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 use MediaWiki\Storage\RevisionRecord;
  25
  26 /**
  27  * General controller for RevDel, used by both SpecialRevisiondelete and
  28  * ApiRevisionDelete.
  29  * @ingroup RevisionDelete
  30  */
  31 class RevisionDeleter {
  32         /** List of known revdel types, with their corresponding list classes */
  33         private static $allowedTypes = [
  34                 'revision' => RevDelRevisionList::class,
  35                 'archive' => RevDelArchiveList::class,
  36                 'oldimage' => RevDelFileList::class,
  37                 'filearchive' => RevDelArchivedFileList::class,
  38                 'logging' => RevDelLogList::class,
  39         ];
  40
  41         /** Type map to support old log entries */
  42         private static $deprecatedTypeMap = [
  43                 'oldid' => 'revision',
  44                 'artimestamp' => 'archive',
  45                 'oldimage' => 'oldimage',
  46                 'fileid' => 'filearchive',
  47                 'logid' => 'logging',
  48         ];
  49
  50         /**
  51          * Lists the valid possible types for revision deletion.
  52          *
  53          * @since 1.22
  54          * @return array
  55          */
  56         public static function getTypes() {
  57                 return array_keys( self::$allowedTypes );
  58         }
  59
  60         /**
  61          * Gets the canonical type name, if any.
  62          *
  63          * @since 1.22
  64          * @param string $typeName
  65          * @return string|null
  66          */
  67         public static function getCanonicalTypeName( $typeName ) {
  68                 if ( isset( self::$deprecatedTypeMap[$typeName] ) ) {
  69                         $typeName = self::$deprecatedTypeMap[$typeName];
  70                 }
  71                 return isset( self::$allowedTypes[$typeName] ) ? $typeName : null;
  72         }
  73
  74         /**
  75          * Instantiate the appropriate list class for a given list of IDs.
  76          *
  77          * @since 1.22
  78          * @param string $typeName RevDel type, see RevisionDeleter::getTypes()
  79          * @param IContextSource $context
  80          * @param Title $title
  81          * @param array $ids
  82          * @return RevDelList
  83          * @throws MWException
  84          */
  85         public static function createList( $typeName, IContextSource $context, Title $title, array $ids ) {
  86                 $typeName = self::getCanonicalTypeName( $typeName );
  87                 if ( !$typeName ) {
  88                         throw new MWException( __METHOD__ . ": Unknown RevDel type '$typeName'" );
  89                 }
  90                 $class = self::$allowedTypes[$typeName];
  91                 return new $class( $context, $title, $ids );
  92         }
  93
  94         /**
  95          * Checks for a change in the bitfield for a certain option and updates the
  96          * provided array accordingly.
  97          *
  98          * @param string $desc Description to add to the array if the option was
  99          * enabled / disabled.
 100          * @param int $field The bitmask describing the single option.
 101          * @param int $diff The xor of the old and new bitfields.
 102          * @param int $new The new bitfield
 103          * @param array &$arr The array to update.
 104          */
 105         protected static function checkItem( $desc, $field, $diff, $new, &$arr ) {
 106                 if ( $diff & $field ) {
 107                         $arr[( $new & $field ) ? 0 : 1][] = $desc;
 108                 }
 109         }
 110
 111         /**
 112          * Gets an array of message keys describing the changes made to the
 113          * visibility of the revision.
 114          *
 115          * If the resulting array is $arr, then $arr[0] will contain an array of
 116          * keys describing the items that were hidden, $arr[1] will contain
 117          * an array of keys describing the items that were unhidden, and $arr[2]
 118          * will contain an array with a single message key, which can be one of
 119          * "revdelete-restricted", "revdelete-unrestricted" indicating (un)suppression
 120          * or null to indicate nothing in particular.
 121          * You can turn the keys in $arr[0] and $arr[1] into message keys by
 122          * appending -hid and -unhid to the keys respectively.
 123          *
 124          * @param int $n The new bitfield.
 125          * @param int $o The old bitfield.
 126          * @return array An array as described above.
 127          * @since 1.19 public
 128          */
 129         public static function getChanges( $n, $o ) {
 130                 $diff = $n ^ $o;
 131                 $ret = [ 0 => [], 1 => [], 2 => [] ];
 132                 // Build bitfield changes in language
 133                 self::checkItem( 'revdelete-content',
 134                         RevisionRecord::DELETED_TEXT, $diff, $n, $ret );
 135                 self::checkItem( 'revdelete-summary',
 136                         RevisionRecord::DELETED_COMMENT, $diff, $n, $ret );
 137                 self::checkItem( 'revdelete-uname',
 138                         RevisionRecord::DELETED_USER, $diff, $n, $ret );
 139                 // Restriction application to sysops
 140                 if ( $diff & RevisionRecord::DELETED_RESTRICTED ) {
 141                         if ( $n & RevisionRecord::DELETED_RESTRICTED ) {
 142                                 $ret[2][] = 'revdelete-restricted';
 143                         } else {
 144                                 $ret[2][] = 'revdelete-unrestricted';
 145                         }
 146                 }
 147                 return $ret;
 148         }
 149
 150         /** Get DB field name for URL param...
 151          * Future code for other things may also track
 152          * other types of revision-specific changes.
 153          * @param string $typeName
 154          * @return string One of log_id/rev_id/fa_id/ar_timestamp/oi_archive_name
 155          */
 156         public static function getRelationType( $typeName ) {
 157                 $typeName = self::getCanonicalTypeName( $typeName );
 158                 if ( !$typeName ) {
 159                         return null;
 160                 }
 161                 return call_user_func( [ self::$allowedTypes[$typeName], 'getRelationType' ] );
 162         }
 163
 164         /**
 165          * Get the user right required for the RevDel type
 166          * @since 1.22
 167          * @param string $typeName
 168          * @return string User right
 169          */
 170         public static function getRestriction( $typeName ) {
 171                 $typeName = self::getCanonicalTypeName( $typeName );
 172                 if ( !$typeName ) {
 173                         return null;
 174                 }
 175                 return call_user_func( [ self::$allowedTypes[$typeName], 'getRestriction' ] );
 176         }
 177
 178         /**
 179          * Get the revision deletion constant for the RevDel type
 180          * @since 1.22
 181          * @param string $typeName
 182          * @return int RevDel constant
 183          */
 184         public static function getRevdelConstant( $typeName ) {
 185                 $typeName = self::getCanonicalTypeName( $typeName );
 186                 if ( !$typeName ) {
 187                         return null;
 188                 }
 189                 return call_user_func( [ self::$allowedTypes[$typeName], 'getRevdelConstant' ] );
 190         }
 191
 192         /**
 193          * Suggest a target for the revision deletion
 194          * @since 1.22
 195          * @param string $typeName
 196          * @param Title|null $target User-supplied target
 197          * @param array $ids
 198          * @return Title|null
 199          */
 200         public static function suggestTarget( $typeName, $target, array $ids ) {
 201                 $typeName = self::getCanonicalTypeName( $typeName );
 202                 if ( !$typeName ) {
 203                         return $target;
 204                 }
 205                 return call_user_func( [ self::$allowedTypes[$typeName], 'suggestTarget' ], $target, $ids );
 206         }
 207
 208         /**
 209          * Checks if a revision still exists in the revision table.
 210          * If it doesn't, returns the corresponding ar_timestamp field
 211          * so that this key can be used instead.
 212          *
 213          * @param Title $title
 214          * @param int $revid
 215          * @return bool|mixed
 216          */
 217         public static function checkRevisionExistence( $title, $revid ) {
 218                 $dbr = wfGetDB( DB_REPLICA );
 219                 $exists = $dbr->selectField( 'revision', '1',
 220                                 [ 'rev_id' => $revid ], __METHOD__ );
 221
 222                 if ( $exists ) {
 223                         return true;
 224                 }
 225
 226                 $timestamp = $dbr->selectField( 'archive', 'ar_timestamp',
 227                                 [ 'ar_namespace' => $title->getNamespace(),
 228                                         'ar_title' => $title->getDBkey(),
 229                                         'ar_rev_id' => $revid ], __METHOD__ );
 230
 231                 return $timestamp;
 232         }
 233
 234         /**
 235          * Put together a rev_deleted bitfield
 236          * @since 1.22
 237          * @param array $bitPars ExtractBitParams() params
 238          * @param int $oldfield Current bitfield
 239          * @return int
 240          */
 241         public static function extractBitfield( array $bitPars, $oldfield ) {
 242                 // Build the actual new rev_deleted bitfield
 243                 $newBits = 0;
 244                 foreach ( $bitPars as $const => $val ) {
 245                         if ( $val == 1 ) {
 246                                 $newBits |= $const; // $const is the *_deleted const
 247                         } elseif ( $val == -1 ) {
 248                                 $newBits |= ( $oldfield & $const ); // use existing
 249                         }
 250                 }
 251                 return $newBits;
 252         }
 253 }