/**
* 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.io.compress;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;
public class DeflateCompressor implements ICompressor
{
public static final DeflateCompressor instance = new DeflateCompressor();
private final ThreadLocal<Deflater> deflater;
private final ThreadLocal<Inflater> inflater;
public static DeflateCompressor create(Map<String, String> compressionOptions)
{
// no specific options supported so far
return instance;
}
private DeflateCompressor()
{
deflater = new ThreadLocal<Deflater>()
{
@Override
protected Deflater initialValue()
{
return new Deflater();
}
};
inflater = new ThreadLocal<Inflater>()
{
@Override
protected Inflater initialValue()
{
return new Inflater();
}
};
}
public int initialCompressedBufferLength(int chunkLength)
{
return chunkLength;
}
public int compress(byte[] input, int inputOffset, int inputLength, ICompressor.WrappedArray output, int outputOffset) throws IOException
{
Deflater def = deflater.get();
def.reset();
def.setInput(input, inputOffset, inputLength);
def.finish();
if (def.needsInput())
return 0;
int offs = outputOffset;
while (true)
{
offs += def.deflate(output.buffer, offs, output.buffer.length - offs);
if (def.needsInput())
{
return offs - outputOffset;
}
else
{
// We're not done, output was too small. Increase it and continue
byte[] newBuffer = new byte[(output.buffer.length*4)/3 + 1];
System.arraycopy(output.buffer, 0, newBuffer, 0, offs);
output.buffer = newBuffer;
}
}
}
public int uncompress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset) throws IOException
{
Inflater inf = inflater.get();
inf.reset();
inf.setInput(input, inputOffset, inputLength);
if (inf.needsInput())
return 0;
// We assume output is big enough
try
{
return inf.inflate(output, outputOffset, output.length - outputOffset);
}
catch (DataFormatException e)
{
throw new IOException(e);
}
}
}