BSSmallBlockAllocator.h

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#pragma once
 
#include "RE/B/BSAtomic.h"
#include "RE/I/IMemoryStore.h"
 
namespace RE
{
    namespace BSSmallBlockAllocatorUtil
    {
        struct FreeBlock
        {
        public:
            // members
            FreeBlock* next;  // 0
        };
        static_assert(sizeof(FreeBlock) == 0x8);
 
        struct BlockPage
        {
        public:
            // members
            BlockPage*    left;       // 00
            BlockPage*    right;      // 08
            FreeBlock*    blocks;     // 10
            std::uint16_t totalElem;  // 18
            std::uint16_t freeElem;   // 1A
            std::uint32_t pad1C;      // 1C
        };
        static_assert(sizeof(BlockPage) == 0x20);
 
        struct Pool
        {
        public:
            // members
            BlockPage*        pageList;              // 00
            BlockPage*        currAlloc;             // 08
            std::uint32_t     totalFreeBlocks;       // 10
            std::uint32_t     totalAllocatedBlocks;  // 14
            std::uint32_t     totalBytes;            // 18
            std::uint32_t     elementSize;           // 1C
            BSCriticalSection lock;                  // 20
        };
        static_assert(sizeof(Pool) == 0x48);
    }
 
    struct BlockPageInternal
    {
    public:
        // members
        BlockPageInternal*                    left;       // 00
        BlockPageInternal*                    right;      // 08
        BSSmallBlockAllocatorUtil::FreeBlock* blocks;     // 10
        std::uint16_t                         totalElem;  // 18
        std::uint16_t                         freeElem;   // 1A
        std::uint16_t                         elemSize;   // 1C
        std::uint16_t                         check;      // 1E
    };
    static_assert(sizeof(BlockPageInternal) == 0x20);
 
    class BSSmallBlockAllocator : public IMemoryStore
    {
    public:
        inline static constexpr auto RTTI = RTTI_BSSmallBlockAllocator;
        inline static constexpr auto VTABLE = VTABLE_BSSmallBlockAllocator;
 
        struct Pool : public BSSmallBlockAllocatorUtil::Pool
        {
        public:
        };
        static_assert(sizeof(Pool) == 0x48);
 
        struct MegaBlockPage
        {
        public:
            // members
            char                                  mem[sizeof(BlockPageInternal[255]) * 256];  // 000000
            BlockPageInternal                     blockPages[255];                            // 1FE000
            MegaBlockPage*                        left;                                       // 1FFFE0
            MegaBlockPage*                        right;                                      // 1FFFE8
            BSSmallBlockAllocatorUtil::BlockPage* freeBlockPages;                             // 1FFFF0
            std::uint16_t                         numFreeBlockPages;                          // 1FFFF8
            std::uint16_t                         nextBlockPageAlloc;                         // 1FFFFA
            bool                                  decommitted;                                // 1FFFFC
            std::uint8_t                          pad1FFFFD;                                  // 1FFFFD
            std::uint16_t                         pad1FFFFE;                                  // 1FFFFE
        };
        static_assert(sizeof(MegaBlockPage) == 0x200000);
 
        ~BSSmallBlockAllocator() override;  // 00
 
        // override (IMemoryStore)
        std::size_t Size(const void* a_block) const override;                                   // 01
        void        GetMemoryStats(MemoryStats* a_stats) override;                              // 02
        bool        ContainsBlockImpl(const void* a_block) const override;                      // 03
        void*       AllocateAlignImpl(std::size_t a_size, std::uint32_t a_alignment) override;  // 04
        void        DeallocateAlignImpl(void*& a_freeBlock) override;                           // 05
        void*       TryAllocateImpl(std::size_t a_size, std::uint32_t a_alignment) override;    // 06
 
        // members
        Pool              pools[64];            // 0008
        BSCriticalSection lock;                 // 1208
        std::uint32_t     addressSpaceSize;     // 1230
        std::uint32_t     pad1234;              // 1234
        char*             allocBase;            // 1238
        char*             blockPageCommitMin;   // 1240
        char*             blockPageCommit;      // 1248
        MegaBlockPage*    megaBlockPageList;    // 1250
        MegaBlockPage*    megaBlockCurrAlloc;   // 1258
        std::uint32_t     totalFreeBlockPages;  // 1260
        bool              allowDecommits;       // 1264
        std::uint8_t      pad1265;              // 1265
        std::uint16_t     pad1266;              // 1266
    };
    static_assert(sizeof(BSSmallBlockAllocator) == 0x1268);
}