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
   *
   *     https://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.avro.protobuf;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  
  import org.apache.avro.Schema;
  import org.apache.avro.generic.GenericDatumReader;
  import org.apache.avro.specific.SpecificData;
  import org.apache.avro.io.Decoder;
  import org.apache.avro.io.ResolvingDecoder;
  
  import com.google.protobuf.ByteString;
  import com.google.protobuf.Message;
  import com.google.protobuf.ProtocolMessageEnum;
  
  /**
   * {@link org.apache.avro.io.DatumReader DatumReader} for generated Protobuf
   * classes.
   */
  public class ProtobufDatumReader<T> extends GenericDatumReader<T> {
    public ProtobufDatumReader() {
      this(null, null, ProtobufData.get());
    }
  
    public ProtobufDatumReader(Class<T> c) {
      this(ProtobufData.get().getSchema(c));
    }
  
    /** Construct where the writer's and reader's schemas are the same. */
    public ProtobufDatumReader(Schema schema) {
      this(schema, schema, ProtobufData.get());
    }
  
    /** Construct given writer's and reader's schema. */
    public ProtobufDatumReader(Schema writer, Schema reader) {
      this(writer, reader, ProtobufData.get());
    }
  
    protected ProtobufDatumReader(Schema writer, Schema reader, ProtobufData data) {
      super(writer, reader, data);
    }
  
    @Override
    protected Object readRecord(Object old, Schema expected, ResolvingDecoder in) throws IOException {
      Message.Builder b = (Message.Builder) super.readRecord(old, expected, in);
      return b.build(); // build instance
    }
  
    @Override
    protected Object createEnum(String symbol, Schema schema) {
      try {
        Class c = SpecificData.get().getClass(schema);
        if (c == null)
          return super.createEnum(symbol, schema); // punt to generic
        return ((ProtocolMessageEnum) Enum.valueOf(c, symbol)).getValueDescriptor();
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
  
    @Override
    protected Object readBytes(Object old, Decoder in) throws IOException {
      return ByteString.copyFrom(((ByteBuffer) super.readBytes(old, in)).array());
    }
  
  }
  