lithium\storage\Cache::key()

public static method

Generates one or multiple safe cache keys optionally adding a suffix with a hash over the provided data. The hash value is generated in an optimized way dependending on the type of data.

Simple usage (in this case noop):

Cache::key('default', 'post');
// returns `'post'`

Cache::key('default', ['posts', 'banners']);
// returns `['posts', 'banners']`

Cache::key('default', ['posts' => 'foo', 'banners' => 'bar]);
// returns `['posts' => 'foo', 'banners' => 'bar']`

Make a key safe to use with adapter (exact result depends on key constraints enforced by the selected adapter:

Cache::key('default', 'posts for Helgi Þorbjörnsson');
// returns `'posts_for_Helgi__orbj_rnsson_c7f8433a'`

Using additional scalar or non-scalar data to generate key:

Cache::key('default', 'post', 2);
// returns `'post:1ad5be0d'`

Cache::key('default', 'post', array(2, 'json'));
// returns `'post:723f0e19'`

Cache::key('default', ['posts', 'banners'], 'json');
// returns `['posts:6b072545', 'banners:6b072545']`

Cache::key('default', ['posts' => 'foo', 'banners' => 'bar'], 'json');
// returns `['posts:38ec40e5' => 'foo', 'banners:38ec40e5' => 'bar']`

Or with a resuable key generator function:

$posts[0] = ['id' => 1];
$posts[1] = ['id' => 2];

$key = function($data) { return 'post:' . $data['id']};

Cache::key('default', $key, $post[0]); // returns `'post:1'`
Cache::key('default', $key, $post[1]); // returns `'post:2'`

This example shows a key mutating generator function:

$base = 'post';
$key  = function($id) use (&base) { return $base .= ":{$id}"; };

Cache::key('default', $key, 1); // returns `'post:1'`
Cache::key('default', $key, 2); // returns `'post:1:2'`

Parameters

string $name
Configuration to be used for generating key/s.
mixed $key
String or an array of strings that will be used as the cache key/s. Also accepts associative arrays where the key part will be modified, but the value left untouched. Also accepts a key generator function that is passed $data and must return a string that will be used as the key.
mixed $data
Additional data to use when generating key. Can be any kind of type except a resource. The method will calculate a hash of the data and append that to the key/s. When $key is a function the data is passed to it instead.

Returns

string|array

The generated cache key/s.

Source

	public static function key($name, $key, $data = null) {
		$adapter = static::adapter($name);

		if (is_callable($key)) {
			return current($adapter->key([$key($data)]));
		}
		$keys = ($isMulti = is_array($key)) ? $key : [$key];
		$keys = ($hasData = !is_integer(key($keys))) ? array_keys($keys) : $keys;

		if ($data !== null) {
			$data = Hash::calculate($data, ['type' => 'crc32b']);
			$keys = array_map(function($key) use ($data) { return $key .= ":{$data}"; }, $keys);
		}
		$keys = $adapter->key($keys);
		$keys = $hasData ? array_combine($keys, array_values((array) $key)) : $keys;

		return $isMulti ? $keys : current($keys);
	}