~satchmo/libvmm

61e03036da7a9ff558521293c3aa7197a32c50dc — Jason Phan 3 months ago 310520d
memory: Remove redundant comments for GuestAddress/MemoryRegionAddress
1 files changed, 8 insertions(+), 82 deletions(-)

M vmm/memory/detail/guest.hpp
M vmm/memory/detail/guest.hpp => vmm/memory/detail/guest.hpp +8 -82
@@ 35,115 35,41 @@ class GuestAddress : public Address<GuestAddress, uint64_t>

        auto data() const noexcept -> size_type override;

        // Returns the bitwise AND of the address and a mask.
        auto operator&(const size_type mask) const noexcept -> size_type override;

        // Returns the bitwise OR of the address and a mask.
        auto operator|(const size_type mask) const noexcept -> size_type override;

        // Returns the address plus some value (sum is wrapped).
        auto operator+(const size_type val) const noexcept -> value_type override;

        // Returns the sum of the address and another address (sum is wrapped).
        auto operator+(const_reference addr) const noexcept -> value_type override;

        // Returns the address minus some value (difference is wrapped).
        auto operator-(const size_type val) const noexcept -> value_type override;

        // Returns the difference between the address and another address
        // (difference is wrapped).
        auto operator-(const_reference addr) const noexcept -> value_type override;

        // Aligns the address to a power of 2.
        auto align(const size_type alignment) noexcept -> reference override;
    private:
        size_type m_addr{};
};

// An offset into a memory region.
class MemoryRegionAddress : public Address<MemoryRegionAddress, uint64_t>
{
    using value_type = MemoryRegionAddress;
    using size_type = uint64_t;
    using reference = value_type&;
    using const_reference = const value_type&;

    private:
        size_type m_addr{};
    public:
        using value_type = MemoryRegionAddress;
        using size_type = uint64_t;
        using reference = value_type&;
        using const_reference = const value_type&;

        explicit MemoryRegionAddress(size_type addr=0) noexcept : m_addr{addr} {}

        auto data() const noexcept -> size_type override;

        // Returns the bitwise AND of the address and a mask.
        auto operator&(const size_type mask) const noexcept -> size_type override;

        // Returns the bitwise OR of the address and a mask.
        auto operator|(const size_type mask) const noexcept -> size_type override;

        // Returns the address plus some value (sum is wrapped).
        auto operator+(const size_type val) const noexcept -> value_type override;

        // Returns the sum of the address and another address (sum is wrapped).
        auto operator+(const_reference addr) const noexcept -> value_type override;

        // Returns the address minus some value (difference is wrapped).
        auto operator-(const size_type val) const noexcept -> value_type override;

        // Returns the difference between the address and another address
        // (difference is wrapped).
        auto operator-(const_reference addr) const noexcept -> value_type override;

        // Aligns the address to a power of 2.
        auto align(const size_type alignment) noexcept -> reference override;
};

// The starting point of a file that backs a GuestMemoryRegion.
class FileOffset {
    private:
        std::shared_ptr<std::fstream> m_fstream;
        long m_start{};
    public:
        FileOffset(const char* filename, std::ios_base::openmode mode,
                   const long start={})
            : m_fstream{std::make_shared<std::fstream>(filename, mode)},
              m_start{start}
        {
            if (start) {
                // TODO (?): Only call these if the appropriate openmode is set.
                m_fstream->seekg(start);
                m_fstream->seekp(start);
            }
        }

        explicit FileOffset(const char* filename, const long start={})
            : FileOffset(filename, std::ios_base::in | std::ios_base::out, start) {}

        explicit FileOffset(const std::string& filename, const long start=0)
            : FileOffset(filename.c_str(), start) {}

        FileOffset(const std::string& filename,
                   const std::ios_base::openmode mode,
                   const long start={})
            : FileOffset(filename.c_str(), mode, start) {}

        explicit FileOffset(const std::filesystem::path& filename, const long start=0)
            : FileOffset(filename.c_str(), start) {}

        FileOffset(const std::filesystem::path& filename,
                   const std::ios_base::openmode mode,
                   const long start={})
            : FileOffset(filename.c_str(), mode, start) {}

        // TODO: thread-safety
        [[nodiscard]] auto data() const -> std::basic_filebuf<std::fstream::char_type,
                                                              std::fstream::traits_type>*
        {
            return m_fstream->rdbuf();
        }

        [[nodiscard]] constexpr auto start() const noexcept -> long
        {
            return m_start;
        }
        size_type m_addr{};
};

}  // vmm::memory::detail