\', '/', $this->getConfigAttribute('Namespace'));
$key = md5($cacheKey->getKey());
$folder = substr($key, 0, 2);
if ($cacheKey instanceof AdvancedCacheKey) {
$subKey = md5($cacheKey->getSubKey());
$subFolder = substr($subKey, 0, 2);
return $baseFolder . '/' . $namespace . '/' . $folder . '/' . $key . '/' . $subFolder . '/' . $subKey . '.apfc';
} else {
return $baseFolder . '/' . $namespace . '/' . $folder . '/' . $key . '.apfc';
}
}