write.hpp

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#ifndef SILICIUM_WRITE_HPP
#define SILICIUM_WRITE_HPP

#include <silicium/error_or.hpp>
#include <silicium/get_last_error.hpp>
#include <silicium/native_file_descriptor.hpp>
#include <silicium/memory_range.hpp>
#include <limits>

namespace Si
{
    SILICIUM_USE_RESULT
    inline error_or<std::size_t> write(native_file_descriptor file, memory_range data)
    {
        std::size_t total_written = 0;
        do
        {
#ifdef _WIN32
            DWORD written = 0;
            assert(std::numeric_limits<decltype(total_written)>::max() >= std::numeric_limits<decltype(written)>::max());
            DWORD const piece = static_cast<DWORD>(std::min(
                static_cast<std::size_t>(std::numeric_limits<DWORD>::max()),
                data.size() - total_written
            ));
            if (!WriteFile(file, data.begin() + total_written, piece, &written, nullptr))
            {
                return get_last_error();
            }
#else
            ssize_t const written = ::write(file, data.begin() + total_written, data.size() - total_written);
            if (written < 0)
            {
                return get_last_error();
            }
#endif
            if (written == 0)
            {
                break;
            }
            total_written += written;
        }
        while (total_written < static_cast<std::size_t>(data.size()));
        return total_written;
    }
}

#endif