/*
* 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;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.jboss.netty.util.internal.DetectionUtil;
/**
* A virtual buffer which shows multiple buffers as a single merged buffer. It
* is recommended to use {@link ChannelBuffers#wrappedBuffer(ChannelBuffer...)}
* instead of calling the constructor explicitly.
*/
public class CompositeChannelBuffer extends AbstractChannelBuffer {
private final ByteOrder order;
private ChannelBuffer[] components;
private int[] indices;
private int lastAccessedComponentId;
public CompositeChannelBuffer(ByteOrder endianness, List<ChannelBuffer> buffers) {
order = endianness;
setComponents(buffers);
}
/**
* Same with {@link #slice(int, int)} except that this method returns a list.
*/
public List<ChannelBuffer> decompose(int index, int length) {
if (length == 0) {
return Collections.emptyList();
}
if (index + length > capacity()) {
throw new IndexOutOfBoundsException();
}
int componentId = componentId(index);
List<ChannelBuffer> slice = new ArrayList<ChannelBuffer>(components.length);
// The first component
ChannelBuffer first = components[componentId].duplicate();
first.readerIndex(index - indices[componentId]);
ChannelBuffer buf = first;
int bytesToSlice = length;
do {
int readableBytes = buf.readableBytes();
if (bytesToSlice <= readableBytes) {
// Last component
buf.writerIndex(buf.readerIndex() + bytesToSlice);
slice.add(buf);
break;
} else {
// Not the last component
slice.add(buf);
bytesToSlice -= readableBytes;
componentId ++;
// Fetch the next component.
buf = components[componentId].duplicate();
}
} while (bytesToSlice > 0);
// Slice all components because only readable bytes are interesting.
for (int i = 0; i < slice.size(); i ++) {
slice.set(i, slice.get(i).slice());
}
return slice;
}
/**
* Setup this ChannelBuffer from the list
*/
private void setComponents(List<ChannelBuffer> newComponents) {
assert !newComponents.isEmpty();
// Clear the cache.
lastAccessedComponentId = 0;
// Build the component array.
components = new ChannelBuffer[newComponents.size()];
for (int i = 0; i < components.length; i ++) {
ChannelBuffer c = newComponents.get(i);
if (c.order() != order()) {
throw new IllegalArgumentException(
"All buffers must have the same endianness.");
}
assert c.readerIndex() == 0;
assert c.writerIndex() == c.capacity();
components[i] = c;
}
// Build the component lookup table.
indices = new int[components.length + 1];
indices[0] = 0;
for (int i = 1; i <= components.length; i ++) {
indices[i] = indices[i - 1] + components[i - 1].capacity();
}
// Reset the indexes.
setIndex(0, capacity());
}
private CompositeChannelBuffer(CompositeChannelBuffer buffer) {
order = buffer.order;
components = buffer.components.clone();
indices = buffer.indices.clone();
setIndex(buffer.readerIndex(), buffer.writerIndex());
}
public ChannelBufferFactory factory() {
return HeapChannelBufferFactory.getInstance(order());
}
public ByteOrder order() {
return order;
}
public boolean isDirect() {
return false;
}
public boolean hasArray() {
return false;
}
public byte[] array() {
throw new UnsupportedOperationException();
}
public int arrayOffset() {
throw new UnsupportedOperationException();
}
public int capacity() {
return indices[components.length];
}
public byte getByte(int index) {
int componentId = componentId(index);
return components[componentId].getByte(index - indices[componentId]);
}
public short getShort(int index) {
int componentId = componentId(index);
if (index + 2 <= indices[componentId + 1]) {
return components[componentId].getShort(index - indices[componentId]);
} else if (order() == ByteOrder.BIG_ENDIAN) {
return (short) ((getByte(index) & 0xff) << 8 | getByte(index + 1) & 0xff);
} else {
return (short) (getByte(index) & 0xff | (getByte(index + 1) & 0xff) << 8);
}
}
public int getUnsignedMedium(int index) {
int componentId = componentId(index);
if (index + 3 <= indices[componentId + 1]) {
return components[componentId].getUnsignedMedium(index - indices[componentId]);
} else if (order() == ByteOrder.BIG_ENDIAN) {
return (getShort(index) & 0xffff) << 8 | getByte(index + 2) & 0xff;
} else {
return getShort(index) & 0xFFFF | (getByte(index + 2) & 0xFF) << 16;
}
}
public int getInt(int index) {
int componentId = componentId(index);
if (index + 4 <= indices[componentId + 1]) {
return components[componentId].getInt(index - indices[componentId]);
} else if (order() == ByteOrder.BIG_ENDIAN) {
return (getShort(index) & 0xffff) << 16 | getShort(index + 2) & 0xffff;
} else {
return getShort(index) & 0xFFFF | (getShort(index + 2) & 0xFFFF) << 16;
}
}
public long getLong(int index) {
int componentId = componentId(index);
if (index + 8 <= indices[componentId + 1]) {
return components[componentId].getLong(index - indices[componentId]);
} else if (order() == ByteOrder.BIG_ENDIAN) {
return (getInt(index) & 0xffffffffL) << 32 | getInt(index + 4) & 0xffffffffL;
} else {
return getInt(index) & 0xFFFFFFFFL | (getInt(index + 4) & 0xFFFFFFFFL) << 32;
}
}
public void getBytes(int index, byte[] dst, int dstIndex, int length) {
int componentId = componentId(index);
if (index > capacity() - length || dstIndex > dst.length - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
s.getBytes(index - adjustment, dst, dstIndex, localLength);
index += localLength;
dstIndex += localLength;
length -= localLength;
i ++;
}
}
public void getBytes(int index, ByteBuffer dst) {
int componentId = componentId(index);
int limit = dst.limit();
int length = dst.remaining();
if (index > capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
try {
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
dst.limit(dst.position() + localLength);
s.getBytes(index - adjustment, dst);
index += localLength;
length -= localLength;
i ++;
}
} finally {
dst.limit(limit);
}
}
public void getBytes(int index, ChannelBuffer dst, int dstIndex, int length) {
int componentId = componentId(index);
if (index > capacity() - length || dstIndex > dst.capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
s.getBytes(index - adjustment, dst, dstIndex, localLength);
index += localLength;
dstIndex += localLength;
length -= localLength;
i ++;
}
}
public int getBytes(int index, GatheringByteChannel out, int length)
throws IOException {
// Disable till 3.5.0.Final
/*
if (DetectionUtil.javaVersion() >= 7) {
return (int) out.write(toByteBuffers(index, length));
}*/
// XXX Gathering write is not supported because of a known issue.
// See http://bugs.sun.com/view_bug.do?bug_id=6210541
// This issue appeared in 2004 and is still unresolved!?
return out.write(toByteBuffer(index, length));
}
public void getBytes(int index, OutputStream out, int length)
throws IOException {
int componentId = componentId(index);
if (index > capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
s.getBytes(index - adjustment, out, localLength);
index += localLength;
length -= localLength;
i ++;
}
}
public void setByte(int index, int value) {
int componentId = componentId(index);
components[componentId].setByte(index - indices[componentId], value);
}
public void setShort(int index, int value) {
int componentId = componentId(index);
if (index + 2 <= indices[componentId + 1]) {
components[componentId].setShort(index - indices[componentId], value);
} else if (order() == ByteOrder.BIG_ENDIAN) {
setByte(index, (byte) (value >>> 8));
setByte(index + 1, (byte) value);
} else {
setByte(index , (byte) value);
setByte(index + 1, (byte) (value >>> 8));
}
}
public void setMedium(int index, int value) {
int componentId = componentId(index);
if (index + 3 <= indices[componentId + 1]) {
components[componentId].setMedium(index - indices[componentId], value);
} else if (order() == ByteOrder.BIG_ENDIAN) {
setShort(index, (short) (value >> 8));
setByte(index + 2, (byte) value);
} else {
setShort(index , (short) value);
setByte(index + 2, (byte) (value >>> 16));
}
}
public void setInt(int index, int value) {
int componentId = componentId(index);
if (index + 4 <= indices[componentId + 1]) {
components[componentId].setInt(index - indices[componentId], value);
} else if (order() == ByteOrder.BIG_ENDIAN) {
setShort(index, (short) (value >>> 16));
setShort(index + 2, (short) value);
} else {
setShort(index , (short) value);
setShort(index + 2, (short) (value >>> 16));
}
}
public void setLong(int index, long value) {
int componentId = componentId(index);
if (index + 8 <= indices[componentId + 1]) {
components[componentId].setLong(index - indices[componentId], value);
} else if (order() == ByteOrder.BIG_ENDIAN) {
setInt(index, (int) (value >>> 32));
setInt(index + 4, (int) value);
} else {
setInt(index , (int) value);
setInt(index + 4, (int) (value >>> 32));
}
}
public void setBytes(int index, byte[] src, int srcIndex, int length) {
int componentId = componentId(index);
if (index > capacity() - length || srcIndex > src.length - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
s.setBytes(index - adjustment, src, srcIndex, localLength);
index += localLength;
srcIndex += localLength;
length -= localLength;
i ++;
}
}
public void setBytes(int index, ByteBuffer src) {
int componentId = componentId(index);
int limit = src.limit();
int length = src.remaining();
if (index > capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
try {
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
src.limit(src.position() + localLength);
s.setBytes(index - adjustment, src);
index += localLength;
length -= localLength;
i ++;
}
} finally {
src.limit(limit);
}
}
public void setBytes(int index, ChannelBuffer src, int srcIndex, int length) {
int componentId = componentId(index);
if (index > capacity() - length || srcIndex > src.capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
s.setBytes(index - adjustment, src, srcIndex, localLength);
index += localLength;
srcIndex += localLength;
length -= localLength;
i ++;
}
}
public int setBytes(int index, InputStream in, int length)
throws IOException {
int componentId = componentId(index);
if (index > capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
int readBytes = 0;
do {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
int localReadBytes = s.setBytes(index - adjustment, in, localLength);
if (localReadBytes < 0) {
if (readBytes == 0) {
return -1;
} else {
break;
}
}
if (localReadBytes == localLength) {
index += localLength;
length -= localLength;
readBytes += localLength;
i ++;
} else {
index += localReadBytes;
length -= localReadBytes;
readBytes += localReadBytes;
}
} while (length > 0);
return readBytes;
}
public int setBytes(int index, ScatteringByteChannel in, int length)
throws IOException {
int componentId = componentId(index);
if (index > capacity() - length) {
throw new IndexOutOfBoundsException();
}
int i = componentId;
int readBytes = 0;
do {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
int localReadBytes = s.setBytes(index - adjustment, in, localLength);
if (localReadBytes == localLength) {
index += localLength;
length -= localLength;
readBytes += localLength;
i ++;
} else {
index += localReadBytes;
length -= localReadBytes;
readBytes += localReadBytes;
}
} while (length > 0);
return readBytes;
}
public ChannelBuffer duplicate() {
ChannelBuffer duplicate = new CompositeChannelBuffer(this);
duplicate.setIndex(readerIndex(), writerIndex());
return duplicate;
}
public ChannelBuffer copy(int index, int length) {
int componentId = componentId(index);
if (index > capacity() - length) {
throw new IndexOutOfBoundsException();
}
ChannelBuffer dst = factory().getBuffer(order(), length);
copyTo(index, length, componentId, dst);
return dst;
}
private void copyTo(int index, int length, int componentId, ChannelBuffer dst) {
int dstIndex = 0;
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
s.getBytes(index - adjustment, dst, dstIndex, localLength);
index += localLength;
dstIndex += localLength;
length -= localLength;
i ++;
}
dst.writerIndex(dst.capacity());
}
public ChannelBuffer slice(int index, int length) {
if (index == 0) {
if (length == 0) {
return ChannelBuffers.EMPTY_BUFFER;
}
} else if (index < 0 || index > capacity() - length) {
throw new IndexOutOfBoundsException();
} else if (length == 0) {
return ChannelBuffers.EMPTY_BUFFER;
}
List<ChannelBuffer> components = decompose(index, length);
switch (components.size()) {
case 0:
return ChannelBuffers.EMPTY_BUFFER;
case 1:
return components.get(0);
default:
return new CompositeChannelBuffer(order(), components);
}
}
public ByteBuffer toByteBuffer(int index, int length) {
if (components.length == 1) {
return components[0].toByteBuffer(index, length);
}
ByteBuffer[] buffers = toByteBuffers(index, length);
ByteBuffer merged = ByteBuffer.allocate(length).order(order());
for (ByteBuffer b: buffers) {
merged.put(b);
}
merged.flip();
return merged;
}
@Override
public ByteBuffer[] toByteBuffers(int index, int length) {
int componentId = componentId(index);
if (index + length > capacity()) {
throw new IndexOutOfBoundsException();
}
List<ByteBuffer> buffers = new ArrayList<ByteBuffer>(components.length);
int i = componentId;
while (length > 0) {
ChannelBuffer s = components[i];
int adjustment = indices[i];
int localLength = Math.min(length, s.capacity() - (index - adjustment));
buffers.add(s.toByteBuffer(index - adjustment, localLength));
index += localLength;
length -= localLength;
i ++;
}
return buffers.toArray(new ByteBuffer[buffers.size()]);
}
private int componentId(int index) {
int lastComponentId = lastAccessedComponentId;
if (index >= indices[lastComponentId]) {
if (index < indices[lastComponentId + 1]) {
return lastComponentId;
}
// Search right
for (int i = lastComponentId + 1; i < components.length; i ++) {
if (index < indices[i + 1]) {
lastAccessedComponentId = i;
return i;
}
}
} else {
// Search left
for (int i = lastComponentId - 1; i >= 0; i --) {
if (index >= indices[i]) {
lastAccessedComponentId = i;
return i;
}
}
}
throw new IndexOutOfBoundsException();
}
@Override
public void discardReadBytes() {
// Only the bytes between readerIndex and writerIndex will be kept.
// New readerIndex and writerIndex will become 0 and
// (previous writerIndex - previous readerIndex) respectively.
final int localReaderIndex = this.readerIndex();
if (localReaderIndex == 0) {
return;
}
int localWriterIndex = this.writerIndex();
final int bytesToMove = capacity() - localReaderIndex;
List<ChannelBuffer> list = decompose(localReaderIndex, bytesToMove);
// Add a new buffer so that the capacity of this composite buffer does
// not decrease due to the discarded components.
// XXX Might create too many components if discarded by small amount.
final ChannelBuffer padding = ChannelBuffers.buffer(order(), localReaderIndex);
padding.writerIndex(localReaderIndex);
list.add(padding);
// Reset the index markers to get the index marker values.
int localMarkedReaderIndex = localReaderIndex;
try {
resetReaderIndex();
localMarkedReaderIndex = this.readerIndex();
} catch (IndexOutOfBoundsException e) {
// ignore
}
int localMarkedWriterIndex = localWriterIndex;
try {
resetWriterIndex();
localMarkedWriterIndex = this.writerIndex();
} catch (IndexOutOfBoundsException e) {
// ignore
}
setComponents(list);
// reset marked Indexes
localMarkedReaderIndex = Math.max(localMarkedReaderIndex - localReaderIndex, 0);
localMarkedWriterIndex = Math.max(localMarkedWriterIndex - localReaderIndex, 0);
setIndex(localMarkedReaderIndex, localMarkedWriterIndex);
markReaderIndex();
markWriterIndex();
// reset real indexes
localWriterIndex = Math.max(localWriterIndex - localReaderIndex, 0);
setIndex(0, localWriterIndex);
}
@Override
public String toString() {
String result = super.toString();
result = result.substring(0, result.length() - 1);
return result + ", components=" + components.length + ")";
}
}