You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
399 lines
17 KiB
399 lines
17 KiB
<?php |
|
/** |
|
* CCache class file. |
|
* |
|
* @author Qiang Xue <qiang.xue@gmail.com> |
|
* @link http://www.yiiframework.com/ |
|
* @copyright Copyright © 2008-2011 Yii Software LLC |
|
* @license http://www.yiiframework.com/license/ |
|
*/ |
|
|
|
/** |
|
* CCache is the base class for cache classes with different cache storage implementation. |
|
* |
|
* A data item can be stored in cache by calling {@link set} and be retrieved back |
|
* later by {@link 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 {@link set}. |
|
* If the data item expires or the dependency changes, calling {@link 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 {@link ICache} with the following methods: |
|
* <ul> |
|
* <li>{@link get} : retrieve the value with a key (if any) from cache</li> |
|
* <li>{@link set} : store the value with a key into cache</li> |
|
* <li>{@link add} : store the value only if cache does not have this key</li> |
|
* <li>{@link delete} : delete the value with the specified key from cache</li> |
|
* <li>{@link flush} : delete all values from cache</li> |
|
* </ul> |
|
* |
|
* Child classes must implement the following methods: |
|
* <ul> |
|
* <li>{@link getValue}</li> |
|
* <li>{@link setValue}</li> |
|
* <li>{@link addValue}</li> |
|
* <li>{@link deleteValue}</li> |
|
* <li>{@link flushValues} (optional)</li> |
|
* <li>{@link serializeValue} (optional)</li> |
|
* <li>{@link unserializeValue} (optional)</li> |
|
* </ul> |
|
* |
|
* CCache also implements ArrayAccess so that it can be used like an array. |
|
* |
|
* @author Qiang Xue <qiang.xue@gmail.com> |
|
* @version $Id$ |
|
* @package system.caching |
|
* @since 1.0 |
|
*/ |
|
abstract class CCache extends CApplicationComponent implements ICache, ArrayAccess |
|
{ |
|
/** |
|
* @var string a string prefixed to every cache key so that it is unique. Defaults to null which means |
|
* to use the {@link CApplication::getId() 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. |
|
*/ |
|
public $keyPrefix; |
|
|
|
/** |
|
* @var boolean 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 {@link get()}, {@link set()}, {@link add()} and {@link 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 {@link 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. |
|
* @since 1.1.11 |
|
**/ |
|
public $hashKey=true; |
|
|
|
/** |
|
* @var boolean whether to automatically serialize/unserialize the cache values. Defaults to true. Setting this property to false makes sure the cache |
|
* value will not be tampered when calling the methods {@link set()} and {@link add()}. This is useful in case you want to store data which simply |
|
* does not require serialization (e.g. integers, strings or raw binary data). Thus there might be a small increase in performance and a smaller overall |
|
* cache size. Take in mind that you will be unable to store PHP structures like arrays or objects, you would have to serialize and unserialize them manually. |
|
* Another negative side effect is that providing a dependency via {@link set()} or {@link add()} will have no effect since dependencies rely on serialization. |
|
* Since all the relevant core application components rely on dependency support, you should be very careful disabling this feature. Usually you want to |
|
* configure a dedicated cache component for the sole purpose of storing raw unserialized data, the main cache component should always support serialization. |
|
* @since 1.1.11 |
|
**/ |
|
public $autoSerialize=true; |
|
|
|
/** |
|
* @var boolean wether to make use of the {@link http://pecl.php.net/package/igbinary igbinary} serializer for cache entry serialization. Defaults to false. |
|
* <strong>NOTE:</strong> If this is set to true while the igbinary extension has not been loaded, cache serialization will silently fall back to PHP's default |
|
* serializer. Since the two serialization formats are incompatible, caches should be purged before switching this on to prevent errors. |
|
* @since 1.1.11 |
|
*/ |
|
public $useIgbinarySerializer=false; |
|
|
|
/** |
|
* Initializes the application component. |
|
* This method overrides the parent implementation by setting default cache key prefix. |
|
*/ |
|
public function init() |
|
{ |
|
parent::init(); |
|
if($this->keyPrefix===null) |
|
$this->keyPrefix=Yii::app()->getId(); |
|
$this->useIgbinarySerializer=$this->useIgbinarySerializer&&extension_loaded('igbinary'); |
|
} |
|
|
|
/** |
|
* @param string $key a key identifying a value to be cached |
|
* @return sring a key generated from the provided key which ensures the uniqueness across applications |
|
*/ |
|
protected function generateUniqueKey($key) |
|
{ |
|
return $this->hashKey ? md5($this->keyPrefix.$key) : $this->keyPrefix.$key; |
|
} |
|
|
|
/** |
|
* Retrieves a value from cache with a specified key. |
|
* @param string $id a key identifying the cached value |
|
* @return mixed the value stored in cache, false if the value is not in the cache, expired or the dependency has changed. |
|
*/ |
|
public function get($id) |
|
{ |
|
if(($value=$this->getValue($this->generateUniqueKey($id)))!==false) |
|
{ |
|
$data=$this->autoSerialize ? $this->unserializeValue($value) : $value; |
|
if(!$this->autoSerialize || (is_array($data) && (!($data[1] instanceof ICacheDependency) || !$data[1]->getHasChanged()))) |
|
{ |
|
Yii::trace('Serving "'.$id.'" from cache','system.caching.'.get_class($this)); |
|
return $this->autoSerialize ? $data[0] : $data; |
|
} |
|
} |
|
return false; |
|
} |
|
|
|
/** |
|
* 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 doesn't support this feature natively, it will be simulated by this method. |
|
* @param array $ids list of keys identifying the cached values |
|
* @return array list of cached values corresponding to the specified keys. The array |
|
* is returned in terms of (key,value) pairs. |
|
* If a value is not cached or expired, the corresponding array value will be false. |
|
*/ |
|
public function mget($ids) |
|
{ |
|
$uniqueIDs=array(); |
|
$results=array(); |
|
foreach($ids as $id) |
|
{ |
|
$uniqueIDs[$id]=$this->generateUniqueKey($id); |
|
$results[$id]=false; |
|
} |
|
$values=$this->getValues($uniqueIDs); |
|
foreach($uniqueIDs as $id=>$uniqueID) |
|
{ |
|
if(!isset($values[$uniqueID])) |
|
continue; |
|
$data=$this->autoSerialize ? $this->unserializeValue($values[$uniqueID]) : $values[$uniqueID]; |
|
if(!$this->autoSerialize || (is_array($data) && (!($data[1] instanceof ICacheDependency) || !$data[1]->getHasChanged()))) |
|
{ |
|
Yii::trace('Serving "'.$id.'" from cache','system.caching.'.get_class($this)); |
|
$results[$id]=$this->autoSerialize ? $data[0] : $data; |
|
} |
|
} |
|
return $results; |
|
} |
|
|
|
/** |
|
* 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 $id the key identifying the value to be cached |
|
* @param mixed $value the value to be cached |
|
* @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire. |
|
* @param ICacheDependency $dependency dependency of the cached item. If the dependency changes, the item is labeled invalid. |
|
* @return boolean true if the value is successfully stored into cache, false otherwise |
|
*/ |
|
public function set($id,$value,$expire=0,$dependency=null) |
|
{ |
|
Yii::trace('Saving "'.$id.'" to cache','system.caching.'.get_class($this)); |
|
if($dependency!==null && $this->autoSerialize) |
|
$dependency->evaluateDependency(); |
|
$data=$this->autoSerialize ? $this->serializeValue(array($value,$dependency)) : $value; |
|
return $this->setValue($this->generateUniqueKey($id),$data,$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 $id the key identifying the value to be cached |
|
* @param mixed $value the value to be cached |
|
* @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire. |
|
* @param ICacheDependency $dependency dependency of the cached item. If the dependency changes, the item is labeled invalid. |
|
* @return boolean true if the value is successfully stored into cache, false otherwise |
|
*/ |
|
public function add($id,$value,$expire=0,$dependency=null) |
|
{ |
|
Yii::trace('Adding "'.$id.'" to cache','system.caching.'.get_class($this)); |
|
if($dependency!==null && $this->autoSerialize) |
|
$dependency->evaluateDependency(); |
|
$data=$this->autoSerialize ? $this->serializeValue(array($value,$dependency)) : $value; |
|
return $this->addValue($this->generateUniqueKey($id),$data,$expire); |
|
} |
|
|
|
/** |
|
* Deletes a value with the specified key from cache |
|
* @param string $id the key of the value to be deleted |
|
* @return boolean if no error happens during deletion |
|
*/ |
|
public function delete($id) |
|
{ |
|
Yii::trace('Deleting "'.$id.'" from cache','system.caching.'.get_class($this)); |
|
return $this->deleteValue($this->generateUniqueKey($id)); |
|
} |
|
|
|
/** |
|
* Deletes all values from cache. |
|
* Be careful of performing this operation if the cache is shared by multiple applications. |
|
* @return boolean whether the flush operation was successful. |
|
*/ |
|
public function flush() |
|
{ |
|
Yii::trace('Flushing cache','system.caching.'.get_class($this)); |
|
return $this->flushValues(); |
|
} |
|
|
|
/** |
|
* 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 {@link get()} already. So only the implementation of data retrieval |
|
* is needed. |
|
* @param string $key a unique key identifying the cached value |
|
* @return string the value stored in cache, false if the value is not in the cache or expired. |
|
* @throws CException if this method is not overridden by child classes |
|
*/ |
|
protected function getValue($key) |
|
{ |
|
throw new CException(Yii::t('yii','{className} does not support get() functionality.', |
|
array('{className}'=>get_class($this)))); |
|
} |
|
|
|
/** |
|
* Retrieves multiple values from cache with the specified keys. |
|
* The default implementation simply calls {@link 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. |
|
* @param array $keys a list of keys identifying the cached values |
|
* @return array a list of cached values indexed by the keys |
|
*/ |
|
protected function getValues($keys) |
|
{ |
|
$results=array(); |
|
foreach($keys as $key) |
|
$results[$key]=$this->getValue($key); |
|
return $results; |
|
} |
|
|
|
/** |
|
* 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 {@link set()} already. So only the implementation of data storage |
|
* is needed. |
|
* |
|
* @param string $key the key identifying the value to be cached |
|
* @param string $value the value to be cached |
|
* @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire. |
|
* @return boolean true if the value is successfully stored into cache, false otherwise |
|
* @throws CException if this method is not overridden by child classes |
|
*/ |
|
protected function setValue($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 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 {@link add()} already. So only the implementation of data storage |
|
* is needed. |
|
* |
|
* @param string $key the key identifying the value to be cached |
|
* @param string $value the value to be cached |
|
* @param integer $expire the number of seconds in which the cached value will expire. 0 means never expire. |
|
* @return boolean true if the value is successfully stored into cache, false otherwise |
|
* @throws CException if this method is not overridden by child classes |
|
*/ |
|
protected function addValue($key,$value,$expire) |
|
{ |
|
throw new CException(Yii::t('yii','{className} does not support add() 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. |
|
* @param string $key the key of the value to be deleted |
|
* @return boolean if no error happens during deletion |
|
* @throws CException if this method is not overridden by child classes |
|
*/ |
|
protected function deleteValue($key) |
|
{ |
|
throw new CException(Yii::t('yii','{className} does not support delete() functionality.', |
|
array('{className}'=>get_class($this)))); |
|
} |
|
|
|
/** |
|
* Deletes all values from cache. |
|
* Child classes may implement this method to realize the flush operation. |
|
* @return boolean whether the flush operation was successful. |
|
* @throws CException if this method is not overridden by child classes |
|
* @since 1.1.5 |
|
*/ |
|
protected function flushValues() |
|
{ |
|
throw new CException(Yii::t('yii','{className} does not support flushValues() functionality.', |
|
array('{className}'=>get_class($this)))); |
|
} |
|
|
|
/** |
|
* Serializes the value before it will be stored in the actual cache backend. |
|
* This method will be called if {@link autoSerialize} is set to true. Child classes may override this method to change |
|
* the way the value is being serialized. The default implementation simply makes use of the PHP serialize() function |
|
* unless {@link useIgbinarySerializer} is set to true and the igbinary extension is installed. |
|
* Make sure to override {@link unserializeValue()} as well if you want to change the serialization process. |
|
* @param mixed $value the unserialized representation of the value |
|
* @return string the serialized representation of the value |
|
* @since 1.1.11 |
|
**/ |
|
protected function serializeValue($value) |
|
{ |
|
if($this->useIgbinarySerializer) |
|
return igbinary_serialize($value); |
|
return serialize($value); |
|
} |
|
|
|
/** |
|
* Unserializes the value after it was retrieved from the actual cache backend. |
|
* This method will be called if {@link autoSerialize} is set to true. Child classes may override this method to change |
|
* the way the value is being unserialized. The default implementation simply makes use of the PHP unserialize() function |
|
* unless {@link useIgbinarySerializer} is set to true and the igbinary extension is installed. |
|
* Make sure to override {@link serializeValue()} as well if you want to change the serialization process. |
|
* @param string $value the serialized representation of the value |
|
* @return mixed the unserialized representation of the value |
|
* @since 1.1.11 |
|
**/ |
|
protected function unserializeValue($value) |
|
{ |
|
if($this->useIgbinarySerializer) |
|
return igbinary_unserialize($value); |
|
return unserialize($value); |
|
} |
|
|
|
/** |
|
* Returns whether there is a cache entry with a specified key. |
|
* This method is required by the interface ArrayAccess. |
|
* @param string $id a key identifying the cached value |
|
* @return boolean |
|
*/ |
|
public function offsetExists($id) |
|
{ |
|
return $this->get($id)!==false; |
|
} |
|
|
|
/** |
|
* Retrieves the value from cache with a specified key. |
|
* This method is required by the interface ArrayAccess. |
|
* @param string $id a key identifying the cached value |
|
* @return mixed the value stored in cache, false if the value is not in the cache or expired. |
|
*/ |
|
public function offsetGet($id) |
|
{ |
|
return $this->get($id); |
|
} |
|
|
|
/** |
|
* 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. |
|
* @param string $id the key identifying the value to be cached |
|
* @param mixed $value the value to be cached |
|
*/ |
|
public function offsetSet($id, $value) |
|
{ |
|
$this->set($id, $value); |
|
} |
|
|
|
/** |
|
* Deletes the value with the specified key from cache |
|
* This method is required by the interface ArrayAccess. |
|
* @param string $id the key of the value to be deleted |
|
* @return boolean if no error happens during deletion |
|
*/ |
|
public function offsetUnset($id) |
|
{ |
|
$this->delete($id); |
|
} |
|
} |