Modules

Cache_Sqlite
extends Kohana_Cache_Sqlite
extends Cache
extends Kohana_Cache

Kohana Cache Sqlite Driver

Requires SQLite3 and PDO

package
Kohana/Cache
category
Base
author
Kohana Team
copyright
© 2009-2010 Kohana Team
license
http://kohanaphp.com/license

Class declared in MODPATH/cache/classes/cache/sqlite.php on line 3.

Constants

DEFAULT_EXPIRE

integer 3600

Properties

public static string $default

default driver to use

string(4) "file"

public static Kohana_Cache $instances

instances

array(0) 

protected Kohana_Config $_config

protected PDO $_db

Database resource

Methods

public delete( string $id ) (defined in Kohana_Cache_Sqlite)

Delete a cache entry based on id

Parameters

  • string $id required - Id

Tags

Return Values

  • boolean

Source Code

public 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();
}

public delete_all( ) (defined in Kohana_Cache_Sqlite)

Delete all cache entries

Return Values

  • boolean

Source Code

public 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();
}

public delete_tag( string $tag ) (defined in Kohana_Cache_Sqlite)

Delete cache entries based on a tag

Parameters

  • string $tag required - Tag

Tags

Return Values

  • boolean

Source Code

public 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();
}

public find( string $tag ) (defined in Kohana_Cache_Sqlite)

Find cache entries based on a tag

Parameters

  • string $tag required - Tag

Tags

Return Values

  • array

Source Code

public 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;
}

public garbage_collect( ) (defined in Kohana_Cache_Sqlite)

Garbage collection method that cleans any expired cache entries from the cache.

Return Values

  • void

Source Code

public 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()));
	}
}

public get( string $id [, string $default = NULL ] ) (defined in Kohana_Cache_Sqlite)

Retrieve a value based on an id

Parameters

  • string $id required - Id
  • string $default = NULL - Default [Optional] Default value to return if id not found

Tags

Return Values

  • mixed

Source Code

public 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;
	}
}

public set( string $id , mixed $data [, integer $lifetime = NULL ] ) (defined in Kohana_Cache_Sqlite)

Set a value based on an id. Optionally add tags.

Parameters

  • string $id required - Id
  • mixed $data required - Data
  • integer $lifetime = NULL - Lifetime [Optional]

Return Values

  • boolean

Source Code

public function set($id, $data, $lifetime = NULL)
{
	return (bool) $this->set_with_tags($id, $data, $lifetime);
}

public set_with_tags( string $id , mixed $data [, integer $lifetime = NULL , array $tags = NULL ] ) (defined in Kohana_Cache_Sqlite)

Set a value based on an id. Optionally add tags.

Parameters

  • string $id required - Id
  • mixed $data required - Data
  • integer $lifetime = NULL - Lifetime [Optional]
  • array $tags = NULL - Tags [Optional]

Tags

Return Values

  • boolean

Source Code

public 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();
}

public __clone( ) (defined in Kohana_Cache)

Overload the __clone() method to prevent cloning

Tags

Return Values

  • void

Source Code

public function __clone()
{
	throw new Kohana_Cache_Exception('Cloning of Kohana_Cache objects is forbidden');
}

public static instance( [ string $group = NULL ] ) (defined in Kohana_Cache)

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'];

Parameters

  • string $group = NULL - The name of the cache group to use [Optional]

Tags

Return Values

  • Kohana_Cache

Source Code

public 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];
}

protected __construct( array $config ) (defined in Kohana_Cache_Sqlite)

Sets up the PDO SQLite table and initialises the PDO connection

Parameters

  • array $config required - Configuration

Tags

Source Code

protected 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()));
		}
	}
}

protected exists( string $id ) (defined in Kohana_Cache_Sqlite)

Tests whether an id exists or not

Parameters

  • string $id required - Id

Tags

Return Values

  • boolean

Source Code

protected 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();
}

protected _sanitize_id( string $id ) (defined in Kohana_Cache)

Replaces troublesome characters with underscores.

// Sanitize a cache id
$id = $this->_sanitize_id($id);

Parameters

  • string $id required - Id of cache to sanitize

Return Values

  • string

Source Code

protected function _sanitize_id($id)
{
	// Change slashes and spaces to underscores
	return str_replace(array('/', '\\', ' '), '_', $id);
}