file.md

File

Save the cache as file to on the filesystem.

You must pass a cache directory to the constructor.

use Desarrolla2\Cache\File as FileCache;

$cache = new FileCache(sys_get_temp_dir() . '/cache');

Options

name	type	default
ttl	int	null	Maximum time to live in seconds
ttl-strategy	string ('embed', 'file', 'mtime')	"embed"	Strategy to store the TTL
prefix	string	""	Key prefix
filename	string or callable	"%s.php.cache"	Filename as sprintf format

TTL strategy option

The ttl strategy determines how the TTL is stored. Typical filesystems don't allow custom file properties, so we'll have to use one of these strategies:

strategy
embed	Embed the TTL as first line of the file
file	Create a TTL file in addition to the cache file
mtime	Use mtime + max ttl

The 'mtime' strategy is not PSR-16 compliant, as the TTL passed to the set() method is ignored. Only the ttl option for is used on get() and has().

Filename option

The filename will be parsed using sprintf where '%s' is substituted with the key. The default extension is automatically determined based on the packer.

Instead of a string, filename may also be set to a callable, like a callable object or closure. In that case the callable will be called to create a filename as

$filename = $callable($key);

BasicFilename

The library comes with invokable object as callable for the filename. The BasicFilename object works as described above.

TrieFilename

The TrieFilename object will create a prefix tree directory structure. This is useful where a lot of cache files would cause to many files in a directory.

Specify the sprintf format and the directory level to the constructor when creating a TrieFilename object.

use Desarrolla2\Cache\File as FileCache;
use Desarrolla2\Cache\File\TrieFilename;

$callback = new TrieFilename('%s.php.cache', 2);

$cache = (new FileCache(sys_get_temp_dir() . '/cache'))
    ->withOption('filename', $callback);

In this case, adding an item with key foobar would be create a file at

/tmp/cache/f/fo/foobar.php.cache

Packer

By default the SerializePacker is used. The NopPacker can be used if the values are strings. Other packers, like the JsonPacker are also useful with file cache.