PX4-Autopilot/src/drivers/cyphal/SubscriptionManager.cpp

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/**
 * @file SubscriptionManager.cpp
 *
 * Manages the UAVCAN subscriptions
 *
 * @author Peter van der Perk <peter.vanderperk@nxp.com>
 */


#include "SubscriptionManager.hpp"

#include "ParamManager.hpp"

SubscriptionManager::~SubscriptionManager()
{
	UavcanDynamicPortSubscriber *dynsub;

	while (_dynsubscribers != nullptr) {
		dynsub = _dynsubscribers;
		_dynsubscribers = dynsub->next();
		delete dynsub;
	}
}

void SubscriptionManager::subscribe()
{
	_heartbeat_sub.subscribe();

#if CONFIG_CYPHAL_GETINFO_RESPONDER
	_getinfo_rsp.subscribe();
#endif

	_access_rsp.subscribe();
	_list_rsp.subscribe();

	updateDynamicSubscriptions();
}

void SubscriptionManager::updateDynamicSubscriptions()
{
	for (auto &sub : _uavcan_subs) {

		bool found_subscriber = false;
		UavcanDynamicPortSubscriber *dynsub = _dynsubscribers;

		while (dynsub != nullptr) {
			// Check if subscriber has already been created
			const char *subj_prefix = dynsub->getSubjectPrefix();
			const char *subj_name = dynsub->getSubjectName();
			const uint8_t instance = dynsub->getInstance();
			char subject_name[90];
			snprintf(subject_name, sizeof(subject_name), "%s%s", subj_prefix, subj_name);

			if (strcmp(subject_name, sub.subject_name) == 0 && instance == sub.instance) {
				found_subscriber = true;
				break;
			}

			dynsub = dynsub->next();
		}

		if (found_subscriber) {
			continue;
		}

		char uavcan_param[90];
		snprintf(uavcan_param, sizeof(uavcan_param), "uavcan.sub.%s.%d.id", sub.subject_name, sub.instance);
		uavcan_register_Value_1_0 value;

		if (_param_manager.GetParamByName(uavcan_param, value)) {
			uint16_t port_id = value.natural16.value.elements[0];

			if (port_id <= CANARD_PORT_ID_MAX) { // PortID is set, create a subscriber
				dynsub = sub.create_sub(_canard_handle, _param_manager);

				if (dynsub == nullptr) {
					PX4_ERR("Out of memory");
					return;
				}

				if (_dynsubscribers == nullptr) {
					// Set the head of our linked list
					_dynsubscribers = dynsub;

				} else {
					// Append the new subscriber to our linked list
					UavcanDynamicPortSubscriber *tmp = _dynsubscribers;

					while (tmp->next() != nullptr) {
						tmp = tmp->next();
					}

					tmp->setNext(dynsub);
				}

				dynsub->updateParam();
			}

		} else {
			PX4_ERR("Port ID param for subscriber %s.%u not found", sub.subject_name, sub.instance);
			return;
		}
	}
}

void SubscriptionManager::printInfo()
{
	UavcanDynamicPortSubscriber *dynsub = _dynsubscribers;

	while (dynsub != nullptr) {
		dynsub->printInfo();
		dynsub = dynsub->next();
	}
}

void SubscriptionManager::updateParams()
{
	UavcanDynamicPortSubscriber *dynsub = _dynsubscribers;

	while (dynsub != nullptr) {
		dynsub->updateParam();
		dynsub = dynsub->next();
	}

	// Check for any newly-enabled subscriptions
	updateDynamicSubscriptions();
}