001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.directory.server.core.partition.impl.btree.jdbm; 021 022 023import java.io.IOException; 024 025import org.apache.directory.api.util.Strings; 026import org.apache.directory.server.core.avltree.Marshaller; 027import org.apache.directory.server.i18n.I18n; 028 029 030/** 031 * Serializes and deserializes a BTreeRedirect object to and from a byte[] 032 * representation. The serialized form is a fixed size byte array of length 033 * 9. The first byte contains the magic number of value 1 for this kind of 034 * object and the last 8 bytes encode the record identifier as a long for 035 * the BTree. 036 * 037 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 038 */ 039public class BTreeRedirectMarshaller implements Marshaller<BTreeRedirect> 040{ 041 /** fixed byte array size of 9 for serialized form */ 042 static final int SIZE = 9; 043 /** a reusable instance of this Marshaller */ 044 public static final BTreeRedirectMarshaller INSTANCE = new BTreeRedirectMarshaller(); 045 046 047 /** 048 * @see Marshaller#serialize(Object) 049 */ 050 public final byte[] serialize( BTreeRedirect redirect ) throws IOException 051 { 052 byte[] bites = new byte[SIZE]; 053 054 bites[0] = 1; 055 056 bites[1] = ( byte ) ( 0xFF & ( redirect.recId >> 56 ) ); 057 bites[2] = ( byte ) ( 0xFF & ( redirect.recId >> 48 ) ); 058 bites[3] = ( byte ) ( 0xFF & ( redirect.recId >> 40 ) ); 059 bites[4] = ( byte ) ( 0xFF & ( redirect.recId >> 32 ) ); 060 bites[5] = ( byte ) ( 0xFF & ( redirect.recId >> 24 ) ); 061 bites[6] = ( byte ) ( 0xFF & ( redirect.recId >> 16 ) ); 062 bites[7] = ( byte ) ( 0xFF & ( redirect.recId >> 8 ) ); 063 bites[8] = ( byte ) ( 0xFF & ( redirect.recId ) ); 064 065 return bites; 066 } 067 068 069 /** 070 * @see Marshaller#deserialize(byte[]) 071 */ 072 public final BTreeRedirect deserialize( byte[] bytes ) throws IOException 073 { 074 if ( ( bytes == null ) || ( bytes.length != SIZE ) || ( bytes[0] != 1 ) ) 075 { 076 if ( bytes != null ) 077 { 078 throw new IOException( I18n.err( I18n.ERR_568, Strings.dumpBytes( bytes ) ) ); 079 } 080 else 081 { 082 throw new IOException( I18n.err( I18n.ERR_569 ) ); 083 } 084 } 085 086 long recId = ( ( long ) ( bytes[1] & 0xFF ) << 56 ) 087 | ( ( long ) ( bytes[2] & 0xFF ) << 48 ) 088 | ( ( long ) ( bytes[3] & 0xFF ) << 40 ) 089 | ( ( long ) ( bytes[4] & 0xFF ) << 32 ) 090 | ( ( long ) ( bytes[5] & 0xFF ) << 24 ) 091 | ( ( long ) ( bytes[6] & 0xFF ) << 16 ) 092 | ( ( long ) ( bytes[7] & 0xFF ) << 8 ) 093 | ( ( long ) ( bytes[8] & 0xFF ) ); 094 095 return new BTreeRedirect( recId ); 096 } 097 098 099 /** 100 * Checks to see if a byte[] contains a redirect. 101 * 102 * @param bites the bites to check for a redirect 103 * @return true if bites contain BTreeRedirect, false otherwise 104 */ 105 public static boolean isRedirect( byte[] bites ) 106 { 107 return ( bites != null ) && ( bites.length == SIZE ) && ( bites[0] == 1 ); 108 } 109}