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.Protocol;
  import org.apache.avro.Schema;
  import org.apache.avro.generic.GenericRecord;
  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 java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  import io.grpc.MethodDescriptor;
  import io.grpc.Status;
  
  /** Marshaller for Avro RPC request. */
  public class AvroRequestMarshaller 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 AvroRequestMarshaller(Protocol.Message message) {
      this.message = message;
    }
  
    @Override
    public InputStream stream(Object[] value) {
      return new AvroRequestInputStream(value, message);
    }
  
    @Override
    public Object[] parse(InputStream stream) {
      try {
        BinaryDecoder in = DECODER_FACTORY.binaryDecoder(stream, null);
        Schema reqSchema = message.getRequest();
        GenericRecord request = (GenericRecord) new SpecificDatumReader<>(reqSchema).read(null, in);
        Object[] args = new Object[reqSchema.getFields().size()];
        int i = 0;
        for (Schema.Field field : reqSchema.getFields()) {
          args[i++] = request.get(field.name());
        }
        return args;
      } catch (IOException e) {
        throw Status.INTERNAL.withCause(e).withDescription("Error deserializing avro request arguments")
            .asRuntimeException();
      } finally {
        AvroGrpcUtils.skipAndCloseQuietly(stream);
      }
    }
  
    private static class AvroRequestInputStream extends AvroInputStream {
      private final Protocol.Message message;
      private Object[] args;
  
      AvroRequestInputStream(Object[] args, Protocol.Message message) {
        this.args = args;
        this.message = message;
      }
  
      @Override
      public int drainTo(OutputStream target) throws IOException {
        int written;
        if (getPartial() != null) {
          written = (int) ByteStreams.copy(getPartial(), target);
        } else {
          Schema reqSchema = message.getRequest();
          CountingOutputStream outputStream = new CountingOutputStream(target);
          BinaryEncoder out = ENCODER_FACTORY.binaryEncoder(outputStream, null);
          int i = 0;
          for (Schema.Field param : reqSchema.getFields()) {
            new SpecificDatumWriter<>(param.schema()).write(args[i++], out);
          }
          out.flush();
          args = null;
          written = outputStream.getWrittenCount();
        }
        return written;
      }
    }
  }
  