HttpCache::validateCache() - Code Metrics - Inspection of "Add "declare (strict_types = 1);" and classes are..." - yiisoft/yii-web - Measure and Improve Code Quality continuously with Scrutinizer

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by Alexander

created 2020-07-07 12:02 UTC

HttpCache::validateCache() A

↳ Parent: HttpCache

Complexity

Conditions	5
Paths	5

Size

Total Lines	14
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	6
CRAP Score	5.0729

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	5
eloc	6
c	1
b	0
f	0
nc	5
nop	3
dl	0
loc	14
ccs	6
cts	7
cp	0.8571
crap	5.0729
rs	9.6111

<?php

declare(strict_types=1);

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 Yiisoft\Http\Method;
use Yiisoft\Http\Status;

/**
 * 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 (ServerRequestInterface $request, $params): int
     * ```
     *
     * where `$request` is the {@see ServerRequestInterface} object that this filter is currently handling;
     * `$params` takes the value of {@see 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 (ServerRequestInterface $request, $params): string
     * ```
     *
     * where `$request` is the {@see ServerRequestInterface} object that this middleware is currently handling;
     * `$params` takes the value of {@see $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 {@see $lastModified} and {@see 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;

    public function __construct(ResponseFactoryInterface $responseFactory)
    {
        $this->responseFactory = $responseFactory;
    }

    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        if (
            ($this->lastModified === null && $this->etagSeed === null) ||
            !\in_array($request->getMethod(), [Method::GET, Method::HEAD], true)
        ) {
            return $handler->handle($request);
        }

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

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

        $cacheIsValid = $this->validateCache($request, $lastModified, $etag);
        $response = $handler->handle($request);

        if ($cacheIsValid) {
            $response = $response->withStatus(Status::NOT_MODIFIED);
        }

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

        // https://tools.ietf.org/html/rfc7232#section-4.1
        if ($lastModified !== null && (!$cacheIsValid || ($cacheIsValid && $etag === null))) {
            $response = $response->withHeader(
                'Last-Modified',
                gmdate('D, d M Y H:i:s', $lastModified) . ' GMT'
            );
        }

        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|null $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
     * If null, the Last-Modified header will not be validated.
     * @param string|null $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, ?int $lastModified, ?string $etag): bool
    {
        if ($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')) {
            $header = $request->getHeaderLine('If-Modified-Since');
            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(string $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 = $request->getHeaderLine('If-None-Match');
            $header = \str_replace('-gzip', '', $header);
            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
3		declare(strict_types=1);
4
5		namespace Yiisoft\Yii\Web\Middleware;
6
7		use Psr\Http\Message\ResponseFactoryInterface;
8		use Psr\Http\Message\ResponseInterface;
9		use Psr\Http\Message\ServerRequestInterface;
10		use Psr\Http\Server\MiddlewareInterface;
11		use Psr\Http\Server\RequestHandlerInterface;
12		use Yiisoft\Http\Method;
13		use Yiisoft\Http\Status;
14
15		/**
16		* HttpCache implements client-side caching by utilizing the `Last-Modified` and `ETag` HTTP headers.
17		*/
18		final class HttpCache implements MiddlewareInterface
19		{
20		private const DEFAULT_HEADER = 'public, max-age=3600';
21
22		/**
23		* @var callable a PHP callback that returns the UNIX timestamp of the last modification time.
24		* The callback's signature should be:
25		*
26		* ```php
27		* function (ServerRequestInterface $request, $params): int
28		* ```
29		*
30		* where `$request` is the {@see ServerRequestInterface} object that this filter is currently handling;
31		* `$params` takes the value of {@see params}. The callback should return a UNIX timestamp.
32		*
33		* @see http://tools.ietf.org/html/rfc7232#section-2.2
34		*/
35		private $lastModified;
36
37		/**
38		* @var callable a PHP callback that generates the ETag seed string.
39		* The callback's signature should be:
40		*
41		* ```php
42		* function (ServerRequestInterface $request, $params): string
43		* ```
44		*
45		* where `$request` is the {@see ServerRequestInterface} object that this middleware is currently handling;
46		* `$params` takes the value of {@see $params}. The callback should return a string serving
47		* as the seed for generating an ETag.
48		*/
49		private $etagSeed;
50
51		/**
52		* @var bool whether to generate weak ETags.
53		*
54		* Weak ETags should be used if the content should be considered semantically equivalent, but not byte-equal.
55		*
56		* @see http://tools.ietf.org/html/rfc7232#section-2.3
57		*/
58		private bool $weakEtag = false;
59
60		/**
61		* @var mixed additional parameters that should be passed to the {@see $lastModified} and {@see etagSeed} callbacks.
62		*/
63		private $params;
64
65		/**
66		* @var string the value of the `Cache-Control` HTTP header. If null, the header will not be sent.
67		* @see http://tools.ietf.org/html/rfc2616#section-14.9
68		*/
69		private ?string $cacheControlHeader = self::DEFAULT_HEADER;
70
71		private ResponseFactoryInterface $responseFactory;
72
73	5	public function __construct(ResponseFactoryInterface $responseFactory)
74		{
75	5	$this->responseFactory = $responseFactory;
76	5	}
77
78	5	public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
79		{
80		if (
81	5	($this->lastModified === null && $this->etagSeed === null) \|\|
82	5	!\in_array($request->getMethod(), [Method::GET, Method::HEAD], true)
83		) {
84	1	return $handler->handle($request);
85		}
86
87	4	$lastModified = null;
88	4	if ($this->lastModified !== null) {
89	2	$lastModified = call_user_func($this->lastModified, $request, $this->params);
90		}
91
92	4	$etag = null;
93	4	if ($this->etagSeed !== null) {
94	2	$seed = call_user_func($this->etagSeed, $request, $this->params);
95	2	if ($seed !== null) {
96	2	$etag = $this->generateEtag($seed);
97		}
98		}
99
100	4	$cacheIsValid = $this->validateCache($request, $lastModified, $etag);
101	4	$response = $handler->handle($request);
102
103	4	if ($cacheIsValid) {
104	2	$response = $response->withStatus(Status::NOT_MODIFIED);
105		}
106
107	4	if ($this->cacheControlHeader !== null) {
108	4	$response = $response->withHeader('Cache-Control', $this->cacheControlHeader);
109		}
110	4	if ($etag !== null) {
111	2	$response = $response->withHeader('Etag', $etag);
112		}
113
114		// https://tools.ietf.org/html/rfc7232#section-4.1
115	4	if ($lastModified !== null && (!$cacheIsValid \|\| ($cacheIsValid && $etag === null))) {
116	2	$response = $response->withHeader(
117	2	'Last-Modified',
118	2	gmdate('D, d M Y H:i:s', $lastModified) . ' GMT'
119		);
120		}
121
122	4	return $response;
123		}
124
125		/**
126		* Validates if the HTTP cache contains valid content.
127		* If both Last-Modified and ETag are null, returns false.
128		* @param ServerRequestInterface $request
129		* @param int\|null $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
130		* If null, the Last-Modified header will not be validated.
131		* @param string\|null $etag the calculated ETag value. If null, the ETag header will not be validated.
132		* @return bool whether the HTTP cache is still valid.
133		*/
134	4	private function validateCache(ServerRequestInterface $request, ?int $lastModified, ?string $etag): bool
135		{
136	4	if ($request->hasHeader('If-None-Match')) {
137		// HTTP_IF_NONE_MATCH takes precedence over HTTP_IF_MODIFIED_SINCE
138		// http://tools.ietf.org/html/rfc7232#section-3.3
139	2	return $etag !== null && \in_array($etag, $this->getETags($request), true);
140		}
141
142	2	if ($request->hasHeader('If-Modified-Since')) {
143	2	$header = $request->getHeaderLine('If-Modified-Since');
144	2	return $lastModified !== null && @strtotime($header) >= $lastModified;
145		}
146
147		return false;
148		}
149
150		/**
151		* Generates an ETag from the given seed string.
152		* @param string $seed Seed for the ETag
153		* @return string the generated ETag
154		*/
155	2	private function generateEtag(string $seed): string
156		{
157	2	$etag = '"' . rtrim(base64_encode(sha1($seed, true)), '=') . '"';
158	2	return $this->weakEtag ? 'W/' . $etag : $etag;
159		}
160
161		/**
162		* Gets the Etags.
163		*
164		* @param ServerRequestInterface $request
165		* @return array The entity tags
166		*/
167	2	private function getETags(ServerRequestInterface $request): array
168		{
169	2	if ($request->hasHeader('If-None-Match')) {
170	2	$header = $request->getHeaderLine('If-None-Match');
171	2	$header = \str_replace('-gzip', '', $header);
172	2	return \preg_split('/[\s,]+/', $header, -1, PREG_SPLIT_NO_EMPTY) ?: [];
173		}
174
175		return [];
176		}
177
178	3	public function setLastModified(callable $lastModified): void
179		{
180	3	$this->lastModified = $lastModified;
181	3	}
182
183	2	public function setEtagSeed(callable $etagSeed): void
184		{
185	2	$this->etagSeed = $etagSeed;
186	2	}
187
188		public function setWeakTag(bool $weakTag): void
189		{
190		$this->weakEtag = $weakTag;
191		}
192
193		public function setParams($params): void
194		{
195		$this->params = $params;
196		}
197
198		public function setCacheControlHeader(?string $header): void
199		{
200		$this->cacheControlHeader = $header;
201		}
202		}
203

yiisoft / yii-web

Push — master ( ddb17c...54000c )

HttpCache::validateCache() A

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