* @link http://getkirby.com
* @copyright Bastian Allgeier
* @license MIT
*/
class Cache
{
/**
* stores all options for the driver
* @var array
*/
protected $options = [];
/**
* Set all parameters which are needed to connect to the cache storage
*
* @param array $options
*/
public function __construct(array $options = [])
{
$this->options = $options;
}
/**
* Write an item to the cache for a given number of minutes.
*
*
* // Put an item in the cache for 15 minutes
* Cache::set('value', 'my value', 15);
*
*
* @param string $key
* @param mixed $value
* @param int $minutes
* @return void
*/
public function set(string $key, $value, int $minutes = 0)
{
return null;
}
/**
* Adds the prefix to the key if given
*
* @param string $key
* @return string
*/
protected function key(string $key): string
{
if (empty($this->options['prefix']) === false) {
$key = $this->options['prefix'] . '/' . $key;
}
return $key;
}
/**
* Private method to retrieve the cache value
* This needs to be defined by the driver
*
* @param string $key
* @return mixed
*/
public function retrieve(string $key)
{
return null;
}
/**
* Get an item from the cache.
*
*
* // Get an item from the cache driver
* $value = Cache::get('value');
*
* // Return a default value if the requested item isn't cached
* $value = Cache::get('value', 'default value');
*
*
* @param string $key
* @param mixed $default
* @return mixed
*/
public function get(string $key, $default = null)
{
// get the Value
$value = $this->retrieve($key);
// check for a valid cache value
if (!is_a($value, 'Kirby\Cache\Value')) {
return $default;
}
// remove the item if it is expired
if (time() >= $value->expires()) {
$this->remove($key);
return $default;
}
// get the pure value
$cache = $value->value();
// return the cache value or the default
return $cache ?? $default;
}
/**
* Calculates the expiration timestamp
*
* @param int $minutes
* @return int
*/
protected function expiration(int $minutes = 0): int
{
// keep forever if minutes are not defined
if ($minutes === 0) {
$minutes = 2628000;
}
// calculate the time
return time() + ($minutes * 60);
}
/**
* Checks when an item in the cache expires
*
* @param string $key
* @return mixed
*/
public function expires(string $key)
{
// get the Value object
$value = $this->retrieve($key);
// check for a valid Value object
if (!is_a($value, 'Kirby\Cache\Value')) {
return false;
}
// return the expires timestamp
return $value->expires();
}
/**
* Checks if an item in the cache is expired
*
* @param string $key
* @return boolean
*/
public function expired(string $key): bool
{
return $this->expires($key) <= time();
}
/**
* Checks when the cache has been created
*
* @param string $key
* @return mixed
*/
public function created(string $key)
{
// get the Value object
$value = $this->retrieve($key);
// check for a valid Value object
if (!is_a($value, 'Kirby\Cache\Value')) {
return false;
}
// return the expires timestamp
return $value->created();
}
/**
* Alternate version for Cache::created($key)
*
* @param string $key
* @return mixed
*/
public function modified(string $key)
{
return static::created($key);
}
/**
* Returns Value object
*
* @param mixed $value The value, which should be cached
* @param int $minutes The number of minutes before expiration
* @return Value
*/
protected function value($value, int $minutes): Value
{
return new Value($value, $minutes);
}
/**
* Determine if an item exists in the cache.
*
* @param string $key
* @return boolean
*/
public function exists(string $key): bool
{
return !$this->expired($key);
}
/**
* Remove an item from the cache
*
* @param string $key
* @return boolean
*/
public function remove(string $key): bool
{
return true;
}
/**
* Flush the entire cache
*
* @return boolean
*/
public function flush(): bool
{
return true;
}
/**
* Returns all passed cache options
*
* @return array
*/
public function options(): array
{
return $this->options;
}
}