Method upload

src/SFML/Network/Sftp.cpp:1252–1362

///////////////////////////////////////////////////////

////////////////////////////////////////////////////////////
Sftp::Result Sftp::upload(const std::filesystem::path&                              remotePath,
                          const std::function<bool(void* data, std::size_t& size)>& callback,
                          std::filesystem::perms                                    permissions,
                          bool                                                      truncate,
                          bool                                                      append,
                          std::uint64_t                                             offset,
                          const TimeoutWithPredicate&                               timeout)
{
    if (!callback)
        return Result(Result::Value::Error);

    LIBSSH2_SFTP_HANDLE* handle{};

    // Open the file for writing
    {
        const auto pathString = pathToUtf8(remotePath);
        const auto result     = m_impl->waitForOperationComplete(
            [&]
            {
                if (handle = libssh2_sftp_open_ex(m_impl->sftpSession.get(),
                                                  pathString.data(),
                                                  static_cast<unsigned int>(pathString.size()),
                                                  static_cast<unsigned int>(LIBSSH2_FXF_WRITE | LIBSSH2_FXF_CREAT |
                                                                            (truncate ? LIBSSH2_FXF_TRUNC : 0) |
                                                                            (append ? LIBSSH2_FXF_APPEND : 0)),
                                                  makePermissions(permissions),
                                                  LIBSSH2_SFTP_OPENFILE);
                    handle)
                    return LIBSSH2_ERROR_NONE;

                return libssh2_session_last_errno(m_impl->ssh2Session.get());
            },
            timeout);

        if (!handle && (result == LIBSSH2_ERROR_EAGAIN))
            return Result(Result::Value::Timeout);

        if (!handle)
            return makeError(m_impl->ssh2Session.get(), m_impl->sftpSession.get());
    }

    // Seek to the offset if one was specified
    if (offset > 0)
        libssh2_sftp_seek64(handle, offset);

    // Write to the file
    {
        static constexpr auto bufferSizeStart = std::size_t{4 * 1024};
        static constexpr auto bufferSizeMax   = std::size_t{1024 * 1024};
        auto                  bufferSize      = bufferSizeStart;
        auto buffer = std::make_unique<char[]>(bufferSize); // NOLINT(cppcoreguidelines-avoid-c-arrays,modernize-avoid-c-arrays)

        while (true)
        {
            std::size_t length = bufferSize;
            const auto  stop   = !callback(buffer.get(), length);
            const auto  expand = (length == bufferSize);
            const auto* ptr    = buffer.get();