forked from yiisoft/yii
-
Notifications
You must be signed in to change notification settings - Fork 0
/
CHttpCacheFilter.php
196 lines (179 loc) · 5.7 KB
/
CHttpCacheFilter.php
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
<?php
/**
* CHttpCacheFilter class file.
*
* @author Da:Sourcerer <webmaster@dasourcerer.net>
* @link http://www.yiiframework.com/
* @copyright Copyright © 2008-2012 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CHttpCacheFilter implements http caching. It works a lot like {@link COutputCache}
* as a filter, except that content caching is being done on the client side.
*
* @author Da:Sourcerer <webmaster@dasourcerer.net>
* @version $Id$
* @package system.web.filters
* @since 1.1.11
*/
class CHttpCacheFilter extends CFilter
{
/**
* Timestamp for the last modification date. Must be either a string parsable by
* {@link http://php.net/strtotime strtotime()} or an integer representing a unix timestamp.
* @var string|integer
*/
public $lastModified;
/**
* Expression for the last modification date. If set, this takes precedence over {@link lastModified}.
* @var string|callback
*/
public $lastModifiedExpression;
/**
* Seed for the ETag. Can be anything that passes through {@link http://php.net/serialize serialize()}.
* @var mixed
*/
public $etagSeed;
/**
* Expression for the ETag seed. If set, this takes precedence over {@link etag}.
* @var string|callback
*/
public $etagSeedExpression;
/**
* Http cache control headers. Set this to an empty string in order to keep this
* header from being sent entirely.
* @var string
*/
public $cacheControl = 'max-age=3600, public';
/**
* Performs the pre-action filtering.
* @param CFilterChain $filterChain the filter chain that the filter is on.
* @return boolean whether the filtering process should continue and the action should be executed.
*/
public function preFilter($filterChain)
{
// Only cache GET and HEAD requests
if(!in_array(Yii::app()->getRequest()->getRequestType(), array('GET', 'HEAD')))
return true;
$lastModified=$this->getLastModifiedValue();
$etag=$this->getEtagValue();
if($etag===false&&$lastModified===false)
return true;
if($etag)
header('ETag: '.$etag);
if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])&&isset($_SERVER['HTTP_IF_NONE_MATCH']))
{
if($this->checkLastModified($lastModified)&&$this->checkEtag($etag))
{
$this->send304Header();
$this->sendCacheControlHeader();
return false;
}
}
else if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE']))
{
if($this->checkLastModified($lastModified))
{
$this->send304Header();
$this->sendCacheControlHeader();
return false;
}
}
else if(isset($_SERVER['HTTP_IF_NONE_MATCH']))
{
if($this->checkEtag($etag))
{
$this->send304Header();
$this->sendCacheControlHeader();
return false;
}
}
if($lastModified)
header('Last-Modified: '.date('r', $lastModified));
$this->sendCacheControlHeader();
return true;
}
/**
* Gets the last modified value from either {@link lastModifiedExpression} or {@link lastModified}
* and converts it into a unix timestamp if necessary
* @throws CException
* @return integer|boolean A unix timestamp or false if neither lastModified nor
* lastModifiedExpression have been set
*/
protected function getLastModifiedValue()
{
if($this->lastModifiedExpression)
{
$value=$this->evaluateExpression($this->lastModifiedExpression);
if(is_numeric($value)&&$value==(int)$value)
return $value;
else if(($lastModified=strtotime($value))===false)
throw new CException(Yii::t('yii','Invalid expression for CHttpCacheFilter.lastModifiedExpression: The evaluation result "{value}" could not be understood by strtotime()',
array('{value}'=>$value)));
return $lastModified;
}
if($this->lastModified)
{
if(is_numeric($this->lastModified)&&$this->lastModified==(int)$this->lastModified)
return $this->lastModified;
else if(($lastModified=strtotime($this->lastModified))===false)
throw new CException(Yii::t('yii','CHttpCacheFilter.lastModified contained a value that could not be understood by strtotime()'));
return $lastModified;
}
return false;
}
/**
* Gets the ETag out of either {@link etagSeedExpression} or {@link etagSeed}
* @return string|boolean Either a quoted string serving as ETag or false if neither etagSeed nor etagSeedExpression have been set
*/
protected function getEtagValue()
{
if($this->etagSeedExpression)
return $this->generateEtag($this->evaluateExpression($this->etagSeedExpression));
else if($this->etagSeed)
return $this->generateEtag($this->etagSeed);
return false;
}
/**
* Check if the etag supplied by the client matches our generated one
* @param string $etag the supplied etag
* @return boolean true if the supplied etag matches $etag
*/
protected function checkEtag($etag)
{
return isset($_SERVER['HTTP_IF_NONE_MATCH'])&&$_SERVER['HTTP_IF_NONE_MATCH']==$etag;
}
/**
* Checks if the last modified date supplied by the client is still up to date
* @param integer $lastModified the last modified date
* @return boolean true if the last modified date sent by the client is newer or equal to $lastModified
*/
protected function checkLastModified($lastModified)
{
return isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])&&@strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])>=$lastModified;
}
/**
* Sends the 304 HTTP status code to the client
*/
protected function send304Header()
{
header('HTTP/1.1 304 Not Modified');
}
/**
* Sends the cache control header to the client
* @see cacheControl
* @since 1.1.12
*/
protected function sendCacheControlHeader()
{
header('Cache-Control: '.$this->cacheControl, true);
}
/**
* Generates a quoted string out of the seed
* @param mixed $seed Seed for the ETag
*/
protected function generateEtag($seed)
{
return '"'.base64_encode(sha1(serialize($seed), true)).'"';
}
}