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.kafka.common.serialization;
  
  import java.nio.ByteBuffer;
  
  /**
   * {@code ByteBufferSerializer} always {@link ByteBuffer#rewind() rewinds} the position of the input buffer to zero for
   * serialization. A manual rewind is not necessary.
   * <p>
   * Note: any existing buffer position is ignored.
   * <p>
   * The position is also rewound back to zero before {@link #serialize(String, ByteBuffer)}
   * returns.
   */
  public class ByteBufferSerializer implements Serializer<ByteBuffer> {
      public byte[] serialize(String topic, ByteBuffer data) {
          if (data == null)
              return null;
  
          data.rewind();
  
          if (data.hasArray()) {
              byte[] arr = data.array();
              if (data.arrayOffset() == 0 && arr.length == data.remaining()) {
                  return arr;
              }
          }
  
          byte[] ret = new byte[data.remaining()];
          data.get(ret, 0, ret.length);
          data.rewind();
          return ret;
      }
  }
  