library/src/main/java/org/apache/apex/malhar/lib/appdata/gpo/SerdeListString.java

/**
 * 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.apex.malhar.lib.appdata.gpo;

import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.commons.lang3.mutable.MutableInt;

import com.google.common.collect.Lists;

/**
 * @since 3.1.0
 */

public class SerdeListString implements Serde
{
  public static final SerdeListString INSTANCE = new SerdeListString();
  private final GPOByteArrayList bytes = new GPOByteArrayList();

  private SerdeListString()
  {
  }

  @Override
  public synchronized Object deserializeObject(byte[] object, MutableInt offset)
  {
    int length = GPOUtils.deserializeInt(object, offset);
    int startIndex = offset.intValue();

    List<String> strings = Lists.newArrayList();
    while (startIndex + length > offset.intValue()) {
      String value = GPOUtils.deserializeString(object, offset);
      strings.add(value);
    }

    return strings;
  }

  @Override
  public synchronized byte[] serializeObject(Object object)
  {
    @SuppressWarnings("unchecked")
    List<String> strings = (List<String>)object;

    for (int index = 0; index < strings.size(); index++) {
      String string = strings.get(index);
      byte[] stringBytes = string.getBytes();
      byte[] lengthBytes = GPOUtils.serializeInt(stringBytes.length);

      bytes.add(lengthBytes);
      bytes.add(stringBytes);
    }

    byte[] byteArray = bytes.toByteArray();
    bytes.clear();
    bytes.add(GPOUtils.serializeInt(byteArray.length));
    bytes.add(byteArray);
    byteArray = bytes.toByteArray();
    bytes.clear();
    return byteArray;
  }

  private static final Logger LOG = LoggerFactory.getLogger(SerdeListString.class);
}