From 66843b23960e17991db0b4f7b01487063b2234bc Mon Sep 17 00:00:00 2001 From: xue <> Date: Tue, 4 Apr 2006 04:08:48 +0000 Subject: Refactored cache classes with support for cache dependency --- framework/Caching/TSqliteCache.php | 102 +++++++++++-------------------------- 1 file changed, 30 insertions(+), 72 deletions(-) (limited to 'framework/Caching/TSqliteCache.php') diff --git a/framework/Caching/TSqliteCache.php b/framework/Caching/TSqliteCache.php index 92cc46a6..dc4bf13f 100644 --- a/framework/Caching/TSqliteCache.php +++ b/framework/Caching/TSqliteCache.php @@ -25,14 +25,12 @@ * - {@link get} : retrieve the value with a key (if any) from cache * - {@link set} : store the value with a key into cache * - {@link add} : store the value only if cache does not have this key - * - {@link replace} : store the value only if cache has this key * - {@link delete} : delete the value with the specified key from cache * - {@link flush} : delete all values from cache * * Each value is associated with an expiration time. The {@link get} operation - * ensures that any expired value will not be returned. The expiration time can - * be specified by the number of seconds (maximum 60*60*24*30) - * or a UNIX timestamp. A expiration time 0 represents never expire. + * ensures that any expired value will not be returned. The expiration time by + * the number of seconds. A expiration time 0 represents never expire. * * By definition, cache does not ensure the existence of a value * even if it never expires. Cache is not meant to be an persistent storage. @@ -40,7 +38,7 @@ * Do not use the same database file for multiple applications using TSqliteCache. * Also note, cache is shared by all user sessions of an application. * - * To use this module, the sqlite PHP extension must be loaded. Sqlite extension + * To use this module, the sqlite PHP extension must be loaded. Note, Sqlite extension * is no longer loaded by default since PHP 5.1. * * Some usage examples of TSqliteCache are as follows, @@ -55,8 +53,10 @@ * If loaded, TSqliteCache will register itself with {@link TApplication} as the * cache module. It can be accessed via {@link TApplication::getCache()}. * - * TMemCache may be configured in application configuration file as follows + * TSqliteCache may be configured in application configuration file as follows + * * + * * where {@link getDbFile DbFile} is a property specifying the location of the * SQLite DB file (in the namespace format). * @@ -65,7 +65,7 @@ * @package System.Caching * @since 3.0 */ -class TSqliteCache extends TModule implements ICache +class TSqliteCache extends TCache { /** * name of the table storing cache data @@ -75,10 +75,6 @@ class TSqliteCache extends TModule implements ICache * extension of the db file name */ const DB_FILE_EXT='.db'; - /** - * maximum number of seconds specified as expire - */ - const EXPIRE_LIMIT=2592000; // 30 days /** * @var boolean if the module has been initialized @@ -125,7 +121,7 @@ class TSqliteCache extends TModule implements ICache { if($res->numRows()===0) { - if($this->_db->query('CREATE TABLE '.self::CACHE_TABLE.' (key CHAR(128) PRIMARY KEY, value BLOB, serialized INT, expire INT)')===false) + if($this->_db->query('CREATE TABLE '.self::CACHE_TABLE.' (key CHAR(128) PRIMARY KEY, value BLOB, expire INT)')===false) throw new TConfigurationException('sqlitecache_table_creation_failed',sqlite_error_string(sqlite_last_error())); } } @@ -133,7 +129,7 @@ class TSqliteCache extends TModule implements ICache throw new TConfigurationException('sqlitecache_table_creation_failed',sqlite_error_string(sqlite_last_error())); $this->_db->query('DELETE FROM '.self::CACHE_TABLE.' WHERE expire<>0 AND expire<'.time()); $this->_initialized=true; - $this->getApplication()->setCache($this); + parent::init($config); } /** @@ -159,96 +155,58 @@ class TSqliteCache extends TModule implements ICache /** * Retrieves a value from cache with a specified key. - * @return mixed the value stored in cache, false if the value is not in the cache or expired. + * This is the implementation of the method declared in the parent class. + * @param string a unique key identifying the cached value + * @return string the value stored in cache, false if the value is not in the cache or expired. */ - public function get($key) + protected function getValue($key) { - $sql='SELECT serialized,value FROM '.self::CACHE_TABLE.' WHERE key=\''.md5($key).'\' AND (expire=0 OR expire>'.time().')'; + $sql='SELECT value FROM '.self::CACHE_TABLE.' WHERE key=\''.$key.'\' AND (expire=0 OR expire>'.time().')'; if(($ret=$this->_db->query($sql))!=false && ($row=$ret->fetch(SQLITE_ASSOC))!==false) - return $row['serialized']?Prado::unserialize($row['value']):$row['value']; + return $row['value']; else return false; } /** - * Stores a value identified by a key into cache. - * If the cache already contains such a key, the existing value and - * expiration time will be replaced with the new ones. - * - * Note, avoid using this method whenever possible. Database insertion is - * very expensive. Try using {@link add} instead, which will not store the value - * if the key is already in cache. + * Stores a value identified by a key in cache. + * This is the implementation of the method declared in the parent class. * * @param string the key identifying the value to be cached - * @param mixed the value to be cached - * @param integer the expiration time of the value, - * 0 means never expire, - * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid. - * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire. + * @param string the value to be cached + * @param integer the number of seconds in which the cached value will expire. 0 means never expire. * @return boolean true if the value is successfully stored into cache, false otherwise */ - public function set($key,$value,$expire=0) + protected function setValue($key,$value,$expire) { - $serialized=is_string($value)?0:1; - $value1=sqlite_escape_string($serialized?Prado::serialize($value):$value); - if($expire && $expire<=self::EXPIRE_LIMIT) - $expire=time()+$expire; - $sql='REPLACE INTO '.self::CACHE_TABLE.' VALUES(\''.md5($key).'\',\''.$value1.'\','.$serialized.','.$expire.')'; + $sql='REPLACE INTO '.self::CACHE_TABLE.' VALUES(\''.$key.'\',\''.sqlite_escape_string($value).'\','.$expire.')'; return $this->_db->query($sql)!==false; } /** * Stores a value identified by a key into cache if the cache does not contain this key. - * Nothing will be done if the cache already contains the key. + * This is the implementation of the method declared in the parent class. + * * @param string the key identifying the value to be cached - * @param mixed the value to be cached - * @param integer the expiration time of the value, - * 0 means never expire, - * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid. - * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire. + * @param string the value to be cached + * @param integer the number of seconds in which the cached value will expire. 0 means never expire. * @return boolean true if the value is successfully stored into cache, false otherwise */ - public function add($key,$value,$expire=0) + protected function addValue($key,$value,$expire) { - $serialized=is_string($value)?0:1; - $value1=sqlite_escape_string($serialized?Prado::serialize($value):$value); - if($expire && $expire<=self::EXPIRE_LIMIT) - $expire=time()+$expire; - $sql='INSERT INTO '.self::CACHE_TABLE.' VALUES(\''.md5($key).'\',\''.$value1.'\','.$serialized.','.$expire.')'; + $sql='INSERT INTO '.self::CACHE_TABLE.' VALUES(\''.$key.'\',\''.sqlite_escape_string($value).'\','.$expire.')'; return @$this->_db->query($sql)!==false; } - /** - * Stores a value identified by a key into cache only if the cache contains this key. - * The existing value and expiration time will be overwritten with the new ones. - * @param string the key identifying the value to be cached - * @param mixed the value to be cached - * @param integer the expiration time of the value, - * 0 means never expire, - * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid. - * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire. - * @return boolean true if the value is successfully stored into cache, false otherwise - */ - public function replace($key,$value,$expire=0) - { - $serialized=is_string($value)?0:1; - $value1=sqlite_escape_string($serialized?Prado::serialize($value):$value); - if($expire && $expire<=self::EXPIRE_LIMIT) - $expire=time()+$expire; - $sql='UPDATE '.self::CACHE_TABLE.' SET value=\''.$value1.'\', serialized='.$serialized.',expire='.$expire.' WHERE key=\''.md5($key).'\''; - $this->_db->query($sql); - $ret=$this->_db->query('SELECT serialized FROM '.self::CACHE_TABLE.' WHERE key=\''.md5($key).'\''); - return ($ret!=false && $ret->numRows()>0); - } - /** * Deletes a value with the specified key from cache + * This is the implementation of the method declared in the parent class. * @param string the key of the value to be deleted * @return boolean if no error happens during deletion */ - public function delete($key) + protected function deleteValue($key) { - $sql='DELETE FROM '.self::CACHE_TABLE.' WHERE key=\''.md5($key).'\''; + $sql='DELETE FROM '.self::CACHE_TABLE.' WHERE key=\''.$key.'\''; return $this->_db->query($sql)!==false; } -- cgit v1.2.3