1 files changed, 204 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/HierarchyTempTableBuilder.php b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/HierarchyTempTableBuilder.php
new file mode 100644
index 00000000..8f0edf37
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/HierarchyTempTableBuilder.php
@@ -0,0 +1,204 @@
+<?php
+
+namespace SMW\SQLStore\QueryEngine;
+
+use RuntimeException;
+use SMW\MediaWiki\Database;
+use SMW\SQLStore\TableBuilder\TemporaryTableBuilder;
+
+/**
+ * @license GNU GPL v2+
+ * @since 2.3
+ *
+ * @author Markus Krötzsch
+ * @author mwjames
+ */
+class HierarchyTempTableBuilder {
+
+	/**
+	 * @var Database
+	 */
+	private $connection;
+
+	/**
+	 * @var TemporaryTableBuilder
+	 */
+	private $temporaryTableBuilder;
+
+	/**
+	 * Cache of computed hierarchy queries for reuse ("catetgory/property value
+	 * string" => "tablename").
+	 *
+	 * @var string[]
+	 */
+	private $hierarchyCache = [];
+
+	/**
+	 * @var array
+	 */
+	private $hierarchyTypeTable = [];
+
+	/**
+	 * @since 2.3
+	 *
+	 * @param Database $connection
+	 * @param TemporaryTableBuilder $temporaryTableBuilder
+	 */
+	public function __construct( Database $connection, TemporaryTableBuilder $temporaryTableBuilder ) {
+		$this->connection = $connection;
+		$this->temporaryTableBuilder = $temporaryTableBuilder;
+	}
+
+	/**
+	 * @since 2.3
+	 */
+	public function emptyHierarchyCache() {
+		$this->hierarchyCache = [];
+	}
+
+	/**
+	 * @since 2.3
+	 *
+	 * @return array
+	 */
+	public function getHierarchyCache() {
+		return $this->hierarchyCache;
+	}
+
+	/**
+	 * @since 2.3
+	 *
+	 * @param string $table
+	 * @param integer $depth
+	 */
+	public function setPropertyHierarchyTableDefinition( $table, $depth ) {
+		$this->hierarchyTypeTable['property'] = [ $this->connection->tableName( $table ), $depth ];
+	}
+
+	/**
+	 * @since 2.3
+	 *
+	 * @param string $table
+	 * @param integer $depth
+	 */
+	public function setClassHierarchyTableDefinition( $table, $depth ) {
+		$this->hierarchyTypeTable['class'] = [ $this->connection->tableName( $table ), $depth ];
+	}
+
+	/**
+	 * @since 2.3
+	 *
+	 * @param string $type
+	 *
+	 * @return array
+	 * @throws RuntimeException
+	 */
+	public function getHierarchyTableDefinitionForType( $type ) {
+
+		if ( !isset( $this->hierarchyTypeTable[$type] ) ) {
+			throw new RuntimeException( "$type is unknown" );
+		}
+
+		return $this->hierarchyTypeTable[$type];
+	}
+
+	/**
+	 * @since 2.3
+	 *
+	 * @param string $type
+	 * @param string $tablename
+	 * @param string $valueComposite
+	 * @param integer|null $depth
+	 *
+	 * @throws RuntimeException
+	 */
+	public function createHierarchyTempTableFor( $type, $tablename, $valueComposite, $depth = null ) {
+
+		$this->temporaryTableBuilder->create( $tablename );
+
+		list( $smwtable, $d ) = $this->getHierarchyTableDefinitionForType( $type );
+
+		if ( $depth === null ) {
+			$depth = $d;
+		}
+
+		if ( array_key_exists( $valueComposite, $this->hierarchyCache ) ) { // Just copy known result.
+
+			$this->connection->query(
+				"INSERT INTO $tablename (id) SELECT id" . ' FROM ' . $this->hierarchyCache[$valueComposite],
+				__METHOD__
+			);
+
+			return;
+		}
+
+		$this->buildTempTable( $tablename, $valueComposite, $smwtable, $depth );
+	}
+
+	/**
+	 * @note we use two helper tables. One holds the results of each new iteration, one holds the
+	 * results of the previous iteration. One could of course do with only the above result table,
+	 * but then every iteration would use all elements of this table, while only the new ones
+	 * obtained in the previous step are relevant. So this is a performance measure.
+	 */
+	private function buildTempTable( $tablename, $values, $smwtable, $depth ) {
+
+		$db = $this->connection;
+
+		$tmpnew = 'smw_new';
+		$tmpres = 'smw_res';
+
+		$this->temporaryTableBuilder->create( $tmpnew );
+		$this->temporaryTableBuilder->create( $tmpres );
+
+		// Adding multiple values for the same column in sqlite is not supported
+		foreach ( explode( ',', $values ) as $value ) {
+
+			$db->query(
+				"INSERT " . "IGNORE" . " INTO $tablename (id) VALUES $value",
+				__METHOD__
+			);
+
+			$db->query(
+				"INSERT " . "IGNORE" . " INTO $tmpnew (id) VALUES $value",
+				__METHOD__
+			);
+		}
+
+		for ( $i = 0; $i < $depth; $i++ ) {
+			$db->query(
+				"INSERT " . 'IGNORE ' .  "INTO $tmpres (id) SELECT s_id" . '@INT' . " FROM $smwtable, $tmpnew WHERE o_id=id",
+				__METHOD__
+			);
+
+			if ( $db->affectedRows() == 0 ) { // no change, exit loop
+				break;
+			}
+
+			$db->query(
+				"INSERT " . 'IGNORE ' . "INTO $tablename (id) SELECT $tmpres.id FROM $tmpres",
+				__METHOD__
+			);
+
+			if ( $db->affectedRows() == 0 ) { // no change, exit loop
+				break;
+			}
+
+			// empty "new" table
+			$db->query(
+				'TRUNCATE TABLE ' . $tmpnew,
+				__METHOD__
+			);
+
+			$tmpname = $tmpnew;
+			$tmpnew = $tmpres;
+			$tmpres = $tmpname;
+		}
+
+		$this->hierarchyCache[$values] = $tablename;
+
+		$this->temporaryTableBuilder->drop( $tmpnew );
+		$this->temporaryTableBuilder->drop( $tmpres );
+	}
+
+}