org.apache.jackrabbit.oak.query.ast.PropertyInexistenceImpl Maven / Gradle / Ivy
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* 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 java.util.Collections;
import java.util.Set;
import org.apache.jackrabbit.oak.api.Tree;
import org.apache.jackrabbit.oak.commons.PathUtils;
import org.apache.jackrabbit.oak.query.index.FilterImpl;
/**
* A condition to check if the property does not exist ("is null").
*
* For Jackrabbit 2.x compatibility: if the property is relative (as in
* "child/propertyName"), then this requires that the given child node exists.
*/
public class PropertyInexistenceImpl extends ConstraintImpl {
private final String selectorName;
private final String propertyName;
private SelectorImpl selector;
public PropertyInexistenceImpl(SelectorImpl selector, String selectorName, String propertyName) {
this.selector = selector;
this.selectorName = selectorName;
this.propertyName = propertyName;
}
public PropertyInexistenceImpl(String selectorName, String propertyName) {
this.selectorName = selectorName;
this.propertyName = propertyName;
}
@Override
public boolean evaluate() {
boolean isRelative = propertyName.indexOf('/') >= 0;
if (!isRelative) {
return selector.currentProperty(propertyName) == null;
}
Tree t = selector.currentTree();
if (t == null) {
return true;
}
String pn = normalizePropertyName(propertyName);
String relativePath = PathUtils.getParentPath(pn);
String name = PathUtils.getName(pn);
for (String p : PathUtils.elements(relativePath)) {
if (t == null || !t.exists()) {
return false;
}
if (p.equals("..")) {
t = t.isRoot() ? null : t.getParent();
} else if (p.equals(".")) {
// same node
} else {
t = t.getChild(p);
}
}
return t != null && t.exists() && !t.hasProperty(name);
}
@Override
public Set getPropertyExistenceConditions() {
return Collections.emptySet();
}
@Override
public Set getSelectors() {
return Collections.singleton(selector);
}
@Override
boolean accept(AstVisitor v) {
return v.visit(this);
}
@Override
public String toString() {
return quote(selectorName) + '.' + quote(propertyName) + " is null";
}
public void bindSelector(SourceImpl source) {
selector = source.getExistingSelector(selectorName);
}
@Override
public void restrict(FilterImpl f) {
// we need to be careful with "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 b.y is null"
// must not result in the index to check for
// "b.y is null", because that would alter the
// result
if (selector.isOuterJoinRightHandSide()) {
return;
}
if (f.getSelector().equals(selector)) {
String pn = normalizePropertyName(propertyName);
f.restrictProperty(pn, Operator.EQUAL, null);
}
}
@Override
public void restrictPushDown(SelectorImpl s) {
if (s.isOuterJoinRightHandSide()) {
// we need to be careful with "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 b.y is null"
// must not check for "b.y is null" too early,
// because that would alter the result
return;
}
if (s.equals(selector)) {
s.restrictSelector(this);
}
}
@Override
public int hashCode() {
String pn = normalizePropertyName(propertyName);
return ((selectorName == null) ? 0 : selectorName.hashCode()) * 31 +
((pn == null) ? 0 : pn.hashCode());
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
} else if (obj == null || getClass() != obj.getClass()) {
return false;
}
PropertyInexistenceImpl other = (PropertyInexistenceImpl) obj;
if (!equalsStrings(selectorName, other.selectorName)) {
return false;
}
String pn = normalizePropertyName(propertyName);
String pn2 = normalizePropertyName(other.propertyName);
return equalsStrings(pn, pn2);
}
private static boolean equalsStrings(String a, String b) {
return a == null || b == null ? a == b : a.equals(b);
}
}