Caching Pdp classes using the filesystem

FilesystemCache.php

<?php

declare(strict_types=1);

use Pdp\Storage\PublicSuffixListCache;
use Pdp\PublicSuffixList;

final class FilesystemCache implements PublicSuffixListCache
{
    public function __construct(
        private DateInterval $ttl,
        private string $cacheDirectory,
        private string $cachePrefix = ''
    ) {
    }

    private function getCacheFilePath(string $uri): string
    {
        return $this->cacheDirectory.DIRECTORY_SEPARATOR.$this->cachePrefix.sha1($uri).'.php';
    }

    public function fetch(string $uri): ?PublicSuffixList
    {
        $path = $this->getCacheFilePath($uri);
        if (!is_readable($path)) {
            return null;
        }

        $fileValidUntil = (new DateTimeImmutable('@'.filemtime($path)))->add($this->ttl);
        $now = new DateTimeImmutable('NOW', new DateTimeZone('UTC'));
        if ($fileValidUntil < $now) {
            $this->forget($uri);

            return null;
        }

        $rules = require $path;
        if (!$rules instanceof PublicSuffixList) {
            $this->forget($uri);

            return null;
        }

        return $rules;
    }

    public function remember(string $uri, PublicSuffixList $publicSuffixList): bool
    {
        $path = $this->getCacheFilePath($uri);
        $data = '<?php' . PHP_EOL . 'return '. var_export($publicSuffixList, true) . ';';
        $result = false !== file_put_contents($path, $data);
        if ($result && function_exists('opcache_invalidate')) {
            opcache_invalidate($path);
        }

        return $result;
    }

    public function forget(string $uri): bool
    {
        return @unlink($this->getCacheFilePath($uri));
    }
}

PHPStreamClient.php

<?php

declare(strict_types=1);

use Pdp\PublicSuffixList;
use Pdp\Rules;
use Pdp\Storage\PublicSuffixListClient;

final class PHPStreamClient implements PublicSuffixListClient
{
    /**
     * @param resource|null $context
     */
    public function __construct(private $context = null)
    {
    }

    public function get(string $uri): PublicSuffixList
    {
        return Rules::fromPath($uri, $this->context);
    }
}

test.php

<?php

require 'vendor/autoload.php';
require 'PublicSuffixListOpCache.php';
require 'PublicSuffixListStreamClient.php';

use Pdp\Storage\RulesStorage;
use Pdp\ResourceUri;

$pslStorage = new RulesStorage(
  new FilesystemCache(new DateInterval('P1D'), __DIR__.'/storage', 'psl'),
  new PHPStreamClient()
);

$rules = $pslStorage->get(ResourceUri::PUBLIC_SUFFIX_LIST_URI);
echo $rules->getCookieDomain('ulb.ac.be')->value(), PHP_EOL;