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 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package java.util;

/**
 * This class provides access to package-private
 * methods of DualPivotQuicksort class.
 *
 * @author Vladimir Yaroslavskiy
 *
 * @version 2018.08.18
 *
 * @since 14
 */
public final class SortingHelper {

    // Heap sort is invoked for this depth
    private static final int BIG_DEPTH = 100;

    private static final SortingHelper DUAL_PIVOT_QUICKSORT_HELPER = new SortingHelper(0);
    private static final SortingHelper PARALLEL_SORT_HELPER = new SortingHelper(87);
    private static final SortingHelper HEAP_SORT_HELPER = new SortingHelper(-1);

    private int parallelism;

    public static SortingHelper getDualPivotQuicksortHelper() {
        return DUAL_PIVOT_QUICKSORT_HELPER;
    }

    public static SortingHelper getParallelSortHelper() {
        return PARALLEL_SORT_HELPER;
    }

    public static SortingHelper getHeapSortHelper() {
        return HEAP_SORT_HELPER;
    }

    private SortingHelper(int parallelism) {
        this.parallelism = parallelism;
    }

    public void sort(int[] a) {
        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, 0, a.length);
        } else {
            DualPivotQuicksort.sort(a, parallelism, 0, a.length);
        }
    }

    public void sort(int[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);

        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, low, high);
        } else {
            DualPivotQuicksort.sort(a, parallelism, low, high);
        }
    }

    public void sort(long[] a) {
        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, 0, a.length);
        } else {
            DualPivotQuicksort.sort(a, parallelism, 0, a.length);
        }
    }

    public void sort(long[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);

        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, low, high);
        } else {
            DualPivotQuicksort.sort(a, parallelism, low, high);
        }
    }

    public void sort(byte[] a) {
        DualPivotQuicksort.sort(a, 0, a.length);
    }

    public void sort(byte[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);
        DualPivotQuicksort.sort(a, low, high);
    }

    public void sort(char[] a) {
        if (parallelism < 0) {
            DualPivotQuicksort.sort(a, BIG_DEPTH, 0, a.length);
        } else {
            DualPivotQuicksort.sort(a, 0, a.length);
        }
    }

    public void sort(char[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);

        if (parallelism < 0) {
            DualPivotQuicksort.sort(a, BIG_DEPTH, low, high);
        } else {
            DualPivotQuicksort.sort(a, low, high);
        }
    }

    public void sort(short[] a) {
        if (parallelism < 0) {
            DualPivotQuicksort.sort(a, BIG_DEPTH, 0, a.length);
        } else {
            DualPivotQuicksort.sort(a, 0, a.length);
        }
    }

    public void sort(short[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);

        if (parallelism < 0) {
            DualPivotQuicksort.sort(a, BIG_DEPTH, low, high);
        } else {
            DualPivotQuicksort.sort(a, low, high);
        }
    }

    public void sort(float[] a) {
        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, 0, a.length);
        } else {
            DualPivotQuicksort.sort(a, parallelism, 0, a.length);
        }
    }

    public void sort(float[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);

        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, low, high);
        } else {
            DualPivotQuicksort.sort(a, parallelism, low, high);
        }
    }

    public void sort(double[] a) {
        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, 0, a.length);
        } else {
            DualPivotQuicksort.sort(a, parallelism, 0, a.length);
        }
    }

    public void sort(double[] a, int low, int high) {
        Arrays.rangeCheck(a.length, low, high);

        if (parallelism < 0) {
            DualPivotQuicksort.sort(null, a, BIG_DEPTH, low, high);
        } else {
            DualPivotQuicksort.sort(a, parallelism, low, high);
        }
    }

    @Override
    public String toString() {
        if (parallelism < 0) {
            return "Heap sort";
        }
        if (parallelism == 0) {
            return "Dual-Pivot Quicksort";
        }
        return "Parallel Sorting";
    }
}