Functions for t3lib cache

This page belongs to the Caching-Rewrite Functions for t3lib_cache project (category Project)

This is the cache-implementation for the new sub-Core API t3lib_cache.

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Hash Functions

these 2 functions are a copy from t3lib_page and t3lib_befunc

PHP script:

/**
 * Returns string value stored for the hash string in the table "cache_hash"
 * Can be used to retrieved a cached value
 * Can be used from your frontend plugins if you like. It is also used to store the parsed TypoScript template structures. You can call it directly like t3lib_pageSelect::getHash()
 *
 * @param	string		The hash-string which was used to store the data value
 * @param	integer		Allowed expiretime in seconds. Basically a record is selected only if it is not older than this value in seconds. If expTime is not set, the hashed value will never expire.
 * @return	string		The "content" field of the "cache_hash" table row.
 * @see tslib_TStemplate::start(), storeHash()
 */
public function getHash($hash,$expTime=0)	{
		// if expTime is not set, the hash will never expire
	$expTime = intval($expTime);
	if ($expTime) {
		$whereAdd = ' AND tstamp > '.(time()-$expTime);
	}
	$res = $GLOBALS['TYPO3_DB']->exec_SELECTquery('content', 'cache_hash', 'hash='.$GLOBALS['TYPO3_DB']->fullQuoteStr($hash, 'cache_hash').$whereAdd);
	$row = $GLOBALS['TYPO3_DB']->sql_fetch_assoc($res);
	$GLOBALS['TYPO3_DB']->sql_free_result($res);
	if ($row)	{
		return $row['content'];
	}
}

/**
 * Stores a string value in the cache_hash table identified by $hash.
 * Can be used from your frontend plugins if you like. You can call it directly like t3lib_pageSelect::storeHash()
 *
 * @param	string		32 bit hash string (eg. a md5 hash of a serialized array identifying the data being stored)
 * @param	string		The data string. If you want to store an array, then just serialize it first.
 * @param	string		$ident is just a textual identification in order to inform about the content! May be 20 characters long.
 * @return	void
 * @see tslib_TStemplate::start(), getHash()
 */
public function storeHash($hash,$data,$ident)	{
	$insertFields = array(
		'hash' => $hash,
		'content' => $data,
		'ident' => $ident,
		'tstamp' => time()
	);
	$GLOBALS['TYPO3_DB']->exec_DELETEquery('cache_hash', 'hash='.$GLOBALS['TYPO3_DB']->fullQuoteStr($hash, 'cache_hash'));
	$GLOBALS['TYPO3_DB']->exec_INSERTquery('cache_hash', $insertFields);
}

delete / add / update cache

PHP script:

public function clearPageCache($pid,$cHash=false) {

	if($pid === false) {
		$where = '1';
	} else {
		if(is_array($pid)) {
			$where = 'page_id IN ('.implode(',', $pid).')';
		} else {
			$where = 'page_id = '.$pid;
		}
	}

	$addWhere = $cHash ? ' and cHash = "'.$cHash.'"' : '';

		//execute delete queries
	$GLOBALS['TYPO3_DB']->exec_DELETEquery('cache_pages', $where.$addWhere);
	$GLOBALS['TYPO3_DB']->exec_DELETEquery('cache_pagesection', $where.$addWhere);
}