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/**
 * 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 tech.mlsql.tool;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.Unsafe;

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


public class UnsafeAccess {
    private static final Logger LOG = LoggerFactory.getLogger(UnsafeAccess.class);
    public static final Unsafe theUnsafe;

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

    public static final boolean LITTLE_ENDIAN = ByteOrder.nativeOrder()
            .equals(ByteOrder.LITTLE_ENDIAN);

    // This number limits the number of bytes to copy per call to Unsafe's
    // copyMemory method. A limit is imposed to allow for safepoint polling
    // during a large copy
    static final long UNSAFE_COPY_THRESHOLD = 1024L * 1024L;
    static {
        theUnsafe = (Unsafe) AccessController.doPrivileged(new PrivilegedAction