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Diffstat (limited to 'lib/prado/framework/Caching/TMemCache.php')
| -rw-r--r-- | lib/prado/framework/Caching/TMemCache.php | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/lib/prado/framework/Caching/TMemCache.php b/lib/prado/framework/Caching/TMemCache.php new file mode 100644 index 0000000..8d09119 --- /dev/null +++ b/lib/prado/framework/Caching/TMemCache.php @@ -0,0 +1,400 @@ +<?php +/** + * TMemCache class file + * + * @author Qiang Xue <qiang.xue@gmail.com> + * @author Carl G. Mathisen <carlgmathisen@gmail.com> + * @link https://github.com/pradosoft/prado + * @copyright Copyright © 2005-2015 The PRADO Group + * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT + * @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 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> + * + * You can configure TMemCache two different ways. If you only need one memcache server + * you may use the method as follows. + * <code> + * <module id="cache" class="System.Caching.TMemCache" Host="localhost" Port="11211" /> + * </code> + * + * If you want a more complex configuration, you may use the method as follows. + * <code> + * <module id="cache" classs="System.Caching.TMemCache"> + * <server Host="localhost" Port="11211" Weight="1" Timeout="300" RetryInterval="15" /> + * <server Host="anotherhost" Port="11211" Weight="1" Timeout="300" RetryInterval="15" /> + * </module> + * </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 + * <code> + * <module id="cache" class="System.Caching.TMemCache" Host="localhost" Port="11211" /> + * </code> + * where {@link getHost Host} and {@link getPort Port} are configurable properties + * of TMemCache. + * + * Automatic compression of values may be used (using zlib extension) by setting {@link getThreshold Threshold} and {@link getMinSavings MinSavings} properties. + * NB : MemCache server(s) must be restarted to apply settings. Require (PECL memcache >= 2.0.0) or memcached if {@link useMemcached} is true. + * + * @author Qiang Xue <qiang.xue@gmail.com> + * @package System.Caching + * @since 3.0 + */ +class TMemCache extends TCache +{ + /** + * @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; + /** + * @var boolean controls the use of a persistent connection. Default to true. + */ + private $_persistence = true; + /** + * @var integer number of buckets to create for this server which in turn control its + * probability of it being selected. The probability is relative to the total weight + * of all servers. + */ + private $_weight = 1; + + private $_timeout = 360; + + private $_retryInterval = 15; + /** + * @var integer Controls the minimum value length before attempting to compress automatically. + */ + private $_threshold=0; + + /** + * @var float Specifies the minimum amount of savings to actually store the value compressed. The supplied value must be between 0 and 1. Default value is 0.2 giving a minimum 20% compression savings. + */ + private $_minSavings=0.0; + + private $_status = true; + + private $_failureCallback = null; + + /** + * @var boolean whether to use memcached or memcache as the underlying caching extension. + * If true {@link http://pecl.php.net/package/memcached memcached} will be used. + * If false {@link http://pecl.php.net/package/memcache memcache}. will be used. + * Defaults to false. + */ + private $_useMemcached=false; + + /** + * @var array list of servers available + */ + private $_servers=array(); + + /** + * Destructor. + * Disconnect the memcache server. + */ + public function __destruct() + { + if($this->_cache!==null && !$this->_useMemcached) + $this->_cache->close(); + } + + /** + * Initializes this module. + * This method is required by the IModule interface. It makes sure that + * UniquePrefix has been set, creates a Memcache instance and connects + * to the memcache server. + * @param TApplication Prado application, can be null + * @param TXmlElement configuration for this module, can be null + * @throws TConfigurationException if memcache extension is not installed or memcache sever connection fails + */ + public function init($config) + { + if(!extension_loaded('memcache') && !$this->_useMemcached) + throw new TConfigurationException('memcache_extension_required'); + if(!extension_loaded('memcached') && $this->_useMemcached) + throw new TConfigurationException('memcached_extension_required'); + + $this->_cache = $this->_useMemcached ? new Memcached : new Memcache; + $this->loadConfig($config); + if(count($this->_servers)) + { + foreach($this->_servers as $server) + { + Prado::trace('Adding server '.$server['Host'].' from serverlist', 'System.Caching.TMemCache'); + if($this->_cache->addServer($server['Host'],$server['Port'],$server['Persistent'], + $server['Weight'],$server['Timeout'],$server['RetryInterval'])===false) + throw new TConfigurationException('memcache_connection_failed',$server['Host'],$server['Port']); + } + } + else + { + Prado::trace('Adding server '.$this->_host, 'System.Caching.TMemCache'); + if($this->_cache->addServer($this->_host,$this->_port)===false) + throw new TConfigurationException('memcache_connection_failed',$this->_host,$this->_port); + } + if($this->_threshold!==0) + $this->_cache->setCompressThreshold($this->_threshold,$this->_minSavings); + $this->_initialized=true; + parent::init($config); + } + + /** + * Loads configuration from an XML element + * @param TXmlElement configuration node + * @throws TConfigurationException if log route class or type is not specified + */ + private function loadConfig($xml) + { + if($xml instanceof TXmlElement) + { + foreach($xml->getElementsByTagName('server') as $serverConfig) + { + $properties=$serverConfig->getAttributes(); + if(($host=$properties->remove('Host'))===null) + throw new TConfigurationException('memcache_serverhost_required'); + if(($port=$properties->remove('Port'))===null) + throw new TConfigurationException('memcache_serverport_required'); + if(!is_numeric($port)) + throw new TConfigurationException('memcache_serverport_invalid'); + $server = array('Host'=>$host,'Port'=>$port,'Weight'=>1,'Timeout'=>1800,'RetryInterval'=>15,'Persistent'=>true); + $checks = array( + 'Weight'=>'memcache_serverweight_invalid', + 'Timeout'=>'memcache_servertimeout_invalid', + 'RetryInterval'=>'memcach_serverretryinterval_invalid' + ); + foreach($checks as $property=>$exception) + { + $value=$properties->remove($property); + if($value!==null && is_numeric($value)) + $server[$property]=$value; + else if($value!==null) + throw new TConfigurationException($exception); + } + $server['Persistent']= TPropertyValue::ensureBoolean($properties->remove('Persistent')); + $this->_servers[]=$server; + } + } + } + + /** + * @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); + } + + /** + * @return boolean if memcached instead memcache + */ + public function getUseMemcached() + { + return $this->_useMemcached; + } + + /** + * @param string if memcached instead memcache + * @throws TInvalidOperationException if the module is already initialized + */ + public function setUseMemcached($value) + { + if($this->_initialized) + throw new TInvalidOperationException('memcache_host_unchangeable'); + else + $this->_useMemcached=$value; + } + + /** + * @return integer minimum value length before attempting to compress + */ + public function getThreshold() + { + return $this->_threshold; + } + + /** + * @param integer minimum value length before attempting to compress + * @throws TInvalidOperationException if the module is already initialized + */ + public function setThreshold($value) + { + if($this->_initialized) + throw new TInvalidOperationException('memcache_threshold_unchangeable'); + else + $this->_threshold=TPropertyValue::ensureInteger($value); + } + + /** + * @return float minimum amount of savings to actually store the value compressed + */ + public function getMinSavings() + { + return $this->_minSavings; + } + + /** + * @param float minimum amount of savings to actually store the value compressed + * @throws TInvalidOperationException if the module is already initialized + */ + public function setMinSavings($value) + { + if($this->_initialized) + throw new TInvalidOperationException('memcache_min_savings_unchangeable'); + else + $this->_minSavings=TPropertyValue::ensureFloat($value); + } + + /** + * Retrieves a value from cache with a specified key. + * This is the implementation of the method declared in the parent class. + * @param string 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. + */ + protected function getValue($key) + { + return $this->_cache->get($key); + } + + /** + * Stores a value identified by a key in cache. + * This is the implementation of the method declared in the parent class. + * + * @param string the key identifying the value to be cached + * @param string the value to be cached + * @param 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 + */ + protected function setValue($key,$value,$expire) + { + if($this->_useMemcached) { + return $this->_cache->set($key,$value,$expire); + } else { + return $this->_cache->set($key,$value,0,$expire); + } + } + + /** + * Stores a value identified by a key into cache if the cache does not contain this key. + * This is the implementation of the method declared in the parent class. + * + * @param string the key identifying the value to be cached + * @param string the value to be cached + * @param 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 + */ + protected function addValue($key,$value,$expire) + { + if($this->_useMemcached) { + $this->_cache->add($key,$value,$expire); + } else { + return $this->_cache->add($key,$value,0,$expire); + } + } + + /** + * Deletes a value with the specified key from cache + * This is the implementation of the method declared in the parent class. + * @param string the key of the value to be deleted + * @return boolean if no error happens during deletion + */ + protected function deleteValue($key) + { + return $this->_cache->delete($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(); + } +} + |