CachingPolicy::getVary() - Code Metrics - Inspection of "API Update for SilverStripe 4 compatibility" - silverstripe/silverstripe-controllerpolicy - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#18)

by Robbie

created 2018-01-16 10:23 UTC

CachingPolicy::getVary() A

↳ Parent: CachingPolicy

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	1

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	3
rs	10
c	0
b	0
f	0
cc	1
eloc	1
nc	1
nop	0

<?php

namespace SilverStripe\ControllerPolicy\Policies;

use SilverStripe\Control\Director;
use SilverStripe\Control\HTTP;
use SilverStripe\Control\HTTPRequest;
use SilverStripe\Control\HTTPResponse;
use SilverStripe\ControllerPolicy\ControllerPolicy;

/**
 * A rewrite of the default SilverStripe behaviour allowing more customisation. Consuming code can provide its own
 * callbacks for providing custom cacheAge, vary and timestamp parameters.
 *
 * See PageControlledPolicy as an example implementation of such customisation that applies on top of default.
 *
 * Extends HTTP to get access to globals describing the Last-Modified and Etag data.
 */

class CachingPolicy extends HTTP implements ControllerPolicy
{
    /**
     * Whether to disable the cache age (set to zero) in dev environments
     *
     * @config
     * @var bool
     */
    private static $disable_cache_age_in_dev = true;


    /**
     * Max-age seconds to cache for if configuration not available from the originator.
     *
     * @var int
     */
    protected $cacheAge = 0;

    /**
     * Vary string to add if configuration is not available from the originator.
     *
     * Note on vary headers: Do not add user-agent unless you vary on it AND you have configured user-agent
     * clustering in some way, otherwise this will be an equivalent to disabling caching as there
     * is a lot of different UAs in the wild.
     *
     * @var string
     */
    protected $vary = 'Cookie, X-Forwarded-Protocol';

    /**
     * Set the cache age
     *
     * @param int $cacheAge
     * @return $this
     */
    public function setCacheAge($cacheAge)
    {
        $this->cacheAge = $cacheAge;
        return $this;
    }

    /**
     * Get the cache age
     *
     * @return int
     */
    public function getCacheAge()
    {
        return $this->cacheAge;
    }

    /**
     * Set the "vary" content header
     *
     * @param string $vary
     * @return $this
     */
    public function setVary($vary)
    {
        $this->vary = $vary;
        return $this;
    }

    /**
     * Get the "vary" content header
     *
     * @return string
     */
    public function getVary()
    {
        return $this->vary;
    }

    /**
     * @see HTTP::add_cache_headers()
     *
     * @param object $originator
     * @param HTTPRequest $request
     * @param HTTPResponse $response
     */
    public function applyToResponse($originator, HTTPRequest $request, HTTPResponse $response)
    {
        $cacheAge = $this->getCacheAge();
        $vary = $this->getVary();

        // Allow overriding max-age from the object hooked up to the policed controller.
        if ($originator->hasMethod('getCacheAge')) {
            $extendedCacheAge = $originator->getCacheAge($cacheAge);
            if ($extendedCacheAge !== null) {
                $cacheAge = $extendedCacheAge;
            }
        }

        // Same for vary, but probably less useful.
        if ($originator->hasMethod('getVary')) {
            $extendedVary = $originator->getVary($vary);
            if ($extendedVary !== null) {
                $vary = $extendedVary;
            }
        }

        // Development sites have frequently changing templates; this can get stuffed up by the code
        // below.
        if (Director::isDev() && $this->config()->get('disable_cache_age_in_dev')) {
            $cacheAge = 0;
        }

        // The headers have been sent and we don't have an HTTPResponse object to attach things to; no point in
        // us trying.
        if (headers_sent() && !$response->getBody()) {
            return;
        }

        // Populate $responseHeaders with all the headers that we want to build
        $responseHeaders = [];

        $cacheControlHeaders = HTTP::config()->uninherited('cache_control');

        if ($cacheAge > 0) {
            // Note: must-revalidate means that the cache must revalidate AFTER the entry has gone stale.
            $cacheControlHeaders['must-revalidate'] = 'true';

            $cacheControlHeaders['max-age'] = $cacheAge;

            // Set empty pragma to avoid PHP's session_cache_limiter adding conflicting caching information,
            // defaulting to "nocache" on most PHP configurations (see http://php.net/session_cache_limiter).
            // Since it's a deprecated HTTP 1.0 option, all modern HTTP clients and proxies should
            // prefer the caching information indicated through the "Cache-Control" header.
            $responseHeaders["Pragma"] = "";

            $responseHeaders['Vary'] = $vary;
        }

        foreach ($cacheControlHeaders as $header => $value) {
            if (is_null($value)) {
                unset($cacheControlHeaders[$header]);
            } elseif ((is_bool($value) && $value) || $value === "true") {
                $cacheControlHeaders[$header] = $header;
            } else {
                $cacheControlHeaders[$header] = $header . "=" . $value;
            }
        }

        $responseHeaders['Cache-Control'] = implode(', ', $cacheControlHeaders);
        unset($cacheControlHeaders, $header, $value);

        // Find out when the URI was last modified. Allows customisation, but fall back HTTP timestamp collector.
        if ($originator->hasMethod('getModificationTimestamp')) {
            $timestamp = $originator->getModificationTimestamp();
        } elseif (self::$modification_date && $cacheAge > 0) {
            $timestamp = self::$modification_date;
        }

        if (isset($timestamp)) {
            $responseHeaders["Last-Modified"] = self::gmt_date($timestamp);

            // Chrome ignores Varies when redirecting back (http://code.google.com/p/chromium/issues/detail?id=79758)
            // which means that if you log out, you get redirected back to a page which Chrome then checks against
            // last-modified (which passes, getting a 304)
            // when it shouldn't be trying to use that page at all because it's the "logged in" version.
            // By also using and etag that includes both the modification date and all the varies
            // values which we also check against we can catch this and not return a 304
            $etagParts = array(self::$modification_date, serialize($_COOKIE));
            $etagParts[] = Director::is_https() ? 'https' : 'http';
            if (isset($_SERVER['HTTP_USER_AGENT'])) {
                $etagParts[] = $_SERVER['HTTP_USER_AGENT'];
            }
            if (isset($_SERVER['HTTP_ACCEPT'])) {
                $etagParts[] = $_SERVER['HTTP_ACCEPT'];
            }

            $etag = sha1(implode(':', $etagParts));
            $responseHeaders["ETag"] = $etag;

            // 304 response detection
            if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
                $ifModifiedSince = strtotime(stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']));

                // As above, only 304 if the last request had all the same varies values
                // (or the etag isn't passed as part of the request - but with chrome it always is)
                $matchesEtag = !isset($_SERVER['HTTP_IF_NONE_MATCH']) || $_SERVER['HTTP_IF_NONE_MATCH'] == $etag;

                if ($ifModifiedSince >= self::$modification_date && $matchesEtag) {
                    if ($body) {

                        $body->setStatusCode(304);
                        $body->setBody('');
                    } else {
                        header('HTTP/1.0 304 Not Modified');
                        die();

                    }
                }
            }

            $expires = time() + $cacheAge;
            $responseHeaders["Expires"] = self::gmt_date($expires);
        }

        if (self::$etag) {
            $responseHeaders['ETag'] = self::$etag;
        }

        // etag needs to be a quoted string according to HTTP spec
        if (!empty($responseHeaders['ETag']) && 0 !== strpos($responseHeaders['ETag'], '"')) {
            $responseHeaders['ETag'] = sprintf('"%s"', $responseHeaders['ETag']);
        }

        // Now that we've generated them, either output them or attach them to the HTTPResponse as appropriate
        foreach ($responseHeaders as $k => $v) {
            $response->addHeader($k, $v);
        }
    }
}


1			<?php
2
3			namespace SilverStripe\ControllerPolicy\Policies;
4
5			use SilverStripe\Control\Director;
6			use SilverStripe\Control\HTTP;
7			use SilverStripe\Control\HTTPRequest;
8			use SilverStripe\Control\HTTPResponse;
9			use SilverStripe\ControllerPolicy\ControllerPolicy;
10
11			/**
12			* A rewrite of the default SilverStripe behaviour allowing more customisation. Consuming code can provide its own
13			* callbacks for providing custom cacheAge, vary and timestamp parameters.
14			*
15			* See PageControlledPolicy as an example implementation of such customisation that applies on top of default.
16			*
17			* Extends HTTP to get access to globals describing the Last-Modified and Etag data.
18			*/
19
20			class CachingPolicy extends HTTP implements ControllerPolicy
21			{
22			/**
23			* Whether to disable the cache age (set to zero) in dev environments
24			*
25			* @config
26			* @var bool
27			*/
28			private static $disable_cache_age_in_dev = true;
			0 ignored issues – show introduced 2018-01-16 10:27 UTC by Report Bug Copy Issue Report The private property `$disable_cache_age_in_dev` is not used, and could be removed. Loading history...
29
30			/**
31			* Max-age seconds to cache for if configuration not available from the originator.
32			*
33			* @var int
34			*/
35			protected $cacheAge = 0;
36
37			/**
38			* Vary string to add if configuration is not available from the originator.
39			*
40			* Note on vary headers: Do not add user-agent unless you vary on it AND you have configured user-agent
41			* clustering in some way, otherwise this will be an equivalent to disabling caching as there
42			* is a lot of different UAs in the wild.
43			*
44			* @var string
45			*/
46			protected $vary = 'Cookie, X-Forwarded-Protocol';
47
48			/**
49			* Set the cache age
50			*
51			* @param int $cacheAge
52			* @return $this
53			*/
54			public function setCacheAge($cacheAge)
55			{
56			$this->cacheAge = $cacheAge;
57			return $this;
58			}
59
60			/**
61			* Get the cache age
62			*
63			* @return int
64			*/
65			public function getCacheAge()
66			{
67			return $this->cacheAge;
68			}
69
70			/**
71			* Set the "vary" content header
72			*
73			* @param string $vary
74			* @return $this
75			*/
76			public function setVary($vary)
77			{
78			$this->vary = $vary;
79			return $this;
80			}
81
82			/**
83			* Get the "vary" content header
84			*
85			* @return string
86			*/
87			public function getVary()
88			{
89			return $this->vary;
90			}
91
92			/**
93			* @see HTTP::add_cache_headers()
94			*
95			* @param object $originator
96			* @param HTTPRequest $request
97			* @param HTTPResponse $response
98			*/
99			public function applyToResponse($originator, HTTPRequest $request, HTTPResponse $response)
100			{
101			$cacheAge = $this->getCacheAge();
102			$vary = $this->getVary();
103
104			// Allow overriding max-age from the object hooked up to the policed controller.
105			if ($originator->hasMethod('getCacheAge')) {
106			$extendedCacheAge = $originator->getCacheAge($cacheAge);
107			if ($extendedCacheAge !== null) {
108			$cacheAge = $extendedCacheAge;
109			}
110			}
111
112			// Same for vary, but probably less useful.
113			if ($originator->hasMethod('getVary')) {
114			$extendedVary = $originator->getVary($vary);
115			if ($extendedVary !== null) {
116			$vary = $extendedVary;
117			}
118			}
119
120			// Development sites have frequently changing templates; this can get stuffed up by the code
121			// below.
122			if (Director::isDev() && $this->config()->get('disable_cache_age_in_dev')) {
123			$cacheAge = 0;
124			}
125
126			// The headers have been sent and we don't have an HTTPResponse object to attach things to; no point in
127			// us trying.
128			if (headers_sent() && !$response->getBody()) {
129			return;
130			}
131
132			// Populate $responseHeaders with all the headers that we want to build
133			$responseHeaders = [];
134
135			$cacheControlHeaders = HTTP::config()->uninherited('cache_control');
136
137			if ($cacheAge > 0) {
138			// Note: must-revalidate means that the cache must revalidate AFTER the entry has gone stale.
139			$cacheControlHeaders['must-revalidate'] = 'true';
140
141			$cacheControlHeaders['max-age'] = $cacheAge;
142
143			// Set empty pragma to avoid PHP's session_cache_limiter adding conflicting caching information,
144			// defaulting to "nocache" on most PHP configurations (see http://php.net/session_cache_limiter).
145			// Since it's a deprecated HTTP 1.0 option, all modern HTTP clients and proxies should
146			// prefer the caching information indicated through the "Cache-Control" header.
147			$responseHeaders["Pragma"] = "";
148
149			$responseHeaders['Vary'] = $vary;
150			}
151
152			foreach ($cacheControlHeaders as $header => $value) {
153			if (is_null($value)) {
154			unset($cacheControlHeaders[$header]);
155			} elseif ((is_bool($value) && $value) \|\| $value === "true") {
156			$cacheControlHeaders[$header] = $header;
157			} else {
158			$cacheControlHeaders[$header] = $header . "=" . $value;
159			}
160			}
161
162			$responseHeaders['Cache-Control'] = implode(', ', $cacheControlHeaders);
163			unset($cacheControlHeaders, $header, $value);
164
165			// Find out when the URI was last modified. Allows customisation, but fall back HTTP timestamp collector.
166			if ($originator->hasMethod('getModificationTimestamp')) {
167			$timestamp = $originator->getModificationTimestamp();
168			} elseif (self::$modification_date && $cacheAge > 0) {
169			$timestamp = self::$modification_date;
170			}
171
172			if (isset($timestamp)) {
173			$responseHeaders["Last-Modified"] = self::gmt_date($timestamp);
174
175			// Chrome ignores Varies when redirecting back (http://code.google.com/p/chromium/issues/detail?id=79758)
176			// which means that if you log out, you get redirected back to a page which Chrome then checks against
177			// last-modified (which passes, getting a 304)
178			// when it shouldn't be trying to use that page at all because it's the "logged in" version.
179			// By also using and etag that includes both the modification date and all the varies
180			// values which we also check against we can catch this and not return a 304
181			$etagParts = array(self::$modification_date, serialize($_COOKIE));
182			$etagParts[] = Director::is_https() ? 'https' : 'http';
183			if (isset($_SERVER['HTTP_USER_AGENT'])) {
184			$etagParts[] = $_SERVER['HTTP_USER_AGENT'];
185			}
186			if (isset($_SERVER['HTTP_ACCEPT'])) {
187			$etagParts[] = $_SERVER['HTTP_ACCEPT'];
188			}
189
190			$etag = sha1(implode(':', $etagParts));
191			$responseHeaders["ETag"] = $etag;
192
193			// 304 response detection
194			if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
195			$ifModifiedSince = strtotime(stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']));
196
197			// As above, only 304 if the last request had all the same varies values
198			// (or the etag isn't passed as part of the request - but with chrome it always is)
199			$matchesEtag = !isset($_SERVER['HTTP_IF_NONE_MATCH']) \|\| $_SERVER['HTTP_IF_NONE_MATCH'] == $etag;
200
201			if ($ifModifiedSince >= self::$modification_date && $matchesEtag) {
202			if ($body) {
			0 ignored issues – show Comprehensibility Best Practice introduced 2018-01-16 10:27 UTC by Report Bug Copy Issue Report The variable `$body` seems to be never defined. Loading history...
203			$body->setStatusCode(304);
204			$body->setBody('');
205			} else {
206			header('HTTP/1.0 304 Not Modified');
207			die();
			0 ignored issues – show Best Practice introduced 2018-01-16 10:27 UTC by Report Bug Copy Issue Report Using `exit` here is not recommended. In general, usage of exit should be done with care and only when running in a scripting context like a CLI script. Loading history...
208			}
209			}
210			}
211
212			$expires = time() + $cacheAge;
213			$responseHeaders["Expires"] = self::gmt_date($expires);
214			}
215
216			if (self::$etag) {
217			$responseHeaders['ETag'] = self::$etag;
218			}
219
220			// etag needs to be a quoted string according to HTTP spec
221			if (!empty($responseHeaders['ETag']) && 0 !== strpos($responseHeaders['ETag'], '"')) {
222			$responseHeaders['ETag'] = sprintf('"%s"', $responseHeaders['ETag']);
223			}
224
225			// Now that we've generated them, either output them or attach them to the HTTPResponse as appropriate
226			foreach ($responseHeaders as $k => $v) {
227			$response->addHeader($k, $v);
228			}
229			}
230			}
231

silverstripe / silverstripe-controllerpolicy

Pull Request — master (#18)

CachingPolicy::getVary() A

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

Filter issues like