Cache

Cache Component

Cache component give you ability to store different information into memory for a limited time.

Install the component

The best way to install the component is using Composer.

{
    "require": {
        "webiny/cache": "1.0.*"
    }
}

For additional versions of the package, visit the Packagist page.

Once you have your composer.json file in place, just run the install command.

$ php composer.phar install

To learn more about Composer, and how to use it, please visit this link.

Alternatively, you can also do a git checkout of the repo.

Supported drivers

The cache component supports following cache drivers:

• APC (http://php.net/manual/en/book.apc.php)
  • only available in PHP 5.4, from PHP 5.5 APC is not supported
• Couchbase (http://www.couchbase.com/develop/php/current)
• Memcache (http://php.net/manual/en/book.memcache.php)
• Redis (http://redis.io/clients)

If you are not sure which driver to use, we suggest Memcache.

Based on the selected driver, you'll have to pass different options to the constructor.

Requirements

The default bridged library is Memory by Jamm (https://github.com/jamm/Memory). It is required that you add this library to the ClassLoader :

    \Webiny\Components\ClassLoader::getInstance()->registerMap(['Jamm\Memory' => 'path to memory lib']);

For example:

    // APC
    $cache = \Webiny\Component\Cache\Cache::APC('cache-id');

    // Couchbase
    $cache = \Webiny\Component\Cache\Cache::Couchbase('CacheService', 'username', 'password', 'bucket', '127.0.0.1:8091');

    // Memcache
    $cache = \Webiny\Component\Cache\Cache::Memcache('CacheService', 'localhost', 11211);

    // Redis
    $cache = \Webiny\Component\Cache\Cache::Redis('CacheService', 'localhost', 6379);

Common operations

Once you have created your Cache instance, you can start using your cache. The cache methods are the same, no matter which driver you use:

    // write to cache
    $cache->save('myKey', 'some value', 600, ['tag1', 'tag2']);

    // read from cache
    $cache->read('myKey');

    // delete from cache
    $cache->delete('myKey');

    // delete by tag
    $cache->deleteByTag(['tag1']);

Cache config

The preferred way of defining cache drivers is creating them inside your the config file of your application.

    Cache:
      TestCache:
        Factory: "\Webiny\Component\Cache\Cache"
        Method: "Apc"
      SomeOtherCache:
          Factory: "\Webiny\Component\Cache\Cache"
          Method: "Memcache"
          Arguments: ['192.168.249.128', '11211']

See the ExampleConfig.yaml for additional details.

Under Cache you define the cache drivers by giving each of them a cache id and underneath you nest its config. The driver configuration depends on which driver you are using.

If you wish to turn off the cache, use the Null driver.

The Method parameter must be a valid callback function that will return an instance of CacheStorage.

The benefit of defining cache drivers in this way is that the drivers are initialized the second Webiny Framework is loaded. This enables you to access the cache by 'CacheTrait'.

    class MyClass
    {
        use \Webiny\Component\Cache\CacheTrait;

        public function myMethod(){
            $this->cache('Frontend')->read('cache_key');
        }
    }

Custom Cache driver

To implement you own custom cache driver you must first create a class that will implement \Webiny\Component\Cache\Bridge\CacheInterface. Once you have that class, create another class with a static function that will return an instance of CacheDriver.

    class CustomCacheDriver implements \Webiny\Component\Cache\Bridge\CacheInterface
    {
        // implement the interface methods

        // static method that will return the CacheDriver
        function getDriver($cacheId, $param1, $param2, array $options){
            $driver = new static($cacheId, $param1, $param2);

            return \Webiny\Component\Cache\CacheDriver($driver, $options);
        }
    }

Now just set your class and the static method as the Method inside your config and you can access the cache over the CacheTrait.

Resources

To run unit tests, you need to use the following command:

$ cd path/to/Webiny/Component/Cache/
$ composer.phar install
$ phpunit

Make sure that you also set your cache driver details in Tests/ExampleConfig.yaml.