/*
* 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.facebook.presto.hadoop;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.PrestoFileSystemCache;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
public final class HadoopFileSystemCache
{
private static PrestoFileSystemCache cache;
private HadoopFileSystemCache() {}
public static synchronized void initialize()
{
if (cache == null) {
cache = setFinalStatic(FileSystem.class, "CACHE", new PrestoFileSystemCache());
}
}
private static <T> T setFinalStatic(Class<?> clazz, String name, T value)
{
try {
Field field = clazz.getDeclaredField(name);
field.setAccessible(true);
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
field.set(null, value);
return value;
}
catch (ReflectiveOperationException e) {
throw new AssertionError(e);
}
}
}