/*
    *  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.directory.server.core.partition.impl.btree.jdbm;
  
  
  import java.io.IOException;
  
  import org.apache.directory.api.util.Strings;
  import org.apache.directory.server.core.avltree.Marshaller;
  import org.apache.directory.server.i18n.I18n;
  
  
  /**
   * Serializes and deserializes a BTreeRedirect object to and from a byte[]
   * representation.  The serialized form is a fixed size byte array of length
   * 9.  The first byte contains the magic number of value 1 for this kind of
   * object and the last 8 bytes encode the record identifier as a long for
   * the BTree.
   *
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class BTreeRedirectMarshaller implements Marshaller<BTreeRedirect>
  {
      /** fixed byte array size of 9 for serialized form */
      static final int SIZE = 9;
      /** a reusable instance of this Marshaller */
      public static final BTreeRedirectMarshaller/partition/impl/btree/jdbm/BTreeRedirectMarshaller.html#BTreeRedirectMarshaller">BTreeRedirectMarshaller INSTANCE = new BTreeRedirectMarshaller();
  
  
      /**
       * @see Marshaller#serialize(Object)
       */
      public final byte[] serialize( BTreeRedirect redirect ) throws IOException
      {
          byte[] bites = new byte[SIZE];
  
          bites[0] = 1;
  
          bites[1] = ( byte ) ( 0xFF & ( redirect.recId >> 56 ) );
          bites[2] = ( byte ) ( 0xFF & ( redirect.recId >> 48 ) );
          bites[3] = ( byte ) ( 0xFF & ( redirect.recId >> 40 ) );
          bites[4] = ( byte ) ( 0xFF & ( redirect.recId >> 32 ) );
          bites[5] = ( byte ) ( 0xFF & ( redirect.recId >> 24 ) );
          bites[6] = ( byte ) ( 0xFF & ( redirect.recId >> 16 ) );
          bites[7] = ( byte ) ( 0xFF & ( redirect.recId >> 8 ) );
          bites[8] = ( byte ) ( 0xFF & ( redirect.recId ) );
  
          return bites;
      }
  
  
      /**
       * @see Marshaller#deserialize(byte[])
       */
      public final BTreeRedirect deserialize( byte[] bytes ) throws IOException
      {
          if ( ( bytes == null ) || ( bytes.length != SIZE ) || ( bytes[0] != 1 ) )
          {
              if ( bytes != null )
              {
                  throw new IOException( I18n.err( I18n.ERR_568, Strings.dumpBytes( bytes ) ) );
              }
              else
              {
                  throw new IOException( I18n.err( I18n.ERR_569 ) );
              }
          }
  
          long recId = ( ( long ) ( bytes[1] & 0xFF ) << 56 )
                  | ( ( long ) ( bytes[2] & 0xFF ) << 48 )
                  | ( ( long ) ( bytes[3] & 0xFF ) << 40 )
                  | ( ( long ) ( bytes[4] & 0xFF ) << 32 )
                  | ( ( long ) ( bytes[5] & 0xFF ) << 24 )
                  | ( ( long ) ( bytes[6] & 0xFF ) << 16 )
                  | ( ( long ) ( bytes[7] & 0xFF ) << 8 )
                  | ( ( long ) ( bytes[8] & 0xFF ) );
  
          return new BTreeRedirect( recId );
      }
  
  
      /**
      * Checks to see if a byte[] contains a redirect.
      *
      * @param bites the bites to check for a redirect
      * @return true if bites contain BTreeRedirect, false otherwise
      */
     public static boolean isRedirect( byte[] bites )
     {
         return ( bites != null ) && ( bites.length == SIZE ) && ( bites[0] == 1 );
     }
 }