Method readQueryInfo

src/Server/GRPCServer.cpp:1295–1356

    }

    void Call::readQueryInfo()
    {
        auto start_reading = [&]
        {
            reading_query_info.set(true);
            responder->read(next_query_info_while_reading, [this](bool ok)
            {
                /// Called on queue_thread.
                if (ok)
                {
                    const auto & nqi = next_query_info_while_reading;
                    if (check_query_info_contains_cancel_only)
                    {
                        if (!nqi.query().empty() || !nqi.query_id().empty() || !nqi.settings().empty() || !nqi.database().empty()
                            || !nqi.input_data().empty() || !nqi.input_data_delimiter().empty() || !nqi.output_format().empty()
                            || !nqi.user_name().empty() || !nqi.password().empty() || !nqi.quota().empty() || !nqi.session_id().empty())
                        {
                            LOG_WARNING(log, "Cannot add extra information to a query which is already executing. Only the 'cancel' field can be set");
                        }
                    }
                    if (nqi.cancel())
                        want_to_cancel = true;
                }
                else
                {
                    /// We cannot throw an exception right here because this code is executed
                    /// on queue_thread.
                    failed_to_read_query_info = true;
                }
                reading_query_info.set(false);
            });
        };

        auto finish_reading = [&]
        {
            if (reading_query_info.get())
            {
                Stopwatch client_writing_watch;
                reading_query_info.wait(false);
                waited_for_client_writing += client_writing_watch.elapsedNanoseconds();
            }
            throwIfFailedToReadQueryInfo();
            query_info = std::move(next_query_info_while_reading);
            initial_query_info_read = true;
        };

        if (!initial_query_info_read)
        {
            /// Initial query info hasn't been read yet, so we're going to read it now.
            start_reading();
        }

        /// Maybe it's reading a query info right now. Let it finish.
        finish_reading();

        if (isInputStreaming(call_type))
        {
            /// Next query info can contain more input data. Now we start reading a next query info,