Refactored cache classes with support for cache dependency

1 files changed, 30 insertions, 72 deletions

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

+ * <code>

  * <module id="cache" type="System.Caching.TSqliteCache" DbFile="Application.Data.site" />

+ * </code>

  * 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;

 	}