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.beam.runners.dataflow.worker;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.nio.channels.Channels;
  import java.nio.channels.WritableByteChannel;
  import org.apache.avro.Schema;
  import org.apache.avro.file.DataFileWriter;
  import org.apache.avro.generic.GenericDatumWriter;
  import org.apache.beam.runners.dataflow.worker.util.common.worker.Sink;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.io.FileSystems;
  import org.apache.beam.sdk.io.fs.ResourceId;
  import org.apache.beam.sdk.util.CoderUtils;
  import org.apache.beam.sdk.util.MimeTypes;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
  
  /**
   * A sink that writes Avro files. Records are written to the Avro file as a series of byte arrays.
   * The coder provided is used to serialize each record into a byte array.
   *
   * @param <T> the type of the elements written to the sink
   */
  public class AvroByteSink<T> extends Sink<T> {
  
    final Coder<T> coder;
    @VisibleForTesting final ResourceId resourceId;
    private final Schema schema = Schema.create(Schema.Type.BYTES);
  
    public AvroByteSink(ResourceId resourceId, Coder<T> coder) {
      this.coder = coder;
      this.resourceId = resourceId;
    }
  
    @Override
    public SinkWriter<T> writer() throws IOException {
      return new AvroByteFileWriter();
    }
  
    class AvroByteFileWriter implements SinkWriter<T> {
      DataFileWriter<ByteBuffer> fileWriter;
  
      public AvroByteFileWriter() throws IOException {
        WritableByteChannel writer = FileSystems.create(resourceId, MimeTypes.BINARY);
  
        fileWriter = new DataFileWriter<>(new GenericDatumWriter<ByteBuffer>(schema));
        fileWriter.create(schema, Channels.newOutputStream(writer));
      }
  
      @Override
      public long add(T value) throws IOException {
        byte[] encodedElem = CoderUtils.encodeToByteArray(coder, value);
        ByteBuffer encodedBuffer = ByteBuffer.wrap(encodedElem);
        fileWriter.append(encodedBuffer);
        return encodedElem.length;
      }
  
      @Override
      public void close() throws IOException {
        fileWriter.close();
      }
  
      @Override
      public void abort() throws IOException {
        // DataFileWriter implements Closeable and is idempotent.
        fileWriter.close();
      }
    }
  }
  