/*
* Copyright 2011 The Netty Project
*
* The Netty Project 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.jboss.netty.buffer;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.ScatteringByteChannel;
/**
* A derived buffer which exposes its parent's sub-region only. It is
* recommended to use {@link ChannelBuffer#slice()} and
* {@link ChannelBuffer#slice(int, int)} instead of calling the constructor
* explicitly.
*/
public class SlicedChannelBuffer extends AbstractChannelBuffer implements WrappedChannelBuffer {
private final ChannelBuffer buffer;
private final int adjustment;
private final int length;
public SlicedChannelBuffer(ChannelBuffer buffer, int index, int length) {
if (index < 0 || index > buffer.capacity()) {
throw new IndexOutOfBoundsException();
}
if (index + length > buffer.capacity()) {
throw new IndexOutOfBoundsException();
}
this.buffer = buffer;
adjustment = index;
this.length = length;
writerIndex(length);
}
public ChannelBuffer unwrap() {
return buffer;
}
public ChannelBufferFactory factory() {
return buffer.factory();
}
public ByteOrder order() {
return buffer.order();
}
public boolean isDirect() {
return buffer.isDirect();
}
public int capacity() {
return length;
}
public boolean hasArray() {
return buffer.hasArray();
}
public byte[] array() {
return buffer.array();
}
public int arrayOffset() {
return buffer.arrayOffset() + adjustment;
}
public byte getByte(int index) {
checkIndex(index);
return buffer.getByte(index + adjustment);
}
public short getShort(int index) {
checkIndex(index, 2);
return buffer.getShort(index + adjustment);
}
public int getUnsignedMedium(int index) {
checkIndex(index, 3);
return buffer.getUnsignedMedium(index + adjustment);
}
public int getInt(int index) {
checkIndex(index, 4);
return buffer.getInt(index + adjustment);
}
public long getLong(int index) {
checkIndex(index, 8);
return buffer.getLong(index + adjustment);
}
public ChannelBuffer duplicate() {
ChannelBuffer duplicate = new SlicedChannelBuffer(buffer, adjustment, length);
duplicate.setIndex(readerIndex(), writerIndex());
return duplicate;
}
public ChannelBuffer copy(int index, int length) {
checkIndex(index, length);
return buffer.copy(index + adjustment, length);
}
public ChannelBuffer slice(int index, int length) {
checkIndex(index, length);
if (length == 0) {
return ChannelBuffers.EMPTY_BUFFER;
}
return new SlicedChannelBuffer(buffer, index + adjustment, length);
}
public void getBytes(int index, ChannelBuffer dst, int dstIndex, int length) {
checkIndex(index, length);
buffer.getBytes(index + adjustment, dst, dstIndex, length);
}
public void getBytes(int index, byte[] dst, int dstIndex, int length) {
checkIndex(index, length);
buffer.getBytes(index + adjustment, dst, dstIndex, length);
}
public void getBytes(int index, ByteBuffer dst) {
checkIndex(index, dst.remaining());
buffer.getBytes(index + adjustment, dst);
}
public void setByte(int index, int value) {
checkIndex(index);
buffer.setByte(index + adjustment, value);
}
public void setShort(int index, int value) {
checkIndex(index, 2);
buffer.setShort(index + adjustment, value);
}
public void setMedium(int index, int value) {
checkIndex(index, 3);
buffer.setMedium(index + adjustment, value);
}
public void setInt(int index, int value) {
checkIndex(index, 4);
buffer.setInt(index + adjustment, value);
}
public void setLong(int index, long value) {
checkIndex(index, 8);
buffer.setLong(index + adjustment, value);
}
public void setBytes(int index, byte[] src, int srcIndex, int length) {
checkIndex(index, length);
buffer.setBytes(index + adjustment, src, srcIndex, length);
}
public void setBytes(int index, ChannelBuffer src, int srcIndex, int length) {
checkIndex(index, length);
buffer.setBytes(index + adjustment, src, srcIndex, length);
}
public void setBytes(int index, ByteBuffer src) {
checkIndex(index, src.remaining());
buffer.setBytes(index + adjustment, src);
}
public void getBytes(int index, OutputStream out, int length)
throws IOException {
checkIndex(index, length);
buffer.getBytes(index + adjustment, out, length);
}
public int getBytes(int index, GatheringByteChannel out, int length)
throws IOException {
checkIndex(index, length);
return buffer.getBytes(index + adjustment, out, length);
}
public int setBytes(int index, InputStream in, int length)
throws IOException {
checkIndex(index, length);
return buffer.setBytes(index + adjustment, in, length);
}
public int setBytes(int index, ScatteringByteChannel in, int length)
throws IOException {
checkIndex(index, length);
return buffer.setBytes(index + adjustment, in, length);
}
public ByteBuffer toByteBuffer(int index, int length) {
checkIndex(index, length);
return buffer.toByteBuffer(index + adjustment, length);
}
private void checkIndex(int index) {
if (index < 0 || index >= capacity()) {
throw new IndexOutOfBoundsException();
}
}
private void checkIndex(int startIndex, int length) {
if (length < 0) {
throw new IllegalArgumentException(
"length is negative: " + length);
}
if (startIndex < 0) {
throw new IndexOutOfBoundsException();
}
if (startIndex + length > capacity()) {
throw new IndexOutOfBoundsException();
}
}
}