1 files changed, 149 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/EntityStore/SubobjectListFinder.php b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/EntityStore/SubobjectListFinder.php
new file mode 100644
index 00000000..f26c3b20
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/EntityStore/SubobjectListFinder.php
@@ -0,0 +1,149 @@
+<?php
+
+namespace SMW\SQLStore\EntityStore;
+
+use SMW\DIProperty;
+use SMW\DIWikiPage;
+use SMW\IteratorFactory;
+use SMW\SQLStore\SQLStore;
+
+/**
+ * @private
+ *
+ * @license GNU GPL v2+
+ * @since 2.5
+ *
+ * @author mwjames
+ */
+class SubobjectListFinder {
+
+	/**
+	 * @var SQLStore
+	 */
+	private $store;
+
+	/**
+	 * @var IteratorFactory
+	 */
+	private $iteratorFactory;
+
+	/**
+	 * @var DIWikiPage
+	 */
+	private $subject;
+
+	/**
+	 * @var []
+	 */
+	private $mappingIterator = [];
+
+	/**
+	 * @var []
+	 */
+	private $skipConditions = [];
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param SQLStore $store
+	 * @param IteratorFactory $iteratorFactory
+	 */
+	public function __construct( SQLStore $store, IteratorFactory $iteratorFactory ) {
+		$this->store = $store;
+		$this->iteratorFactory = $iteratorFactory;
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param DIWikiPage $subject
+	 *
+	 * @return MappingIterator
+	 */
+	public function find( DIWikiPage $subject ) {
+
+		$key = $subject->getHash() . ':' . $subject->getId();
+
+		if ( !isset( $this->mappingIterator[$key] ) ) {
+			$this->mappingIterator[$key] = $this->newMappingIterator( $subject );
+		}
+
+		return $this->mappingIterator[$key];
+	}
+
+	/**
+	 * Fetch all subobjects for a given subject using a lazy-mapping iterator
+	 * in order to only resolve one subobject per iteration step.
+	 *
+	 * @since 2.5
+	 *
+	 * @param DIWikiPage $subject
+	 *
+	 * @return MappingIterator
+	 */
+	private function newMappingIterator( DIWikiPage $subject ) {
+
+		$callback = function( $row ) use ( $subject ) {
+
+			// #1955
+			if ( $subject->getNamespace() === SMW_NS_PROPERTY ) {
+				$property = new DIProperty( $subject->getDBkey() );
+				$subobject = $property->getCanonicalDiWikiPage( $row->smw_subobject );
+			} else {
+				$subobject = new DIWikiPage(
+					$subject->getDBkey(),
+					$subject->getNamespace(),
+					$subject->getInterwiki(),
+					$row->smw_subobject
+				);
+			}
+
+			$subobject->setSortKey( $row->smw_sortkey );
+			$subobject->setId( $row->smw_id );
+
+			return $subobject;
+		};
+
+		return $this->iteratorFactory->newMappingIterator(
+			$this->newResultIterator( $subject ),
+			$callback
+		);
+	}
+
+	private function newResultIterator( DIWikiPage $subject ) {
+
+		$connection = $this->store->getConnection( 'mw.db' );
+		$key = $subject->getDBkey();
+
+		// #1955 Ensure to match a possible predefined property
+		// (Modification date -> _MDAT)
+		if ( $subject->getNamespace() === SMW_NS_PROPERTY ) {
+			$key = DIProperty::newFromUserLabel( $key )->getKey();
+		}
+
+		$conditions = [
+			'smw_title='      . $connection->addQuotes( $key ),
+			'smw_namespace='  . $connection->addQuotes( $subject->getNamespace() ),
+			'smw_iw='         . $connection->addQuotes( $subject->getInterwiki() ),
+			'smw_subobject!=' . $connection->addQuotes( '' )
+		];
+
+		foreach ( $this->skipConditions as $skipOn ) {
+			$conditions[] = 'smw_subobject!=' . $connection->addQuotes( $skipOn );
+		}
+
+		$res = $connection->select(
+			$connection->tablename( SQLStore::ID_TABLE ),
+			[
+				'smw_id',
+				'smw_subobject',
+				'smw_sortkey'
+			],
+			implode( ' AND ' , $conditions ),
+			__METHOD__
+		);
+
+		return $this->iteratorFactory->newResultIterator( $res );
+	}
+
+}