This backend uses the following types of cache keys:
- tag_xxx
xxx is tag name, value is array of associated identifiers identifier. This
is "forward" tag index. It is mainly used for obtaining content by tag
(get identifier by tag -> get content by identifier)
- ident_xxx
xxx is identifier, value is array of associated tags. This is "reverse" tag
index. It provides quick access for all tags associated with this identifier
and used when removing the identifier
- tagIndex
Value is a List of all tags (array)
Each key is prepended with a prefix. By default prefix consists from two parts
separated by underscore character and ends in yet another underscore character:
- "Flow"
- MD5 of script path and filename and SAPI name
This prefix makes sure that keys from the different installations do not
conflict.
Note: When using the Memcache backend to store values of more than ~1 MB, the
data will be split into chunks to make them fit into the caches limits.
/**
* Sets up the memcached backend used for testing
*
* @param array $backendOptions Options for the memcache backend
* @return MemcachedBackend
*/
protected function setUpBackend(array $backendOptions = [])
{
$cache = $this->createMock(FrontendInterface::class, [], [], '', false);
if ($backendOptions == []) {
$backendOptions = ['servers' => ['localhost:11211']];
}
$backend = new MemcachedBackend($this->getEnvironmentConfiguration(), $backendOptions);
$backend->setCache($cache);
return $backend;
}
/**
* Constructs this backend
*
* @param ApplicationContext $context Flow's application context
* @param array $options Configuration options - depends on the actual backend
*/
public function __construct(ApplicationContext $context, array $options = [])
{
$this->context = $context;
$environmentConfiguration = $this->createEnvironmentConfiguration($context);
parent::__construct($environmentConfiguration, $options);
}