maintenance/userDupes.inc

   1 <?php
   2 /**
   3  * Helper class for update.php.
   4  *
   5  * Copyright © 2005 Brion Vibber <brion@pobox.com>
   6  * https://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  * @ingroup Maintenance
  25  */
  26
  27 /**
  28  * Look for duplicate user table entries and optionally prune them.
  29  *
  30  * This is still used by our MysqlUpdater at:
  31  * includes/installer/MysqlUpdater.php
  32  *
  33  * @ingroup Maintenance
  34  */
  35 class UserDupes {
  36         private $db;
  37         private $reassigned;
  38         private $trimmed;
  39         private $failed;
  40         private $outputCallback;
  41
  42         function __construct( &$database, $outputCallback ) {
  43                 $this->db = $database;
  44                 $this->outputCallback = $outputCallback;
  45         }
  46
  47         /**
  48          * Output some text via the output callback provided
  49          * @param $str String Text to print
  50          */
  51         private function out( $str ) {
  52                 call_user_func( $this->outputCallback, $str );
  53         }
  54
  55         /**
  56          * Check if this database's user table has already had a unique
  57          * user_name index applied.
  58          * @return bool
  59          */
  60         function hasUniqueIndex() {
  61                 $info = $this->db->indexInfo( 'user', 'user_name', __METHOD__ );
  62                 if ( !$info ) {
  63                         $this->out( "WARNING: doesn't seem to have user_name index at all!\n" );
  64                         return false;
  65                 }
  66
  67                 # Confusingly, 'Non_unique' is 0 for *unique* indexes,
  68                 # and 1 for *non-unique* indexes. Pass the crack, MySQL,
  69                 # it's obviously some good stuff!
  70                 return ( $info[0]->Non_unique == 0 );
  71         }
  72
  73         /**
  74          * Checks the database for duplicate user account records
  75          * and remove them in preparation for application of a unique
  76          * index on the user_name field. Returns true if the table is
  77          * clean or if duplicates have been resolved automatically.
  78          *
  79          * May return false if there are unresolvable problems.
  80          * Status information will be echo'd to stdout.
  81          *
  82          * @return bool
  83          */
  84         function clearDupes() {
  85                 return $this->checkDupes( true );
  86         }
  87
  88         /**
  89          * Checks the database for duplicate user account records
  90          * in preparation for application of a unique index on the
  91          * user_name field. Returns true if the table is clean or
  92          * if duplicates can be resolved automatically.
  93          *
  94          * Returns false if there are duplicates and resolution was
  95          * not requested. (If doing resolution, edits may be reassigned.)
  96          * Status information will be echo'd to stdout.
  97          *
  98          * @param $doDelete bool: pass true to actually remove things
  99          *                  from the database; false to just check.
 100          * @return bool
 101          */
 102         function checkDupes( $doDelete = false ) {
 103                 if ( $this->hasUniqueIndex() ) {
 104                         echo wfWikiID() . " already has a unique index on its user table.\n";
 105                         return true;
 106                 }
 107
 108                 $this->lock();
 109
 110                 $this->out( "Checking for duplicate accounts...\n" );
 111                 $dupes = $this->getDupes();
 112                 $count = count( $dupes );
 113
 114                 $this->out( "Found $count accounts with duplicate records on " . wfWikiID() . ".\n" );
 115                 $this->trimmed = 0;
 116                 $this->reassigned = 0;
 117                 $this->failed = 0;
 118                 foreach ( $dupes as $name ) {
 119                         $this->examine( $name, $doDelete );
 120                 }
 121
 122                 $this->unlock();
 123
 124                 $this->out( "\n" );
 125
 126                 if ( $this->reassigned > 0 ) {
 127                         if ( $doDelete ) {
 128                                 $this->out( "$this->reassigned duplicate accounts had edits reassigned to a canonical record id.\n" );
 129                         } else {
 130                                 $this->out( "$this->reassigned duplicate accounts need to have edits reassigned.\n" );
 131                         }
 132                 }
 133
 134                 if ( $this->trimmed > 0 ) {
 135                         if ( $doDelete ) {
 136                                 $this->out( "$this->trimmed duplicate user records were deleted from " . wfWikiID() . ".\n" );
 137                         } else {
 138                                 $this->out( "$this->trimmed duplicate user accounts were found on " . wfWikiID() . " which can be removed safely.\n" );
 139                         }
 140                 }
 141
 142                 if ( $this->failed > 0 ) {
 143                         $this->out( "Something terribly awry; $this->failed duplicate accounts were not removed.\n" );
 144                         return false;
 145                 }
 146
 147                 if ( $this->trimmed == 0 || $doDelete ) {
 148                         $this->out( "It is now safe to apply the unique index on user_name.\n" );
 149                         return true;
 150                 } else {
 151                         $this->out( "Run this script again with the --fix option to automatically delete them.\n" );
 152                         return false;
 153                 }
 154         }
 155
 156         /**
 157          * We don't want anybody to mess with our stuff...
 158          * @access private
 159          */
 160         function lock() {
 161                 $set = array( 'user', 'revision' );
 162                 $names = array_map( array( $this, 'lockTable' ), $set );
 163                 $tables = implode( ',', $names );
 164
 165                 $this->db->query( "LOCK TABLES $tables", __METHOD__ );
 166         }
 167
 168         function lockTable( $table ) {
 169                 return $this->db->tableName( $table ) . ' WRITE';
 170         }
 171
 172         /**
 173          * @access private
 174          */
 175         function unlock() {
 176                 $this->db->query( "UNLOCK TABLES", __METHOD__ );
 177         }
 178
 179         /**
 180          * Grab usernames for which multiple records are present in the database.
 181          * @return array
 182          * @access private
 183          */
 184         function getDupes() {
 185                 $user = $this->db->tableName( 'user' );
 186                 $result = $this->db->query(
 187                         "SELECT user_name,COUNT(*) AS n
 188                                 FROM $user
 189                         GROUP BY user_name
 190                           HAVING n > 1", __METHOD__ );
 191
 192                 $list = array();
 193                 foreach ( $result as $row ) {
 194                         $list[] = $row->user_name;
 195                 }
 196                 return $list;
 197         }
 198
 199         /**
 200          * Examine user records for the given name. Try to see which record
 201          * will be the one that actually gets used, then check remaining records
 202          * for edits. If the dupes have no edits, we can safely remove them.
 203          * @param $name string
 204          * @param $doDelete bool
 205          * @access private
 206          */
 207         function examine( $name, $doDelete ) {
 208                 $result = $this->db->select( 'user',
 209                         array( 'user_id' ),
 210                         array( 'user_name' => $name ),
 211                         __METHOD__ );
 212
 213                 $firstRow = $this->db->fetchObject( $result );
 214                 $firstId = $firstRow->user_id;
 215                 $this->out( "Record that will be used for '$name' is user_id=$firstId\n" );
 216
 217                 foreach ( $result as $row ) {
 218                         $dupeId = $row->user_id;
 219                         $this->out( "... dupe id $dupeId: " );
 220                         $edits = $this->editCount( $dupeId );
 221                         if ( $edits > 0 ) {
 222                                 $this->reassigned++;
 223                                 $this->out( "has $edits edits! " );
 224                                 if ( $doDelete ) {
 225                                         $this->reassignEdits( $dupeId, $firstId );
 226                                         $newEdits = $this->editCount( $dupeId );
 227                                         if ( $newEdits == 0 ) {
 228                                                 $this->out( "confirmed cleaned. " );
 229                                         } else {
 230                                                 $this->failed++;
 231                                                 $this->out( "WARNING! $newEdits remaining edits for $dupeId; NOT deleting user.\n" );
 232                                                 continue;
 233                                         }
 234                                 } else {
 235                                         $this->out( "(will need to reassign edits on fix)" );
 236                                 }
 237                         } else {
 238                                 $this->out( "ok, no edits. " );
 239                         }
 240                         $this->trimmed++;
 241                         if ( $doDelete ) {
 242                                 $this->trimAccount( $dupeId );
 243                         }
 244                         $this->out( "\n" );
 245                 }
 246         }
 247
 248         /**
 249          * Count the number of edits attributed to this user.
 250          * Does not currently check log table or other things
 251          * where it might show up...
 252          * @param $userid int
 253          * @return int
 254          * @access private
 255          */
 256         function editCount( $userid ) {
 257                 return intval( $this->db->selectField(
 258                         'revision',
 259                         'COUNT(*)',
 260                         array( 'rev_user' => $userid ),
 261                         __METHOD__ ) );
 262         }
 263
 264         /**
 265          * @param $from int
 266          * @param $to int
 267          * @access private
 268          */
 269         function reassignEdits( $from, $to ) {
 270                 $this->out( 'reassigning... ' );
 271                 $this->db->update( 'revision',
 272                         array( 'rev_user' => $to ),
 273                         array( 'rev_user' => $from ),
 274                         __METHOD__ );
 275                 $this->out( "ok. " );
 276         }
 277
 278         /**
 279          * Remove a user account line.
 280          * @param $userid int
 281          * @access private
 282          */
 283         function trimAccount( $userid ) {
 284                 $this->out( "deleting..." );
 285                 $this->db->delete( 'user', array( 'user_id' => $userid ), __METHOD__ );
 286                 $this->out( " ok" );
 287         }
 288
 289 }