A super simple PHP file based cache for any data type or structure

cache.php

<?php

/*
 * A super simple PHP file based cache for any data type or structure
 *
 * Released with the karmaware tag - https://pete-rai.github.io/karmaware
 *
 * Website  : http://www.rai.org.uk
 * GitHub   : https://github.com/pete-rai
 * LinkedIn : https://uk.linkedin.com/in/raipete
 * NPM      : https://www.npmjs.com/~peterai
 *
 */

class Cache
{
    protected static $dir = './cache/';  // with the trailing slash
    protected static $ext = '.txt';      // with leading dot

    protected static function file ($tags)
    {
        return self::$dir.implode ('-', is_array ($tags) ? $tags : [$tags]).self::$ext;
    }

    public static function has ($tags)
    {
        return file_exists (self::file ($tags));
    }

    public static function lacking ($tags)
    {
        return !self::has ($tags);
    }

    public static function get ($tags)
    {
        return unserialize (file_get_contents (self::file ($tags)));
    }

    public static function put ($tags, $data)
    {
        file_put_contents (self::file ($tags), serialize ($data));
    }

    public static function clear ($tags)
    {
        if (self::has ($tags)) unlink (self::file ($tags));
    }

    public static function flush ()
    {
        array_map ('unlink', glob (self::file ('*')));
    }
}

/*

// --- test code only - leave commented out once working

// you can store any type of data: simple data types, arrays, objects, etc

$data1 =  "test string";
$data2 = ["test array item 1", "test array item 2", "test array item 3"];

// you use tags to build up the cache filename

$tags1 =  "foo";          // ./cache/foo.txt
$tags2 = ["foo", "bar"];  // ./cache/foo-bar.txt

// helper function to show boolean output

function show ($bool) { echo ($bool ? 'T' : 'F')."\n"; }

// start tests

Cache::flush ();  // deletes all existing cache files

// first test

show (Cache::has     ($tags1));   // will give F
show (Cache::lacking ($tags1));   // will give T

Cache::put ($tags1, $data1);  // makes the cache file

show (Cache::has     ($tags1));  // will give T
show (Cache::lacking ($tags1));  // will give F

var_dump (Cache::get ($tags1));                   // will give $data1

Cache::clear ($tags1);  // deletes the cache file

show (Cache::has     ($tags1));   // will give F
show (Cache::lacking ($tags1));   // will give T

// second test

show (Cache::has     ($tags2));   // will give F
show (Cache::lacking ($tags2));   // will give T

Cache::put ($tags2, $data2);  // makes the cache file

show (Cache::has     ($tags2));  // will give T
show (Cache::lacking ($tags2));  // will give F

var_dump (Cache::get ($tags2));                   // will give $data2

Cache::clear ($tags2);  // deletes the cache file

show (Cache::has     ($tags2));   // will give F
show (Cache::lacking ($tags2));   // will give T

// end tests

Cache::flush ();  // deletes all existing cache files

*/

If you need a cache which supports automatic file expiry, take a look at my other PHP cache gist here