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.grpc;
  
  import com.google.common.io.ByteStreams;
  import org.apache.avro.AvroRuntimeException;
  import org.apache.avro.Protocol;
  import org.apache.avro.io.BinaryDecoder;
  import org.apache.avro.io.BinaryEncoder;
  import org.apache.avro.io.DecoderFactory;
  import org.apache.avro.io.EncoderFactory;
  import org.apache.avro.specific.SpecificDatumReader;
  import org.apache.avro.specific.SpecificDatumWriter;
  import org.apache.avro.util.Utf8;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  import io.grpc.MethodDescriptor;
  import io.grpc.Status;
  
  /** Marshaller for Avro RPC response. */
  public class AvroResponseMarshaller implements MethodDescriptor.Marshaller<Object> {
    private static final EncoderFactory ENCODER_FACTORY = new EncoderFactory();
    private static final DecoderFactory DECODER_FACTORY = new DecoderFactory();
    private final Protocol.Message message;
  
    public AvroResponseMarshaller(Protocol.Message message) {
      this.message = message;
    }
  
    @Override
    public InputStream stream(Object value) {
      return new AvroResponseInputStream(value, message);
    }
  
    @Override
    public Object parse(InputStream stream) {
      try {
        if (message.isOneWay())
          return null;
        BinaryDecoder in = DECODER_FACTORY.binaryDecoder(stream, null);
        if (!in.readBoolean()) {
          Object response = new SpecificDatumReader(message.getResponse()).read(null, in);
          return response;
        } else {
          Object value = new SpecificDatumReader(message.getErrors()).read(null, in);
          if (value instanceof Exception) {
            return value;
          }
          return new AvroRuntimeException(value.toString());
        }
      } catch (IOException e) {
        throw Status.INTERNAL.withCause(e).withDescription("Error deserializing avro response").asRuntimeException();
      } finally {
        AvroGrpcUtils.skipAndCloseQuietly(stream);
      }
    }
  
    private static class AvroResponseInputStream extends AvroInputStream {
      private final Protocol.Message message;
      private Object response;
  
      AvroResponseInputStream(Object response, Protocol.Message message) {
        this.response = response;
        this.message = message;
      }
  
      @Override
      public int drainTo(OutputStream target) throws IOException {
        int written;
        if (getPartial() != null) {
          written = (int) ByteStreams.copy(getPartial(), target);
        } else {
          written = writeResponse(target);
        }
        return written;
      }
  
      private int writeResponse(OutputStream target) throws IOException {
        int written;
        if (message.isOneWay()) {
          written = 0;
        } else if (response instanceof Exception) {
          ByteArrayOutputStream bao = new ByteArrayOutputStream();
          BinaryEncoder out = ENCODER_FACTORY.binaryEncoder(bao, null);
          try {
            out.writeBoolean(true);
            new SpecificDatumWriter(message.getErrors()).write(response, out);
          } catch (Exception e) {
            bao = new ByteArrayOutputStream();
            out = ENCODER_FACTORY.binaryEncoder(bao, null);
            out.writeBoolean(true);
            new SpecificDatumWriter(Protocol.SYSTEM_ERRORS).write(new Utf8(e.toString()), out);
          }
          out.flush();
          byte[] serializedError = bao.toByteArray();
          target.write(serializedError);
          written = serializedError.length;
        } else {
          CountingOutputStream outputStream = new CountingOutputStream(target);
          BinaryEncoder out = ENCODER_FACTORY.binaryEncoder(outputStream, null);
          out.writeBoolean(false);
          new SpecificDatumWriter(message.getResponse()).write(response, out);
          out.flush();
          written = outputStream.getWrittenCount();
        }
        response = null;
        return written;
      }
    }
  }
  