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The Adobe Experience Manager SDK

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/*
 * Copyright (C) 2008 The Guava 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
 *
 * 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.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.primitives.Ints;
import javax.annotation.Nullable;

/**
 *  Static methods for implementing hash-based collections.
 *
 *  @author Kevin Bourrillion
 *  @author Jesse Wilson
 *  @author Austin Appleby
 *
 * @deprecated The Google Guava Core Libraries are deprecated and will not be part of the AEM SDK after April 2023
 */
@GwtCompatible
@Deprecated(since = "2022-12-01")
final class Hashing {

    private Hashing() {
    }

    private static final int C1 = 0xcc9e2d51;

    private static final int C2 = 0x1b873593;

    /*
   * This method was rewritten in Java from an intermediate step of the Murmur hash function in
   * http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp, which contained the
   * following header:
   *
   * MurmurHash3 was written by Austin Appleby, and is placed in the public domain. The author
   * hereby disclaims copyright to this source code.
   */
    static int smear(int hashCode) {
        return C2 * Integer.rotateLeft(hashCode * C1, 15);
    }

    static int smearedHash(@Nullable Object o) {
        return smear((o == null) ? 0 : o.hashCode());
    }

    private static int MAX_TABLE_SIZE = Ints.MAX_POWER_OF_TWO;

    static int closedTableSize(int expectedEntries, double loadFactor) {
        // Get the recommended table size.
        // Round down to the nearest power of 2.
        expectedEntries = Math.max(expectedEntries, 2);
        int tableSize = Integer.highestOneBit(expectedEntries);
        // Check to make sure that we will not exceed the maximum load factor.
        if (expectedEntries > (int) (loadFactor * tableSize)) {
            tableSize <<= 1;
            return (tableSize > 0) ? tableSize : MAX_TABLE_SIZE;
        }
        return tableSize;
    }

    static boolean needsResizing(int size, int tableSize, double loadFactor) {
        return size > loadFactor * tableSize && tableSize < MAX_TABLE_SIZE;
    }
}