// Copyright (c) 2013, Facebook, Inc. All rights reserved.
/**
* 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.facebook.hive.orc.compression;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;
import com.facebook.hive.orc.OrcConf;
import com.facebook.hive.orc.compression.CompressionCodec;
import org.apache.hadoop.conf.Configuration;
public class ZlibCodec implements CompressionCodec {
private int compressionLevel;
public ZlibCodec() {
compressionLevel = Deflater.DEFAULT_COMPRESSION;
}
public ZlibCodec(Configuration conf) {
if (conf == null) {
compressionLevel = Deflater.DEFAULT_COMPRESSION;
} else {
compressionLevel = OrcConf.getIntVar(conf, OrcConf.ConfVars.HIVE_ORC_ZLIB_COMPRESSION_LEVEL);
}
}
public void reloadConfigurations(Configuration conf) {
compressionLevel = OrcConf.getIntVar(conf, OrcConf.ConfVars.HIVE_ORC_ZLIB_COMPRESSION_LEVEL);
}
@Override
public boolean compress(ByteBuffer in, ByteBuffer out,
ByteBuffer overflow) throws IOException {
Deflater deflater = new Deflater(compressionLevel, true);
int length = in.remaining();
deflater.setInput(in.array(), in.arrayOffset() + in.position(), length);
deflater.finish();
int outSize = 0;
int offset = out.arrayOffset() + out.position();
while (!deflater.finished() && (length > outSize)) {
int size = deflater.deflate(out.array(), offset, out.remaining());
out.position(size + out.position());
outSize += size;
offset += size;
// if we run out of space in the out buffer, use the overflow
if (out.remaining() == 0) {
if (overflow == null) {
deflater.end();
return false;
}
out = overflow;
offset = out.arrayOffset() + out.position();
}
}
deflater.end();
return length > outSize;
}
@Override
public void decompress(ByteBuffer in, ByteBuffer out) throws IOException {
Inflater inflater = new Inflater(true);
inflater.setInput(in.array(), in.arrayOffset() + in.position(),
in.remaining());
while (!(inflater.finished() || inflater.needsDictionary() ||
inflater.needsInput())) {
try {
int count = inflater.inflate(out.array(),
out.arrayOffset() + out.position(),
out.remaining());
out.position(count + out.position());
} catch (DataFormatException dfe) {
throw new IOException("Bad compression data", dfe);
}
}
out.flip();
inflater.end();
in.position(in.limit());
}
}