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 2020-01-02 12:36 UTC

HttpCache::validateCache() A

↳ Parent: HttpCache

Complexity

Conditions	5
Paths	5

Size

Total Lines	15
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Importance

Changes	3
Bugs	0	Features	0

Metric	Value
cc	5
eloc	7
c	3
b	0
f	0
nc	5
nop	3
dl	0
loc	15
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;

/**
 * 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;

    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
    {
        $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);
            }
        }

        $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, $etag): bool
    {
        if ($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);
        }

        if ($request->hasHeader('If-Modified-Since')) {
            $headers = $request->getHeader('If-Modified-Since');
            $header = \reset($headers);
            return $lastModified !== null && @strtotime($header) >= $lastModified;
        }

        return false;
    }

    /**
     * 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')) {
            $headers = $request->getHeader('If-None-Match');
            $header = \str_replace('-gzip', '', \reset($headers));
            return \preg_split('/[\s,]+/', $header, -1, PREG_SPLIT_NO_EMPTY) ?: [];
        }

        return [];
    }

    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;
    }
}


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
13			/**
14			* HttpCache implements client-side caching by utilizing the `Last-Modified` and `ETag` HTTP headers.
15			*/
16			final class HttpCache implements MiddlewareInterface
17			{
18			private const DEFAULT_HEADER = 'public, max-age=3600';
19			/**
20			* @internal Frozen session data
21			*/
22			private ?array $sessionData;
			0 ignored issues – show introduced 2020-01-02 12:51 UTC by Report Bug Copy Issue Report The private property `$sessionData` is not used, and could be removed. Loading history...
23
24			/**
25			* @var callable a PHP callback that returns the UNIX timestamp of the last modification time.
26			* The callback's signature should be:
27			*
28			* ```php
29			* function ($request, $params)
30			* ```
31			*
32			* where `$request` is the [[ServerRequestInterface]] object that this filter is currently handling;
33			* `$params` takes the value of [[params]]. The callback should return a UNIX timestamp.
34			*
35			* @see http://tools.ietf.org/html/rfc7232#section-2.2
36			*/
37			private $lastModified;
38
39			/**
40			* @var callable a PHP callback that generates the ETag seed string.
41			* The callback's signature should be:
42			*
43			* ```php
44			* function ($request, $params)
45			* ```
46			*
47			* where `$request` is the [[ServerRequestInterface]] object that this filter is currently handling;
48			* `$params` takes the value of [[params]]. The callback should return a string serving
49			* as the seed for generating an ETag.
50			*/
51			private $etagSeed;
52
53			/**
54			* @var bool whether to generate weak ETags.
55			*
56			* Weak ETags should be used if the content should be considered semantically equivalent, but not byte-equal.
57			*
58			* @see http://tools.ietf.org/html/rfc7232#section-2.3
59			*/
60			private bool $weakEtag = false;
61
62			/**
63			* @var mixed additional parameters that should be passed to the [[lastModified]] and [[etagSeed]] callbacks.
64			*/
65			private $params;
66
67			/**
68			* @var string the value of the `Cache-Control` HTTP header. If null, the header will not be sent.
69			* @see http://tools.ietf.org/html/rfc2616#section-14.9
70			*/
71			private ?string $cacheControlHeader = self::DEFAULT_HEADER;
72
73			private ResponseFactoryInterface $responseFactory;
74			private SessionInterface $session;
75			private LoggerInterface $logger;
76
77			public function __construct(
78			ResponseFactoryInterface $responseFactory,
79			SessionInterface $session,
80			LoggerInterface $logger
81			) {
82			$this->responseFactory = $responseFactory;
83			$this->session = $session;
84			$this->logger = $logger;
85			}
86
87			public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
88			{
89			$method = $request->getMethod();
90			if (
91			!\in_array($method, [Method::GET, Method::HEAD])
92			\|\| ($this->lastModified === null && $this->etagSeed === null)
93			) {
94			return $handler->handle($request);
95			}
96
97			$lastModified = $etag = null;
98			if ($this->lastModified !== null) {
99			$lastModified = call_user_func($this->lastModified, $request, $this->params);
100			}
101			if ($this->etagSeed !== null) {
102			$seed = call_user_func($this->etagSeed, $request, $this->params);
103			if ($seed !== null) {
104			$etag = $this->generateEtag($seed);
105			}
106			}
107
108			$response = $handler->handle($request);
109			if ($this->cacheControlHeader !== null) {
110			$response = $response->withHeader('Cache-Control', $this->cacheControlHeader);
111			}
112			if ($etag !== null) {
113			$response = $response->withHeader('Etag', $etag);
114			}
115
116			$cacheValid = $this->validateCache($request, $lastModified, $etag);
117			// https://tools.ietf.org/html/rfc7232#section-4.1
118			if ($lastModified !== null && (!$cacheValid \|\| ($cacheValid && $etag === null))) {
119			$response = $response->withHeader(
120			'Last-Modified',
121			gmdate('D, d M Y H:i:s', $lastModified) . ' GMT'
122			);
123			}
124			if ($cacheValid) {
125			$response = $this->responseFactory->createResponse(304);
126			$response->getBody()->write('Not Modified');
127			return $response;
128			}
129			return $response;
130			}
131
132			/**
133			* Validates if the HTTP cache contains valid content.
134			* If both Last-Modified and ETag are null, returns false.
135			* @param ServerRequestInterface $request
136			* @param int $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
137			* If null, the Last-Modified header will not be validated.
138			* @param string $etag the calculated ETag value. If null, the ETag header will not be validated.
139			* @return bool whether the HTTP cache is still valid.
140			*/
141			private function validateCache(ServerRequestInterface $request, $lastModified, $etag): bool
142			{
143			if ($request->hasHeader('If-None-Match')) {
144			// HTTP_IF_NONE_MATCH takes precedence over HTTP_IF_MODIFIED_SINCE
145			// http://tools.ietf.org/html/rfc7232#section-3.3
146			return $etag !== null && \in_array($etag, $this->getETags($request), true);
147			}
148
149			if ($request->hasHeader('If-Modified-Since')) {
150			$headers = $request->getHeader('If-Modified-Since');
151			$header = \reset($headers);
152			return $lastModified !== null && @strtotime($header) >= $lastModified;
153			}
154
155			return false;
156			}
157
158			/**
159			* Generates an ETag from the given seed string.
160			* @param string $seed Seed for the ETag
161			* @return string the generated ETag
162			*/
163			private function generateEtag($seed): string
164			{
165			$etag = '"' . rtrim(base64_encode(sha1($seed, true)), '=') . '"';
166			return $this->weakEtag ? 'W/' . $etag : $etag;
167			}
168
169			/**
170			* Gets the Etags.
171			*
172			* @param ServerRequestInterface $request
173			* @return array The entity tags
174			*/
175			private function getETags(ServerRequestInterface $request): array
176			{
177			if ($request->hasHeader('If-None-Match')) {
178			$headers = $request->getHeader('If-None-Match');
179			$header = \str_replace('-gzip', '', \reset($headers));
180			return \preg_split('/[\s,]+/', $header, -1, PREG_SPLIT_NO_EMPTY) ?: [];
181			}
182
183			return [];
184			}
185
186			public function setLastModified(callable $lastModified): void
187			{
188			$this->lastModified = $lastModified;
189			}
190
191			public function setEtagSeed(callable $etagSeed): void
192			{
193			$this->etagSeed = $etagSeed;
194			}
195
196			public function setWeakTag(bool $weakTag): void
197			{
198			$this->weakEtag = $weakTag;
199			}
200
201			public function setParams($params): void
202			{
203			$this->params = $params;
204			}
205
206			public function setCacheControlHeader(?string $header): void
207			{
208			$this->cacheControlHeader = $header;
209			}
210			}
211

yiisoft / yii-web

Pull Request — master (#199)

HttpCache::validateCache() A

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