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