| /* |
| * 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.avltree; |
| |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| import java.util.Comparator; |
| |
| import org.apache.directory.server.i18n.I18n; |
| import org.apache.directory.shared.util.Strings; |
| |
| |
| /** |
| * Class to serialize the Array data. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| @SuppressWarnings("unchecked") |
| public class ArrayMarshaller<E> implements Marshaller<ArrayTree<E>> |
| { |
| /** used for serialized form of an empty AvlTree */ |
| private static final byte[] EMPTY_TREE = new byte[1]; |
| |
| /** marshaller to be used for marshalling the keys */ |
| private Marshaller<E> keyMarshaller; |
| |
| /** key Comparator for the AvlTree */ |
| private Comparator<E> comparator; |
| |
| |
| /** |
| * Creates a new instance of AvlTreeMarshaller with a custom key |
| * Marshaller. |
| * |
| * @param comparator Comparator to be used for key comparision |
| * @param keyMarshaller marshaller for keys |
| */ |
| public ArrayMarshaller( Comparator<E> comparator, Marshaller<E> keyMarshaller ) |
| { |
| this.comparator = comparator; |
| this.keyMarshaller = keyMarshaller; |
| } |
| |
| |
| /** |
| * Creates a new instance of AvlTreeMarshaller with the default key |
| * Marshaller which uses Java Serialization. |
| * |
| * @param comparator Comparator to be used for key comparision |
| */ |
| public ArrayMarshaller( Comparator<E> comparator ) |
| { |
| this.comparator = comparator; |
| this.keyMarshaller = ( Marshaller<E> ) DefaultMarshaller.INSTANCE; |
| } |
| |
| |
| /** |
| * Marshals the given tree to bytes |
| * @param tree the tree to be marshalled |
| */ |
| public byte[] serialize( ArrayTree<E> tree ) |
| { |
| if ( ( tree == null ) || ( tree.size() == 0 ) ) |
| { |
| return EMPTY_TREE; |
| } |
| |
| ByteArrayOutputStream byteStream = new ByteArrayOutputStream(); |
| DataOutputStream out = new DataOutputStream( byteStream ); |
| byte[] data = null; |
| |
| try |
| { |
| out.writeByte( 0 ); // represents the start of an Array byte stream |
| out.writeInt( tree.size() ); |
| |
| for ( int position = 0; position < tree.size(); position++ ) |
| { |
| E value = tree.get( position ); |
| byte[] bytes = keyMarshaller.serialize( value ); |
| |
| // Write the key length |
| out.writeInt( bytes.length ); |
| |
| // Write the key if its length is not null |
| if ( bytes.length != 0 ) |
| { |
| out.write( bytes ); |
| } |
| } |
| |
| out.flush(); |
| data = byteStream.toByteArray(); |
| |
| // Try to deserialize, just to see |
| /* |
| try |
| { |
| deserialize( data ); |
| } |
| catch ( NullPointerException npe ) |
| { |
| System.out.println( I18n.err( I18n.ERR_438, Strings.dumpBytes( data ) ) ); |
| throw npe; |
| } |
| */ |
| |
| out.close(); |
| } |
| catch ( IOException e ) |
| { |
| e.printStackTrace(); |
| } |
| |
| return data; |
| } |
| |
| |
| /** |
| * Creates an Array from given bytes of data. |
| * |
| * @param data byte array to be converted into an array |
| */ |
| public ArrayTree<E> deserialize( byte[] data ) throws IOException |
| { |
| //LOG.debug( "Deserializing the tree, called by {}", Reflection.getCallerClass( 2 ).getSimpleName() ); |
| |
| try |
| { |
| if ( ( data == null ) || ( data.length == 0 ) ) |
| { |
| throw new IOException( I18n.err( I18n.ERR_439 ) ); |
| } |
| |
| if ( ( data.length == 1 ) && ( data[0] == 0 ) ) |
| { |
| E[] array = ( E[] ) new Object[] |
| {}; |
| ArrayTree<E> tree = new ArrayTree<E>( comparator, array ); |
| return tree; |
| } |
| |
| ByteArrayInputStream bin = new ByteArrayInputStream( data ); |
| DataInputStream din = new DataInputStream( bin ); |
| |
| byte startByte = din.readByte(); |
| |
| if ( startByte != 0 ) |
| { |
| throw new IOException( I18n.err( I18n.ERR_440 ) ); |
| } |
| |
| int size = din.readInt(); |
| E[] nodes = ( E[] ) new Object[size]; |
| |
| for ( int i = 0; i < size; i++ ) |
| { |
| // Read the object's size |
| int dataSize = din.readInt(); |
| |
| if ( dataSize != 0 ) |
| { |
| byte[] bytes = new byte[dataSize]; |
| |
| din.readFully( bytes ); |
| E key = keyMarshaller.deserialize( bytes ); |
| nodes[i] = key; |
| } |
| } |
| |
| ArrayTree<E> arrayTree = new ArrayTree<E>( comparator, nodes ); |
| |
| return arrayTree; |
| } |
| catch ( NullPointerException npe ) |
| { |
| System.out.println( I18n.err( I18n.ERR_441, Strings.dumpBytes( data ) ) ); |
| throw npe; |
| } |
| } |
| } |