io.trino.rcfile.HadoopCodecFactory Maven / Gradle / Ivy
/*
* 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 io.trino.rcfile;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.compress.CompressionCodec;
import java.lang.reflect.Constructor;
public class HadoopCodecFactory
implements RcFileCodecFactory
{
private final ClassLoader classLoader;
public HadoopCodecFactory(ClassLoader classLoader)
{
this.classLoader = classLoader;
}
@Override
public RcFileCompressor createCompressor(String codecName)
{
CompressionCodec codec = createCompressionCodec(codecName);
return new HadoopCompressor(codec);
}
@Override
public RcFileDecompressor createDecompressor(String codecName)
{
CompressionCodec codec = createCompressionCodec(codecName);
return new HadoopDecompressor(codec);
}
private CompressionCodec createCompressionCodec(String codecName)
{
try {
Class codecClass = classLoader.loadClass(codecName).asSubclass(CompressionCodec.class);
Constructor constructor = codecClass.getDeclaredConstructor();
constructor.setAccessible(true);
CompressionCodec codec = constructor.newInstance();
if (codec instanceof Configurable) {
// Hadoop is crazy... you have to give codecs an empty configuration or they throw NPEs
// but you need to make sure the configuration doesn't "load" defaults or it spends
// forever loading XML with no useful information
((Configurable) codec).setConf(new Configuration(false));
}
return codec;
}
catch (ReflectiveOperationException e) {
throw new IllegalArgumentException("Unknown codec: " + codecName, e);
}
}
}