Cache¶

Cache::read()¶

Cache::read($key, $config = null)

Cache::read() is used to read the cached value stored under $key from the $config. If $config is null the default config will be used. Cache::read() will return the cached value if it is a valid cache or false if the cache has expired or doesn’t exist. The contents of the cache might evaluate false, so make sure you use the strict comparison operator === or !==.

For example:

$cloud = Cache::read('cloud');

if ($cloud !== false) {
    return $cloud;
}

// generate cloud data
// ...

// store data in cache
Cache::write('cloud', $cloud);
return $cloud;

Cache::write()¶

Cache::write($key, $value, $config = null);

Cache::write() will write a $value to the Cache. You can read or delete this value later by refering to it by $key. You may specify an optional configuration to store the cache in as well. If no $config is specified default will be used. Cache::write() can store any type of object and is ideal for storing results of model finds.

if (($posts = Cache::read('posts')) === false) {
    $posts = $this->Post->find('all');
    Cache::write('posts', $posts);
}

Using Cache::write() and Cache::read() to easily reduce the number of trips made to the database to fetch posts.

Cache::delete()¶

Cache::delete($key, $config = null)

Cache::delete() will allow you to completely remove a cached object from the Cache store.

Cache::config()¶

Cache::config() is used to create additional Cache configurations. These additional configurations can have different duration, engines, paths, or prefixes than your default cache config. Using multiple cache configurations can help reduce the number of times you need to use Cache::set() as well as centralize all your cache settings.

You must specify which engine to use. It does not default to File.

Cache::config('short', array(
    'engine' => 'File',
    'duration'=> '+1 hours',
    'path' => CACHE,
    'prefix' => 'cake_short_'
));

// long
Cache::config('long', array(
    'engine' => 'File',
    'duration'=> '+1 week',
    'probability'=> 100,
    'path' => CACHE . 'long' . DS,
));

By placing the above code in your app/config/core.php you will have two additional Cache configurations. The name of these configurations ‘short’ or ‘long’ is used as the $config parameter for Cache::write() and Cache::read().

You can provide custom Cache adapters in app/libs as well as in plugins using $plugin/libs. App/plugin cache engines can also override the core engines. Cache adapters must be in a cache directory. If you had a cache engine named MyCustomCacheEngine it would be placed in either app/libs/cache/my_custom_cache.php as an app/libs. Or in $plugin/libs/cache/my_custom_cache.php as part of a plugin. Cache configs from plugins need to use the plugin dot syntax.

Cache::config('custom', array(
    'engine' => 'CachePack.MyCustomCache',
    ...
));

App and Plugin cache engines should be configured in app/bootstrap.php. If you try to configure them in core.php they will not work correctly.

Cache::set()¶

Cache::set() allows you to temporarily override a cache configs settings for one operation (usually a read or write). If you use Cache::set() to change the settings for a write, you should also use Cache::set() before reading the data back in. If you fail to do so, the default settings will be used when the cache key is read.

Cache::set(array('duration' => '+30 days'));
Cache::write('results', $data);

// Later on

Cache::set(array('duration' => '+30 days'));
$results = Cache::read('results');

If you find yourself repeatedly calling Cache::set() perhaps you should create a new Cache. This will remove the need to call Cache::set().