Implements: Kohana_Cache_GarbageCollect | Kohana_Cache_Tagging
Kohana Cache Sqlite Driver
Requires SQLite3 and PDO
Class declared in MODPATH/cache/classes/cache/sqlite.php on line 3.
integer 3600
string $defaultdefault driver to use
string(4) "file"Kohana_Cache $instancesinstances
array(0) Config $_configPDO $_dbDatabase resource
Delete a cache entry based on id
string
$id
required - Idbooleanpublic function delete($id)
{
// Prepare statement
$statement = $this->_db->prepare('DELETE FROM caches WHERE id = :id');
// Remove the entry
try
{
$statement->execute(array(':id' => $this->_sanitize_id($id)));
}
catch (PDOException $e)
{
throw new Kohana_Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
return (bool) $statement->rowCount();
}Delete all cache entries
booleanpublic function delete_all()
{
// Prepare statement
$statement = $this->_db->prepare('DELETE FROM caches');
// Remove the entry
try
{
$statement->execute();
}
catch (PDOException $e)
{
throw new Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
return (bool) $statement->rowCount();
}Delete cache entries based on a tag
string
$tag
required - Tagbooleanpublic function delete_tag($tag)
{
// Prepare the statement
$statement = $this->_db->prepare('DELETE FROM caches WHERE tags LIKE :tag');
// Try to delete
try
{
$statement->execute(array(':tag' => "%<{$tag}>%"));
}
catch (PDOException $e)
{
throw new Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
return (bool) $statement->rowCount();
}Find cache entries based on a tag
string
$tag
required - Tagarraypublic function find($tag)
{
// Prepare the statement
$statement = $this->_db->prepare('SELECT id, cache FROM caches WHERE tags LIKE :tag');
// Try to find
try
{
if ( ! $statement->execute(array(':tag' => "%<{$tag}>%")))
{
return array();
}
}
catch (PDOException $e)
{
throw new Kohana_Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
$result = array();
while ($row = $statement->fetchObject())
{
// Disable notices for unserializing
$ER = error_reporting(~E_NOTICE);
$result[$row->id] = unserialize($row->cache);
// Turn notices back on
error_reporting($ER);
}
return $result;
}Garbage collection method that cleans any expired cache entries from the cache.
voidpublic function garbage_collect()
{
// Create the sequel statement
$statement = $this->_db->prepare('DELETE FROM caches WHERE expiration < :expiration');
try
{
$statement->execute(array(':expiration' => time()));
}
catch (PDOException $e)
{
throw new Kohana_Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
}Retrieve a value based on an id
string
$id
required - Idstring
$default
= NULL - Default [Optional] Default value to return if id not foundmixedpublic function get($id, $default = NULL)
{
// Prepare statement
$statement = $this->_db->prepare('SELECT id, expiration, cache FROM caches WHERE id = :id LIMIT 0, 1');
// Try and load the cache based on id
try
{
$statement->execute(array(':id' => $this->_sanitize_id($id)));
}
catch (PDOException $e)
{
throw new Kohana_Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
if ( ! $result = $statement->fetch(PDO::FETCH_OBJ))
{
return $default;
}
// If the cache has expired
if ($result->expiration != 0 and $result->expiration <= time())
{
// Delete it and return default value
$this->delete($id);
return $default;
}
// Otherwise return cached object
else
{
// Disable notices for unserializing
$ER = error_reporting(~E_NOTICE);
// Return the valid cache data
$data = unserialize($result->cache);
// Turn notices back on
error_reporting($ER);
// Return the resulting data
return $data;
}
}Set a value based on an id. Optionally add tags.
string
$id
required - Idmixed
$data
required - Datainteger
$lifetime
= NULL - Lifetime [Optional]booleanpublic function set($id, $data, $lifetime = NULL)
{
return (bool) $this->set_with_tags($id, $data, $lifetime);
}Set a value based on an id. Optionally add tags.
string
$id
required - Idmixed
$data
required - Datainteger
$lifetime
= NULL - Lifetime [Optional]array
$tags
= NULL - Tags [Optional]booleanpublic function set_with_tags($id, $data, $lifetime = NULL, array $tags = NULL)
{
// Serialize the data
$data = serialize($data);
// Normalise tags
$tags = (NULL === $tags) ? NULL : ('<'.implode('>,<', $tags).'>');
// Setup lifetime
if ($lifetime === NULL)
{
$lifetime = (0 === Arr::get('default_expire', NULL)) ? 0 : (Arr::get($this->_config, 'default_expire', Cache::DEFAULT_EXPIRE) + time());
}
else
{
$lifetime = (0 === $lifetime) ? 0 : ($lifetime + time());
}
// Prepare statement
// $this->exists() may throw Kohana_Cache_Exception, no need to catch/rethrow
$statement = $this->exists($id) ? $this->_db->prepare('UPDATE caches SET expiration = :expiration, cache = :cache, tags = :tags WHERE id = :id') : $this->_db->prepare('INSERT INTO caches (id, cache, expiration, tags) VALUES (:id, :cache, :expiration, :tags)');
// Try to insert
try
{
$statement->execute(array(':id' => $this->_sanitize_id($id), ':cache' => $data, ':expiration' => $lifetime, ':tags' => $tags));
}
catch (PDOException $e)
{
throw new Kohana_Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
return (bool) $statement->rowCount();
}Overload the __clone() method to prevent cloning
voidpublic function __clone()
{
throw new Kohana_Cache_Exception('Cloning of Kohana_Cache objects is forbidden');
}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
$group
= NULL - The name of the cache group to use [Optional]Cachepublic static function instance($group = NULL)
{
// If there is no group supplied
if ($group === NULL)
{
// Use the default setting
$group = Cache::$default;
}
if (isset(Cache::$instances[$group]))
{
// Return the current group if initiated already
return Cache::$instances[$group];
}
$config = Kohana::config('cache');
if ( ! $config->offsetExists($group))
{
throw new Kohana_Cache_Exception('Failed to load Kohana Cache group: :group', array(':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 instance
return Cache::$instances[$group];
}Sets up the PDO SQLite table and initialises the PDO connection
array
$config
required - Configurationprotected function __construct(array $config)
{
parent::__construct($config);
$database = Arr::get($this->_config, 'database', NULL);
if ($database === NULL)
{
throw new Kohana_Cache_Exception('Database path not available in Kohana Cache configuration');
}
// Load new Sqlite DB
$this->_db = new PDO('sqlite:'.$database);
// Test for existing DB
$result = $this->_db->query("SELECT * FROM sqlite_master WHERE name = 'caches' AND type = 'table'")->fetchAll();
// If there is no table, create a new one
if (0 == count($result))
{
$database_schema = Arr::get($this->_config, 'schema', NULL);
if ($database_schema === NULL)
{
throw new Kohana_Cache_Exception('Database schema not found in Kohana Cache configuration');
}
try
{
// Create the caches table
$this->_db->query(Arr::get($this->_config, 'schema', NULL));
}
catch (PDOException $e)
{
throw new Kohana_Cache_Exception('Failed to create new SQLite caches table with the following error : :error', array(':error' => $e->getMessage()));
}
}
}Tests whether an id exists or not
string
$id
required - Idbooleanprotected function exists($id)
{
$statement = $this->_db->prepare('SELECT id FROM caches WHERE id = :id');
try
{
$statement->execute(array(':id' => $this->_sanitize_id($id)));
}
catch (PDOExeption $e)
{
throw new Kohana_Cache_Exception('There was a problem querying the local SQLite3 cache. :error', array(':error' => $e->getMessage()));
}
return (bool) $statement->fetchAll();
}Replaces troublesome characters with underscores.
// Sanitize a cache id
$id = $this->_sanitize_id($id);
string
$id
required - Id of cache to sanitizestringprotected function _sanitize_id($id)
{
// Change slashes and spaces to underscores
return str_replace(array('/', '\\', ' '), '_', $id);
}