includes/linker/LinksMigration.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 namespace MediaWiki\Linker;
  22
  23 use InvalidArgumentException;
  24 use MediaWiki\Config\Config;
  25 use MediaWiki\MainConfigNames;
  26
  27 /**
  28  * Service for compat reading of links tables
  29  *
  30  * @since 1.39
  31  */
  32 class LinksMigration {
  33
  34         /** @var Config */
  35         private $config;
  36
  37         /** @var LinkTargetLookup */
  38         private $linkTargetLookup;
  39
  40         /** @var array[] */
  41         public static $mapping = [
  42                 'templatelinks' => [
  43                         'config' => -1,
  44                         'page_id' => 'tl_from',
  45                         // Used by the updater only
  46                         'ns' => 'tl_namespace',
  47                         // Used by the updater only
  48                         'title' => 'tl_title',
  49                         'target_id' => 'tl_target_id',
  50                         'deprecated_configs' => [],
  51                 ],
  52                 'pagelinks' => [
  53                         'config' => MainConfigNames::PageLinksSchemaMigrationStage,
  54                         'page_id' => 'pl_from',
  55                         'ns' => 'pl_namespace',
  56                         'title' => 'pl_title',
  57                         'target_id' => 'pl_target_id',
  58                         'deprecated_configs' => [
  59                                 SCHEMA_COMPAT_WRITE_OLD,
  60                                 SCHEMA_COMPAT_READ_OLD
  61                         ],
  62                 ],
  63         ];
  64
  65         /** @var string[] */
  66         public static $prefixToTableMapping = [
  67                 'tl' => 'templatelinks',
  68                 'pl' => 'pagelinks',
  69         ];
  70
  71         /**
  72          * @param Config $config
  73          * @param LinkTargetLookup $linktargetLookup
  74          */
  75         public function __construct( Config $config, LinkTargetLookup $linktargetLookup ) {
  76                 $this->config = $config;
  77                 $this->linkTargetLookup = $linktargetLookup;
  78         }
  79
  80         /**
  81          * Return the conditions to be used in querying backlinks to a page
  82          *
  83          * @param string $table
  84          * @param LinkTarget $linkTarget
  85          * @return array
  86          */
  87         public function getLinksConditions( string $table, LinkTarget $linkTarget ): array {
  88                 $this->assertMapping( $table );
  89                 if ( $this->isMigrationReadNew( $table ) ) {
  90                         $targetId = $this->linkTargetLookup->getLinkTargetId( $linkTarget );
  91                         // Not found, it shouldn't pick anything
  92                         if ( !$targetId ) {
  93                                 return [ '1=0' ];
  94                         }
  95                         return [
  96                                 self::$mapping[$table]['target_id'] => $targetId,
  97                         ];
  98                 } else {
  99                         return [
 100                                 self::$mapping[$table]['ns'] => $linkTarget->getNamespace(),
 101                                 self::$mapping[$table]['title'] => $linkTarget->getDBkey(),
 102                         ];
 103                 }
 104         }
 105
 106         /**
 107          * Return the query to be used when you want to or from a group of pages
 108          *
 109          * @param string $table
 110          * @param string $joinTable table to end the join chain. Most of the time it's linktarget
 111          * @param string $joinType
 112          * @return array
 113          */
 114         public function getQueryInfo( string $table, string $joinTable = 'linktarget', string $joinType = 'JOIN' ) {
 115                 $this->assertMapping( $table );
 116                 if ( $this->isMigrationReadNew( $table ) ) {
 117                         $targetId = self::$mapping[$table]['target_id'];
 118                         if ( $joinTable === 'linktarget' ) {
 119                                 $tables = [ $table, 'linktarget' ];
 120                         } else {
 121                                 $tables = [ 'linktarget', $table ];
 122                         }
 123                         return [
 124                                 'tables' => $tables,
 125                                 'fields' => [
 126                                         $targetId,
 127                                         'lt_namespace',
 128                                         'lt_title'
 129                                 ],
 130                                 'joins' => [ $joinTable => [
 131                                         $joinType,
 132                                         [ "$targetId=lt_id" ]
 133                                 ] ],
 134                         ];
 135                 } else {
 136                         return [
 137                                 'fields' => [
 138                                         self::$mapping[$table]['ns'],
 139                                         self::$mapping[$table]['title']
 140                                 ],
 141                                 'tables' => [ $table ],
 142                                 'joins' => [],
 143                         ];
 144                 }
 145         }
 146
 147         public function getTitleFields( $table ) {
 148                 $this->assertMapping( $table );
 149
 150                 if ( $this->isMigrationReadNew( $table ) ) {
 151                         return [ 'lt_namespace', 'lt_title' ];
 152                 } else {
 153                         return [ self::$mapping[$table]['ns'], self::$mapping[$table]['title'] ];
 154                 }
 155         }
 156
 157         private function isMigrationReadNew( string $table ): bool {
 158                 return self::$mapping[$table]['config'] === -1 ||
 159                         $this->config->get( self::$mapping[$table]['config'] ) & SCHEMA_COMPAT_READ_NEW;
 160         }
 161
 162         private function assertMapping( string $table ) {
 163                 if ( !isset( self::$mapping[$table] ) ) {
 164                         throw new InvalidArgumentException(
 165                                 "LinksMigration doesn't support the $table table yet"
 166                         );
 167                 }
 168
 169                 if ( self::$mapping[$table]['config'] !== -1 && self::$mapping[$table]['deprecated_configs'] ) {
 170                         $config = $this->config->get( self::$mapping[$table]['config'] );
 171                         foreach ( self::$mapping[$table]['deprecated_configs'] as $deprecatedConfig ) {
 172                                 if ( $config & $deprecatedConfig ) {
 173                                         throw new InvalidArgumentException(
 174                                                 "LinksMigration config $config on $table table is not supported anymore"
 175                                         );
 176                                 }
 177                         }
 178
 179                 }
 180         }
 181 }