376 lines
15 KiB
PHP
376 lines
15 KiB
PHP
|
<?php
|
||
|
/**
|
||
|
* CCache class file.
|
||
|
*
|
||
|
* @author Qiang Xue <qiang.xue@gmail.com>
|
||
|
* @link http://www.yiiframework.com/
|
||
|
* @copyright 2008-2013 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 getValues} (optional)</li>
|
||
|
* <li>{@link flushValues} (optional)</li>
|
||
|
* <li>{@link serializer} (optional)</li>
|
||
|
* </ul>
|
||
|
*
|
||
|
* CCache also implements ArrayAccess so that it can be used like an array.
|
||
|
*
|
||
|
* @author Qiang Xue <qiang.xue@gmail.com>
|
||
|
* @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 array|boolean 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. {@link http://pecl.php.net/package/igbinary 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 {@link CCacheDependency cache dependency}, because it relies on data serialization.
|
||
|
*/
|
||
|
public $serializer;
|
||
|
|
||
|
/**
|
||
|
* Initializes the application component.
|
||
|
* This method overrides the parent implementation by setting default cache key prefix.
|
||
|
*/
|
||
|
public function init()
|
||
|
{
|
||
|
parent::init();
|
||
|
if($this->keyPrefix===null)
|
||
|
$this->keyPrefix=Yii::app()->getId();
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* @param string $key a key identifying a value to be cached
|
||
|
* @return string a key generated from the provided key which ensures the uniqueness across applications
|
||
|
*/
|
||
|
protected function generateUniqueKey($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)
|
||
|
{
|
||
|
$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 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.
|
||
|
* @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)
|
||
|
{
|
||
|
$uids = array();
|
||
|
foreach ($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;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* 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->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 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->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);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* 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 $key a unique key identifying the cached value
|
||
|
* @return string|boolean the value stored in cache, false if the value is not in the cache or expired.
|
||
|
* @throws CException if this method is not overridden by child classes
|
||
|
*/
|
||
|
protected function getValue($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))));
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* 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);
|
||
|
}
|
||
|
}
|