shm/Project4/size_map.h

#pragma once
#include "shm_config.h"
#include "shm_helper.h"
namespace bg
{
    namespace detail
    {
        class SizeMap
        {
        public:
            bool Init();

            static size_t CalcAlignment(size_t bytes);

            size_t GetIndexByBytes(size_t bytes)
            {
                if(bytes <= BYTES_COMP_VALUE)
                {
                    return  m_index_to_class[SMALL_BYTES_TO_INDEX(bytes)];
                }
                return BIG_BYTES_TO_INDEX(bytes);
            }

            size_t ClassToSize(size_t index)
            {
                if(index >= CLASS_MAX_COUNT)
                {
                    __SHM_DO_ASSERT(index < CLASS_MAX_COUNT);
                    return 0;
                }

                return m_class_to_size[index];
            }

            size_t ClassToPages(size_t index)
            {
                if(index >= CLASS_MAX_COUNT)
                {
                    __SHM_DO_ASSERT(index < CLASS_MAX_COUNT);
                    return 0;
                }

                return m_class_to_pages[index];
            }


            char m_index_to_class[2176]{0};

            size_t m_class_to_size[CLASS_MAX_COUNT]{0};

            size_t m_class_to_pages[CLASS_MAX_COUNT]{0};
        };


    }
}