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Packages: default System System.Caching System.Collections System.Data System.Data.ActiveRecord System.Data.ActiveRecord.Relations System.Data.ActiveRecord.Scaffold System.Data.ActiveReecord.Scaffold.InputBuilder System.Data.Commom.Sqlite System.Data.Common System.Data.Common.Mssql System.Data.Common.Mysql System.Data.Common.Oracle System.Data.Common.Pgsql System.Data.Common.Sqlite System.Data.DataGateway System.Data.SqlMap System.Data.SqlMap.Configuration System.Data.SqlMap.Statements System.Exceptions System.I18N System.IO System.Security System.Util System.Web System.Web.Services System.Web.UI System.Web.UI.ActiveControls System.Web.UI.WebControls System.Web.UI.WebControls.assets System.Xml Classes: TAPCCache TApplicationStateCacheDependency TCache TCacheDependency TCacheDependencyList TChainedCacheDependency TDbCache TDirectoryCacheDependency TFileCacheDependency TGlobalStateCacheDependency TMemCache TSqliteCache TXCache |
Keyword
# Class TCache
    TComponent
       |
       --TApplicationComponent
          |
          --TModule
             |
             --TCache
#### Direct Known Sub-classes: TMemCache , TDbCache , TXCache , TSqliteCache , TAPCCache TCache class TCache is the base class for cache classes with different cache storage implementation. TCache implements the interface ICache with the following methods, get : retrieve the value with a key (if any) from cache set : store the value with a key into cache add : store the value only if cache does not have this key delete : delete the value with the specified key from cache flush : delete all values from cache Each value is associated with an expiration time. The get operation 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. Child classes must implement the following methods: getValue setValue addValue deleteValue and optionally flush Since version 3.1.2, TCache implements the ArrayAccess interface such that the cache acts as an array. Since: 3.0 Author: Qiang Xue <qiang.xue@gmail.com>
Method Summary
boolean | add ( string $id, mixed $value, integer $expire, ICacheDependency $dependency) Stores a value identified by a key into cache if the cache does not contain this key.
protected abstract boolean | addValue ( string $key, string $value, integer $expire) Stores a value identified by a key into cache if the cache does not contain this key.
boolean | delete ( string $id) Deletes a value with the specified key from cache
protected abstract boolean | deleteValue ( string $key) Deletes a value with the specified key from cache This method should be implemented by child classes to delete the data from actual cache storage.
void | flush () Deletes all values from cache.
protected sring | generateUniqueKey ( string $key)
mixed | get ( string $id) Retrieves a value from cache with a specified key.
string | getKeyPrefix ()
boolean | getPrimaryCache ()
protected abstract string | getValue ( string $key) Retrieves a value from cache with a specified key.
void | init ( TXmlElement $config) Initializes the cache module.
boolean | offsetExists ( string $id) Returns whether there is a cache entry with a specified key.
void | offsetGet ( mixed $id)
void | offsetSet ( mixed $id, mixed $value)
void | offsetUnset ( mixed $id)
boolean | set ( string $id, mixed $value, integer $expire, ICacheDependency $dependency) Stores a value identified by a key into cache.
void | setKeyPrefix ( string $value)
void | setPrimaryCache ( boolean $value)
protected abstract boolean | setValue ( string $key, string $value, integer $expire) Stores a value identified by a key in cache.
Methods Inherited From TModule
TModule::getID(), TModule::init(), TModule::setID()
Methods Inherited From TApplicationComponent
TApplicationComponent::getApplication(), TApplicationComponent::getRequest(), TApplicationComponent::getResponse(), TApplicationComponent::getService(), TApplicationComponent::getSession(), TApplicationComponent::getUser(), TApplicationComponent::publishAsset(), TApplicationComponent::publishFilePath()
Methods Inherited From TComponent
TComponent::addParsedObject(), TComponent::attachEventHandler(), TComponent::canGetProperty(), TComponent::canSetProperty(), TComponent::createdOnTemplate(), TComponent::detachEventHandler(), TComponent::evaluateExpression(), TComponent::evaluateStatements(), TComponent::getEventHandlers(), TComponent::getSubProperty(), TComponent::hasEvent(), TComponent::hasEventHandler(), TComponent::hasProperty(), TComponent::raiseEvent(), TComponent::setSubProperty(), TComponent::__get(), TComponent::__set()
Method Details
## add
public boolean add | (string $id , mixed $value , integer $expire , ICacheDependency $dependency )
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 or if value is empty.
Input
string | $id | the key identifying the value to be cached
mixed | $value | the value to be cached
integer | $expire | the number of seconds in which the cached value will expire. 0 means never expire.
ICacheDependency | $dependency | dependency of the cached item. If the dependency changes, the item is labeled invalid.
Output
boolean | true if the value is successfully stored into cache, false otherwise
Exception
## addValue
protected abstract boolean addValue | (string $key , string $value , integer $expire )
Stores a value identified by a key into cache if the cache does not contain this key. This method should be implemented by child classes to store the data in specific cache storage. The uniqueness and dependency are handled in add() already. So only the implementation of data storage is needed.
Input
string | $key | the key identifying the value to be cached
string | $value | the value to be cached
integer | $expire | the number of seconds in which the cached value will expire. 0 means never expire.
Output
boolean | true if the value is successfully stored into cache, false otherwise
Exception
## delete
public boolean delete | (string $id )
Deletes a value with the specified key from cache
Input
string | $id | the key of the value to be deleted
Output
boolean | if no error happens during deletion
Exception
## deleteValue
protected abstract boolean deleteValue | (string $key )
Deletes a value with the specified key from cache This method should be implemented by child classes to delete the data from actual cache storage.
Input
string | $key | the key of the value to be deleted
Output
boolean | if no error happens during deletion
Exception
## flush
public void flush | ()
Deletes all values from cache. Be careful of performing this operation if the cache is shared by multiple applications. Child classes may implement this method to realize the flush operation.
Output
Exception
throws | TNotSupportedException if this method is not overridden by child classes
## generateUniqueKey
protected sring generateUniqueKey | (string $key )
Input
string | $key | a key identifying a value to be cached
Output
sring | a key generated from the provided key which ensures the uniqueness across applications
Exception
## get
public mixed get | (string $id )
Retrieves a value from cache with a specified key.
Input
string | $id | a key identifying the cached value
Output
mixed | the value stored in cache, false if the value is not in the cache or expired.
Exception
## getKeyPrefix
public string getKeyPrefix | ()
Output
string | a unique prefix for the keys of cached values. If it is not explicitly set, it will take the value of TApplication::getUniqueID.
Exception
## getPrimaryCache
public boolean getPrimaryCache | ()
Output
boolean | whether this cache module is used as primary/system cache. A primary cache is used by PRADO core framework to cache data such as parsed templates, themes, etc.
Exception
## getValue
protected abstract string getValue | (string $key )
Retrieves a value from cache with a specified key. This method should be implemented by child classes to store the data in specific cache storage. The uniqueness and dependency are handled in get() already. So only the implementation of data retrieval is needed.
Input
string | $key | a unique key identifying the cached value
Output
string | the value stored in cache, false if the value is not in the cache or expired.
Exception
## init
public void init | (TXmlElement $config )
Initializes the cache module. This method initializes the cache key prefix and registers the cache module with the application if the cache is primary.
Input
TXmlElement | $config | the module configuration
Output
Exception
## offsetExists
public boolean offsetExists | (string $id )
Returns whether there is a cache entry with a specified key. This method is required by the interface ArrayAccess.
Input
string | $id | a key identifying the cached value
Output
Exception
## offsetGet
public void offsetGet | (mixed $id )
Input
mixed | $id |
Output
Exception
## offsetSet
public void offsetSet | (mixed $id , mixed $value )
Input
mixed | $id |
mixed | $value |
Output
Exception
## offsetUnset
public void offsetUnset | (mixed $id )
Input
mixed | $id |
Output
Exception
## set
public boolean set | (string $id , mixed $value , integer $expire , ICacheDependency $dependency )
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. If the value is empty, the cache key will be deleted.
Input
string | $id | the key identifying the value to be cached
mixed | $value | the value to be cached
integer | $expire | the number of seconds in which the cached value will expire. 0 means never expire.
ICacheDependency | $dependency | dependency of the cached item. If the dependency changes, the item is labeled invalid.
Output
boolean | true if the value is successfully stored into cache, false otherwise
Exception
## setKeyPrefix
public void setKeyPrefix | (string $value )
Input
string | $value | a unique prefix for the keys of cached values
Output
Exception
## setPrimaryCache
public void setPrimaryCache | (boolean $value )
Input
boolean | $value | whether this cache module is used as primary/system cache. Defaults to false.
Output
Exception
## setValue
protected abstract boolean setValue | (string $key , string $value , integer $expire )
Stores a value identified by a key in cache. This method should be implemented by child classes to store the data in specific cache storage. The uniqueness and dependency are handled in set() already. So only the implementation of data storage is needed.
Input
string | $key | the key identifying the value to be cached
string | $value | the value to be cached
integer | $expire | the number of seconds in which the cached value will expire. 0 means never expire.
Output
boolean | true if the value is successfully stored into cache, false otherwise
Exception