| /* |
| * 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.mavibot.btree.serializer; |
| |
| |
| import java.io.IOException; |
| import java.io.UnsupportedEncodingException; |
| import java.nio.ByteBuffer; |
| import java.util.Comparator; |
| |
| import org.apache.directory.mavibot.btree.comparator.StringComparator; |
| import org.apache.directory.mavibot.btree.exception.SerializerCreationException; |
| import org.apache.directory.mavibot.btree.util.Strings; |
| |
| |
| /** |
| * The String serializer. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class StringSerializer extends AbstractElementSerializer<String> |
| { |
| /** A static instance of a StringSerializer */ |
| public static final StringSerializer INSTANCE = new StringSerializer(); |
| |
| /** |
| * Create a new instance of StringSerializer |
| */ |
| private StringSerializer() |
| { |
| super( StringComparator.INSTANCE ); |
| } |
| |
| |
| /** |
| * Create a new instance of StringSerializer with custom comparator |
| */ |
| public StringSerializer( Comparator<String> comparator ) |
| { |
| super( comparator ); |
| } |
| |
| |
| /** |
| * A static method used to deserialize a String from a byte array. |
| * @param in The byte array containing the String |
| * @return A String |
| */ |
| public static String deserialize( byte[] in ) |
| { |
| return deserialize( in, 0 ); |
| } |
| |
| |
| /** |
| * A static method used to deserialize a String from a byte array. |
| * @param in The byte array containing the String |
| * @return A String |
| */ |
| public static String deserialize( byte[] in, int start ) |
| { |
| int length = IntSerializer.deserialize( in, start ); |
| |
| if ( length == 0xFFFFFFFF ) |
| { |
| return null; |
| } |
| |
| if ( in.length < length + 4 + start ) |
| { |
| throw new SerializerCreationException( "Cannot extract a String from a buffer with not enough bytes" ); |
| } |
| |
| return Strings.utf8ToString( in, start + 4, length ); |
| } |
| |
| |
| /** |
| * A method used to deserialize a String from a byte array. |
| * @param in The byte array containing the String |
| * @return A String |
| */ |
| public String fromBytes( byte[] in ) |
| { |
| return deserialize( in, 0 ); |
| } |
| |
| |
| /** |
| * A method used to deserialize a String from a byte array. |
| * @param in The byte array containing the String |
| * @return A String |
| */ |
| public String fromBytes( byte[] in, int start ) |
| { |
| int length = IntSerializer.deserialize( in, start ); |
| |
| if ( length == 0xFFFFFFFF ) |
| { |
| return null; |
| } |
| |
| if ( in.length < length + start ) |
| { |
| throw new SerializerCreationException( "Cannot extract a String from a buffer with not enough bytes" ); |
| } |
| |
| return Strings.utf8ToString( in, start + 4, length ); |
| } |
| |
| |
| /** |
| * Serialize a String. We store the length on 4 bytes, then the String |
| * |
| * @param buffer the Buffer that will contain the serialized value |
| * @param start the position in the buffer we will store the serialized String |
| * @param value the value to serialize |
| * @return The byte[] containing the serialized String |
| */ |
| public static byte[] serialize( byte[] buffer, int start, String element ) |
| { |
| int len = -1; |
| |
| if ( element != null ) |
| { |
| len = element.length(); |
| } |
| |
| switch ( len ) |
| { |
| case 0: |
| buffer[start] = 0x00; |
| buffer[start + 1] = 0x00; |
| buffer[start + 2] = 0x00; |
| buffer[start + 3] = 0x00; |
| |
| break; |
| |
| case -1: |
| buffer[start] = ( byte ) 0xFF; |
| buffer[start + 1] = ( byte ) 0xFF; |
| buffer[start + 2] = ( byte ) 0xFF; |
| buffer[start + 3] = ( byte ) 0xFF; |
| |
| break; |
| |
| default: |
| try |
| { |
| byte[] strBytes = element.getBytes( "UTF-8" ); |
| |
| buffer = new byte[strBytes.length + 4]; |
| |
| System.arraycopy( strBytes, 0, buffer, 4, strBytes.length ); |
| |
| buffer[start] = ( byte ) ( strBytes.length >>> 24 ); |
| buffer[start + 1] = ( byte ) ( strBytes.length >>> 16 ); |
| buffer[start + 2] = ( byte ) ( strBytes.length >>> 8 ); |
| buffer[start + 3] = ( byte ) ( strBytes.length ); |
| } |
| catch ( UnsupportedEncodingException uee ) |
| { |
| // if this happens something is really strange |
| throw new SerializerCreationException( uee ); |
| } |
| } |
| |
| return buffer; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public byte[] serialize( String element ) |
| { |
| int len = -1; |
| |
| if ( element != null ) |
| { |
| len = element.length(); |
| } |
| |
| byte[] bytes = null; |
| |
| switch ( len ) |
| { |
| case 0: |
| bytes = new byte[4]; |
| |
| bytes[0] = 0x00; |
| bytes[1] = 0x00; |
| bytes[2] = 0x00; |
| bytes[3] = 0x00; |
| |
| break; |
| |
| case -1: |
| bytes = new byte[4]; |
| |
| bytes[0] = ( byte ) 0xFF; |
| bytes[1] = ( byte ) 0xFF; |
| bytes[2] = ( byte ) 0xFF; |
| bytes[3] = ( byte ) 0xFF; |
| |
| break; |
| |
| default: |
| char[] chars = element.toCharArray(); |
| byte[] tmpBytes = new byte[chars.length * 2]; |
| |
| int pos = 0; |
| len = 0; |
| |
| for ( char c : chars ) |
| { |
| if ( ( c & 0xFF80 ) == 0 ) |
| { |
| tmpBytes[pos++] = ( byte ) c; |
| } |
| else if ( ( c & 0xF800 ) == 0 ) |
| { |
| tmpBytes[pos++] = ( byte ) ( ( byte ) 0x00C0 | ( byte ) ( ( c & 0x07C0 ) >> 6 ) ); |
| tmpBytes[pos++] = ( byte ) ( ( byte ) 0x80 | ( byte ) ( c & 0x003F ) ); |
| } |
| else |
| { |
| tmpBytes[pos++] = ( byte ) ( ( byte ) 0x80 | ( byte ) ( c & 0x001F ) ); |
| tmpBytes[pos++] = ( byte ) ( ( byte ) 0x80 | ( byte ) ( c & 0x07C0 ) ); |
| tmpBytes[pos++] = ( byte ) ( ( byte ) 0xE0 | ( byte ) ( c & 0x7800 ) ); |
| } |
| } |
| |
| bytes = new byte[pos + 4]; |
| |
| bytes[0] = ( byte ) ( pos >>> 24 ); |
| bytes[1] = ( byte ) ( pos >>> 16 ); |
| bytes[2] = ( byte ) ( pos >>> 8 ); |
| bytes[3] = ( byte ) ( pos ); |
| |
| System.arraycopy( tmpBytes, 0, bytes, 4, pos ); |
| } |
| |
| return bytes; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| * @throws IOException |
| */ |
| public String deserialize( BufferHandler bufferHandler ) throws IOException |
| { |
| byte[] in = bufferHandler.read( 4 ); |
| |
| int len = IntSerializer.deserialize( in ); |
| |
| switch ( len ) |
| { |
| case 0: |
| return ""; |
| |
| case -1: |
| return null; |
| |
| default: |
| in = bufferHandler.read( len ); |
| |
| return Strings.utf8ToString( in ); |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String deserialize( ByteBuffer buffer ) throws IOException |
| { |
| int len = buffer.getInt(); |
| |
| switch ( len ) |
| { |
| case 0: |
| return ""; |
| |
| case -1: |
| return null; |
| |
| default: |
| byte[] bytes = new byte[len]; |
| |
| buffer.get( bytes ); |
| char[] chars = new char[len]; |
| int clen = 0; |
| |
| for ( int i = 0; i < len; i++ ) |
| { |
| byte b = bytes[i]; |
| |
| if ( b >= 0 ) |
| { |
| chars[clen++] = ( char ) b; |
| } |
| else |
| { |
| if ( ( b & 0xE0 ) == 0 ) |
| { |
| // 3 bytes long char |
| i++; |
| byte b2 = bytes[i]; |
| i++; |
| byte b3 = bytes[i]; |
| chars[clen++] = ( char ) ( ( ( b & 0x000F ) << 12 ) | ( ( b2 & 0x003F ) << 6 ) | ( ( b3 & 0x003F ) ) ); |
| } |
| else |
| { |
| // 2 bytes long char |
| i++; |
| byte b2 = bytes[i]; |
| chars[clen++] = ( char ) ( ( ( b & 0x001F ) << 6 ) | ( b2 & 0x003F ) ); |
| } |
| } |
| } |
| |
| return new String( chars, 0, clen ); |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int compare( String type1, String type2 ) |
| { |
| if ( type1 == type2 ) |
| { |
| return 0; |
| } |
| |
| if ( type1 == null ) |
| { |
| if ( type2 == null ) |
| { |
| return 0; |
| } |
| else |
| { |
| return -1; |
| } |
| } |
| else |
| { |
| if ( type2 == null ) |
| { |
| return 1; |
| } |
| else |
| { |
| return type1.compareTo( type2 ); |
| } |
| } |
| } |
| } |