HttpCache::setCacheLimiter() - 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 19:20 UTC

HttpCache::setCacheLimiter() A

↳ Parent: HttpCache

Complexity

Conditions	4
Paths	6

Size

Total Lines	16
Code Lines	9

Duplication

Lines	0
Ratio	0 %

Importance

Changes	3
Bugs	0	Features	0

Metric	Value
cc	4
eloc	9
c	3
b	0
f	0
nc	6
nop	0
dl	0
loc	16
rs	9.9666

<?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')) {
            $header = str_replace('-gzip', '', reset($request->getHeader('If-None-Match')));
            return preg_split('/[\s,]+/', $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(
99			ResponseFactoryInterface $responseFactory,
100			SessionInterface $session,
101			LoggerInterface $logger
102			) {
103			$this->responseFactory = $responseFactory;
104			$this->session = $session;
105			$this->logger = $logger;
106			}
107
108			public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
109			{
110			if (!$this->enabled) {
111			return $handler->handle($request);
112			}
113
114			$method = $request->getMethod();
115			if (
116			!in_array($method, [Method::GET, Method::HEAD])
117			\|\| $this->lastModified === null
118			&& $this->etagSeed === null
119			) {
120			return $handler->handle($request);
121			}
122
123			$lastModified = $etag = null;
124			if ($this->lastModified !== null) {
125			$lastModified = call_user_func($this->lastModified, $request, $this->params);
126			}
127			if ($this->etagSeed !== null) {
128			$seed = call_user_func($this->etagSeed, $request, $this->params);
129			if ($seed !== null) {
130			$etag = $this->generateEtag($seed);
131			}
132			}
133
134			$this->sendCacheControlHeader($request);
135
136			$response = $handler->handle($request);
137			if ($this->cacheControlHeader !== null) {
138			$response = $response->withHeader('Cache-Control', $this->cacheControlHeader);
139			}
140			if ($etag !== null) {
141			$response = $response->withHeader('Etag', $etag);
142			}
143
144			$cacheValid = $this->validateCache($request, $lastModified, $etag);
145			// https://tools.ietf.org/html/rfc7232#section-4.1
146			if ($lastModified !== null && (!$cacheValid \|\| ($cacheValid && $etag === null))) {
147			$response = $response->withHeader(
148			'Last-Modified',
149			gmdate('D, d M Y H:i:s', $lastModified) . ' GMT'
150			);
151			}
152			if ($cacheValid) {
153			$response = $this->responseFactory->createResponse(304);
154			$response->getBody()->write('Not Modified');
155			return $response;
156			}
157			return $response;
158			}
159
160			/**
161			* Validates if the HTTP cache contains valid content.
162			* If both Last-Modified and ETag are null, returns false.
163			* @param ServerRequestInterface $request
164			* @param int $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
165			* If null, the Last-Modified header will not be validated.
166			* @param string $etag the calculated ETag value. If null, the ETag header will not be validated.
167			* @return bool whether the HTTP cache is still valid.
168			*/
169			private function validateCache(ServerRequestInterface $request, $lastModified, $etag)
170			{
171			if ($request->hasHeader('If-None-Match')) {
172			// HTTP_IF_NONE_MATCH takes precedence over HTTP_IF_MODIFIED_SINCE
173			// http://tools.ietf.org/html/rfc7232#section-3.3
174			return $etag !== null && in_array($etag, $this->getETags($request), true);
175			} elseif ($request->hasHeader('If-Modified-Since')) {
176			$header = reset($request->getHeader('If-Modified-Since'));
177			return $lastModified !== null && @strtotime($header) >= $lastModified;
178			}
179
180			return false;
181			}
182
183			/**
184			* Sends the cache control header to the client.
185			* @param ServerRequestInterface $request
186			* @see cacheControlHeader
187			*/
188			private function sendCacheControlHeader(ServerRequestInterface $request): void
189			{
190			if ($this->sessionCacheLimiter !== null) {
191			if ($this->sessionCacheLimiter === '' && !headers_sent() && $this->session->isActive()) {
192			header_remove('Expires');
193			header_remove('Cache-Control');
194			header_remove('Last-Modified');
195			header_remove('Pragma');
196			}
197
198			$this->setCacheLimiter();
199			}
200			}
201
202			/**
203			* Generates an ETag from the given seed string.
204			* @param string $seed Seed for the ETag
205			* @return string the generated ETag
206			*/
207			private function generateEtag($seed): string
208			{
209			$etag = '"' . rtrim(base64_encode(sha1($seed, true)), '=') . '"';
210			return $this->weakEtag ? 'W/' . $etag : $etag;
211			}
212
213			/**
214			* Gets the Etags.
215			*
216			* @param ServerRequestInterface $request
217			* @return array The entity tags
218			*/
219			private function getETags(ServerRequestInterface $request): array
220			{
221			if ($request->hasHeader('If-None-Match')) {
222			$header = str_replace('-gzip', '', reset($request->getHeader('If-None-Match')));
223			return preg_split('/[\s,]+/', $header, -1, PREG_SPLIT_NO_EMPTY) ?: [];
224			}
225
226			return [];
227			}
228
229			private function setCacheLimiter()
230			{
231			if ($this->session->isActive()) {
232			if (isset($_SESSION)) {
233			$this->sessionData = $_SESSION;
234			}
235			$this->session->close();
236			}
237
238			session_cache_limiter($this->sessionCacheLimiter);
239
240			if (null !== $this->sessionData) {
241			$this->session->open();
242
243			$_SESSION = $this->sessionData;
244			$this->sessionData = null;
245			}
246			}
247
248			public function setLastModified(callable $lastModified): void
249			{
250			$this->lastModified = $lastModified;
251			}
252
253			public function setEtagSeed(callable $etagSeed): void
254			{
255			$this->etagSeed = $etagSeed;
256			}
257
258			public function setWeakTag(bool $weakTag): void
259			{
260			$this->weakEtag = $weakTag;
261			}
262
263			public function setParams($params): void
264			{
265			$this->params = $params;
266			}
267
268			public function setCacheControlHeader(?string $header): void
269			{
270			$this->cacheControlHeader = $header;
271			}
272
273			public function setSessionCacheLimiter(?string $cacheLimiter): void
274			{
275			$this->sessionCacheLimiter = $cacheLimiter;
276			}
277
278			public function setEnabled(bool $enabled): void
279			{
280			$this->enabled = $enabled;
281			}
282			}
283

yiisoft / yii-web

Pull Request — master (#199)

HttpCache::setCacheLimiter() A

Complexity

Size

Duplication

Importance

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