content: /*
   * 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.controller.spi;
  
  
  import java.util.Set;
  
  /**
   * The schema is used to describe all of the properties that a resource type
   * supports.
   */
  public interface Schema {
  
    /**
     * Get the property id for the property that uniquely identifies
     * the given resource type for the resource described by this schema.
     * </p>
     * For example, the resource 'HostComponent' is uniquely identified by
     * its associated 'Cluster', 'Host' and 'Component' resources.  Passing
     * the 'Host' resource type to this method on a schema object of a 'HostComponent'
     * resource will return the id of the property of the foreign key reference from
     * the 'HostComponent' to the 'Host'.
     *
     * @param type the resource type
     * @return the key property id for the given resource type
     */
    String getKeyPropertyId(Resource.Type type);
  
    /**
     * Get the set of resource types used in the key that uniquely identifies
     * the resource type described by this schema.
     * </p>
     * For example, the resource 'HostComponent' is uniquely identified by
     * its associated 'Cluster', 'Host' and 'Component' resources.  Calling
     * this method should return a set of those resource types.
     *
     * @return the set of resource types used in the key that uniquely identifies
     *         the resource type described by this schema.
     */
    Set<Resource.Type> getKeyTypes();
    }
  