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.asterix.metadata.api;
  
  import java.rmi.RemoteException;
  import java.util.List;
  import java.util.function.Function;
  
  import org.apache.asterix.common.api.IExtension;
  import org.apache.asterix.common.dataflow.ICcApplicationContext;
  import org.apache.asterix.common.exceptions.ACIDException;
  import org.apache.asterix.metadata.bootstrap.MetadataIndexesProvider;
  import org.apache.asterix.metadata.entitytupletranslators.MetadataTupleTranslatorProvider;
  import org.apache.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
  import org.apache.hyracks.api.application.INCServiceContext;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  
  /**
   * An interface for Metadata Extensions
   */
  public interface IMetadataExtension extends IExtension {
  
      @Override
      default ExtensionKind getExtensionKind() {
          return ExtensionKind.METADATA;
      }
  
      /**
       * @return The tuple translator provider that must be used by the {@code IMetadataNode } to read and write core
       *         {@code IMetadataEntity} objects
       */
      MetadataTupleTranslatorProvider getMetadataTupleTranslatorProvider(MetadataIndexesProvider metadataIndexesProvider,
              INCServiceContext ncServiceCtx);
  
      MetadataIndexesProvider getMetadataIndexesProvider(boolean usingDatabase);
  
      /**
       * @return A list of additional extension instances of {@code IMetadataIndex} that are introduced by the extension
       */
      @SuppressWarnings("rawtypes")
      List<ExtensionMetadataDataset> getExtensionIndexes(MetadataIndexesProvider metadataIndexesProvider);
  
      /**
       * Called when booting the {@code IMetadataNode}
       *
       * @throws HyracksDataException
       * @throws RemoteException
       * @throws ACIDException
       */
      void initializeMetadata(INCServiceContext ncServiceCtx, MetadataIndexesProvider mdIndexesProvider)
              throws HyracksDataException, RemoteException, ACIDException;
  
      /**
       * Returns a factory for {@link org.apache.asterix.metadata.declared.MetadataProvider},
       * or {@code null} if this extension doesn't define this factory.
       */
      default Function<ICcApplicationContext, IMetadataProvider<?, ?>> getMetadataProviderFactory() {
          return null;
      }
  }
  