Method poll

src/Client/LocalConnection.cpp:459–621

}

bool LocalConnection::poll(size_t)
{
    if (!state)
        return false;

    /// Wait for next poll to collect current packet.
    if (next_packet_type)
        return true;

    if (state->exception)
    {
        /// Flush any buffered logs before delivering the exception, otherwise
        /// the user would not see log messages produced before the failure.
        if (needSendLogs())
            return true;

        next_packet_type = Protocol::Server::Exception;
        return true;
    }

    if (!state->is_finished)
    {
        if (needSendProgressOrMetrics())
            return true;

        if (needSendLogs())
            return true;

        try
        {
            while (pollImpl())
            {
                LOG_TEST(&Poco::Logger::get("LocalConnection"), "Executor timeout encountered, will retry");

                if (needSendProgressOrMetrics())
                    return true;

                if (needSendLogs())
                    return true;
            }
        }
        catch (const Exception & e)
        {
            state->io.onException();
            state->exception.reset(e.clone());
        }
        catch (const std::exception & e)
        {
            state->io.onException();
            state->exception = std::make_unique<Exception>(Exception::CreateFromSTDTag{}, e);
        }
        catch (...) // Ok: wrap unknown exception for the client
        {
            state->io.onException();
            state->exception = std::make_unique<Exception>(Exception(ErrorCodes::UNKNOWN_EXCEPTION, "Unknown exception"));
        }
    }