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/*
 * Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
 *
 * Licensed 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. See accompanying
 * LICENSE file.
 */
package com.gemstone.gemfire.internal.cache;

import com.gemstone.gemfire.internal.shared.Version;

/**
 * Used to fetch a record's raw bytes and user bits.
 * The actual data length in byte array may be less than
 * the size of the byte array itself. An integer field contains
 * the valid length. This class is used exclusively by the Oplog Compactor
 * for rolling the entries. The reason for this class is to reuse the
 * underlying byte array for rolling multiple entries there by
 * reducing the garbage.
 * @author Asif 
 * @since 5.5
 */
public class BytesAndBitsForCompactor {
  private  byte[] data;
  private  byte userBits=0;
  // length of the data present in the byte array 
  private  int validLength;
  private static final byte[] INIT_FOR_WRAPPER = new byte[0];
  // boolean indicating if the object can be reused.
  // Typically if the data stores the reference of a value byte [] directly
  // from the RegionEntry than this byte array cannot be reused for
  //storing another entry's data 
  private boolean isReusable;

  private transient Version version;

  public BytesAndBitsForCompactor() {
    this.data = INIT_FOR_WRAPPER;
    //this.userBits = userBits;
    this.validLength = INIT_FOR_WRAPPER.length;
    this.isReusable = true;
  }

  public final byte[] getBytes() {
    return this.data;
  }
  public final byte getBits() {
    return this.userBits;
  }
  
  public final int getValidLength() {
    return this.validLength;
  }
  
  public boolean isReusable() {
    return this.isReusable;
  }
  
  /**
   * 
   * @param data byte array storing the data 
   * @param userBits byte with appropriate bits set
   * @param validLength  The number of bytes representing the data , starting from 0 as offset
   * @param isReusable true if this object is safe for reuse as a data holder
   */
  public void setData(byte[] data, byte userBits, int validLength, boolean isReusable) {
    this.data = data;
    this.userBits = userBits;
    this.validLength = validLength;    
    this.isReusable = isReusable;
  }

  public Version getVersion() { 
    return version; 
  } 

  public void setVersion(Version version) { 
    this.version = version; 
  }
}