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 org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.dataflow.common.data.accessors.ITupleReference;
  
  /**
   * Interface for translating the representation of metadata entities (datasets,
   * types, etc.) from their Java object representation to a serialized
   * representation in a Hyracks tuple, and vice versa. Implementations of this
   * interface are intended to be used within an IMetadataNode.
   */
  public interface IMetadataEntityTupleTranslator<T> {
  
      /**
       * Transforms a metadata entity of type T from a given tuple to a Java object
       * (deserializing the appropriate field(s) in the tuple as necessary).
       *
       * @param tuple
       *            Tuple containing a serialized representation of a metadata entity
       *            of type T.
       * @return A new instance of a metadata entity of type T.
       * @throws AlgebricksException
       * @throws HyracksDataException
       */
      T getMetadataEntityFromTuple(ITupleReference tuple) throws AlgebricksException, HyracksDataException;
  
      /**
       * Serializes the given metadata entity of type T into an appropriate tuple
       * representation (i.e., some number of fields containing bytes).
       *
       * @param metadataEntity
       *            Metadata entity to be written into a tuple.
       * @throws AlgebricksException
       * @throws HyracksDataException
       */
      ITupleReference getTupleFromMetadataEntity(T metadataEntity) throws AlgebricksException, HyracksDataException;
  }
  