/*
* 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 com.datastax.cassandra.transport;
import org.apache.cassandra.transport.ProtocolException;
import org.jboss.netty.buffer.ChannelBuffers;
import org.xerial.snappy.Snappy;
import org.xerial.snappy.SnappyError;
import java.io.IOException;
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 = new byte[frame.body.readableBytes()];
byte[] output = new byte[Snappy.maxCompressedLength(input.length)];
frame.body.readBytes(input);
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 = new byte[frame.body.readableBytes()];
frame.body.readBytes(input);
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));
}
}
}