includes/cache/UserCache.php

   1 <?php
   2 /**
   3  * Caches current user names and other info based on user IDs.
   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 Cache
  22  */
  23
  24 /**
  25  * @since 1.20
  26  */
  27 class UserCache {
  28         protected $cache = array(); // (uid => property => value)
  29         protected $typesCached = array(); // (uid => cache type => 1)
  30
  31         /**
  32          * @return UserCache
  33          */
  34         public static function singleton() {
  35                 static $instance = null;
  36                 if ( $instance === null ) {
  37                         $instance = new self();
  38                 }
  39                 return $instance;
  40         }
  41
  42         protected function __construct() {}
  43
  44         /**
  45          * Get a property of a user based on their user ID
  46          *
  47          * @param $userId integer User ID
  48          * @param $prop string User property
  49          * @return mixed The property or false if the user does not exist
  50          */
  51         public function getProp( $userId, $prop ) {
  52                 if ( !isset( $this->cache[$userId][$prop] ) ) {
  53                         wfDebug( __METHOD__ . ": querying DB for prop '$prop' for user ID '$userId'.\n" );
  54                         $this->doQuery( array( $userId ) ); // cache miss
  55                 }
  56                 return isset( $this->cache[$userId][$prop] )
  57                         ? $this->cache[$userId][$prop]
  58                         : false; // user does not exist?
  59         }
  60
  61         /**
  62          * Preloads user names for given list of users.
  63          * @param $userIds Array List of user IDs
  64          * @param $options Array Option flags; include 'userpage' and 'usertalk'
  65          * @param $caller String: the calling method
  66          */
  67         public function doQuery( array $userIds, $options = array(), $caller = '' ) {
  68                 wfProfileIn( __METHOD__ );
  69
  70                 $usersToCheck = array();
  71                 $usersToQuery = array();
  72
  73                 foreach ( $userIds as $userId ) {
  74                         $userId = (int)$userId;
  75                         if ( $userId <= 0 ) {
  76                                 continue; // skip anons
  77                         }
  78                         if ( isset( $this->cache[$userId]['name'] ) ) {
  79                                 $usersToCheck[$userId] = $this->cache[$userId]['name']; // already have name
  80                         } else {
  81                                 $usersToQuery[] = $userId; // we need to get the name
  82                         }
  83                 }
  84
  85                 // Lookup basic info for users not yet loaded...
  86                 if ( count( $usersToQuery ) ) {
  87                         $dbr = wfGetDB( DB_SLAVE );
  88                         $table = array( 'user' );
  89                         $conds = array( 'user_id' => $usersToQuery );
  90                         $fields = array( 'user_name', 'user_real_name', 'user_registration', 'user_id' );
  91
  92                         $comment = __METHOD__;
  93                         if ( strval( $caller ) !== '' ) {
  94                                 $comment .= "/$caller";
  95                         }
  96
  97                         $res = $dbr->select( $table, $fields, $conds, $comment );
  98                         foreach ( $res as $row ) { // load each user into cache
  99                                 $userId = (int)$row->user_id;
 100                                 $this->cache[$userId]['name'] = $row->user_name;
 101                                 $this->cache[$userId]['real_name'] = $row->user_real_name;
 102                                 $this->cache[$userId]['registration'] = $row->user_registration;
 103                                 $usersToCheck[$userId] = $row->user_name;
 104                         }
 105                 }
 106
 107                 $lb = new LinkBatch();
 108                 foreach ( $usersToCheck as $userId => $name ) {
 109                         if ( $this->queryNeeded( $userId, 'userpage', $options ) ) {
 110                                 $lb->add( NS_USER, str_replace( ' ', '_', $row->user_name ) );
 111                                 $this->typesCached[$userId]['userpage'] = 1;
 112                         }
 113                         if ( $this->queryNeeded( $userId, 'usertalk', $options ) ) {
 114                                 $lb->add( NS_USER_TALK, str_replace( ' ', '_', $row->user_name ) );
 115                                 $this->typesCached[$userId]['usertalk'] = 1;
 116                         }
 117                 }
 118                 $lb->execute();
 119
 120                 wfProfileOut( __METHOD__ );
 121         }
 122
 123         /**
 124          * Check if a cache type is in $options and was not loaded for this user
 125          *
 126          * @param $uid integer user ID
 127          * @param $type string Cache type
 128          * @param $options Array Requested cache types
 129          * @return bool
 130          */
 131         protected function queryNeeded( $uid, $type, array $options ) {
 132                 return ( in_array( $type, $options ) && !isset( $this->typesCached[$uid][$type] ) );
 133         }
 134 }