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 = []; // (uid => property => value)
  29         protected $typesCached = []; // (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( [ $userId ] ); // cache miss
  57                 }
  58
  59                 return $this->cache[$userId][$prop] ?? false; // user does not exist?
  60         }
  61
  62         /**
  63          * Get the name of a user or return $ip if the user ID is 0
  64          *
  65          * @param int $userId
  66          * @param string $ip
  67          * @return string
  68          * @since 1.22
  69          */
  70         public function getUserName( $userId, $ip ) {
  71                 return $userId > 0 ? $this->getProp( $userId, 'name' ) : $ip;
  72         }
  73
  74         /**
  75          * Preloads user names for given list of users.
  76          * @param array $userIds List of user IDs
  77          * @param array $options Option flags; include 'userpage' and 'usertalk'
  78          * @param string $caller The calling method
  79          */
  80         public function doQuery( array $userIds, $options = [], $caller = '' ) {
  81                 global $wgActorTableSchemaMigrationStage;
  82
  83                 $usersToCheck = [];
  84                 $usersToQuery = [];
  85
  86                 $userIds = array_unique( $userIds );
  87
  88                 foreach ( $userIds as $userId ) {
  89                         $userId = (int)$userId;
  90                         if ( $userId <= 0 ) {
  91                                 continue; // skip anons
  92                         }
  93                         if ( isset( $this->cache[$userId]['name'] ) ) {
  94                                 $usersToCheck[$userId] = $this->cache[$userId]['name']; // already have name
  95                         } else {
  96                                 $usersToQuery[] = $userId; // we need to get the name
  97                         }
  98                 }
  99
 100                 // Lookup basic info for users not yet loaded...
 101                 if ( count( $usersToQuery ) ) {
 102                         $dbr = wfGetDB( DB_REPLICA );
 103                         $tables = [ 'user' ];
 104                         $conds = [ 'user_id' => $usersToQuery ];
 105                         $fields = [ 'user_name', 'user_real_name', 'user_registration', 'user_id' ];
 106                         $joinConds = [];
 107
 108                         // Technically we shouldn't allow this without SCHEMA_COMPAT_READ_NEW,
 109                         // but it does little harm and might be needed for write callers loading a User.
 110                         if ( $wgActorTableSchemaMigrationStage & SCHEMA_COMPAT_NEW ) {
 111                                 $tables[] = 'actor';
 112                                 $fields[] = 'actor_id';
 113                                 $joinConds['actor'] = [
 114                                         ( $wgActorTableSchemaMigrationStage & SCHEMA_COMPAT_READ_NEW ) ? 'JOIN' : 'LEFT JOIN',
 115                                         [ 'actor_user = user_id' ]
 116                                 ];
 117                         }
 118
 119                         $comment = __METHOD__;
 120                         if ( strval( $caller ) !== '' ) {
 121                                 $comment .= "/$caller";
 122                         }
 123
 124                         $res = $dbr->select( $tables, $fields, $conds, $comment, [], $joinConds );
 125                         foreach ( $res as $row ) { // load each user into cache
 126                                 $userId = (int)$row->user_id;
 127                                 $this->cache[$userId]['name'] = $row->user_name;
 128                                 $this->cache[$userId]['real_name'] = $row->user_real_name;
 129                                 $this->cache[$userId]['registration'] = $row->user_registration;
 130                                 if ( $wgActorTableSchemaMigrationStage & SCHEMA_COMPAT_NEW ) {
 131                                         $this->cache[$userId]['actor'] = $row->actor_id;
 132                                 }
 133                                 $usersToCheck[$userId] = $row->user_name;
 134                         }
 135                 }
 136
 137                 $lb = new LinkBatch();
 138                 foreach ( $usersToCheck as $userId => $name ) {
 139                         if ( $this->queryNeeded( $userId, 'userpage', $options ) ) {
 140                                 $lb->add( NS_USER, $name );
 141                                 $this->typesCached[$userId]['userpage'] = 1;
 142                         }
 143                         if ( $this->queryNeeded( $userId, 'usertalk', $options ) ) {
 144                                 $lb->add( NS_USER_TALK, $name );
 145                                 $this->typesCached[$userId]['usertalk'] = 1;
 146                         }
 147                 }
 148                 $lb->execute();
 149         }
 150
 151         /**
 152          * Check if a cache type is in $options and was not loaded for this user
 153          *
 154          * @param int $uid User ID
 155          * @param string $type Cache type
 156          * @param array $options Requested cache types
 157          * @return bool
 158          */
 159         protected function queryNeeded( $uid, $type, array $options ) {
 160                 return ( in_array( $type, $options ) && !isset( $this->typesCached[$uid][$type] ) );
 161         }
 162 }