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         var     $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
  40         /**
  41          * @return string TS_MW timestamp
  42          */
  43         function getCacheTime() {
  44                 return wfTimestamp( TS_MW, $this->mCacheTime );
  45         }
  46
  47         /**
  48          * @return bool
  49          */
  50         function containsOldMagic() {
  51                 return $this->mContainsOldMagic;
  52         }
  53
  54         /**
  55          * @param $com bool
  56          * @return bool
  57          */
  58         function setContainsOldMagic( $com ) {
  59                 return wfSetVar( $this->mContainsOldMagic, $com );
  60         }
  61
  62         /**
  63          * setCacheTime() sets the timestamp expressing when the page has been rendered.
  64          * This does not control expiry, see updateCacheExpiry() for that!
  65          * @param $t string
  66          * @return string
  67          */
  68         function setCacheTime( $t ) {
  69                 return wfSetVar( $this->mCacheTime, $t );
  70         }
  71
  72         /**
  73          * Sets the number of seconds after which this object should expire.
  74          * This value is used with the ParserCache.
  75          * If called with a value greater than the value provided at any previous call,
  76          * the new call has no effect. The value returned by getCacheExpiry is smaller
  77          * or equal to the smallest number that was provided as an argument to
  78          * updateCacheExpiry().
  79          *
  80          * @param $seconds number
  81          */
  82         function updateCacheExpiry( $seconds ) {
  83                 $seconds = (int)$seconds;
  84
  85                 if ( $this->mCacheExpiry === null || $this->mCacheExpiry > $seconds ) {
  86                         $this->mCacheExpiry = $seconds;
  87                 }
  88
  89                 // hack: set old-style marker for uncacheable entries.
  90                 if ( $this->mCacheExpiry !== null && $this->mCacheExpiry <= 0 ) {
  91                         $this->mCacheTime = -1;
  92                 }
  93         }
  94
  95         /**
  96          * Returns the number of seconds after which this object should expire.
  97          * This method is used by ParserCache to determine how long the ParserOutput can be cached.
  98          * The timestamp of expiry can be calculated by adding getCacheExpiry() to getCacheTime().
  99          * The value returned by getCacheExpiry is smaller or equal to the smallest number
 100          * that was provided to a call of updateCacheExpiry(), and smaller or equal to the
 101          * value of $wgParserCacheExpireTime.
 102          * @return int|mixed|null
 103          */
 104         function getCacheExpiry() {
 105                 global $wgParserCacheExpireTime;
 106
 107                 if ( $this->mCacheTime < 0 ) {
 108                         return 0;
 109                 } // old-style marker for "not cachable"
 110
 111                 $expire = $this->mCacheExpiry;
 112
 113                 if ( $expire === null ) {
 114                         $expire = $wgParserCacheExpireTime;
 115                 } else {
 116                         $expire = min( $expire, $wgParserCacheExpireTime );
 117                 }
 118
 119                 if ( $this->containsOldMagic() ) { //compatibility hack
 120                         $expire = min( $expire, 3600 ); # 1 hour
 121                 }
 122
 123                 if ( $expire <= 0 ) {
 124                         return 0; // not cachable
 125                 } else {
 126                         return $expire;
 127                 }
 128         }
 129
 130         /**
 131          * @return bool
 132          */
 133         function isCacheable() {
 134                 return $this->getCacheExpiry() > 0;
 135         }
 136
 137         /**
 138          * Return true if this cached output object predates the global or
 139          * per-article cache invalidation timestamps, or if it comes from
 140          * an incompatible older version.
 141          *
 142          * @param string $touched the affected article's last touched timestamp
 143          * @return Boolean
 144          */
 145         public function expired( $touched ) {
 146                 global $wgCacheEpoch;
 147                 return !$this->isCacheable() || // parser says it's uncacheable
 148                         $this->getCacheTime() < $touched ||
 149                         $this->getCacheTime() <= $wgCacheEpoch ||
 150                         $this->getCacheTime() < wfTimestamp( TS_MW, time() - $this->getCacheExpiry() ) || // expiry period has passed
 151                         !isset( $this->mVersion ) ||
 152                         version_compare( $this->mVersion, Parser::VERSION, "lt" );
 153         }
 154
 155 }