alibaba/transmittable-thread-local

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ttl-core/src/main/java/com/alibaba/ttl3/internal/util/ObjectUtils.java

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/*
 * Copyright 2002-2021 the original author or authors.
 *
 * 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
 *
 *      https://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.alibaba.ttl3.internal.util;


////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// This source code file is copied from spring v5.3.24:
//
// https://github.com/spring-projects/spring-framework/blob/v5.3.24/spring-core/src/main/java/org/springframework/util/ObjectUtils.java
//
// with adoption:
// - remove unused elements
// - adjust visible modifier and code format
//
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

import edu.umd.cs.findbugs.annotations.Nullable;

import java.util.Arrays;

/**
 * Miscellaneous object utility methods.
 *
 * <p>Mainly for internal use within the framework.
 *
 * <p>Thanks to Alex Ruiz for contributing several enhancements to this class!
 *
 * @author Juergen Hoeller
 * @author Keith Donald
 * @author Rod Johnson
 * @author Rob Harrop
 * @author Chris Beams
 * @author Sam Brannen
 */
final class ObjectUtils {

    private static final int INITIAL_HASH = 7;
    private static final int MULTIPLIER = 31;


    //---------------------------------------------------------------------
    // Convenience methods for content-based equality/hash-code handling
    //---------------------------------------------------------------------

    /**
     * Determine if the given objects are equal, returning {@code true} if
     * both are {@code null} or {@code false} if only one is {@code null}.
     * <p>Compares arrays with {@code Arrays.equals}, performing an equality
     * check based on the array elements rather than the array reference.
     *
     * @param o1 first Object to compare
     * @param o2 second Object to compare
     * @return whether the given objects are equal
     * @see Object#equals(Object)
     * @see java.util.Arrays#equals
     */
    public static boolean nullSafeEquals(@Nullable Object o1, @Nullable Object o2) {
        if (o1 == o2) {
            return true;
        }
        if (o1 == null || o2 == null) {
            return false;
        }
        if (o1.equals(o2)) {
            return true;
        }
        if (o1.getClass().isArray() && o2.getClass().isArray()) {
            return arrayEquals(o1, o2);
        }
        return false;
    }

    /**
     * Compare the given arrays with {@code Arrays.equals}, performing an equality
     * check based on the array elements rather than the array reference.
     *
     * @param o1 first array to compare
     * @param o2 second array to compare
     * @return whether the given objects are equal
     * @see #nullSafeEquals(Object, Object)
     * @see java.util.Arrays#equals
     */
    private static boolean arrayEquals(Object o1, Object o2) {
        if (o1 instanceof Object[] && o2 instanceof Object[]) {
            return Arrays.equals((Object[]) o1, (Object[]) o2);
        }
        if (o1 instanceof boolean[] && o2 instanceof boolean[]) {
            return Arrays.equals((boolean[]) o1, (boolean[]) o2);
        }
        if (o1 instanceof byte[] && o2 instanceof byte[]) {
            return Arrays.equals((byte[]) o1, (byte[]) o2);
        }
        if (o1 instanceof char[] && o2 instanceof char[]) {
            return Arrays.equals((char[]) o1, (char[]) o2);
        }
        if (o1 instanceof double[] && o2 instanceof double[]) {
            return Arrays.equals((double[]) o1, (double[]) o2);
        }
        if (o1 instanceof float[] && o2 instanceof float[]) {
            return Arrays.equals((float[]) o1, (float[]) o2);
        }
        if (o1 instanceof int[] && o2 instanceof int[]) {
            return Arrays.equals((int[]) o1, (int[]) o2);
        }
        if (o1 instanceof long[] && o2 instanceof long[]) {
            return Arrays.equals((long[]) o1, (long[]) o2);
        }
        if (o1 instanceof short[] && o2 instanceof short[]) {
            return Arrays.equals((short[]) o1, (short[]) o2);
        }
        return false;
    }

    /**
     * Return as hash code for the given object; typically the value of
     * {@code Object#hashCode()}}. If the object is an array,
     * this method will delegate to any of the {@code nullSafeHashCode}
     * methods for arrays in this class. If the object is {@code null},
     * this method returns 0.
     *
     * @see Object#hashCode()
     * @see #nullSafeHashCode(Object[])
     * @see #nullSafeHashCode(boolean[])
     * @see #nullSafeHashCode(byte[])
     * @see #nullSafeHashCode(char[])
     * @see #nullSafeHashCode(double[])
     * @see #nullSafeHashCode(float[])
     * @see #nullSafeHashCode(int[])
     * @see #nullSafeHashCode(long[])
     * @see #nullSafeHashCode(short[])
     */
    public static int nullSafeHashCode(@Nullable Object obj) {
        if (obj == null) {
            return 0;
        }
        if (obj.getClass().isArray()) {
            if (obj instanceof Object[]) {
                return nullSafeHashCode((Object[]) obj);
            }
            if (obj instanceof boolean[]) {
                return nullSafeHashCode((boolean[]) obj);
            }
            if (obj instanceof byte[]) {
                return nullSafeHashCode((byte[]) obj);
            }
            if (obj instanceof char[]) {
                return nullSafeHashCode((char[]) obj);
            }
            if (obj instanceof double[]) {
                return nullSafeHashCode((double[]) obj);
            }
            if (obj instanceof float[]) {
                return nullSafeHashCode((float[]) obj);
            }
            if (obj instanceof int[]) {
                return nullSafeHashCode((int[]) obj);
            }
            if (obj instanceof long[]) {
                return nullSafeHashCode((long[]) obj);
            }
            if (obj instanceof short[]) {
                return nullSafeHashCode((short[]) obj);
            }
        }
        return obj.hashCode();
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable Object[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (Object element : array) {
            hash = MULTIPLIER * hash + nullSafeHashCode(element);
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable boolean[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (boolean element : array) {
            hash = MULTIPLIER * hash + Boolean.hashCode(element);
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable byte[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (byte element : array) {
            hash = MULTIPLIER * hash + element;
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable char[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (char element : array) {
            hash = MULTIPLIER * hash + element;
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable double[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (double element : array) {
            hash = MULTIPLIER * hash + Double.hashCode(element);
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable float[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (float element : array) {
            hash = MULTIPLIER * hash + Float.hashCode(element);
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable int[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (int element : array) {
            hash = MULTIPLIER * hash + element;
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable long[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (long element : array) {
            hash = MULTIPLIER * hash + Long.hashCode(element);
        }
        return hash;
    }

    /**
     * Return a hash code based on the contents of the specified array.
     * If {@code array} is {@code null}, this method returns 0.
     */
    public static int nullSafeHashCode(@Nullable short[] array) {
        if (array == null) {
            return 0;
        }
        int hash = INITIAL_HASH;
        for (short element : array) {
            hash = MULTIPLIER * hash + element;
        }
        return hash;
    }

}