This is documentation for Kohana v2.3.x. For v3.x documentation, see .

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Cache Library

Kohana lets you cache any data in order to achieve maximum performance.

The majority of web pages served today are generated dynamically, usually by an application server querying a back-end database. Caching consists in storing objects or pages in their fully rendered state so that they are directly loaded for next requests. It allows to cut response times and save server resources and memory.

What should I cache? Any objects or content requiring “heavy” dynamic generation.

Kohana's cache library can currently store caches in various containers including file and database. This is configurable by setting the driver. Cached objects or contents can be loaded using a powerful tag system or with their identifier.

For the API documentation:


Configuration is done in the application/config/cache.php file, if it's not there take the one from system/config and copy it to the application folder (see cascading filesystem):

$config['default'] = array(
  'driver' => 'file',
  'params' => APPPATH.'cache',
  'lifetime' => 1800,
  'requests' => 1000


config['driver'] sets the driver, which is the container for your cached files. There are 6 different drivers:

Driver parameters

$config['params'] contains driver specific parameters. (in above example - path to server writable cache dir)

Cache Lifetime

$config['lifetime'] sets the lifetime of the cache (in seconds). Specific lifetime can be set when creating a new cache. 0 means it will never be deleted automatically

Garbage Collector

$config['requests'] average number of requests before automatic garbage collection begins. Set to a negative number will disable automatic garbage collection

How do I set up caching in my application?

Suppose you want to retrieve some information from your database and build a table of the entries you get. To cache the generated content, you would use in your controller code like this:

$this->cache= Cache::instance();
$table = $this->cache->get('table');
if ( ! $table) {
    $table = build_table();
    $this->cache->set('table', $table, array('mytag1', 'mytag2'), 3600);
echo $table;

There are 3 main steps:

Loading the library

 $this->cache = Cache::instance();


Setting caches


$this→cache→set($id,$data,$tags = NULL, $lifetime = NULL) is used to set caches.

$data=array('Jean Paul Sartre', 'Albert Camus', 'Simone de Beauvoir');

Finding and getting caches


$this→cache→get($id) retrieves a cache with the given $id, returns the data or NULL

// Array ( [0] => Jean Paul Sartre [1] => Albert Camus [2] => Simone de Beauvoir )


$this→cache→find($tag) supply with a string, retrieves all caches with the given tag.

$food=array('French bread','French wine','French cheese');
//Array ( [existentialists] => Array ( [0] => Jean Paul Sartre [1] => Albert Camus [2] => Simone de Beauvoir ) [food] => Array ( [0] => French bread [1] => French wine [2] => French cheese) )

Deleting caches

There are several methods to delete caches


$this→cache→delete($id) deletes a cache item by id, returns a boolean



$this→cache→delete_tag($tag) deletes all cache items with a given tag, returns a boolean



$this→cache→delete_all() deletes all cache items, returns a boolean


SQLite Driver Schema

If you use the SQlite driver to store the caches the table can be constructed with this query.

	id varchar(127),
	hash char(40),
	tags varchar(255),
	expiration int,
	cache blob);
libraries/cache.txt · Last modified: 2009/03/19 07:36 by pitch_invasion