--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qoptimizationpasses.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,182 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtXmlPatterns module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcommonsequencetypes_p.h"
+#include "qoptimizerblocks_p.h"
+
+#include "qoptimizationpasses_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+OptimizationPass::List OptimizationPasses::comparisonPasses;
+OptimizationPass::List OptimizationPasses::forPasses;
+OptimizationPass::List OptimizationPasses::ifThenPasses;
+OptimizationPass::List OptimizationPasses::notFN;
+
+void OptimizationPasses::Coordinator::init()
+{
+ static bool isInitialized = false; // STATIC DATA
+
+ if(isInitialized)
+ return;
+
+ isInitialized = true;
+
+ /* Note, below is many of the building blocks re-used in several passes
+ * in order to reduce memory use. Thus, when changing one building block
+ * it potentially affects many passes. */
+
+ /* ****************************************************** */
+ /* Rewrite "count(<expr>) ge 1" into "exists(<expr>)" */
+ OptimizationPass::ExpressionMarker firstFirstChild;
+ firstFirstChild.append(0);
+ firstFirstChild.append(0);
+
+ ExpressionIdentifier::List geOpIDs;
+ const ExpressionIdentifier::Ptr countFN(new ByIDIdentifier(Expression::IDCountFN));
+ geOpIDs.append(countFN);
+ geOpIDs.append(ExpressionIdentifier::Ptr(new IntegerIdentifier(1)));
+
+ QVector<Expression::ID> geMatcher;
+ geMatcher.append(Expression::IDValueComparison);
+ geMatcher.append(Expression::IDGeneralComparison);
+
+ const ExpressionIdentifier::Ptr ge(new ComparisonIdentifier(geMatcher,
+ AtomicComparator::OperatorGreaterOrEqual));
+
+ const ExpressionCreator::Ptr existsFN(new ByIDCreator(Expression::IDExistsFN));
+ const OptimizationPass::Ptr geToExists(new OptimizationPass(ge, geOpIDs, firstFirstChild, existsFN));
+ comparisonPasses.append(geToExists);
+ /* ****************************************************** */
+
+ /* ****************************************************** */
+ /* Rewrite "count(<expr>) gt 0" into "exists(<expr>)" */
+ ExpressionIdentifier::List countAndIntZero;
+ countAndIntZero.append(countFN);
+ const ExpressionIdentifier::Ptr zeroInteger(new IntegerIdentifier(0));
+ countAndIntZero.append(zeroInteger);
+
+ const ExpressionIdentifier::Ptr gt(new ComparisonIdentifier(geMatcher,
+ AtomicComparator::OperatorGreaterThan));
+
+ const OptimizationPass::Ptr gtToExists(new OptimizationPass(gt, countAndIntZero,
+ firstFirstChild, existsFN));
+ comparisonPasses.append(gtToExists);
+ /* ****************************************************** */
+
+ /* ****************************************************** */
+ /* Rewrite "count(<expr>) ne 0" into "exists(<expr>)" */
+
+ const ExpressionIdentifier::Ptr ne(new ComparisonIdentifier(geMatcher,
+ AtomicComparator::OperatorNotEqual));
+ const OptimizationPass::Ptr neToExists(new OptimizationPass(ne, countAndIntZero, firstFirstChild,
+ existsFN,
+ OptimizationPass::AnyOrder));
+ comparisonPasses.append(neToExists);
+ /* ****************************************************** */
+
+ /* ****************************************************** */
+ /* Rewrite "count(<expr>) eq 0" into "empty(<expr>)" */
+ ExpressionIdentifier::List eqOpIDs;
+ eqOpIDs.append(countFN);
+ eqOpIDs.append(zeroInteger);
+ const ExpressionCreator::Ptr emptyFN(new ByIDCreator(Expression::IDEmptyFN));
+ const ExpressionIdentifier::Ptr eq(new ComparisonIdentifier(geMatcher,
+ AtomicComparator::OperatorEqual));
+ const OptimizationPass::Ptr eqToEmpty(new OptimizationPass(eq, eqOpIDs, firstFirstChild,
+ emptyFN,
+ OptimizationPass::AnyOrder));
+ comparisonPasses.append(eqToEmpty);
+
+ /* ****************************************************** */
+
+ /* ****************************************************** */
+ /* Rewrite "for $var in <expr> return $var" into "<expr>" */
+ ExpressionIdentifier::List forOps;
+ OptimizationPass::ExpressionMarker firstChild;
+ firstChild.append(0);
+
+ forOps.append(ExpressionIdentifier::Ptr());
+ forOps.append(ExpressionIdentifier::Ptr(new ByIDIdentifier(Expression::IDRangeVariableReference)));
+ const OptimizationPass::Ptr simplifyFor(new OptimizationPass(ExpressionIdentifier::Ptr(), forOps,
+ firstChild, ExpressionCreator::Ptr()));
+ forPasses.append(simplifyFor);
+ /* ****************************************************** */
+
+ /* ****************************************************** */
+ /* Rewrite "if(<expr>) then true() else false()" to "<expr>" */
+ OptimizationPass::ExpressionMarker marker;
+ marker.append(0);
+
+ ExpressionIdentifier::List opIDs;
+ opIDs.append(ExpressionIdentifier::Ptr(new BySequenceTypeIdentifier(
+ CommonSequenceTypes::ExactlyOneBoolean)));
+ opIDs.append(ExpressionIdentifier::Ptr(new BooleanIdentifier(true)));
+ opIDs.append(ExpressionIdentifier::Ptr(new BooleanIdentifier(false)));
+
+ const OptimizationPass::Ptr pass(new OptimizationPass(ExpressionIdentifier::Ptr(), opIDs, marker));
+ ifThenPasses.append(pass);
+ /* ****************************************************** */
+
+ /* ****************************************************** */
+ /* Rewrite "not(exists(X))" into "empty(X)" */
+ ExpressionIdentifier::List idExistsFN;
+ idExistsFN.append(ExpressionIdentifier::Ptr(new ByIDIdentifier(Expression::IDExistsFN)));
+
+ notFN.append(OptimizationPass::Ptr(new OptimizationPass(ExpressionIdentifier::Ptr(),
+ idExistsFN,
+ firstFirstChild,
+ emptyFN)));
+
+ /* Rewrite "not(empty(X))" into "exists(X)" */
+ ExpressionIdentifier::List idEmptyFN;
+ idEmptyFN.append(ExpressionIdentifier::Ptr(new ByIDIdentifier(Expression::IDEmptyFN)));
+
+ notFN.append(OptimizationPass::Ptr(new OptimizationPass(ExpressionIdentifier::Ptr(),
+ idEmptyFN,
+ firstFirstChild,
+ existsFN)));
+ /* ****************************************************** */
+}
+
+QT_END_NAMESPACE