org.apache.hadoop.hbase.util.UnsafeAccess Maven / Gradle / Ivy

/**
 * 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.hadoop.hbase.util;

import java.lang.reflect.Field;
import java.nio.ByteOrder;
import java.security.AccessController;
import java.security.PrivilegedAction;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;

import sun.misc.Unsafe;

@InterfaceAudience.Private
@InterfaceStability.Evolving
@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="REC_CATCH_EXCEPTION",
  justification="If exception, presume unaligned")
public final class UnsafeAccess {

  private static final Log LOG = LogFactory.getLog(UnsafeAccess.class);

  public static final Unsafe theUnsafe;

  /** The offset to the first element in a byte array. */
  public static final int BYTE_ARRAY_BASE_OFFSET;

  static {
    theUnsafe = (Unsafe) AccessController.doPrivileged(new PrivilegedAction