HttpCache::process() - 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 12:44 UTC

HttpCache::process() C

↳ Parent: HttpCache

Complexity

Conditions	14
Paths	97

Size

Total Lines	43
Code Lines	27

Duplication

Lines	0
Ratio	0 %

Importance

Changes	4
Bugs	0	Features	0

Metric	Value
cc	14
eloc	27
c	4
b	0
f	0
nc	97
nop	2
dl	0
loc	43
rs	6.2666

How to fix Complexity

<?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';

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

yiisoft / yii-web

Pull Request — master (#199)

HttpCache::process() C

Complexity

Size

Duplication

Importance

How to fix Complexity

Long Method

Duplication Side-by-Side

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