Caching Driver¶

Example Usage¶

The following example will load the cache driver, specify APC as the driver to use, and fall back to file-based caching if APC is not available in the hosting environment.

$this->load->driver('cache', array('adapter' => 'apc', 'backup' => 'file'));

if ( ! $foo = $this->cache->get('foo'))
{
        echo 'Saving to the cache!<br />';
        $foo = 'foobarbaz!';

        // Save into the cache for 5 minutes
        $this->cache->save('foo', $foo, 300);
}

echo $foo;

You can also prefix cache item names via the key_prefix setting, which is useful to avoid collisions when you’re running multiple applications on the same environment.

$this->load->driver('cache',
        array('adapter' => 'apc', 'backup' => 'file', 'key_prefix' => 'my_')
);

$this->cache->get('foo'); // Will get the cache entry named 'my_foo'

Class Reference¶

class CI_Cache¶

is_supported($driver)¶

Parameters:	$driver (string) – the name of the caching driver
Returns:	TRUE if supported, FALSE if not
Return type:	bool

This method is automatically called when accessing drivers via $this->cache->get(). However, if the individual drivers are used, make sure to call this method to ensure the driver is supported in the hosting environment.

if ($this->cache->apc->is_supported()
{
        if ($data = $this->cache->apc->get('my_cache'))
        {
                // do things.
        }
}

get($id)¶

Parameters:	$id (string) – Cache item name
Returns:	Item value or FALSE if not found
Return type:	mixed

This method will attempt to fetch an item from the cache store. If the item does not exist, the method will return FALSE.

$foo = $this->cache->get('my_cached_item');

save($id, $data[, $ttl = 60[, $raw = FALSE]])¶

Parameters:	$id (string) – Cache item name $data (mixed) – the data to save $ttl (int) – Time To Live, in seconds (default 60) $raw (bool) – Whether to store the raw value
Returns:	TRUE on success, FALSE on failure
Return type:	string

This method will save an item to the cache store. If saving fails, the method will return FALSE.

$this->cache->save('cache_item_id', 'data_to_cache');

Note

The $raw parameter is only utilized by APC and Memcache, in order to allow usage of increment() and decrement().

delete($id)¶

Parameters:	$id (string) – name of cached item
Returns:	TRUE on success, FALSE on failure
Return type:	bool

This method will delete a specific item from the cache store. If item deletion fails, the method will return FALSE.

$this->cache->delete('cache_item_id');

increment($id[, $offset = 1])¶

Parameters:	$id (string) – Cache ID $offset (int) – Step/value to add
Returns:	New value on success, FALSE on failure
Return type:	mixed

Performs atomic incrementation of a raw stored value.

// 'iterator' has a value of 2

$this->cache->increment('iterator'); // 'iterator' is now 3

$this->cache->increment('iterator', 3); // 'iterator' is now 6

decrement($id[, $offset = 1])¶

Parameters:	$id (string) – Cache ID $offset (int) – Step/value to reduce by
Returns:	New value on success, FALSE on failure
Return type:	mixed

Performs atomic decrementation of a raw stored value.

// 'iterator' has a value of 6

$this->cache->decrement('iterator'); // 'iterator' is now 5

$this->cache->decrement('iterator', 2); // 'iterator' is now 3

clean()¶

Returns:	TRUE on success, FALSE on failure
Return type:	bool

This method will ‘clean’ the entire cache. If the deletion of the cache files fails, the method will return FALSE.

$this->cache->clean();

cache_info()¶

Returns:	Information on the entire cache database
Return type:	mixed

This method will return information on the entire cache.

var_dump($this->cache->cache_info());

Note

The information returned and the structure of the data is dependent on which adapter is being used.

get_metadata($id)¶

Parameters:	$id (string) – Cache item name
Returns:	Metadata for the cached item
Return type:	mixed

This method will return detailed information on a specific item in the cache.

var_dump($this->cache->get_metadata('my_cached_item'));

Note

The information returned and the structure of the data is dependent on which adapter is being used.

Drivers¶

$this->load->driver('cache');
$this->cache->apc->save('foo', 'bar', 10);

$this->load->driver('cache');
$this->cache->file->save('foo', 'bar', 10);

$this->load->driver('cache');
$this->cache->memcached->save('foo', 'bar', 10);

$this->load->driver('cache');
$this->cache->wincache->save('foo', 'bar', 10);

$config['socket_type'] = 'tcp'; //`tcp` or `unix`
$config['socket'] = '/var/run/redis.sock'; // in case of `unix` socket type
$config['host'] = '127.0.0.1';
$config['password'] = NULL;
$config['port'] = 6379;
$config['timeout'] = 0;

$this->load->driver('cache');
$this->cache->redis->save('foo', 'bar', 10);