| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.jackrabbit.oak.query.ast; |
| |
| import static org.apache.jackrabbit.oak.query.ast.AstElementFactory.copyElementAndCheckReference; |
| |
| import java.util.Collections; |
| import java.util.Set; |
| |
| import org.apache.jackrabbit.oak.query.index.FilterImpl; |
| |
| /** |
| * A "not" condition. |
| */ |
| public class NotImpl extends ConstraintImpl { |
| |
| private ConstraintImpl constraint; |
| |
| public NotImpl(ConstraintImpl constraint) { |
| this.constraint = constraint; |
| } |
| |
| public ConstraintImpl getConstraint() { |
| return constraint; |
| } |
| |
| /** |
| * Apply DeMorgan's Laws to push AND/OR constraints higher. |
| */ |
| @Override |
| public ConstraintImpl simplify() { |
| ConstraintImpl simple = constraint.simplify(); |
| ConstraintImpl not = simple.not(); |
| if (not != null) { |
| return not.simplify(); |
| } else if (simple != constraint) { |
| return new NotImpl(simple); |
| } |
| return this; |
| } |
| |
| @Override |
| ConstraintImpl not() { |
| // not not X == X -> X == X |
| return constraint; |
| } |
| |
| @Override |
| public boolean evaluate() { |
| return !constraint.evaluate(); |
| } |
| |
| @Override |
| public Set<PropertyExistenceImpl> getPropertyExistenceConditions() { |
| return Collections.emptySet(); |
| } |
| |
| @Override |
| public Set<SelectorImpl> getSelectors() { |
| return constraint.getSelectors(); |
| } |
| |
| @Override |
| boolean accept(AstVisitor v) { |
| return v.visit(this); |
| } |
| |
| @Override |
| public String toString() { |
| return "not " + protect(constraint); |
| } |
| |
| @Override |
| public void restrict(FilterImpl f) { |
| if (f.getSelector().isOuterJoinRightHandSide()) { |
| // we need to be careful with the condition |
| // "NOT (property IS NOT NULL)" |
| // (which is the same as "property IS NULL") |
| // because this might cause an index |
| // to ignore the join condition "property = x" |
| // for example in: |
| // "select * from a left outer join b on a.x = b.y |
| // where not b.y is not null" |
| // must not result in the index to check for |
| // "b.y is null", because that would alter the |
| // result |
| return; |
| } |
| // ignore |
| // TODO convert NOT conditions |
| } |
| |
| @Override |
| public void restrictPushDown(SelectorImpl s) { |
| // ignore |
| // TODO convert NOT conditions |
| } |
| |
| @Override |
| public AstElement copyOf() { |
| return new NotImpl((ConstraintImpl) copyElementAndCheckReference(constraint)); |
| } |
| |
| @Override |
| public boolean requiresFullTextIndex() { |
| return constraint.requiresFullTextIndex(); |
| } |
| |
| @Override |
| public boolean containsUnfilteredFullTextCondition() { |
| // If the constraint is a fulltext condition, |
| // then we can not apply it, as in "not contains(., 'x')". |
| // Also, if the constraint _contains_ a unfiltered fulltext condition, as in |
| // "not (x=1 or contains(., 'x')". |
| return constraint.containsUnfilteredFullTextCondition() || |
| constraint.requiresFullTextIndex(); |
| } |
| |
| } |