Merge "Add a function to determine cow op size" into main

    uint8_t read_ahead_state;

} __attribute__((packed));

constexpr size_t GetCowOpSize(size_t version) {

    if (version == 3) {

        return sizeof(CowOperationV3);

    } else if (version == 2 || version == 1) {

        return sizeof(CowOperationV2);

    } else {

        return 0;

    }

}

// 2MB Scratch space used for read-ahead

static constexpr uint64_t BUFFER_REGION_DEFAULT_SIZE = (1ULL << 21);