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authoremkael <emkael@tlen.pl>2016-02-24 23:18:07 +0100
committeremkael <emkael@tlen.pl>2016-02-24 23:18:07 +0100
commit6f7fdef0f500cd4bb540affd3bc1482243f337c1 (patch)
tree4853eecd0769a903e6130c1896e1d070848150dd /lib/prado/framework/Caching/TMemCache.php
parent61f2ea48a4e11cb5fb941b3783e19c9e9ef38a45 (diff)
* Prado 3.3.0
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+<?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 &copy; 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();
+ }
+}
+