Implements: Kohana_Cache_Arithmetic | Cache_Arithmetic
Kohana Cache Memcached driver. Provides a memcached based driver for the Kohana Cache library.
Below is an example of a memcached server configuration.
return[// Default group'default'=> [// Using Memcached driver'driver'=>'memcached',// Available server definitions'servers'=> [// First memcached server['host'=>'localhost','port'=> 11211,'weight'=> 1,'options'=> []],// Second memcached server['host'=>'192.168.1.5','port'=> 22122,'options'=> [Memcached::OPT_COMPRESSION => false,]]]],];
In cases where only one cache group is required, if the group is named
default there is no need to pass the group name when instantiating a cache
instance.
Below are the settings available to a memcached driver.
| Name | Required | Description |
|---|---|---|
| driver | YES | (string) The driver type to use |
| default_expire | NO | (integer) The default expiration value |
| servers | YES | (array) Associative array of server details, must include a host key. (See Memcached server configuration below) |
The following settings should be used when defining each memcached server.
| Name | Required | Description |
|---|---|---|
| host | YES | (string) The host of the memcached server, i.e. localhost; or 127.0.0.1; or memcached.domain.tld |
| port | NO | (integer) The port on which memcached is running. Set this parameter to 0 when using UNIX domain sockets. Default to 11211 |
| weight | NO | (integer) The weight of the server relative to the total weight of all the servers in the pool. This controls the probability of the server being selected for operations. Default to 1 |
| options | NO | (array) An associative array of options where the key is the option to set and the value is the new value for the option. Default to array() |
Class declared in MODPATH/cache/classes/Cache/Memcached.php on line 3.
integer 2592000
integer 3600
string $defaultlink to thisdefault driver to use
string(4) "file"Kohana_Cache $instanceslink to thisinstances
array(0) Config $_configlink to thisarray(0) array $defaultConfiglink to thisThe default configuration for the memcached server.
array(0) Memcached $memcachedlink to thisMemcached resource.
NULL
array $optionslink to thisMemcached options.
array(0) Decrement a given value by the step value supplied. Useful for shared counters and other persistent integer based tracking.
string
$id
required - Id of cache entry to decrement. int
$step
= integer 1 - Step value to decrement by. intbool
publicfunctiondecrement($id,$step= 1){return$this->memcached->decrement($id,$step);}
Delete a cache entry based on id.
// Delete the 'foo' cache entry immediately.Cache::instance('memcached')->delete('foo');// Delete the 'bar' cache entry after 30 seconds.Cache::instance('memcached')->delete('bar', 30);
string
$id
required - Id of entry to delete. int
$time
= integer 0 - The amount of time the server will wait to delete the entry. bool
publicfunctiondelete($id,$time= 0){return$this->memcached->delete($this->_sanitize_id($id),$time);}
Delete all cache entries.
Beware of using this method when using shared memory cache systems, as it will wipe every entry within the system for all clients.
// Delete all cache entries in the default group.Cache::instance('memcached')->delete_all();
bool
publicfunctiondelete_all(){return$this->memcached->flush();}
Retrieve a cached value entry by id.
// Retrieve cache entry from memcached group.$data= Cache::instance('memcached')->get('foo');// Retrieve cache entry from memcached group and return 'bar' if miss.$data= Cache::instance('memcached')->get('foo','bar');
string
$id
required - Id of cache to entry. string
$default
= NULL - Default value to return if cache miss. mixed
publicfunctionget($id,$default= null){// Get the value from Memcached.$value=$this->memcached->get($this->_sanitize_id($id));// If the value wasn't found, normalise it.if($value=== false) {$value= null ===$default? null :$default;}// Return the value.return$value;}
Increment a given value by the step value supplied. Useful for shared counters and other persistent integer based tracking.
string
$id
required - Id of cache entry to increment. int
$step
= integer 1 - Step value to increment by. intbool
publicfunctionincrement($id,$step= 1){return$this->memcached->increment($id,$step);}
Set a value to cache with id and lifetime.
$data='bar';// Set 'bar' to 'foo' in memcached group for 10 minutes.if(Cache::instance('memcached')->set('foo',$data, 600)) {// Cache was set successfully.returntrue;}
string
$id
required - Id of cache entry. mixed
$data
required - Data to set to cache. int
$lifetime
= NULL - Lifetime in seconds, maximum value 2592000. bool
publicfunctionset($id,$data,$lifetime= null){// If lifetime is null, set to the default expiry.if($lifetime=== null) {$lifetime= Arr::get($this->_config,'default_expire', Cache::DEFAULT_EXPIRE);}// If the lifetime is greater than the ceiling.if($lifetime> Cache_Memcached::CACHE_CEILING) {// Set the lifetime to maximum cache time.$lifetime= Cache_Memcached::CACHE_CEILING + time();}// Else if the lifetime is greater than zero.elseif($lifetime> 0) {$lifetime+= time();}// Elseelse{// Normalise the lifetime.$lifetime= 0;}// Set the data to memcached.return$this->memcached->set($this->_sanitize_id($id),$data,$lifetime);}
Overload the __clone() method to prevent cloning
void
finalpublicfunction__clone(){thrownewCache_Exception('Cloning of Kohana_Cache objects is forbidden');}
Getter and setter for the configuration. If no argument provided, the current configuration is returned. Otherwise the configuration is set to this class.
// Overwrite all configuration$cache->config(['driver'=>'memcache','...']);// Set a new configuration setting$cache->config('servers', ['foo'=>'bar','...']);// Get a configuration setting$servers=$cache->config('servers);
mixed
$key
= NULL - Key to set to array, either array or config path mixed
$value
= NULL - Value to associate with key mixed
publicfunctionconfig($key= null,$value= null){if($key=== null)return$this->_config;if(is_array($key)) {$this->_config =$key;}else{if($value=== null)returnArr::get($this->_config,$key);$this->_config[$key] =$value;}return$this;}
Creates a singleton of a Kohana Cache group. If no group is supplied the default cache group is used.
// Create an instance of the default group$default_group= Cache::instance();// Create an instance of a group$foo_group= Cache::instance('foo');// Access an instantiated group directly$foo_group= Cache::$instances['default'];
string
$group
= NULL - The name of the cache group to use [Optional] Cache
publicstaticfunctioninstance($group= null){// If there is no group suppliedif($group=== null) {// Use the default setting$group= Cache::$default;}if(isset(Cache::$instances[$group])) {// Return the current group if initiated alreadyreturnCache::$instances[$group];}$config= Kohana::$config->load('cache');if(!$config->offsetExists($group)) {thrownewCache_Exception('Failed to load Kohana Cache group: :group', [':group'=>$group]);}$config=$config->get($group);// Create a new cache type instance$cache_class='Cache_'. ucfirst($config['driver']);Cache::$instances[$group] =new$cache_class($config);// Return the instancereturnCache::$instances[$group];}
Construct the memcached cache driver. This method cannot be invoked
externally. The file cache driver must be instantiated using the
Cache::instance() method.
array
$config
required - Configuration
protectedfunction__construct(array$config){// Check for the memcached extention.if(!extension_loaded('memcached')) {thrownewCache_Exception('Memcached PHP extention not loaded');}parent::__construct($config);// Setup Memcached.$this->memcached =newMemcached;// Load servers from configuration.$servers= Arr::get($this->_config,'servers', null);if(!$servers) {// Throw an exception if no server found.thrownewCache_Exception('No Memcached servers defined in configuration');}// Setup default server configuration.$this->defaultConfig = ['host'=>'localhost','port'=> 11211,'weight'=> 1,'options'=> []];// Add the memcached servers to the pool.foreach($serversas$server) {// Merge the defined config with defaults.$server+=$this->defaultConfig;if(!$this->memcached->addServer($server['host'],$server['port'],$server['weight'])) {thrownewCache_Exception('Memcached could not connect to host \':host\' using port \':port\'', [':host'=>$server['host'],':port'=>$server['port']]);}// Set options.if($server['options']) {$this->memcached->setOptions($server['options']);}}}
Replaces troublesome characters with underscores.
// Sanitize a cache id$id=$this->_sanitize_id($id);
string
$id
required - Id of cache to sanitize string
protectedfunction_sanitize_id($id){// Change slashes and spaces to underscoresreturnstr_replace(['/','\\',' '],'_',$id);}