driver: break up cache drivers

inc/Data/Driver/ArrayCacheDriver.php

@@ -0,0 +1,28 @@
+<?php
+namespace Vichan\Data\Driver;
+
+defined('TINYBOARD') or exit;
+
+
+/**
+ * A simple process-wide PHP array.
+ */
+class ArrayCacheDriver implements CacheDriver {
+	private static array $inner = [];
+
+	public function get(string $key): mixed {
+		return isset(self::$inner[$key]) ? self::$inner[$key] : null;
+	}
+
+	public function set(string $key, mixed $value, mixed $expires = false): void {
+		self::$inner[$key] = $value;
+	}
+
+	public function delete(string $key): void {
+		unset(self::$inner[$key]);
+	}
+
+	public function flush(): void {
+		self::$inner = [];
+	}
+}