1 files changed, 142 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/EntityStore/TraversalPropertyLookup.php b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/EntityStore/TraversalPropertyLookup.php
new file mode 100644
index 00000000..1ca99e48
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/EntityStore/TraversalPropertyLookup.php
@@ -0,0 +1,142 @@
+<?php
+
+namespace SMW\SQLStore\EntityStore;
+
+use RuntimeException;
+use SMW\DIContainer;
+use SMW\MediaWiki\Connection\OptionsBuilder;
+use SMW\Options;
+use SMW\RequestOptions;
+use SMW\SQLStore\PropertyTableDefinition as PropertyTableDef;
+use SMW\SQLStore\SQLStore;
+use SMWDataItem as DataItem;
+
+/**
+ * @license GNU GPL v2
+ * @since 3.0
+ *
+ * @author mwjames
+ */
+class TraversalPropertyLookup {
+
+	/**
+	 * @var SQLStore
+	 */
+	private $store;
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param SQLStore $store
+	 */
+	public function __construct( SQLStore $store ) {
+		$this->store = $store;
+	}
+
+	/**
+	 * @see Store::getInProperties
+	 *
+	 * @since 3.0
+	 *
+	 * {@inheritDoc}
+	 */
+	public function fetchFromTable( PropertyTableDef $propertyTableDef, DataItem $dataItem, RequestOptions $requestOptions = null ) {
+
+		$connection = $this->store->getConnection( 'mw.db' );
+
+		if ( $dataItem instanceof DIContainer ) {
+			throw new RuntimeException( "DIContainer: " . $dataItem->getSerialization() );
+		}
+
+		// Potentially need to get more results, since options apply to union.
+		if ( $requestOptions !== null ) {
+			$subOptions = clone $requestOptions;
+			$subOptions->limit = $requestOptions->limit + $requestOptions->offset;
+			$subOptions->offset = 0;
+		} else {
+			$subOptions = null;
+		}
+
+		if ( !$propertyTableDef->isFixedPropertyTable() ) {
+
+			$cond = $this->getWhereConds( $dataItem );
+			$conditions = '';
+
+			// No sorting
+			$options = $this->store->getSQLOptions( $subOptions, '' );
+
+			// Avoid any limit or offset for the sub-query in order to find all
+			// incoming properties
+			unset( $options['LIMIT'] );
+			unset( $options['OFFSET'] );
+
+			// Ensure to group same IDs to reduce the amount of data transferred
+			// from the inner join
+			$options['GROUP BY'] = 'p_id';
+
+			$opt = OptionsBuilder::toString( $options );
+
+			$cond = ( $cond !== '' ? ' WHERE ' : '' ) . $cond;
+
+			// Use a subquery to match all possible IDs, no ORDER BY or DISTINCT to avoid
+			// a filesort
+			$from = $connection->tableName( SQLStore::ID_TABLE ) .
+				" INNER JOIN (" .
+				" SELECT p_id FROM " . $connection->tableName( $propertyTableDef->getName() ) .
+				" $cond $opt ) AS t1 ON t1.p_id=smw_id";
+
+			$conditions .= ( $conditions ? ' AND ' : ' ' ) .
+				" smw_iw!=" . $connection->addQuotes( SMW_SQL3_SMWIW_OUTDATED ) .
+				" AND smw_iw!=" . $connection->addQuotes( SMW_SQL3_SMWDELETEIW );
+
+			$conditions .= $this->store->getSQLConditions( $subOptions, 'smw_sortkey', 'smw_sortkey', $conditions !== '' );
+
+			$options = $this->store->getSQLOptions( $subOptions, '' ) + [ 'DISTINCT' ];
+
+			$result = $connection->select(
+				$from,
+				' smw_title,smw_sortkey,smw_iw',
+				$conditions,
+				__METHOD__,
+				$options
+			);
+
+		} else {
+			$from = $connection->tableName( $propertyTableDef->getName() ) . " AS t1";
+			$where = $this->getWhereConds( $dataItem );
+			$fields = $propertyTableDef->usesIdSubject() ? 's_id' : '*';
+
+			$result = $connection->select(
+				$from,
+				$fields,
+				$where,
+				__METHOD__,
+				[ 'LIMIT' => 1 ]
+			);
+
+			if ( $result->numRows() > 0 ) {
+				$res = new \stdClass;
+				$res->smw_title = $propertyTableDef->getFixedProperty();
+				$result = [ $res ];
+			}
+		}
+
+		return $result;
+	}
+
+	private function getWhereConds( $dataItem ) {
+
+		$where = '';
+		$connection = $this->store->getConnection( 'mw.db' );
+
+		if ( $dataItem !== null ) {
+			$dataItemHandler = $this->store->getDataItemHandlerForDIType( $dataItem->getDIType() );
+			foreach ( $dataItemHandler->getWhereConds( $dataItem ) as $fieldname => $value ) {
+				$where .= ( $where ? ' AND ' : '' ) . "$fieldname=" . $connection->addQuotes( $value );
+			}
+		}
+
+		return $where;
+	}
+
+}