/**
* 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.render;
import org.apache.ambari.server.api.query.QueryInfo;
import org.apache.ambari.server.api.resources.ResourceDefinition;
import org.apache.ambari.server.api.resources.SubResourceDefinition;
import org.apache.ambari.server.api.util.TreeNode;
import org.apache.ambari.server.controller.spi.Resource;
import org.apache.ambari.server.controller.spi.Schema;
import org.apache.ambari.server.controller.spi.SchemaFactory;
import java.util.HashSet;
import java.util.Set;
/**
* Base renderer.
* Contains functionality which may be common across implementations.
*/
public abstract class BaseRenderer implements Renderer {
/**
* Factory for creating schema instances.
*/
private SchemaFactory m_schemaFactory;
@Override
public void init(SchemaFactory schemaFactory) {
m_schemaFactory = schemaFactory;
}
/**
* Obtain a schema instance based on resource type.
*
* @param type resource type
*
* @return schema instance for the provided resource type
*/
protected Schema getSchema(Resource.Type type) {
return m_schemaFactory.getSchema(type);
}
/**
* Copies a tree of QueryInfo to a tree of Set<String>.
* This is useful in {@link Renderer#finalizeProperties(TreeNode, boolean)} for converting
* the passed in tree of query info to the return type which is a set of property names.
*
* @param queryTree source tree
* @param propertyTree target tree
*/
protected void copyPropertiesToResult(TreeNode<QueryInfo> queryTree, TreeNode<Set<String>> propertyTree) {
for (TreeNode<QueryInfo> node : queryTree.getChildren()) {
TreeNode<Set<String>> child = propertyTree.addChild(
node.getObject().getProperties(), node.getName());
copyPropertiesToResult(node, child);
}
}
/**
* Add primary key for the specified resource type to the provided set.
*
* @param resourceType resource type
* @param properties set of properties which pk will be added to
*/
protected void addPrimaryKey(Resource.Type resourceType, Set<String> properties) {
properties.add(getSchema(resourceType).getKeyPropertyId(resourceType));
}
/**
* Add primary and all foreign keys for the specified resource type to the provided set.
*
* @param resourceType resource type
* @param properties set of properties which keys will be added to
*/
protected void addKeys(Resource.Type resourceType, Set<String> properties) {
Schema schema = getSchema(resourceType);
for (Resource.Type type : Resource.Type.values()) {
String propertyId = schema.getKeyPropertyId(type);
if (propertyId != null) {
properties.add(propertyId);
}
}
}
/**
* Determine if the query node contains no properties and no children.
*
* @param queryNode the query node to check
*
* @return true if the node contains no properties or children; false otherwise
*/
protected boolean isRequestWithNoProperties(TreeNode<QueryInfo> queryNode) {
return queryNode.getChildren().isEmpty() &&
queryNode.getObject().getProperties().size() == 0;
}
/**
* Add available sub resources to property node.
*
* @param queryTree query tree
* @param propertyTree property tree
*/
protected void addSubResources(TreeNode<QueryInfo> queryTree,
TreeNode<Set<String>> propertyTree) {
QueryInfo queryInfo = queryTree.getObject();
ResourceDefinition resource = queryInfo.getResource();
Set<SubResourceDefinition> subResources = resource.getSubResourceDefinitions();
for (SubResourceDefinition subResource : subResources) {
Set<String> resourceProperties = new HashSet<String>();
populateSubResourceDefaults(subResource, resourceProperties);
propertyTree.addChild(resourceProperties, subResource.getType().name());
}
}
/**
* Populate sub-resource properties.
*
* @param subResource definition of sub-resource
* @param properties property set to update
*/
protected void populateSubResourceDefaults(
SubResourceDefinition subResource, Set<String> properties) {
Schema schema = getSchema(subResource.getType());
Set<Resource.Type> foreignKeys = subResource.getAdditionalForeignKeys();
for (Resource.Type fk : foreignKeys) {
properties.add(schema.getKeyPropertyId(fk));
}
addPrimaryKey(subResource.getType(), properties);
addKeys(subResource.getType(), properties);
}
/**
* Add required primary and foreign keys properties based on request type.
*
* @param propertyTree tree of properties
* @param addIfEmpty whether keys should be added to node with no properties
*/
protected void ensureRequiredProperties(
TreeNode<Set<String>> propertyTree, boolean addIfEmpty) {
Resource.Type type = Resource.Type.valueOf(propertyTree.getName());
Set<String> properties = propertyTree.getObject();
if (!properties.isEmpty() || addIfEmpty) {
addKeys(type, properties);
}
for (TreeNode<Set<String>> child : propertyTree.getChildren()) {
ensureRequiredProperties(child, addIfEmpty);
}
}
}