STATUSTEXT.hpp 4.32 KB
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#ifndef STATUSTEXT_HPP
#define STATUSTEXT_HPP

#include <uORB/topics/mavlink_log.h>

#include <lib/perf/perf_counter.h>

class MavlinkStreamStatustext : public MavlinkStream
{
public:
	static MavlinkStream *new_instance(Mavlink *mavlink) { return new MavlinkStreamStatustext(mavlink); }

	static constexpr const char *get_name_static() { return "STATUSTEXT"; }
	static constexpr uint16_t get_id_static() { return MAVLINK_MSG_ID_STATUSTEXT; }

	const char *get_name() const override { return get_name_static(); }
	uint16_t get_id() override { return get_id_static(); }

	unsigned get_size() override
	{
		return _mavlink_log_sub.updated() ? (MAVLINK_MSG_ID_STATUSTEXT_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES) : 0;
	}

private:
	explicit MavlinkStreamStatustext(Mavlink *mavlink) : MavlinkStream(mavlink) {}

	~MavlinkStreamStatustext()
	{
		perf_free(_missed_msg_count_perf);
	}

	uORB::Subscription _mavlink_log_sub{ORB_ID(mavlink_log)};
	perf_counter_t _missed_msg_count_perf{perf_alloc(PC_COUNT, MODULE_NAME": STATUSTEXT missed messages")};
	uint16_t _id{0};

	bool send() override
	{
		if (_mavlink->is_connected()) {
			while (_mavlink_log_sub.updated() && (_mavlink->get_free_tx_buf() >= get_size())) {

				const unsigned last_generation = _mavlink_log_sub.get_last_generation();

				mavlink_log_s mavlink_log;

				if (_mavlink_log_sub.update(&mavlink_log)) {
					// don't send stale messages
					if (hrt_elapsed_time(&mavlink_log.timestamp) < 2_s) {

						if (_mavlink_log_sub.get_last_generation() != (last_generation + 1)) {
							perf_count(_missed_msg_count_perf);
							PX4_DEBUG("channel %d has missed %d mavlink log messages", _mavlink->get_channel(),
								  perf_event_count(_missed_msg_count_perf));
						}

						mavlink_statustext_t msg{};
						const char *text = mavlink_log.text;
						constexpr unsigned max_chunk_size = sizeof(msg.text);
						msg.severity = mavlink_log.severity;
						msg.chunk_seq = 0;
						msg.id = _id++;
						unsigned text_size;

						while ((text_size = strlen(text)) > 0) {
							unsigned chunk_size = math::min(text_size, max_chunk_size);

							if (chunk_size < max_chunk_size) {
								memcpy(&msg.text[0], &text[0], chunk_size);
								// pad with zeros
								memset(&msg.text[0] + chunk_size, 0, max_chunk_size - chunk_size);

							} else {
								memcpy(&msg.text[0], &text[0], chunk_size);
							}

							mavlink_msg_statustext_send_struct(_mavlink->get_channel(), &msg);

							if (text_size <= max_chunk_size) {
								break;

							} else {
								text += max_chunk_size;
							}

							msg.chunk_seq += 1;
						}

						return true;
					}
				}
			}
		}

		return false;
	}
};

#endif // STATUSTEXT_HPP