1 files changed, 276 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/QuerySegmentListBuilder.php b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/QuerySegmentListBuilder.php
new file mode 100644
index 00000000..dbe02754
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/QuerySegmentListBuilder.php
@@ -0,0 +1,276 @@
+<?php
+
+namespace SMW\SQLStore\QueryEngine;
+
+use InvalidArgumentException;
+use OutOfBoundsException;
+use SMW\Message;
+use SMW\Query\Language\Conjuncton;
+use SMW\Query\Language\Description;
+use SMW\Store;
+use SMW\Utils\CircularReferenceGuard;
+
+/**
+ * @license GNU GPL v2+
+ * @since 2.2
+ *
+ * @author Markus Krötzsch
+ * @author Jeroen De Dauw
+ * @author mwjames
+ */
+class QuerySegmentListBuilder {
+
+	/**
+	 * @var Store
+	 */
+	private $store;
+
+	/**
+	 * @var DispatchingDescriptionInterpreter
+	 */
+	private $dispatchingDescriptionInterpreter = null;
+
+	/**
+	 * @var boolean
+	 */
+	private $isFilterDuplicates = true;
+
+	/**
+	 * Array of generated QueryContainer query descriptions (index => object).
+	 *
+	 * @var QuerySegment[]
+	 */
+	private $querySegments = [];
+
+	/**
+	 * Array of sorting requests ("Property_name" => "ASC"/"DESC"). Used during query
+	 * processing (where these property names are searched while compiling the query
+	 * conditions).
+	 *
+	 * @var string[]
+	 */
+	private $sortKeys = [];
+
+	/**
+	 * @var string[]
+	 */
+	private $errors = [];
+
+	/**
+	 * @var integer
+	 */
+	private $lastQuerySegmentId = -1;
+
+	/**
+	 * @since 2.2
+	 *
+	 * @param Store $store
+	 * @param DescriptionInterpreterFactory $descriptionInterpreterFactory
+	 */
+	public function __construct( Store $store, DescriptionInterpreterFactory $descriptionInterpreterFactory ) {
+		$this->store = $store;
+		$this->dispatchingDescriptionInterpreter = $descriptionInterpreterFactory->newDispatchingDescriptionInterpreter( $this );
+		$this->circularReferenceGuard = new CircularReferenceGuard( 'sql-query' );
+		$this->circularReferenceGuard->setMaxRecursionDepth( 2 );
+
+		QuerySegment::$qnum = 0;
+	}
+
+	/**
+	 * Filter dulicate segments that represent the same query and to be identified
+	 * by the same hash.
+	 *
+	 * @since 2.5
+	 *
+	 * @param boolean $isFilterDuplicates
+	 */
+	public function isFilterDuplicates( $isFilterDuplicates ) {
+		$this->isFilterDuplicates = (bool)$isFilterDuplicates;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @return Store
+	 */
+	public function getStore() {
+		return $this->store;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @param array $sortKeys
+	 *
+	 * @return $this
+	 */
+	public function setSortKeys( $sortKeys ) {
+		$this->sortKeys = $sortKeys;
+		return $this;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @return string[]
+	 */
+	public function getSortKeys() {
+		return $this->sortKeys;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @return CircularReferenceGuard
+	 */
+	public function getCircularReferenceGuard() {
+		return $this->circularReferenceGuard;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @param int $id
+	 *
+	 * @return QuerySegment
+	 * @throws InvalidArgumentException
+	 * @throws OutOfBoundsException
+	 */
+	public function findQuerySegment( $id ) {
+
+		if ( !is_int( $id ) ) {
+			throw new InvalidArgumentException( '$id needs to be an integer' );
+		}
+
+		if ( !array_key_exists( $id, $this->querySegments ) ) {
+			throw new OutOfBoundsException( 'There is no query segment with id ' . $id );
+		}
+
+		return $this->querySegments[$id];
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @return QuerySegment[]
+	 */
+	public function getQuerySegmentList() {
+		return $this->querySegments;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @param QuerySegment $query
+	 */
+	public function addQuerySegment( QuerySegment $query ) {
+		$this->querySegments[$query->queryNumber] = $query;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @return integer
+	 */
+	public function getLastQuerySegmentId() {
+		return $this->lastQuerySegmentId;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @return array
+	 */
+	public function getErrors() {
+		return $this->errors;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * @param string $error
+	 */
+	public function addError( $error, $type = Message::TEXT ) {
+		$this->errors[Message::getHash( $error, $type )] = Message::encode( $error, $type );
+	}
+
+	/**
+	 * Create a new QueryContainer object that can be used to obtain results
+	 * for the given description. The result is stored in $this->queries
+	 * using a numeric key that is returned as a result of the function.
+	 * Returns -1 if no query was created.
+	 *
+	 * @param Description $description
+	 *
+	 * @return integer
+	 */
+	public function getQuerySegmentFrom( Description $description ) {
+
+		$fingerprint = $description->getFingerprint();
+
+		// Get membership of descriptions that are resolved recursively
+		if ( $description->getMembership() !== '' ) {
+			$fingerprint = $fingerprint . $description->getMembership();
+		}
+
+		if ( ( $querySegment = $this->findDuplicates( $fingerprint ) ) ) {
+			return $querySegment;
+		}
+
+		$querySegment = $this->dispatchingDescriptionInterpreter->interpretDescription(
+			$description
+		);
+
+		$querySegment->fingerprint = $fingerprint;
+		//$querySegment->membership = $description->getMembership();
+		//$querySegment->queryString = $description->getQueryString();
+
+		$this->lastQuerySegmentId = $this->registerQuerySegment(
+			$querySegment
+		);
+
+		return $this->lastQuerySegmentId;
+	}
+
+	/**
+	 * Register a query object to the internal query list, if the query is
+	 * valid. Also make sure that sortkey information is propagated down
+	 * from subqueries of this query.
+	 *
+	 * @param QuerySegment $query
+	 */
+	private function registerQuerySegment( QuerySegment $query ) {
+		if ( $query->type === QuerySegment::Q_NOQUERY ) {
+			return -1;
+		}
+
+		$this->addQuerySegment( $query );
+
+		// Propagate sortkeys from subqueries:
+		if ( $query->type !== QuerySegment::Q_DISJUNCTION ) {
+			// Sortkeys are killed by disjunctions (not all parts may have them),
+			// NOTE: preprocessing might try to push disjunctions downwards to safe sortkey, but this seems to be minor
+			foreach ( $query->components as $cid => $field ) {
+				$query->sortfields = array_merge( $this->findQuerySegment( $cid )->sortfields, $query->sortfields );
+			}
+		}
+
+		return $query->queryNumber;
+	}
+
+	private function findDuplicates( $fingerprint ) {
+
+		if ( $this->errors !== [] || $this->isFilterDuplicates === false ) {
+			return false;
+		}
+
+		foreach ( $this->querySegments as $querySegment ) {
+			if ( $querySegment->fingerprint === $fingerprint ) {
+				return $querySegment->queryNumber;
+			};
+		}
+
+		return false;
+	}
+
+}