system system.base system.caching system.caching.dependencies system.collections system.console system.db system.db.ar system.db.schema system.db.schema.cubrid system.db.schema.mssql system.db.schema.mysql system.db.schema.oci system.db.schema.pgsql system.db.schema.sqlite system.gii system.i18n system.i18n.gettext system.logging system.test system.utils system.validators system.web system.web.actions system.web.auth system.web.filters system.web.form system.web.helpers system.web.renderers system.web.services system.web.widgets system.web.widgets.captcha system.web.widgets.pagers zii.behaviors zii.widgets zii.widgets.grid zii.widgets.jui

CCache

system.caching
继承 abstract class CCache » CApplicationComponent » CComponent
实现 IApplicationComponent, ICache, ArrayAccess
子类 CApcCache, CDbCache, CEAcceleratorCache, CFileCache, CMemCache, CRedisCache, CWinCache, CXCache, CZendDataCache
可用自 1.0
源码 framework/caching/CCache.php
CCache is the base class for cache classes with different cache storage implementation.

A data item can be stored in cache by calling set and be retrieved back later by get. In both operations, a key identifying the data item is required. An expiration time and/or a dependency can also be specified when calling set. If the data item expires or the dependency changes, calling get will not return back the data item.

Note, by definition, cache does not ensure the existence of a value even if it does not expire. Cache is not meant to be a persistent storage.

CCache 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


Child classes must implement the following methods:

CCache also implements ArrayAccess so that it can be used like an array.

公共属性

隐藏继承的属性

属性类型描述被定义在
behaviors array the behaviors that should be attached to this component. CApplicationComponent
hashKey boolean whether to md5-hash the cache key for normalization purposes. CCache
isInitialized boolean Checks if this application component has been initialized. CApplicationComponent
keyPrefix string a string prefixed to every cache key so that it is unique. CCache
serializer array|boolean the functions used to serialize and unserialize cached data. CCache

公共方法

隐藏继承的方法

方法描述被定义在
__call() Calls the named method which is not a class method. CComponent
__get() Returns a property value, an event handler list or a behavior based on its name. CComponent
__isset() Checks if a property value is null. CComponent
__set() Sets value of a component property. CComponent
__unset() Sets a component property to be null. CComponent
add() Stores a value identified by a key into cache if the cache does not contain this key. CCache
asa() Returns the named behavior object. CComponent
attachBehavior() Attaches a behavior to this component. CComponent
attachBehaviors() Attaches a list of behaviors to the component. CComponent
attachEventHandler() Attaches an event handler to an event. CComponent
canGetProperty() Determines whether a property can be read. CComponent
canSetProperty() Determines whether a property can be set. CComponent
delete() Deletes a value with the specified key from cache CCache
detachBehavior() Detaches a behavior from the component. CComponent
detachBehaviors() Detaches all behaviors from the component. CComponent
detachEventHandler() Detaches an existing event handler. CComponent
disableBehavior() Disables an attached behavior. CComponent
disableBehaviors() Disables all behaviors attached to this component. CComponent
enableBehavior() Enables an attached behavior. CComponent
enableBehaviors() Enables all behaviors attached to this component. CComponent
evaluateExpression() Evaluates a PHP expression or callback under the context of this component. CComponent
flush() Deletes all values from cache. CCache
get() Retrieves a value from cache with a specified key. CCache
getEventHandlers() Returns the list of attached event handlers for an event. CComponent
getIsInitialized() Checks if this application component has been initialized. CApplicationComponent
hasEvent() Determines whether an event is defined. CComponent
hasEventHandler() Checks whether the named event has attached handlers. CComponent
hasProperty() Determines whether a property is defined. CComponent
init() Initializes the application component. CCache
mget() Retrieves multiple values from cache with the specified keys. CCache
offsetExists() Returns whether there is a cache entry with a specified key. CCache
offsetGet() Retrieves the value from cache with a specified key. CCache
offsetSet() Stores the value identified by a key into cache. CCache
offsetUnset() Deletes the value with the specified key from cache CCache
raiseEvent() Raises an event. CComponent
set() Stores a value identified by a key into cache. CCache

受保护的方法

隐藏继承的方法

方法描述被定义在
addValue() Stores a value identified by a key into cache if the cache does not contain this key. CCache
deleteValue() Deletes a value with the specified key from cache CCache
flushValues() Deletes all values from cache. CCache
generateUniqueKey() CCache
getValue() Retrieves a value from cache with a specified key. CCache
getValues() Retrieves multiple values from cache with the specified keys. CCache
setValue() Stores a value identified by a key in cache. CCache

属性详情

hashKey 属性 (自版本 v1.1.11 可用)
public boolean $hashKey;

whether to md5-hash the cache key for normalization purposes. Defaults to true. Setting this property to false makes sure the cache key will not be tampered when calling the relevant methods get(), set(), add() and delete(). This is useful if a Yii application as well as an external application need to access the same cache pool (also see description of keyPrefix regarding this use case). However, without normalization you should make sure the affected cache backend does support the structure (charset, length, etc.) of all the provided cache keys, otherwise there might be unexpected behavior.

keyPrefix 属性
public string $keyPrefix;

a string prefixed to every cache key so that it is unique. Defaults to null which means to use the application ID. If different applications need to access the same pool of cached data, the same prefix should be set for each of the applications explicitly.

serializer 属性
public array|boolean $serializer;

the functions used to serialize and unserialize cached data. Defaults to null, meaning using the default PHP `serialize()` and `unserialize()` functions. If you want to use some more efficient serializer (e.g. igbinary), you may configure this property with a two-element array. The first element specifies the serialization function, and the second the deserialization function. If this property is set false, data will be directly sent to and retrieved from the underlying cache component without any serialization or deserialization. You should not turn off serialization if you are using cache dependency, because it relies on data serialization.

方法详情

add() 方法
public boolean add(string $id, mixed $value, integer $expire=0, ICacheDependency $dependency=NULL)
$id string the key identifying the value to be cached
$value mixed the value to be cached
$expire integer the number of seconds in which the cached value will expire. 0 means never expire.
$dependency ICacheDependency dependency of the cached item. If the dependency changes, the item is labeled invalid.
{return} boolean true if the value is successfully stored into cache, false otherwise
源码: framework/caching/CCache.php#197 (显示)
public function add($id,$value,$expire=0,$dependency=null)
{
    
Yii::trace('Adding "'.$id.'" to cache','system.caching.'.get_class($this));

    if (
$dependency !== null && $this->serializer !== false)
        
$dependency->evaluateDependency();

    if (
$this->serializer === null)
        
$value serialize(array($value,$dependency));
    elseif (
$this->serializer !== false)
        
$value call_user_func($this->serializer[0], array($value,$dependency));

    return 
$this->addValue($this->generateUniqueKey($id), $value$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.

addValue() 方法
protected boolean addValue(string $key, string $value, integer $expire)
$key string the key identifying the value to be cached
$value string the value to be cached
$expire integer the number of seconds in which the cached value will expire. 0 means never expire.
{return} boolean true if the value is successfully stored into cache, false otherwise
源码: framework/caching/CCache.php#299 (显示)
protected function addValue($key,$value,$expire)
{
    throw new 
CException(Yii::t('yii','{className} does not support add() functionality.',
        array(
'{className}'=>get_class($this))));
}

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.

delete() 方法
public boolean delete(string $id)
$id string the key of the value to be deleted
{return} boolean if no error happens during deletion
源码: framework/caching/CCache.php#217 (显示)
public function delete($id)
{
    
Yii::trace('Deleting "'.$id.'" from cache','system.caching.'.get_class($this));
    return 
$this->deleteValue($this->generateUniqueKey($id));
}

Deletes a value with the specified key from cache

deleteValue() 方法
protected boolean deleteValue(string $key)
$key string the key of the value to be deleted
{return} boolean if no error happens during deletion
源码: framework/caching/CCache.php#312 (显示)
protected function deleteValue($key)
{
    throw new 
CException(Yii::t('yii','{className} does not support delete() functionality.',
        array(
'{className}'=>get_class($this))));
}

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.

flush() 方法
public boolean flush()
{return} boolean whether the flush operation was successful.
源码: framework/caching/CCache.php#228 (显示)
public function flush()
{
    
Yii::trace('Flushing cache','system.caching.'.get_class($this));
    return 
$this->flushValues();
}

Deletes all values from cache. Be careful of performing this operation if the cache is shared by multiple applications.

flushValues() 方法 (自版本 v1.1.5 可用)
protected boolean flushValues()
{return} boolean whether the flush operation was successful.
源码: framework/caching/CCache.php#325 (显示)
protected function flushValues()
{
    throw new 
CException(Yii::t('yii','{className} does not support flushValues() functionality.',
        array(
'{className}'=>get_class($this))));
}

Deletes all values from cache. Child classes may implement this method to realize the flush operation.

generateUniqueKey() 方法
protected string generateUniqueKey(string $key)
$key string a key identifying a value to be cached
{return} string a key generated from the provided key which ensures the uniqueness across applications
源码: framework/caching/CCache.php#92 (显示)
protected function generateUniqueKey($key)
{
    return 
$this->hashKey md5($this->keyPrefix.$key) : $this->keyPrefix.$key;
}

get() 方法
public mixed get(string $id)
$id string a key identifying the cached value
{return} mixed the value stored in cache, false if the value is not in the cache, expired or the dependency has changed.
源码: framework/caching/CCache.php#102 (显示)
public function get($id)
{
    
$value $this->getValue($this->generateUniqueKey($id));
    if(
$value===false || $this->serializer===false)
        return 
$value;
    if(
$this->serializer===null)
        
$value=unserialize($value);
    else
        
$value=call_user_func($this->serializer[1], $value);
    if(
is_array($value) && (!$value[1] instanceof ICacheDependency || !$value[1]->getHasChanged()))
    {
        
Yii::trace('Serving "'.$id.'" from cache','system.caching.'.get_class($this));
        return 
$value[0];
    }
    else
        return 
false;
}

Retrieves a value from cache with a specified key.

getValue() 方法
protected string|boolean getValue(string $key)
$key string a unique key identifying the cached value
{return} string|boolean the value stored in cache, false if the value is not in the cache or expired.
源码: framework/caching/CCache.php#244 (显示)
protected function getValue($key)
{
    throw new 
CException(Yii::t('yii','{className} does not support get() functionality.',
        array(
'{className}'=>get_class($this))));
}

Retrieves a value from cache with a specified key. This method should be implemented by child classes to retrieve the data from specific cache storage. The uniqueness and dependency are handled in get() already. So only the implementation of data retrieval is needed.

getValues() 方法
protected array getValues(array $keys)
$keys array a list of keys identifying the cached values
{return} array a list of cached values indexed by the keys
源码: framework/caching/CCache.php#259 (显示)
protected function getValues($keys)
{
    
$results=array();
    foreach(
$keys as $key)
        
$results[$key]=$this->getValue($key);
    return 
$results;
}

Retrieves multiple values from cache with the specified keys. The default implementation simply calls getValue multiple times to retrieve the cached values one by one. If the underlying cache storage supports multiget, this method should be overridden to exploit that feature.

init() 方法
public void init()
源码: framework/caching/CCache.php#81 (显示)
public function init()
{
    
parent::init();
    if(
$this->keyPrefix===null)
        
$this->keyPrefix=Yii::app()->getId();
}

Initializes the application component. This method overrides the parent implementation by setting default cache key prefix.

mget() 方法
public array mget(array $ids)
$ids array list of keys identifying the cached values
{return} array list of cached values corresponding to the specified keys. The array is returned in terms of (key,value) pairs. If a value is not cached or expired, the corresponding array value will be false.
源码: framework/caching/CCache.php#130 (显示)
public function mget($ids)
{
    
$uids = array();
    foreach (
$ids as $id)
        
$uids[$id] = $this->generateUniqueKey($id);

    
$values $this->getValues($uids);
    
$results = array();
    if(
$this->serializer === false)
    {
        foreach (
$uids as $id => $uid)
            
$results[$id] = isset($values[$uid]) ? $values[$uid] : false;
    }
    else
    {
        foreach(
$uids as $id => $uid)
        {
            
$results[$id] = false;
            if(isset(
$values[$uid]))
            {
                
$value $this->serializer === null unserialize($values[$uid]) : call_user_func($this->serializer[1], $values[$uid]);
                if(
is_array($value) && (!$value[1] instanceof ICacheDependency || !$value[1]->getHasChanged()))
                {
                    
Yii::trace('Serving "'.$id.'" from cache','system.caching.'.get_class($this));
                    
$results[$id] = $value[0];
                }
            }
        }
    }
    return 
$results;
}

Retrieves multiple values from cache with the specified keys. Some caches (such as memcache, apc) allow retrieving multiple cached values at one time, which may improve the performance since it reduces the communication cost. In case a cache does not support this feature natively, it will be simulated by this method.

offsetExists() 方法
public boolean offsetExists(string $id)
$id string a key identifying the cached value
{return} boolean
源码: framework/caching/CCache.php#337 (显示)
public function offsetExists($id)
{
    return 
$this->get($id)!==false;
}

Returns whether there is a cache entry with a specified key. This method is required by the interface ArrayAccess.

offsetGet() 方法
public mixed offsetGet(string $id)
$id string a key identifying the cached value
{return} mixed the value stored in cache, false if the value is not in the cache or expired.
源码: framework/caching/CCache.php#348 (显示)
public function offsetGet($id)
{
    return 
$this->get($id);
}

Retrieves the value from cache with a specified key. This method is required by the interface ArrayAccess.

offsetSet() 方法
public void offsetSet(string $id, mixed $value)
$id string the key identifying the value to be cached
$value mixed the value to be cached
源码: framework/caching/CCache.php#361 (显示)
public function offsetSet($id$value)
{
    
$this->set($id$value);
}

Stores the value identified by a key into cache. If the cache already contains such a key, the existing value will be replaced with the new ones. To add expiration and dependencies, use the set() method. This method is required by the interface ArrayAccess.

offsetUnset() 方法
public boolean offsetUnset(string $id)
$id string the key of the value to be deleted
{return} boolean if no error happens during deletion
源码: framework/caching/CCache.php#372 (显示)
public function offsetUnset($id)
{
    
$this->delete($id);
}

Deletes the value with the specified key from cache This method is required by the interface ArrayAccess.

set() 方法
public boolean set(string $id, mixed $value, integer $expire=0, ICacheDependency $dependency=NULL)
$id string the key identifying the value to be cached
$value mixed the value to be cached
$expire integer the number of seconds in which the cached value will expire. 0 means never expire.
$dependency ICacheDependency dependency of the cached item. If the dependency changes, the item is labeled invalid.
{return} boolean true if the value is successfully stored into cache, false otherwise
源码: framework/caching/CCache.php#173 (显示)
public function set($id,$value,$expire=0,$dependency=null)
{
    
Yii::trace('Saving "'.$id.'" to cache','system.caching.'.get_class($this));

    if (
$dependency !== null && $this->serializer !== false)
        
$dependency->evaluateDependency();

    if (
$this->serializer === null)
        
$value serialize(array($value,$dependency));
    elseif (
$this->serializer !== false)
        
$value call_user_func($this->serializer[0], array($value,$dependency));

    return 
$this->setValue($this->generateUniqueKey($id), $value$expire);
}

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.

setValue() 方法
protected boolean setValue(string $key, string $value, integer $expire)
$key string the key identifying the value to be cached
$value string the value to be cached
$expire integer the number of seconds in which the cached value will expire. 0 means never expire.
{return} boolean true if the value is successfully stored into cache, false otherwise
源码: framework/caching/CCache.php#280 (显示)
protected function setValue($key,$value,$expire)
{
    throw new 
CException(Yii::t('yii','{className} does not support set() functionality.',
        array(
'{className}'=>get_class($this))));
}

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.