/**
* Returns a cache instance.
*
* @param bool $apply_proxied_operations Whether or not to apply any
* proxied (disable this in tests!)
* @return StudipCache the cache instance
*/
public static function getCache($apply_proxied_operations = true)
{
if (is_null(self::$cache)) {
$proxied = false;
if (!$GLOBALS['CACHING_ENABLE']) {
self::$cache = new StudipNullCache();
// Proxy cache operations if CACHING_ENABLE is different from the globally set
// caching value. This should only be the case in cli mode.
if (isset($GLOBALS['GLOBAL_CACHING_ENABLE']) && $GLOBALS['GLOBAL_CACHING_ENABLE']) {
$proxied = true;
}
} else {
try {
$class = self::loadCacheClass();
$args = self::retrieveConstructorArguments();
self::$cache = self::instantiateCache($class, $args);
} catch (Exception $e) {
error_log(__METHOD__ . ': ' . $e->getMessage());
PageLayout::addBodyElements(MessageBox::error(__METHOD__ . ': ' . $e->getMessage()));
$class = self::DEFAULT_CACHE_CLASS;
self::$cache = new $class();
}
}
// If proxy should be used, inject it. Otherwise apply pending
// operations, if any.
if ($proxied) {
self::$cache = new StudipCacheProxy(self::$cache);
} elseif ($GLOBALS['CACHING_ENABLE'] && $apply_proxied_operations) {
// Even if the above condition will try to eliminate most
// failures, the following operation still needs to be wrapped
// in a try/catch block. Otherwise there are no means to
// execute migration 166 which creates the neccessary tables
// for said operation.
try {
StudipCacheOperation::apply(self::$cache);
} catch (Exception $e) {
}
}
}
return self::$cache;
}
