/*
* 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.cassandra.transport;
import java.io.IOException;
import org.jboss.netty.buffer.ChannelBuffers;
import org.xerial.snappy.Snappy;
import org.xerial.snappy.SnappyError;
import net.jpountz.lz4.LZ4Exception;
import net.jpountz.lz4.LZ4Factory;
public interface FrameCompressor
{
public Frame compress(Frame frame) throws IOException;
public Frame decompress(Frame frame) throws IOException;
/*
* TODO: We can probably do more efficient, like by avoiding copy.
* Also, we don't reuse ICompressor because the API doesn't expose enough.
*/
public static class SnappyCompressor implements FrameCompressor
{
public static final SnappyCompressor instance;
static
{
SnappyCompressor i;
try
{
i = new SnappyCompressor();
}
catch (Exception e)
{
i = null;
}
catch (NoClassDefFoundError e)
{
i = null;
}
catch (SnappyError e)
{
i = null;
}
catch (UnsatisfiedLinkError e)
{
i = null;
}
instance = i;
}
private SnappyCompressor()
{
// this would throw java.lang.NoClassDefFoundError if Snappy class
// wasn't found at runtime which should be processed by the calling method
Snappy.getNativeLibraryVersion();
}
public Frame compress(Frame frame) throws IOException
{
byte[] input = CBUtil.readRawBytes(frame.body);
byte[] output = new byte[Snappy.maxCompressedLength(input.length)];
int written = Snappy.compress(input, 0, input.length, output, 0);
return frame.with(ChannelBuffers.wrappedBuffer(output, 0, written));
}
public Frame decompress(Frame frame) throws IOException
{
byte[] input = CBUtil.readRawBytes(frame.body);
if (!Snappy.isValidCompressedBuffer(input, 0, input.length))
throw new ProtocolException("Provided frame does not appear to be Snappy compressed");
byte[] output = new byte[Snappy.uncompressedLength(input)];
int size = Snappy.uncompress(input, 0, input.length, output, 0);
return frame.with(ChannelBuffers.wrappedBuffer(output, 0, size));
}
}
/*
* This is very close to the ICompressor implementation, and in particular
* it also layout the uncompressed size at the beginning of the message to
* make uncompression faster, but contrarly to the ICompressor, that length
* is written in big-endian. The native protocol is entirely big-endian, so
* it feels like putting little-endian here would be a annoying trap for
* client writer.
*/
public static class LZ4Compressor implements FrameCompressor
{
public static final LZ4Compressor instance = new LZ4Compressor();
private static final int INTEGER_BYTES = 4;
private final net.jpountz.lz4.LZ4Compressor compressor;
private final net.jpountz.lz4.LZ4Decompressor decompressor;
private LZ4Compressor()
{
final LZ4Factory lz4Factory = LZ4Factory.fastestInstance();
compressor = lz4Factory.fastCompressor();
decompressor = lz4Factory.decompressor();
}
public Frame compress(Frame frame) throws IOException
{
byte[] input = CBUtil.readRawBytes(frame.body);
int maxCompressedLength = compressor.maxCompressedLength(input.length);
byte[] output = new byte[INTEGER_BYTES + maxCompressedLength];
output[0] = (byte) (input.length >>> 24);
output[1] = (byte) (input.length >>> 16);
output[2] = (byte) (input.length >>> 8);
output[3] = (byte) (input.length);
try
{
int written = compressor.compress(input, 0, input.length, output, INTEGER_BYTES, maxCompressedLength);
return frame.with(ChannelBuffers.wrappedBuffer(output, 0, INTEGER_BYTES + written));
}
catch (LZ4Exception e)
{
throw new IOException(e);
}
}
public Frame decompress(Frame frame) throws IOException
{
byte[] input = CBUtil.readRawBytes(frame.body);
int uncompressedLength = ((input[0] & 0xFF) << 24)
| ((input[1] & 0xFF) << 16)
| ((input[2] & 0xFF) << 8)
| ((input[3] & 0xFF));
byte[] output = new byte[uncompressedLength];
try
{
int read = decompressor.decompress(input, INTEGER_BYTES, output, 0, uncompressedLength);
if (read != input.length - INTEGER_BYTES)
throw new IOException("Compressed lengths mismatch");
return frame.with(ChannelBuffers.wrappedBuffer(output));
}
catch (LZ4Exception e)
{
throw new IOException(e);
}
}
}
}