LinksMigration.php

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<?php
namespace MediaWiki\Linker;
 
use InvalidArgumentException;
use MediaWiki\Config\Config;
use MediaWiki\MainConfigNames;
 
class LinksMigration {
 
    private $config;
 
    private $linkTargetLookup;
 
    public static $mapping = [
        'templatelinks' => [
            'config' => -1,
            'page_id' => 'tl_from',
            // Used by the updater only
            'ns' => 'tl_namespace',
            // Used by the updater only
            'title' => 'tl_title',
            'target_id' => 'tl_target_id',
            'deprecated_configs' => [],
        ],
        'pagelinks' => [
            'config' => -1,
            'page_id' => 'pl_from',
            'ns' => 'pl_namespace',
            'title' => 'pl_title',
            'target_id' => 'pl_target_id',
            'deprecated_configs' => [],
        ],
        'categorylinks' => [
            'config' => MainConfigNames::CategoryLinksSchemaMigrationStage,
            'page_id' => 'cl_from',
            'ns' => 14,
            'title' => 'cl_to',
            'target_id' => 'cl_target_id',
            'deprecated_configs' => [],
        ],
        'existencelinks' => [
            'config' => -1,
            'page_id' => 'exl_from',
            // Fake field just for phan
            'ns' => 'exl_namespace',
            // Fake field just for phan
            'title' => 'exl_title',
            'target_id' => 'exl_target_id',
            'deprecated_configs' => [],
        ],
    ];
 
    public static $prefixToTableMapping = [
        'tl' => 'templatelinks',
        'pl' => 'pagelinks',
        'cl' => 'categorylinks',
        'exl' => 'existencelinks',
    ];
 
    public function __construct( Config $config, LinkTargetLookup $linktargetLookup ) {
        $this->config = $config;
        $this->linkTargetLookup = $linktargetLookup;
    }
 
    public function getLinksConditions( string $table, LinkTarget $linkTarget ): array {
        $this->assertMapping( $table );
        if ( $this->isMigrationReadNew( $table ) ) {
            $targetId = $this->linkTargetLookup->getLinkTargetId( $linkTarget );
            // Not found, it shouldn't pick anything
            if ( !$targetId ) {
                return [ '1=0' ];
            }
            return [
                self::$mapping[$table]['target_id'] => $targetId,
            ];
        } else {
            return [
                self::$mapping[$table]['ns'] => $linkTarget->getNamespace(),
                self::$mapping[$table]['title'] => $linkTarget->getDBkey(),
            ];
        }
    }
 
    public function getQueryInfo( string $table, string $joinTable = 'linktarget', string $joinType = 'JOIN' ) {
        $this->assertMapping( $table );
        if ( $this->isMigrationReadNew( $table ) ) {
            $targetId = self::$mapping[$table]['target_id'];
            if ( $joinTable === 'linktarget' ) {
                $tables = [ $table, 'linktarget' ];
            } else {
                $tables = [ 'linktarget', $table ];
            }
            return [
                'tables' => $tables,
                'fields' => [
                    $targetId,
                    'lt_namespace',
                    'lt_title'
                ],
                'joins' => [ $joinTable => [
                    $joinType,
                    [ "$targetId=lt_id" ]
                ] ],
            ];
        } else {
            return [
                'fields' => [
                    self::$mapping[$table]['ns'],
                    self::$mapping[$table]['title']
                ],
                'tables' => [ $table ],
                'joins' => [],
            ];
        }
    }
 
    public function getTitleFields( $table ) {
        $this->assertMapping( $table );
 
        if ( $this->isMigrationReadNew( $table ) ) {
            return [ 'lt_namespace', 'lt_title' ];
        } else {
            return [ self::$mapping[$table]['ns'], self::$mapping[$table]['title'] ];
        }
    }
 
    private function isMigrationReadNew( string $table ): bool {
        return self::$mapping[$table]['config'] === -1 ||
            $this->config->get( self::$mapping[$table]['config'] ) & SCHEMA_COMPAT_READ_NEW;
    }
 
    private function assertMapping( string $table ) {
        if ( !isset( self::$mapping[$table] ) ) {
            throw new InvalidArgumentException(
                "LinksMigration doesn't support the $table table yet"
            );
        }
 
        if ( self::$mapping[$table]['config'] !== -1 && self::$mapping[$table]['deprecated_configs'] ) {
            $config = $this->config->get( self::$mapping[$table]['config'] );
            foreach ( self::$mapping[$table]['deprecated_configs'] as $deprecatedConfig ) {
                if ( $config & $deprecatedConfig ) {
                    throw new InvalidArgumentException(
                        "LinksMigration config $config on $table table is not supported anymore"
                    );
                }
            }
 
        }
    }
}