includes/parser/CacheTime.php

   1 <?php
   2 /**
   3  * Parser cache specific expiry check.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Parser
  22  */
  23
  24 /**
  25  * Parser cache specific expiry check.
  26  *
  27  * @ingroup Parser
  28  */
  29 class CacheTime {
  30         /** @var array|bool ParserOptions which have been taken into account to
  31          * produce output or false if not available.
  32          */
  33         public $mUsedOptions;
  34
  35         public $mVersion = Parser::VERSION,  # Compatibility check
  36                 $mCacheTime = '',             # Time when this object was generated, or -1 for uncacheable. Used in ParserCache.
  37                 $mCacheExpiry = null,         # Seconds after which the object should expire, use 0 for uncachable. Used in ParserCache.
  38                 $mContainsOldMagic,           # Boolean variable indicating if the input contained variables like {{CURRENTDAY}}
  39                 $mCacheRevisionId = null;     # Revision ID that was parsed
  40
  41         /**
  42          * @return string TS_MW timestamp
  43          */
  44         public function getCacheTime() {
  45                 return wfTimestamp( TS_MW, $this->mCacheTime );
  46         }
  47
  48         /**
  49          * @return bool
  50          */
  51         public function containsOldMagic() {
  52                 return $this->mContainsOldMagic;
  53         }
  54
  55         /**
  56          * @param bool $com
  57          * @return bool
  58          */
  59         public function setContainsOldMagic( $com ) {
  60                 return wfSetVar( $this->mContainsOldMagic, $com );
  61         }
  62
  63         /**
  64          * setCacheTime() sets the timestamp expressing when the page has been rendered.
  65          * This does not control expiry, see updateCacheExpiry() for that!
  66          * @param string $t
  67          * @return string
  68          */
  69         public function setCacheTime( $t ) {
  70                 return wfSetVar( $this->mCacheTime, $t );
  71         }
  72
  73         /**
  74          * @since 1.23
  75          * @return int|null Revision id, if any was set
  76          */
  77         public function getCacheRevisionId() {
  78                 return $this->mCacheRevisionId;
  79         }
  80
  81         /**
  82          * @since 1.23
  83          * @param int $id Revision id
  84          */
  85         public function setCacheRevisionId( $id ) {
  86                 $this->mCacheRevisionId = $id;
  87         }
  88
  89         /**
  90          * Sets the number of seconds after which this object should expire.
  91          * This value is used with the ParserCache.
  92          * If called with a value greater than the value provided at any previous call,
  93          * the new call has no effect. The value returned by getCacheExpiry is smaller
  94          * or equal to the smallest number that was provided as an argument to
  95          * updateCacheExpiry().
  96          *
  97          * @param int $seconds
  98          */
  99         public function updateCacheExpiry( $seconds ) {
 100                 $seconds = (int)$seconds;
 101
 102                 if ( $this->mCacheExpiry === null || $this->mCacheExpiry > $seconds ) {
 103                         $this->mCacheExpiry = $seconds;
 104                 }
 105
 106                 // hack: set old-style marker for uncacheable entries.
 107                 if ( $this->mCacheExpiry !== null && $this->mCacheExpiry <= 0 ) {
 108                         $this->mCacheTime = -1;
 109                 }
 110         }
 111
 112         /**
 113          * Returns the number of seconds after which this object should expire.
 114          * This method is used by ParserCache to determine how long the ParserOutput can be cached.
 115          * The timestamp of expiry can be calculated by adding getCacheExpiry() to getCacheTime().
 116          * The value returned by getCacheExpiry is smaller or equal to the smallest number
 117          * that was provided to a call of updateCacheExpiry(), and smaller or equal to the
 118          * value of $wgParserCacheExpireTime.
 119          * @return int|mixed|null
 120          */
 121         public function getCacheExpiry() {
 122                 global $wgParserCacheExpireTime;
 123
 124                 if ( $this->mCacheTime < 0 ) {
 125                         return 0;
 126                 } // old-style marker for "not cachable"
 127
 128                 $expire = $this->mCacheExpiry;
 129
 130                 if ( $expire === null ) {
 131                         $expire = $wgParserCacheExpireTime;
 132                 } else {
 133                         $expire = min( $expire, $wgParserCacheExpireTime );
 134                 }
 135
 136                 if ( $this->containsOldMagic() ) { //compatibility hack
 137                         $expire = min( $expire, 3600 ); # 1 hour
 138                 }
 139
 140                 if ( $expire <= 0 ) {
 141                         return 0; // not cachable
 142                 } else {
 143                         return $expire;
 144                 }
 145         }
 146
 147         /**
 148          * @return bool
 149          */
 150         public function isCacheable() {
 151                 return $this->getCacheExpiry() > 0;
 152         }
 153
 154         /**
 155          * Return true if this cached output object predates the global or
 156          * per-article cache invalidation timestamps, or if it comes from
 157          * an incompatible older version.
 158          *
 159          * @param string $touched The affected article's last touched timestamp
 160          * @return bool
 161          */
 162         public function expired( $touched ) {
 163                 global $wgCacheEpoch;
 164
 165                 return !$this->isCacheable() // parser says it's uncacheable
 166                         || $this->getCacheTime() < $touched
 167                         || $this->getCacheTime() <= $wgCacheEpoch
 168                         || $this->getCacheTime() <
 169                                 wfTimestamp( TS_MW, time() - $this->getCacheExpiry() ) // expiry period has passed
 170                         || !isset( $this->mVersion )
 171                         || version_compare( $this->mVersion, Parser::VERSION, "lt" );
 172         }
 173
 174         /**
 175          * Return true if this cached output object is for a different revision of
 176          * the page.
 177          *
 178          * @todo We always return false if $this->getCacheRevisionId() is null;
 179          * this prevents invalidating the whole parser cache when this change is
 180          * deployed. Someday that should probably be changed.
 181          *
 182          * @since 1.23
 183          * @param int $id The affected article's current revision id
 184          * @return bool
 185          */
 186         public function isDifferentRevision( $id ) {
 187                 $cached = $this->getCacheRevisionId();
 188                 return $cached !== null && $id !== $cached;
 189         }
 190 }