/*
* Copyright (C) 2012-2014 DataStax Inc.
*
* Licensed 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.driver.core;
import java.io.IOException;
import net.jpountz.lz4.LZ4Factory;
import org.jboss.netty.buffer.ChannelBuffers;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xerial.snappy.Snappy;
import com.datastax.driver.core.exceptions.DriverInternalError;
abstract class FrameCompressor {
private static final Logger logger = LoggerFactory.getLogger(FrameCompressor.class);
public abstract Frame compress(Frame frame) throws IOException;
public abstract Frame decompress(Frame frame) throws IOException;
public static class SnappyCompressor extends FrameCompressor {
public static final SnappyCompressor instance;
static {
SnappyCompressor i;
try {
i = new SnappyCompressor();
} catch (NoClassDefFoundError e) {
i = null;
logger.warn("Cannot find Snappy class, you should make sure the Snappy library is in the classpath if you intend to use it. Snappy compression will not be available for the protocol.");
} catch (Throwable e) {
i = null;
logger.warn("Error loading Snappy library ({}). Snappy compression will not be available for the protocol.", e.toString());
}
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 DriverInternalError("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));
}
}
public static class LZ4Compressor extends FrameCompressor {
public static final LZ4Compressor instance;
static {
LZ4Compressor i;
try {
i = new LZ4Compressor();
} catch (NoClassDefFoundError e) {
i = null;
logger.warn("Cannot find LZ4 class, you should make sure the LZ4 library is in the classpath if you intend to use it. LZ4 compression will not be available for the protocol.");
} catch (Throwable e) {
i = null;
logger.warn("Error loading LZ4 library ({}). LZ4 compression will not be available for the protocol.", e.toString());
}
instance = i;
}
private static final int INTEGER_BYTES = 4;
private final net.jpountz.lz4.LZ4Compressor compressor;
private final net.jpountz.lz4.LZ4FastDecompressor decompressor;
private LZ4Compressor() {
final LZ4Factory lz4Factory = LZ4Factory.fastestInstance();
compressor = lz4Factory.fastCompressor();
decompressor = lz4Factory.fastDecompressor();
}
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 (Exception 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 (Exception e) {
throw new IOException(e);
}
}
}
}