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authorxue <>2006-03-31 12:42:22 +0000
committerxue <>2006-03-31 12:42:22 +0000
commit6845c00a3f752abecd9ef763848329bceaf63df4 (patch)
treed573c37ad864edde9a04f1c7b415afe6c2a9c1ef /framework/Caching
parent06fdd252452217716b1062b632fd2fc2195a66e2 (diff)
Reorganized folders under framework. This may break existing applications.
Diffstat (limited to 'framework/Caching')
-rw-r--r--framework/Caching/TAPCCache.php152
-rw-r--r--framework/Caching/TCache.php88
-rw-r--r--framework/Caching/TMemCache.php256
-rw-r--r--framework/Caching/TSqliteCache.php265
4 files changed, 761 insertions, 0 deletions
diff --git a/framework/Caching/TAPCCache.php b/framework/Caching/TAPCCache.php
new file mode 100644
index 00000000..da493f63
--- /dev/null
+++ b/framework/Caching/TAPCCache.php
@@ -0,0 +1,152 @@
+<?php
+/**
+ * TAPCCache class file
+ *
+ * @author Alban Hanry <compte_messagerie@hotmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ */
+
+/**
+ * TAPCCache class
+ *
+ * TAPCCache implements a cache application module based on {@link http://www.php.net/apc APC}.
+ *
+ * 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.
+ *
+ * To use this module, the APC PHP extension must be loaded and set in the php.ini file the following:
+ * <code>
+ * apc.cache_by_default=0
+ * </code>
+ *
+ * Some usage examples of TAPCCache are as follows,
+ * <code>
+ * $cache=new TAPCCache; // TAPCCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * If loaded, TAPCCache will register itself with {@link TApplication} as the
+ * cache module. It can be accessed via {@link TApplication::getCache()}.
+ *
+ * TAPCCache may be configured in application configuration file as follows
+ * <module id="cache" class="System.Data.TAPCCache" />
+ *
+ * @author Alban Hanry <compte_messagerie@hotmail.com>
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ * @since 3.0b
+ */
+class TAPCCache extends TModule implements ICache
+{
+ /**
+ * @var boolean if the module is initialized
+ */
+ private $_initialized=false;
+
+ /**
+ * @var string a unique prefix used to identify this cache instance from the others
+ */
+ protected $_prefix=null;
+
+ /**
+ * Initializes this module.
+ * This method is required by the IModule interface.
+ * @param TXmlElement configuration for this module, can be null
+ * @throws TConfigurationException if apc extension is not installed or not started, check your php.ini
+ */
+ public function init($config)
+ {
+ if(!extension_loaded('apc'))
+ throw new TConfigurationException('apccache_extension_required');
+ $application=$this->getApplication();
+ $this->_prefix=$application->getUniqueID();
+ $application->setCache($this);
+ $this->_initialized=true;
+ }
+
+ /**
+ * Retrieves a value from cache with a specified key.
+ * @return mixed the value stored in cache, false if the value is not in the cache or expired.
+ */
+ public function get($key)
+ {
+ if(($value=apc_fetch($this->_prefix.$key))!==false)
+ return Prado::unserialize($value);
+ else
+ return $value;
+ }
+
+ /**
+ * Stores a value identified by a key into cache.
+ * If the cache already contains such a key, the existing value and
+ * expiration time will be replaced with the new ones.
+ *
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function set($key,$value,$expiry=0)
+ {
+ return apc_store($this->_prefix.$key,Prado::serialize($value),$expiry);
+ }
+
+ /**
+ * Stores a value identified by a key into cache if the cache does not contain this key.
+ * APC does not support this mode. So calling this method will raise an exception.
+ * @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,
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ * @throw new TNotSupportedException if this method is invoked
+ */
+ public function add($key,$value,$expiry=0)
+ {
+ throw new TNotSupportedException('apccache_add_unsupported');
+ }
+
+ /**
+ * Stores a value identified by a key into cache only if the cache contains this key.
+ * The existing value and expiration time will be overwritten with the new ones.
+ * APC does not support this mode. So calling this method will raise an exception.
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ * @throw new TNotSupportedException if this method is invoked
+ */
+ public function replace($key,$value,$expiry=0)
+ {
+ throw new TNotSupportedException('apccache_replace_unsupported');
+ }
+
+ /**
+ * Deletes a value with the specified key from cache
+ * @param string the key of the value to be deleted
+ * @return boolean if no error happens during deletion
+ */
+ public function delete($key)
+ {
+ return apc_delete($this->_prefix.$key);
+ }
+
+ /**
+ * Deletes all values from cache.
+ */
+ public function flush()
+ {
+ return apc_clear_cache('user');
+ }
+
+}
+
+?> \ No newline at end of file
diff --git a/framework/Caching/TCache.php b/framework/Caching/TCache.php
new file mode 100644
index 00000000..d246b9d0
--- /dev/null
+++ b/framework/Caching/TCache.php
@@ -0,0 +1,88 @@
+<?php
+
+/**
+ * ICache interface.
+ *
+ * This interface must be implemented by cache managers.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ * @since 3.0
+ */
+interface 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.
+ */
+ public function get($id);
+ /**
+ * Stores a value identified by a key into cache.
+ * If the cache already contains such a key, the existing value and
+ * expiration time will be replaced with the new ones.
+ *
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid.
+ * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire.
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function set($id,$value,$expire=0);
+ /**
+ * 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.
+ * @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 add($id,$value,$expire=0);
+ /**
+ * Stores a value identified by a key into cache only if the cache contains this key.
+ * The existing value and expiration time will be overwritten with the new ones.
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid.
+ * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire.
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function replace($id,$value,$expire=0);
+ /**
+ * Deletes a value with the specified key from cache
+ * @param string the key of the value to be deleted
+ * @return boolean if no error happens during deletion
+ */
+ public function delete($id);
+ /**
+ * Deletes all values from cache.
+ * Be careful of performing this operation if the cache is shared by multiple applications.
+ */
+ public function flush();
+}
+
+interface IDependency
+{
+
+}
+
+class TTimeDependency
+{
+}
+
+class TFileDependency
+{
+}
+
+class TDirectoryDependency
+{
+}
+
+?> \ No newline at end of file
diff --git a/framework/Caching/TMemCache.php b/framework/Caching/TMemCache.php
new file mode 100644
index 00000000..bcd49036
--- /dev/null
+++ b/framework/Caching/TMemCache.php
@@ -0,0 +1,256 @@
+<?php
+/**
+ * TMemCache class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ */
+
+/**
+ * TMemCache class
+ *
+ * TMemCache implements a cache application module based on {@link http://www.danga.com/memcached/ memcached}.
+ *
+ * TMemCache can be configured with the Host and Port properties, which
+ * specify the host and port of the memcache server to be used.
+ * By default, they take the value 'localhost' and 11211, respectively.
+ * These properties must be set before {@link init} is invoked.
+ *
+ * The following basic cache operations are implemented:
+ * - {@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.
+ *
+ * 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.
+ *
+ * Also note, there is no security measure to protected data in memcache.
+ * All data in memcache can be accessed by any process running in the system.
+ *
+ * To use this module, the memcache PHP extension must be loaded.
+ *
+ * Some usage examples of TMemCache are as follows,
+ * <code>
+ * $cache=new TMemCache; // TMemCache may also be loaded as a Prado application module
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * If loaded, TMemCache 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
+ * <module id="cache" type="System.Data.TMemCache" Host="localhost" Port=11211 />
+ * where {@link getHost Host} and {@link getPort Port} are configurable properties
+ * of TMemCache.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ * @since 3.0
+ */
+class TMemCache extends TModule implements ICache
+{
+ /**
+ * @var boolean if the module is initialized
+ */
+ private $_initialized=false;
+ /**
+ * @var Memcache the Memcache instance
+ */
+ private $_cache=null;
+ /**
+ * @var string a unique prefix used to identify this cache instance from the others
+ */
+ private $_prefix=null;
+ /**
+ * @var string host name of the memcache server
+ */
+ private $_host='localhost';
+ /**
+ * @var integer the port number of the memcache server
+ */
+ private $_port=11211;
+
+ /**
+ * Destructor.
+ * Disconnect the memcache server.
+ */
+ public function __destruct()
+ {
+ if($this->_cache!==null)
+ $this->_cache->close();
+ }
+
+ /**
+ * Initializes this module.
+ * This method is required by the IModule interface. It makes sure that
+ * UniquePrefix has been set, creates a Memcache instance and connects
+ * to the memcache server.
+ * @param TApplication Prado application, can be null
+ * @param TXmlElement configuration for this module, can be null
+ * @throws TConfigurationException if memcache extension is not installed or memcache sever connection fails
+ */
+ public function init($config)
+ {
+ if(!extension_loaded('memcache'))
+ throw new TConfigurationException('memcache_extension_required');
+ $this->_cache=new Memcache;
+ if($this->_cache->connect($this->_host,$this->_port)===false)
+ throw new TConfigurationException('memcache_connection_failed',$this->_host,$this->_port);
+ $application=$this->getApplication();
+ $this->_prefix=$application->getUniqueID();
+ $application->setCache($this);
+ $this->_initialized=true;
+ }
+
+ /**
+ * @return string host name of the memcache server
+ */
+ public function getHost()
+ {
+ return $this->_host;
+ }
+
+ /**
+ * @param string host name of the memcache server
+ * @throws TInvalidOperationException if the module is already initialized
+ */
+ public function setHost($value)
+ {
+ if($this->_initialized)
+ throw new TInvalidOperationException('memcache_host_unchangeable');
+ else
+ $this->_host=$value;
+ }
+
+ /**
+ * @return integer port number of the memcache server
+ */
+ public function getPort()
+ {
+ return $this->_port;
+ }
+
+ /**
+ * @param integer port number of the memcache server
+ * @throws TInvalidOperationException if the module is already initialized
+ */
+ public function setPort($value)
+ {
+ if($this->_initialized)
+ throw new TInvalidOperationException('memcache_port_unchangeable');
+ else
+ $this->_port=TPropertyValue::ensureInteger($value);
+ }
+
+ /**
+ * 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.
+ */
+ public function get($key)
+ {
+ return $this->_cache->get($this->generateUniqueKey($key));
+ }
+
+ /**
+ * Stores a value identified by a key into cache.
+ * If the cache already contains such a key, the existing value and
+ * expiration time will be replaced with the new ones.
+ *
+ * Note, avoid using this method whenever possible. Database insertion is
+ * very expensive. Try using {@link add} instead, which will not store the value
+ * if the key is already in cache.
+ *
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid.
+ * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire.
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function set($key,$value,$expire=0)
+ {
+ return $this->_cache->set($this->generateUniqueKey($key),$value,0,$expire);
+ }
+
+ /**
+ * Stores a value identified by a key into cache if the cache does not contain this key.
+ * Nothing will be done if the cache already contains the key.
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid.
+ * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire.
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function add($key,$value,$expiry=0)
+ {
+ return $this->_cache->add($this->generateUniqueKey($key),$value,0,$expiry);
+ }
+
+ /**
+ * Stores a value identified by a key into cache only if the cache contains this key.
+ * The existing value and expiration time will be overwritten with the new ones.
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid.
+ * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire.
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function replace($key,$value,$expiry=0)
+ {
+ return $this->_cache->replace($this->generateUniqueKey($key),$value,0,$expiry);
+ }
+
+ /**
+ * Deletes a value with the specified key from cache
+ * @param string the key of the value to be deleted
+ * @return boolean if no error happens during deletion
+ */
+ public function delete($key)
+ {
+ return $this->_cache->delete($this->generateUniqueKey($key));
+ }
+
+ /**
+ * Deletes all values from cache.
+ * Be careful of performing this operation if the cache is shared by multiple applications.
+ */
+ public function flush()
+ {
+ return $this->_cache->flush();
+ }
+
+ /**
+ * Generates a unique key based on a given user key.
+ * This method generates a unique key with the memcache.
+ * The key is made unique by prefixing with a unique string that is supposed
+ * to be unique among applications using the same memcache.
+ * @param string user key
+ * @param string a unique key
+ */
+ protected function generateUniqueKey($key)
+ {
+ return md5($this->_prefix.$key);
+ }
+}
+
+?> \ No newline at end of file
diff --git a/framework/Caching/TSqliteCache.php b/framework/Caching/TSqliteCache.php
new file mode 100644
index 00000000..13aac8ca
--- /dev/null
+++ b/framework/Caching/TSqliteCache.php
@@ -0,0 +1,265 @@
+<?php
+/**
+ * TSqliteCache class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ */
+
+/**
+ * TSqliteCache class
+ *
+ * TSqliteCache implements a cache application module based on SQLite database.
+ *
+ * The database file is specified by the {@link setDbFile DbFile} property.
+ * If not set, the database file will be created under the system state path.
+ * If the specified database file does not exist, it will be created automatically.
+ * Make sure the directory containing the specified DB file and the file itself is
+ * writable by the Web server process.
+ *
+ * The following basic cache operations are implemented:
+ * - {@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.
+ *
+ * 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.
+ *
+ * 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
+ * is no longer loaded by default since PHP 5.1.
+ *
+ * Some usage examples of TSqliteCache are as follows,
+ * <code>
+ * $cache=new TSqliteCache; // TSqliteCache may also be loaded as a Prado application module
+ * $cache->setDbFile($dbFilePath);
+ * $cache->init(null);
+ * $cache->add('object',$object);
+ * $object2=$cache->get('object');
+ * </code>
+ *
+ * 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
+ * <module id="cache" type="System.Data.TSqliteCache" DbFile="Application.Data.site" />
+ * where {@link getDbFile DbFile} is a property specifying the location of the
+ * SQLite DB file (in the namespace format).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Revision: $ $Date: $
+ * @package System.Caching
+ * @since 3.0
+ */
+class TSqliteCache extends TModule implements ICache
+{
+ /**
+ * name of the table storing cache data
+ */
+ const CACHE_TABLE='cache';
+ /**
+ * 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
+ */
+ private $_initialized=false;
+ /**
+ * @var SQLiteDatabase the sqlite database instance
+ */
+ private $_db=null;
+ /**
+ * @var string the database file name
+ */
+ private $_file=null;
+
+ /**
+ * Destructor.
+ * Disconnect the db connection.
+ */
+ public function __destruct()
+ {
+ $this->_db=null;
+ }
+
+ /**
+ * Initializes this module.
+ * This method is required by the IModule interface. It checks if the DbFile
+ * property is set, and creates a SQLiteDatabase instance for it.
+ * The database or the cache table does not exist, they will be created.
+ * Expired values are also deleted.
+ * @param TXmlElement configuration for this module, can be null
+ * @throws TConfigurationException if sqlite extension is not installed,
+ * DbFile is set invalid, or any error happens during creating database or cache table.
+ */
+ public function init($config)
+ {
+ if(!function_exists('sqlite_open'))
+ throw new TConfigurationException('sqlitecache_extension_required');
+ if($this->_file===null)
+ $this->_file=$this->getApplication()->getRuntimePath().'/sqlite.cache';
+ $error='';
+ if(($this->_db=new SQLiteDatabase($this->_file,0666,$error))===false)
+ throw new TConfigurationException('sqlitecache_connection_failed',$error);
+ if(($res=$this->_db->query('SELECT * FROM sqlite_master WHERE tbl_name=\''.self::CACHE_TABLE.'\' AND type=\'table\''))!=false)
+ {
+ if($res->numRows()===0)
+ {
+ if($this->_db->query('CREATE TABLE '.self::CACHE_TABLE.' (key CHAR(128) PRIMARY KEY, value BLOB, serialized INT, expire INT)')===false)
+ throw new TConfigurationException('sqlitecache_table_creation_failed',sqlite_error_string(sqlite_last_error()));
+ }
+ }
+ else
+ 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);
+ }
+
+ /**
+ * @return string database file path (in namespace form)
+ */
+ public function getDbFile()
+ {
+ return $this->_file;
+ }
+
+ /**
+ * @param string database file path (in namespace form)
+ * @throws TInvalidOperationException if the module is already initialized
+ * @throws TConfigurationException if the file is not in proper namespace format
+ */
+ public function setDbFile($value)
+ {
+ if($this->_initialized)
+ throw new TInvalidOperationException('sqlitecache_dbfile_unchangeable');
+ else if(($this->_file=Prado::getPathOfNamespace($value,self::DB_FILE_EXT))===null)
+ throw new TConfigurationException('sqlitecache_dbfile_invalid',$value);
+ }
+
+ /**
+ * 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.
+ */
+ public function get($key)
+ {
+ $sql='SELECT serialized,value FROM '.self::CACHE_TABLE.' WHERE key=\''.md5($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']):$row['value'];
+ else
+ return false;
+ }
+
+ /**
+ * Stores a value identified by a key into cache.
+ * If the cache already contains such a key, the existing value and
+ * expiration time will be replaced with the new ones.
+ *
+ * Note, avoid using this method whenever possible. Database insertion is
+ * very expensive. Try using {@link add} instead, which will not store the value
+ * if the key is already in cache.
+ *
+ * @param string the key identifying the value to be cached
+ * @param mixed the value to be cached
+ * @param integer the expiration time of the value,
+ * 0 means never expire,
+ * a number less or equal than 60*60*24*30 means the number of seconds that the value will remain valid.
+ * a number greater than 60*60*24*30 means a UNIX timestamp after which the value will expire.
+ * @return boolean true if the value is successfully stored into cache, false otherwise
+ */
+ public function set($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;
+ $sql='REPLACE INTO '.self::CACHE_TABLE.' VALUES(\''.md5($key).'\',\''.$value1.'\','.$serialized.','.$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.
+ * @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 add($key,$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;
+ $sql='INSERT INTO '.self::CACHE_TABLE.' VALUES(\''.md5($key).'\',\''.$value1.'\','.$serialized.','.$expire.')';
+ return @$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 && $ret->numRows()>0);
+ }
+
+ /**
+ * Deletes a value with the specified key from cache
+ * @param string the key of the value to be deleted
+ * @return boolean if no error happens during deletion
+ */
+ public function delete($key)
+ {
+ $sql='DELETE FROM '.self::CACHE_TABLE.' WHERE key=\''.md5($key).'\'';
+ return $this->_db->query($sql)!==false;
+ }
+
+ /**
+ * Deletes all values from cache.
+ * Be careful of performing this operation if the cache is shared by multiple applications.
+ */
+ public function flush()
+ {
+ return $this->_db->query('DELETE FROM '.self::CACHE_TABLE)!==false;
+ }
+}
+
+?> \ No newline at end of file