HttpCache::validateCache() - Code Metrics - Inspection of "Porting http cache" - yiisoft/yii-web - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#199)

by Rustam

created 2020-01-01 18:47 UTC

HttpCache::validateCache() A

↳ Parent: HttpCache

Complexity

Conditions	5
Paths	5

Size

Total Lines	12
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	0	Features	0

Metric	Value
cc	5
eloc	6
c	2
b	0
f	0
nc	5
nop	3
dl	0
loc	12
rs	9.6111

<?php
namespace Yiisoft\Yii\Web\Middleware;

use Psr\Http\Message\ResponseFactoryInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;
use Psr\Log\LoggerInterface;
use Yiisoft\Router\Method;
use Yiisoft\Yii\Web\Session\SessionInterface;
use function in_array;
use function preg_split;
use function reset;
use function str_replace;

/**
 * HttpCache implements client-side caching by utilizing the `Last-Modified` and `ETag` HTTP headers.
 */
final class HttpCache implements MiddlewareInterface
{
    private const DEFAULT_HEADER = 'public, max-age=3600';
    /**
     * @internal Frozen session data
     */
    private ?array $sessionData;

    /**
     * @var callable a PHP callback that returns the UNIX timestamp of the last modification time.
     * The callback's signature should be:
     *
     * ```php
     * function ($request, $params)
     * ```
     *
     * where `$request` is the [[ServerRequestInterface]] object that this filter is currently handling;
     * `$params` takes the value of [[params]]. The callback should return a UNIX timestamp.
     *
     * @see http://tools.ietf.org/html/rfc7232#section-2.2
     */
    private $lastModified;

    /**
     * @var callable a PHP callback that generates the ETag seed string.
     * The callback's signature should be:
     *
     * ```php
     * function ($request, $params)
     * ```
     *
     * where `$request` is the [[ServerRequestInterface]] object that this filter is currently handling;
     * `$params` takes the value of [[params]]. The callback should return a string serving
     * as the seed for generating an ETag.
     */
    private $etagSeed;

    /**
     * @var bool whether to generate weak ETags.
     *
     * Weak ETags should be used if the content should be considered semantically equivalent, but not byte-equal.
     *
     * @see http://tools.ietf.org/html/rfc7232#section-2.3
     */
    private bool $weakEtag = false;

    /**
     * @var mixed additional parameters that should be passed to the [[lastModified]] and [[etagSeed]] callbacks.
     */
    private $params;

    /**
     * @var string the value of the `Cache-Control` HTTP header. If null, the header will not be sent.
     * @see http://tools.ietf.org/html/rfc2616#section-14.9
     */
    private ?string $cacheControlHeader = self::DEFAULT_HEADER;

    /**
     * @var string the name of the cache limiter to be set when [session_cache_limiter()](https://secure.php.net/manual/en/function.session-cache-limiter.php)
     * is called. The default value is an empty string, meaning turning off automatic sending of cache headers entirely.
     * You may set this property to be `public`, `private`, `private_no_expire`, and `nocache`.
     * Please refer to [session_cache_limiter()](https://secure.php.net/manual/en/function.session-cache-limiter.php)
     * for detailed explanation of these values.
     *
     * If this property is `null`, then `session_cache_limiter()` will not be called. As a result,
     * PHP will send headers according to the `session.cache_limiter` PHP ini setting.
     */
    private ?string $sessionCacheLimiter = '';

    /**
     * @var bool a value indicating whether this filter should be enabled.
     */
    private bool $enabled = true;

    private ResponseFactoryInterface $responseFactory;
    private SessionInterface $session;
    private LoggerInterface $logger;

    public function __construct(ResponseFactoryInterface $responseFactory, SessionInterface $session, LoggerInterface $logger)
    {
        $this->responseFactory = $responseFactory;
        $this->session = $session;
        $this->logger = $logger;
    }

    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        if (!$this->enabled) {
            return $handler->handle($request);
        }

        $method = $request->getMethod();
        if (!in_array($method, [Method::GET, Method::HEAD]) || $this->lastModified === null && $this->etagSeed === null) {
            return $handler->handle($request);
        }

        $lastModified = $etag = null;
        if ($this->lastModified !== null) {
            $lastModified = call_user_func($this->lastModified, $request, $this->params);
        }
        if ($this->etagSeed !== null) {
            $seed = call_user_func($this->etagSeed, $request, $this->params);
            if ($seed !== null) {
                $etag = $this->generateEtag($seed);
            }
        }

        $this->sendCacheControlHeader($request);

        $response = $handler->handle($request);
        if ($this->cacheControlHeader !== null) {
            $response = $response->withHeader('Cache-Control', $this->cacheControlHeader);
        }
        if ($etag !== null) {
            $response = $response->withHeader('Etag', $etag);
        }

        $cacheValid = $this->validateCache($request, $lastModified, $etag);
        // https://tools.ietf.org/html/rfc7232#section-4.1
        if ($lastModified !== null && (!$cacheValid || ($cacheValid && $etag === null))) {
            $response = $response->withHeader('Last-Modified', gmdate('D, d M Y H:i:s', $lastModified) . ' GMT');
        }
        if ($cacheValid) {
            $response = $this->responseFactory->createResponse(304);
            $response->getBody()->write('Not Modified');
            return $response;
        }
        return $response;
    }

    /**
     * Validates if the HTTP cache contains valid content.
     * If both Last-Modified and ETag are null, returns false.
     * @param ServerRequestInterface $request
     * @param int $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
     * If null, the Last-Modified header will not be validated.
     * @param string $etag the calculated ETag value. If null, the ETag header will not be validated.
     * @return bool whether the HTTP cache is still valid.
     */
    private function validateCache(ServerRequestInterface $request, $lastModified, $etag)
    {
        if ($request->hasHeader('If-None-Match')) {
            // HTTP_IF_NONE_MATCH takes precedence over HTTP_IF_MODIFIED_SINCE
            // http://tools.ietf.org/html/rfc7232#section-3.3
            return $etag !== null && in_array($etag, $this->getETags($request), true);
        } elseif ($request->hasHeader('If-Modified-Since')) {
            $header = reset($request->getHeader('If-Modified-Since'));
            return $lastModified !== null && @strtotime($header) >= $lastModified;
        }

        return false;
    }

    /**
     * Sends the cache control header to the client.
     * @param ServerRequestInterface $request
     * @see cacheControlHeader
     */
    private function sendCacheControlHeader(ServerRequestInterface $request): void
    {
        if ($this->sessionCacheLimiter !== null) {
            if ($this->sessionCacheLimiter === '' && !headers_sent() && $this->session->isActive()) {
                header_remove('Expires');
                header_remove('Cache-Control');
                header_remove('Last-Modified');
                header_remove('Pragma');
            }

            $this->setCacheLimiter();
        }
    }

    /**
     * Generates an ETag from the given seed string.
     * @param string $seed Seed for the ETag
     * @return string the generated ETag
     */
    private function generateEtag($seed): string
    {
        $etag = '"' . rtrim(base64_encode(sha1($seed, true)), '=') . '"';
        return $this->weakEtag ? 'W/' . $etag : $etag;
    }

    /**
     * Gets the Etags.
     *
     * @param ServerRequestInterface $request
     * @return array The entity tags
     */
    private function getETags(ServerRequestInterface $request): array
    {
        if ($request->hasHeader('If-None-Match')) {
            $header = reset($request->getHeader('If-None-Match'));
            return preg_split('/[\s,]+/', str_replace('-gzip', '', $header), -1, PREG_SPLIT_NO_EMPTY) ?? [];

        }

        return [];
    }

    private function setCacheLimiter()
    {
        if ($this->session->isActive()) {
            if (isset($_SESSION)) {
                $this->sessionData = $_SESSION;
            }
            $this->session->close();
        }

        session_cache_limiter($this->sessionCacheLimiter);

        if (null !== $this->sessionData) {
            $this->session->open();

            $_SESSION = $this->sessionData;
            $this->sessionData = null;
        }
    }

    public function setLastModified(callable $lastModified): void
    {
        $this->lastModified = $lastModified;
    }

    public function setEtagSeed(callable $etagSeed): void
    {
        $this->etagSeed = $etagSeed;
    }

    public function setWeakTag(bool $weakTag): void
    {
        $this->weakEtag = $weakTag;
    }

    public function setParams($params): void
    {
        $this->params = $params;
    }

    public function setCacheControlHeader(?string $header): void
    {
        $this->cacheControlHeader = $header;
    }

    public function setSessionCacheLimiter(?string $cacheLimiter): void
    {
        $this->sessionCacheLimiter = $cacheLimiter;
    }

    public function setEnabled(bool $enabled): void
    {
        $this->enabled = $enabled;
    }
}


1			<?php
2			namespace Yiisoft\Yii\Web\Middleware;
3
4			use Psr\Http\Message\ResponseFactoryInterface;
5			use Psr\Http\Message\ResponseInterface;
6			use Psr\Http\Message\ServerRequestInterface;
7			use Psr\Http\Server\MiddlewareInterface;
8			use Psr\Http\Server\RequestHandlerInterface;
9			use Psr\Log\LoggerInterface;
10			use Yiisoft\Router\Method;
11			use Yiisoft\Yii\Web\Session\SessionInterface;
12			use function in_array;
13			use function preg_split;
14			use function reset;
15			use function str_replace;
16
17			/**
18			* HttpCache implements client-side caching by utilizing the `Last-Modified` and `ETag` HTTP headers.
19			*/
20			final class HttpCache implements MiddlewareInterface
21			{
22			private const DEFAULT_HEADER = 'public, max-age=3600';
23			/**
24			* @internal Frozen session data
25			*/
26			private ?array $sessionData;
27
28			/**
29			* @var callable a PHP callback that returns the UNIX timestamp of the last modification time.
30			* The callback's signature should be:
31			*
32			* ```php
33			* function ($request, $params)
34			* ```
35			*
36			* where `$request` is the [[ServerRequestInterface]] object that this filter is currently handling;
37			* `$params` takes the value of [[params]]. The callback should return a UNIX timestamp.
38			*
39			* @see http://tools.ietf.org/html/rfc7232#section-2.2
40			*/
41			private $lastModified;
42
43			/**
44			* @var callable a PHP callback that generates the ETag seed string.
45			* The callback's signature should be:
46			*
47			* ```php
48			* function ($request, $params)
49			* ```
50			*
51			* where `$request` is the [[ServerRequestInterface]] object that this filter is currently handling;
52			* `$params` takes the value of [[params]]. The callback should return a string serving
53			* as the seed for generating an ETag.
54			*/
55			private $etagSeed;
56
57			/**
58			* @var bool whether to generate weak ETags.
59			*
60			* Weak ETags should be used if the content should be considered semantically equivalent, but not byte-equal.
61			*
62			* @see http://tools.ietf.org/html/rfc7232#section-2.3
63			*/
64			private bool $weakEtag = false;
65
66			/**
67			* @var mixed additional parameters that should be passed to the [[lastModified]] and [[etagSeed]] callbacks.
68			*/
69			private $params;
70
71			/**
72			* @var string the value of the `Cache-Control` HTTP header. If null, the header will not be sent.
73			* @see http://tools.ietf.org/html/rfc2616#section-14.9
74			*/
75			private ?string $cacheControlHeader = self::DEFAULT_HEADER;
76
77			/**
78			* @var string the name of the cache limiter to be set when [session_cache_limiter()](https://secure.php.net/manual/en/function.session-cache-limiter.php)
79			* is called. The default value is an empty string, meaning turning off automatic sending of cache headers entirely.
80			* You may set this property to be `public`, `private`, `private_no_expire`, and `nocache`.
81			* Please refer to [session_cache_limiter()](https://secure.php.net/manual/en/function.session-cache-limiter.php)
82			* for detailed explanation of these values.
83			*
84			* If this property is `null`, then `session_cache_limiter()` will not be called. As a result,
85			* PHP will send headers according to the `session.cache_limiter` PHP ini setting.
86			*/
87			private ?string $sessionCacheLimiter = '';
88
89			/**
90			* @var bool a value indicating whether this filter should be enabled.
91			*/
92			private bool $enabled = true;
93
94			private ResponseFactoryInterface $responseFactory;
95			private SessionInterface $session;
96			private LoggerInterface $logger;
97
98			public function __construct(ResponseFactoryInterface $responseFactory, SessionInterface $session, LoggerInterface $logger)
99			{
100			$this->responseFactory = $responseFactory;
101			$this->session = $session;
102			$this->logger = $logger;
103			}
104
105			public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
106			{
107			if (!$this->enabled) {
108			return $handler->handle($request);
109			}
110
111			$method = $request->getMethod();
112			if (!in_array($method, [Method::GET, Method::HEAD]) \|\| $this->lastModified === null && $this->etagSeed === null) {
113			return $handler->handle($request);
114			}
115
116			$lastModified = $etag = null;
117			if ($this->lastModified !== null) {
118			$lastModified = call_user_func($this->lastModified, $request, $this->params);
119			}
120			if ($this->etagSeed !== null) {
121			$seed = call_user_func($this->etagSeed, $request, $this->params);
122			if ($seed !== null) {
123			$etag = $this->generateEtag($seed);
124			}
125			}
126
127			$this->sendCacheControlHeader($request);
128
129			$response = $handler->handle($request);
130			if ($this->cacheControlHeader !== null) {
131			$response = $response->withHeader('Cache-Control', $this->cacheControlHeader);
132			}
133			if ($etag !== null) {
134			$response = $response->withHeader('Etag', $etag);
135			}
136
137			$cacheValid = $this->validateCache($request, $lastModified, $etag);
138			// https://tools.ietf.org/html/rfc7232#section-4.1
139			if ($lastModified !== null && (!$cacheValid \|\| ($cacheValid && $etag === null))) {
140			$response = $response->withHeader('Last-Modified', gmdate('D, d M Y H:i:s', $lastModified) . ' GMT');
141			}
142			if ($cacheValid) {
143			$response = $this->responseFactory->createResponse(304);
144			$response->getBody()->write('Not Modified');
145			return $response;
146			}
147			return $response;
148			}
149
150			/**
151			* Validates if the HTTP cache contains valid content.
152			* If both Last-Modified and ETag are null, returns false.
153			* @param ServerRequestInterface $request
154			* @param int $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
155			* If null, the Last-Modified header will not be validated.
156			* @param string $etag the calculated ETag value. If null, the ETag header will not be validated.
157			* @return bool whether the HTTP cache is still valid.
158			*/
159			private function validateCache(ServerRequestInterface $request, $lastModified, $etag)
160			{
161			if ($request->hasHeader('If-None-Match')) {
162			// HTTP_IF_NONE_MATCH takes precedence over HTTP_IF_MODIFIED_SINCE
163			// http://tools.ietf.org/html/rfc7232#section-3.3
164			return $etag !== null && in_array($etag, $this->getETags($request), true);
165			} elseif ($request->hasHeader('If-Modified-Since')) {
166			$header = reset($request->getHeader('If-Modified-Since'));
167			return $lastModified !== null && @strtotime($header) >= $lastModified;
168			}
169
170			return false;
171			}
172
173			/**
174			* Sends the cache control header to the client.
175			* @param ServerRequestInterface $request
176			* @see cacheControlHeader
177			*/
178			private function sendCacheControlHeader(ServerRequestInterface $request): void
179			{
180			if ($this->sessionCacheLimiter !== null) {
181			if ($this->sessionCacheLimiter === '' && !headers_sent() && $this->session->isActive()) {
182			header_remove('Expires');
183			header_remove('Cache-Control');
184			header_remove('Last-Modified');
185			header_remove('Pragma');
186			}
187
188			$this->setCacheLimiter();
189			}
190			}
191
192			/**
193			* Generates an ETag from the given seed string.
194			* @param string $seed Seed for the ETag
195			* @return string the generated ETag
196			*/
197			private function generateEtag($seed): string
198			{
199			$etag = '"' . rtrim(base64_encode(sha1($seed, true)), '=') . '"';
200			return $this->weakEtag ? 'W/' . $etag : $etag;
201			}
202
203			/**
204			* Gets the Etags.
205			*
206			* @param ServerRequestInterface $request
207			* @return array The entity tags
208			*/
209			private function getETags(ServerRequestInterface $request): array
210			{
211			if ($request->hasHeader('If-None-Match')) {
212			$header = reset($request->getHeader('If-None-Match'));
213			return preg_split('/[\s,]+/', str_replace('-gzip', '', $header), -1, PREG_SPLIT_NO_EMPTY) ?? [];
			0 ignored issues – show Bug Best Practice introduced 2020-01-01 18:49 UTC by Report Bug Copy Issue Report The expression `return preg_split('/[\s,...IT_NO_EMPTY) ?? array()` could return the type `false` which is incompatible with the type-hinted return `array`. Consider adding an additional type-check to rule them out. Loading history...
214			}
215
216			return [];
217			}
218
219			private function setCacheLimiter()
220			{
221			if ($this->session->isActive()) {
222			if (isset($_SESSION)) {
223			$this->sessionData = $_SESSION;
224			}
225			$this->session->close();
226			}
227
228			session_cache_limiter($this->sessionCacheLimiter);
229
230			if (null !== $this->sessionData) {
231			$this->session->open();
232
233			$_SESSION = $this->sessionData;
234			$this->sessionData = null;
235			}
236			}
237
238			public function setLastModified(callable $lastModified): void
239			{
240			$this->lastModified = $lastModified;
241			}
242
243			public function setEtagSeed(callable $etagSeed): void
244			{
245			$this->etagSeed = $etagSeed;
246			}
247
248			public function setWeakTag(bool $weakTag): void
249			{
250			$this->weakEtag = $weakTag;
251			}
252
253			public function setParams($params): void
254			{
255			$this->params = $params;
256			}
257
258			public function setCacheControlHeader(?string $header): void
259			{
260			$this->cacheControlHeader = $header;
261			}
262
263			public function setSessionCacheLimiter(?string $cacheLimiter): void
264			{
265			$this->sessionCacheLimiter = $cacheLimiter;
266			}
267
268			public function setEnabled(bool $enabled): void
269			{
270			$this->enabled = $enabled;
271			}
272			}
273

yiisoft / yii-web

Pull Request — master (#199)

HttpCache::validateCache() A

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

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