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
  40                 return $instance;
  41         }
  42
  43         protected function __construct() {
  44         }
  45
  46         /**
  47          * Get a property of a user based on their user ID
  48          *
  49          * @param int $userId User ID
  50          * @param string $prop User property
  51          * @return mixed|bool The property or false if the user does not exist
  52          */
  53         public function getProp( $userId, $prop ) {
  54                 if ( !isset( $this->cache[$userId][$prop] ) ) {
  55                         wfDebug( __METHOD__ . ": querying DB for prop '$prop' for user ID '$userId'.\n" );
  56                         $this->doQuery( array( $userId ) ); // cache miss
  57                 }
  58
  59                 return isset( $this->cache[$userId][$prop] )
  60                         ? $this->cache[$userId][$prop]
  61                         : false; // user does not exist?
  62         }
  63
  64         /**
  65          * Get the name of a user or return $ip if the user ID is 0
  66          *
  67          * @param int $userId
  68          * @param string $ip
  69          * @return string
  70          * @since 1.22
  71          */
  72         public function getUserName( $userId, $ip ) {
  73                 return $userId > 0 ? $this->getProp( $userId, 'name' ) : $ip;
  74         }
  75
  76         /**
  77          * Preloads user names for given list of users.
  78          * @param array $userIds List of user IDs
  79          * @param array $options Option flags; include 'userpage' and 'usertalk'
  80          * @param string $caller The calling method
  81          */
  82         public function doQuery( array $userIds, $options = array(), $caller = '' ) {
  83
  84                 $usersToCheck = array();
  85                 $usersToQuery = array();
  86
  87                 $userIds = array_unique( $userIds );
  88
  89                 foreach ( $userIds as $userId ) {
  90                         $userId = (int)$userId;
  91                         if ( $userId <= 0 ) {
  92                                 continue; // skip anons
  93                         }
  94                         if ( isset( $this->cache[$userId]['name'] ) ) {
  95                                 $usersToCheck[$userId] = $this->cache[$userId]['name']; // already have name
  96                         } else {
  97                                 $usersToQuery[] = $userId; // we need to get the name
  98                         }
  99                 }
 100
 101                 // Lookup basic info for users not yet loaded...
 102                 if ( count( $usersToQuery ) ) {
 103                         $dbr = wfGetDB( DB_SLAVE );
 104                         $table = array( 'user' );
 105                         $conds = array( 'user_id' => $usersToQuery );
 106                         $fields = array( 'user_name', 'user_real_name', 'user_registration', 'user_id' );
 107
 108                         $comment = __METHOD__;
 109                         if ( strval( $caller ) !== '' ) {
 110                                 $comment .= "/$caller";
 111                         }
 112
 113                         $res = $dbr->select( $table, $fields, $conds, $comment );
 114                         foreach ( $res as $row ) { // load each user into cache
 115                                 $userId = (int)$row->user_id;
 116                                 $this->cache[$userId]['name'] = $row->user_name;
 117                                 $this->cache[$userId]['real_name'] = $row->user_real_name;
 118                                 $this->cache[$userId]['registration'] = $row->user_registration;
 119                                 $usersToCheck[$userId] = $row->user_name;
 120                         }
 121                 }
 122
 123                 $lb = new LinkBatch();
 124                 foreach ( $usersToCheck as $userId => $name ) {
 125                         if ( $this->queryNeeded( $userId, 'userpage', $options ) ) {
 126                                 $lb->add( NS_USER, $name );
 127                                 $this->typesCached[$userId]['userpage'] = 1;
 128                         }
 129                         if ( $this->queryNeeded( $userId, 'usertalk', $options ) ) {
 130                                 $lb->add( NS_USER_TALK, $name );
 131                                 $this->typesCached[$userId]['usertalk'] = 1;
 132                         }
 133                 }
 134                 $lb->execute();
 135
 136         }
 137
 138         /**
 139          * Check if a cache type is in $options and was not loaded for this user
 140          *
 141          * @param int $uid User ID
 142          * @param string $type Cache type
 143          * @param array $options Requested cache types
 144          * @return bool
 145          */
 146         protected function queryNeeded( $uid, $type, array $options ) {
 147                 return ( in_array( $type, $options ) && !isset( $this->typesCached[$uid][$type] ) );
 148         }
 149 }