/**
* 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.ambari.server.api.query;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.ambari.server.controller.internal.ResourceImpl;
import org.apache.ambari.server.controller.predicate.AlwaysPredicate;
import org.apache.ambari.server.controller.predicate.ArrayPredicate;
import org.apache.ambari.server.controller.predicate.CategoryPredicate;
import org.apache.ambari.server.controller.predicate.ComparisonPredicate;
import org.apache.ambari.server.controller.predicate.PredicateVisitor;
import org.apache.ambari.server.controller.predicate.UnaryPredicate;
import org.apache.ambari.server.controller.spi.Predicate;
import org.apache.ambari.server.controller.spi.Resource;
import org.apache.ambari.server.controller.utilities.PredicateHelper;
/**
* A predicate visitor used to generate a new predicate so that the resources
* referenced by the predicate will be extended to include the joined properties
* of their sub-resources.
*/
public class ExtendedResourcePredicateVisitor implements PredicateVisitor {
/**
* The last visited predicate.
*/
private Predicate lastVisited = null;
/**
* The joined resource map.
*/
private final Map<Resource, Set<Map<String, Object>>> joinedResources;
// ----- Constructors ------------------------------------------------------
/**
* Constructor.
*
* @param extendedProperties the map of sets of extended properties
*/
public ExtendedResourcePredicateVisitor(Map<Resource,
Set<Map<String, Object>>> extendedProperties) {
this.joinedResources = extendedProperties;
}
// ----- PredicateVisitor --------------------------------------------------
@Override
public void acceptComparisonPredicate(ComparisonPredicate predicate) {
lastVisited = new ExtendedResourcePredicate(predicate, joinedResources);
}
@Override
public void acceptArrayPredicate(ArrayPredicate arrayPredicate) {
List<Predicate> predicateList = new LinkedList<>();
Predicate[] predicates = arrayPredicate.getPredicates();
if (predicates.length > 0) {
for (Predicate predicate : predicates) {
PredicateHelper.visit(predicate, this);
predicateList.add(lastVisited);
}
}
lastVisited = arrayPredicate.create(predicateList.toArray(new Predicate[predicateList.size()]));
}
@Override
public void acceptUnaryPredicate(UnaryPredicate predicate) {
lastVisited = new ExtendedResourcePredicate(predicate, joinedResources);
}
@Override
public void acceptAlwaysPredicate(AlwaysPredicate predicate) {
lastVisited = predicate;
}
@Override
public void acceptCategoryPredicate(CategoryPredicate predicate) {
lastVisited = new ExtendedResourcePredicate(predicate, joinedResources);
}
// ----- utility methods -------------------------------------------------
/**
* Get the extended predicate.
*
* @return the predicate
*/
public Predicate getExtendedPredicate() {
return lastVisited;
}
// ----- inner classes -----------------------------------------------------
// ----- ExtendedResourcePredicate -----------------------------------------
/**
* Predicate implementation used to replace any existing predicate and
* extend the resource being evaluated with an extended set of property
* values.
*/
private static class ExtendedResourcePredicate implements Predicate {
/**
* The predicate being extended.
*/
private final Predicate predicate;
/**
* The map of extended property sets keyed by resource.
*/
private final Map<Resource, Set<Map<String, Object>>> joinedResources;
// ----- Constructors ----------------------------------------------------
/**
* Constructor
*
* @param predicate the predicate being extended
* @param joinedResources the map of extended sets of property values
*/
public ExtendedResourcePredicate(Predicate predicate,
Map<Resource, Set<Map<String, Object>>> joinedResources) {
this.predicate = predicate;
this.joinedResources = joinedResources;
}
// ----- Predicate -------------------------------------------------------
@Override
public boolean evaluate(Resource resource) {
Set<Map<String, Object>> extendedPropertySet = joinedResources.get(resource);
if (extendedPropertySet == null) {
return predicate.evaluate(resource);
}
for (Map<String, Object> extendedProperties : extendedPropertySet) {
Resource extendedResource = new ExtendedResourceImpl(resource, extendedProperties);
if (predicate.evaluate(extendedResource)) {
return true;
}
}
return false;
}
}
// ----- ExtendedResourceImpl ----------------------------------------------
/**
* A resource that extends a given resource by copying it and adding additional
* properties.
*/
private static class ExtendedResourceImpl extends ResourceImpl {
// ----- Constructors ----------------------------------------------------
/**
* Constructor
*
* @param resource the resource to copy
* @param extendedProperties the map of extended properties
*/
public ExtendedResourceImpl(Resource resource, Map<String, Object> extendedProperties) {
super(resource);
initProperties(extendedProperties);
}
// ----- utility methods -------------------------------------------------
/**
* Initialize this resource by setting the extended properties.
*/
private void initProperties(Map<String, Object> extendedProperties) {
for (Map.Entry<String, Object> entry : extendedProperties.entrySet()) {
setProperty(entry.getKey(), entry.getValue());
}
}
}
}