HttpCache::__construct() - Code Metrics - Inspection of "Cleanup (#276)" - yiisoft/yii-web - Measure and Improve Code Quality continuously with Scrutinizer

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Push — master ( 80aac7...ae3a29 )

by Alexander

created 2020-07-12 20:07 UTC

HttpCache::__construct() A

↳ Parent: HttpCache::process()

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	1

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	1
eloc	1
c	1
b	0
f	0
nc	1
nop	1
dl	0
loc	3
ccs	2
cts	2
cp	1
crap	1
rs	10

<?php

declare(strict_types=1);

namespace Yiisoft\Yii\Web\Middleware;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;
use Yiisoft\Http\Header;
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;

    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(Header::CACHE_CONTROL, $this->cacheControlHeader);
        }
        if ($etag !== null) {
            $response = $response->withHeader(Header::ETAG, $etag);
        }

        // https://tools.ietf.org/html/rfc7232#section-4.1
        if ($lastModified !== null && (!$cacheIsValid || $etag === null)) {
            $response = $response->withHeader(
                Header::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(Header::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(Header::IF_MODIFIED_SINCE)) {
            $header = $request->getHeaderLine(Header::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(Header::IF_NONE_MATCH)) {
            $header = $request->getHeaderLine(Header::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\ResponseInterface;
8		use Psr\Http\Message\ServerRequestInterface;
9		use Psr\Http\Server\MiddlewareInterface;
10		use Psr\Http\Server\RequestHandlerInterface;
11		use Yiisoft\Http\Header;
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	5	public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
72		{
73		if (
74	5	($this->lastModified === null && $this->etagSeed === null) \|\|
75	5	!\in_array($request->getMethod(), [Method::GET, Method::HEAD], true)
76		) {
77	1	return $handler->handle($request);
78		}
79
80	4	$lastModified = null;
81	4	if ($this->lastModified !== null) {
82	2	$lastModified = call_user_func($this->lastModified, $request, $this->params);
83		}
84
85	4	$etag = null;
86	4	if ($this->etagSeed !== null) {
87	2	$seed = call_user_func($this->etagSeed, $request, $this->params);
88	2	if ($seed !== null) {
89	2	$etag = $this->generateEtag($seed);
90		}
91		}
92
93	4	$cacheIsValid = $this->validateCache($request, $lastModified, $etag);
94	4	$response = $handler->handle($request);
95
96	4	if ($cacheIsValid) {
97	2	$response = $response->withStatus(Status::NOT_MODIFIED);
98		}
99
100	4	if ($this->cacheControlHeader !== null) {
101	4	$response = $response->withHeader(Header::CACHE_CONTROL, $this->cacheControlHeader);
102		}
103	4	if ($etag !== null) {
104	2	$response = $response->withHeader(Header::ETAG, $etag);
105		}
106
107		// https://tools.ietf.org/html/rfc7232#section-4.1
108	4	if ($lastModified !== null && (!$cacheIsValid \|\| $etag === null)) {
109	2	$response = $response->withHeader(
110	2	Header::LAST_MODIFIED,
111	2	gmdate('D, d M Y H:i:s', $lastModified) . ' GMT'
112		);
113		}
114
115	4	return $response;
116		}
117
118		/**
119		* Validates if the HTTP cache contains valid content.
120		* If both Last-Modified and ETag are null, returns false.
121		* @param ServerRequestInterface $request
122		* @param int\|null $lastModified the calculated Last-Modified value in terms of a UNIX timestamp.
123		* If null, the Last-Modified header will not be validated.
124		* @param string\|null $etag the calculated ETag value. If null, the ETag header will not be validated.
125		* @return bool whether the HTTP cache is still valid.
126		*/
127	4	private function validateCache(ServerRequestInterface $request, ?int $lastModified, ?string $etag): bool
128		{
129	4	if ($request->hasHeader(Header::IF_NONE_MATCH)) {
130		// HTTP_IF_NONE_MATCH takes precedence over HTTP_IF_MODIFIED_SINCE
131		// http://tools.ietf.org/html/rfc7232#section-3.3
132	2	return $etag !== null && \in_array($etag, $this->getETags($request), true);
133		}
134
135	2	if ($request->hasHeader(Header::IF_MODIFIED_SINCE)) {
136	2	$header = $request->getHeaderLine(Header::IF_MODIFIED_SINCE);
137	2	return $lastModified !== null && @strtotime($header) >= $lastModified;
138		}
139
140		return false;
141		}
142
143		/**
144		* Generates an ETag from the given seed string.
145		* @param string $seed Seed for the ETag
146		* @return string the generated ETag
147		*/
148	2	private function generateEtag(string $seed): string
149		{
150	2	$etag = '"' . rtrim(base64_encode(sha1($seed, true)), '=') . '"';
151	2	return $this->weakEtag ? 'W/' . $etag : $etag;
152		}
153
154		/**
155		* Gets the Etags.
156		*
157		* @param ServerRequestInterface $request
158		* @return array The entity tags
159		*/
160	2	private function getETags(ServerRequestInterface $request): array
161		{
162	2	if ($request->hasHeader(Header::IF_NONE_MATCH)) {
163	2	$header = $request->getHeaderLine(Header::IF_NONE_MATCH);
164	2	$header = \str_replace('-gzip', '', $header);
165	2	return \preg_split('/[\s,]+/', $header, -1, PREG_SPLIT_NO_EMPTY) ?: [];
166		}
167
168		return [];
169		}
170
171	3	public function setLastModified(callable $lastModified): void
172		{
173	3	$this->lastModified = $lastModified;
174	3	}
175
176	2	public function setEtagSeed(callable $etagSeed): void
177		{
178	2	$this->etagSeed = $etagSeed;
179	2	}
180
181		public function setWeakTag(bool $weakTag): void
182		{
183		$this->weakEtag = $weakTag;
184		}
185
186		public function setParams($params): void
187		{
188		$this->params = $params;
189		}
190
191		public function setCacheControlHeader(?string $header): void
192		{
193		$this->cacheControlHeader = $header;
194		}
195		}
196

yiisoft / yii-web

Push — master ( 80aac7...ae3a29 )

HttpCache::__construct() A

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