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The Cache class in CakePHP provides a generic frontend for several backend caching systems. Different Cache configurations and engines can be setup in your app/config/core.php
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 $cloud;
Cache::write($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', $posts);
}
Using Cache::write() and Cache::read() to easily reduce the number of trips made to the database to fetch posts.
Cache::delete($key, $config = null)
Cache::delete()
will allow you to completely remove a cached object
from the Cache store.
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()
.
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()
.