/*
 * Copyright (C) 2014 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#ifndef Sizes_h
#define Sizes_h

#include "Algorithm.h"
#include <algorithm>
#include <cstdint>
#include <cstddef>
#include <limits>
#include <type_traits>
#include <chrono>

namespace bmalloc {

// Repository for malloc sizing constants and calculations.

namespace Sizes {
    static const size_t kB = 1024;
    static const size_t MB = kB * kB;

    static const size_t alignment = 8;
    static const size_t alignmentMask = alignment - 1ul;

    static const size_t superChunkSize = 32 * MB;

    static const size_t smallMax = 256;
    static const size_t smallLineSize = 512;
    static const size_t smallLineMask = ~(smallLineSize - 1ul);

    static const size_t smallChunkSize = superChunkSize / 4;
    static const size_t smallChunkOffset = superChunkSize * 3 / 4;
    static const size_t smallChunkMask = ~(smallChunkSize - 1ul);

    static const size_t mediumMax = 1024;
    static const size_t mediumLineSize = 2048;
    static const size_t mediumLineMask = ~(mediumLineSize - 1ul);

    static const size_t mediumChunkSize = superChunkSize / 4;
    static const size_t mediumChunkOffset = superChunkSize * 2 / 4;
    static const size_t mediumChunkMask = ~(mediumChunkSize - 1ul);

    static const size_t largeChunkSize = superChunkSize / 2;
    static const size_t largeChunkOffset = 0;
    static const size_t largeChunkMask = ~(largeChunkSize - 1ul);

    static const size_t largeAlignment = 64;
    static const size_t largeMax = largeChunkSize * 99 / 100; // Plenty of room for metadata.
    static const size_t largeMin = 1024;

    static const size_t segregatedFreeListSearchDepth = 16;

    static const uintptr_t typeMask = (superChunkSize - 1) & ~((superChunkSize / 4) - 1); // 4 taggable chunks
    static const uintptr_t smallType = (superChunkSize + smallChunkOffset) & typeMask;
    static const uintptr_t mediumType = (superChunkSize + mediumChunkOffset) & typeMask;
    static const uintptr_t largeTypeMask = ~(mediumType & smallType);
    static const uintptr_t smallOrMediumTypeMask = mediumType & smallType;
    static const uintptr_t smallOrMediumSmallTypeMask = smallType ^ mediumType; // Only valid if object is known to be small or medium.

    static const size_t deallocatorLogCapacity = 256;

    static const size_t smallLineCacheCapacity = 16;
    static const size_t mediumLineCacheCapacity = 8;

    static const size_t smallAllocatorLogCapacity = 16;
    static const size_t mediumAllocatorLogCapacity = 8;
    
    static const std::chrono::milliseconds scavengeSleepDuration = std::chrono::milliseconds(512);

    inline size_t smallSizeClassFor(size_t size)
    {
        static const size_t smallSizeClassMask = (smallMax / alignment) - 1;
        return mask((size - 1ul) / alignment, smallSizeClassMask);
    }
};

using namespace Sizes;

} // namespace bmalloc

#endif // Sizes_h