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.mina.core.file;
021
022import java.io.IOException;
023import java.nio.channels.FileChannel;
024
025/**
026 * TODO Add documentation
027 * 
028 * 
029 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
030 */
031public class DefaultFileRegion implements FileRegion {
032
033    private final FileChannel channel;
034
035    private final long originalPosition;
036
037    private long position;
038
039    private long remainingBytes;
040
041    public DefaultFileRegion(FileChannel channel) throws IOException {
042        this(channel, 0, channel.size());
043    }
044
045    public DefaultFileRegion(FileChannel channel, long position, long remainingBytes) {
046        if (channel == null) {
047            throw new IllegalArgumentException("channel can not be null");
048        }
049        
050        if (position < 0) {
051            throw new IllegalArgumentException("position may not be less than 0");
052        }
053        
054        if (remainingBytes < 0) {
055            throw new IllegalArgumentException("remainingBytes may not be less than 0");
056        }
057        
058        this.channel = channel;
059        this.originalPosition = position;
060        this.position = position;
061        this.remainingBytes = remainingBytes;
062    }
063
064    public long getWrittenBytes() {
065        return position - originalPosition;
066    }
067
068    public long getRemainingBytes() {
069        return remainingBytes;
070    }
071
072    public FileChannel getFileChannel() {
073        return channel;
074    }
075
076    public long getPosition() {
077        return position;
078    }
079
080    public void update(long value) {
081        position += value;
082        remainingBytes -= value;
083    }
084
085    public String getFilename() {
086        return null;
087    }
088
089}