add perfomance chapters

implementation/18-caching/src/Middleware/Cache.php

@@ -0,0 +1,38 @@
+<?php declare(strict_types=1);
+
+namespace Lubian\NoFramework\Middleware;
+
+use Laminas\Diactoros\Response\Serializer;
+use Lubian\NoFramework\Service\Cache\EasyCache;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+use function assert;
+use function base64_encode;
+use function is_string;
+
+final class Cache implements MiddlewareInterface
+{
+    public function __construct(
+        private readonly EasyCache $cache,
+        private readonly Serializer $serializer,
+    ) {
+    }
+
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        if ($request->getMethod() !== 'GET') {
+            return $handler->handle($request);
+        }
+        $keyHash = base64_encode($request->getUri()->getPath());
+        $result = $this->cache->get(
+            $keyHash,
+            fn () => $this->serializer::toString($handler->handle($request)),
+            300
+        );
+        assert(is_string($result));
+        return $this->serializer::fromString($result);
+    }
+}