/**
* This function will compress data for storage in `tbl_cache`.
* It is left to the user to define a unique hash for this data so that it can be
* retrieved in the future. Optionally, a `$ttl` parameter can
* be passed for this data. If this is omitted, it data is considered to be valid
* forever. This function utilizes the Mutex class to act as a crude locking
* mechanism.
*
* @see toolkit.Mutex
* @throws DatabaseException
* @param string $hash
* The hash of the Cached object, as defined by the user
* @param string $data
* The data to be cached, this will be compressed prior to saving.
* @param integer $ttl
* A integer representing how long the data should be valid for in minutes.
* By default this is null, meaning the data is valid forever
* @param string $namespace
* The namespace allows data to be grouped and saved so it can be
* retrieved later.
* @return boolean
* If an error occurs, this function will return false otherwise true
*/
public function write($hash, $data, $ttl = null, $namespace = null)
{
if (!Mutex::acquire($hash, 2, TMP)) {
return false;
}
$creation = time();
$expiry = null;
$ttl = intval($ttl);
if ($ttl > 0) {
$expiry = $creation + $ttl * 60;
}
if (!($data = Cacheable::compressData($data))) {
return false;
}
$this->delete($hash, $namespace);
$this->Database->insert(array('hash' => $hash, 'creation' => $creation, 'expiry' => $expiry, 'data' => $data, 'namespace' => $namespace), 'tbl_cache');
Mutex::release($hash, TMP);
return true;
}
