includes/revisiondelete/RevisionDeleter.php

   1 <?php
   2 /**
   3  * Revision/log/file deletion backend
   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 RevisionDelete
  22  */
  23
  24 /**
  25  * General controller for RevDel, used by both SpecialRevisiondelete and
  26  * ApiRevisionDelete.
  27  * @ingroup RevisionDelete
  28  */
  29 class RevisionDeleter {
  30         /** List of known revdel types, with their corresponding list classes */
  31         private static $allowedTypes = [
  32                 'revision' => 'RevDelRevisionList',
  33                 'archive' => 'RevDelArchiveList',
  34                 'oldimage' => 'RevDelFileList',
  35                 'filearchive' => 'RevDelArchivedFileList',
  36                 'logging' => 'RevDelLogList',
  37         ];
  38
  39         /** Type map to support old log entries */
  40         private static $deprecatedTypeMap = [
  41                 'oldid' => 'revision',
  42                 'artimestamp' => 'archive',
  43                 'oldimage' => 'oldimage',
  44                 'fileid' => 'filearchive',
  45                 'logid' => 'logging',
  46         ];
  47
  48         /**
  49          * Lists the valid possible types for revision deletion.
  50          *
  51          * @since 1.22
  52          * @return array
  53          */
  54         public static function getTypes() {
  55                 return array_keys( self::$allowedTypes );
  56         }
  57
  58         /**
  59          * Gets the canonical type name, if any.
  60          *
  61          * @since 1.22
  62          * @param string $typeName
  63          * @return string|null
  64          */
  65         public static function getCanonicalTypeName( $typeName ) {
  66                 if ( isset( self::$deprecatedTypeMap[$typeName] ) ) {
  67                         $typeName = self::$deprecatedTypeMap[$typeName];
  68                 }
  69                 return isset( self::$allowedTypes[$typeName] ) ? $typeName : null;
  70         }
  71
  72         /**
  73          * Instantiate the appropriate list class for a given list of IDs.
  74          *
  75          * @since 1.22
  76          * @param string $typeName RevDel type, see RevisionDeleter::getTypes()
  77          * @param IContextSource $context
  78          * @param Title $title
  79          * @param array $ids
  80          * @return RevDelList
  81          * @throws MWException
  82          */
  83         public static function createList( $typeName, IContextSource $context, Title $title, array $ids ) {
  84                 $typeName = self::getCanonicalTypeName( $typeName );
  85                 if ( !$typeName ) {
  86                         throw new MWException( __METHOD__ . ": Unknown RevDel type '$typeName'" );
  87                 }
  88                 $class = self::$allowedTypes[$typeName];
  89                 return new $class( $context, $title, $ids );
  90         }
  91
  92         /**
  93          * Checks for a change in the bitfield for a certain option and updates the
  94          * provided array accordingly.
  95          *
  96          * @param string $desc Description to add to the array if the option was
  97          * enabled / disabled.
  98          * @param int $field The bitmask describing the single option.
  99          * @param int $diff The xor of the old and new bitfields.
 100          * @param int $new The new bitfield
 101          * @param array $arr The array to update.
 102          */
 103         protected static function checkItem( $desc, $field, $diff, $new, &$arr ) {
 104                 if ( $diff & $field ) {
 105                         $arr[( $new & $field ) ? 0 : 1][] = $desc;
 106                 }
 107         }
 108
 109         /**
 110          * Gets an array of message keys describing the changes made to the
 111          * visibility of the revision.
 112          *
 113          * If the resulting array is $arr, then $arr[0] will contain an array of
 114          * keys describing the items that were hidden, $arr[1] will contain
 115          * an array of keys describing the items that were unhidden, and $arr[2]
 116          * will contain an array with a single message key, which can be one of
 117          * "revdelete-restricted", "revdelete-unrestricted" indicating (un)suppression
 118          * or null to indicate nothing in particular.
 119          * You can turn the keys in $arr[0] and $arr[1] into message keys by
 120          * appending -hid and -unhid to the keys respectively.
 121          *
 122          * @param int $n The new bitfield.
 123          * @param int $o The old bitfield.
 124          * @return array An array as described above.
 125          * @since 1.19 public
 126          */
 127         public static function getChanges( $n, $o ) {
 128                 $diff = $n ^ $o;
 129                 $ret = [ 0 => [], 1 => [], 2 => [] ];
 130                 // Build bitfield changes in language
 131                 self::checkItem( 'revdelete-content',
 132                         Revision::DELETED_TEXT, $diff, $n, $ret );
 133                 self::checkItem( 'revdelete-summary',
 134                         Revision::DELETED_COMMENT, $diff, $n, $ret );
 135                 self::checkItem( 'revdelete-uname',
 136                         Revision::DELETED_USER, $diff, $n, $ret );
 137                 // Restriction application to sysops
 138                 if ( $diff & Revision::DELETED_RESTRICTED ) {
 139                         if ( $n & Revision::DELETED_RESTRICTED ) {
 140                                 $ret[2][] = 'revdelete-restricted';
 141                         } else {
 142                                 $ret[2][] = 'revdelete-unrestricted';
 143                         }
 144                 }
 145                 return $ret;
 146         }
 147
 148         /** Get DB field name for URL param...
 149          * Future code for other things may also track
 150          * other types of revision-specific changes.
 151          * @param string $typeName
 152          * @return string One of log_id/rev_id/fa_id/ar_timestamp/oi_archive_name
 153          */
 154         public static function getRelationType( $typeName ) {
 155                 $typeName = self::getCanonicalTypeName( $typeName );
 156                 if ( !$typeName ) {
 157                         return null;
 158                 }
 159                 return call_user_func( [ self::$allowedTypes[$typeName], 'getRelationType' ] );
 160         }
 161
 162         /**
 163          * Get the user right required for the RevDel type
 164          * @since 1.22
 165          * @param string $typeName
 166          * @return string User right
 167          */
 168         public static function getRestriction( $typeName ) {
 169                 $typeName = self::getCanonicalTypeName( $typeName );
 170                 if ( !$typeName ) {
 171                         return null;
 172                 }
 173                 return call_user_func( [ self::$allowedTypes[$typeName], 'getRestriction' ] );
 174         }
 175
 176         /**
 177          * Get the revision deletion constant for the RevDel type
 178          * @since 1.22
 179          * @param string $typeName
 180          * @return int RevDel constant
 181          */
 182         public static function getRevdelConstant( $typeName ) {
 183                 $typeName = self::getCanonicalTypeName( $typeName );
 184                 if ( !$typeName ) {
 185                         return null;
 186                 }
 187                 return call_user_func( [ self::$allowedTypes[$typeName], 'getRevdelConstant' ] );
 188         }
 189
 190         /**
 191          * Suggest a target for the revision deletion
 192          * @since 1.22
 193          * @param string $typeName
 194          * @param Title|null $target User-supplied target
 195          * @param array $ids
 196          * @return Title|null
 197          */
 198         public static function suggestTarget( $typeName, $target, array $ids ) {
 199                 $typeName = self::getCanonicalTypeName( $typeName );
 200                 if ( !$typeName ) {
 201                         return $target;
 202                 }
 203                 return call_user_func( [ self::$allowedTypes[$typeName], 'suggestTarget' ], $target, $ids );
 204         }
 205
 206         /**
 207          * Checks if a revision still exists in the revision table.
 208          * If it doesn't, returns the corresponding ar_timestamp field
 209          * so that this key can be used instead.
 210          *
 211          * @param Title $title
 212          * @param int $revid
 213          * @return bool|mixed
 214          */
 215         public static function checkRevisionExistence( $title, $revid ) {
 216                 $dbr = wfGetDB( DB_REPLICA );
 217                 $exists = $dbr->selectField( 'revision', '1',
 218                                 [ 'rev_id' => $revid ], __METHOD__ );
 219
 220                 if ( $exists ) {
 221                         return true;
 222                 }
 223
 224                 $timestamp = $dbr->selectField( 'archive', 'ar_timestamp',
 225                                 [ 'ar_namespace' => $title->getNamespace(),
 226                                         'ar_title' => $title->getDBkey(),
 227                                         'ar_rev_id' => $revid ], __METHOD__ );
 228
 229                 return $timestamp;
 230         }
 231
 232         /**
 233          * Put together a rev_deleted bitfield
 234          * @since 1.22
 235          * @param array $bitPars ExtractBitParams() params
 236          * @param int $oldfield Current bitfield
 237          * @return integer
 238          */
 239         public static function extractBitfield( array $bitPars, $oldfield ) {
 240                 // Build the actual new rev_deleted bitfield
 241                 $newBits = 0;
 242                 foreach ( $bitPars as $const => $val ) {
 243                         if ( $val == 1 ) {
 244                                 $newBits |= $const; // $const is the *_deleted const
 245                         } elseif ( $val == -1 ) {
 246                                 $newBits |= ( $oldfield & $const ); // use existing
 247                         }
 248                 }
 249                 return $newBits;
 250         }
 251 }