mavlink_orb_subscription.h

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/**
 * @file mavlink_orb_subscription.h
 * uORB subscription definition.
 *
 * @author Anton Babushkin <anton.babushkin@me.com>
 */

#ifndef MAVLINK_ORB_SUBSCRIPTION_H_
#define MAVLINK_ORB_SUBSCRIPTION_H_

#include <drivers/drv_hrt.h>
#include <containers/List.hpp>
#include <uORB/Subscription.hpp>

class MavlinkOrbSubscription : public ListNode<MavlinkOrbSubscription *>
{
public:

    MavlinkOrbSubscription(const orb_id_t topic, int instance) : _sub(topic, instance) {}
    ~MavlinkOrbSubscription() = default;

    /**
     * Check if subscription updated based on timestamp.
     *
     * @return true only if topic was updated based on a timestamp and
     * copied to buffer successfully.
     * If topic was not updated since last check it will return false but
     * still copy the data.
     * If no data available data buffer will be filled with zeros.
     */
    bool update(uint64_t *time, void *data) { return _sub.update(time, data); }

    /**
     * Copy topic data to given buffer.
     *
     * @return true only if topic data copied successfully.
     */
    bool update(void *data) { return _sub.copy(data); }

    /**
     * Check if the subscription has been updated.
     *
     * @return true if there has been an update which has been
     * copied successfully.
     */
    bool update_if_changed(void *data) { return _sub.update(data); }

    /**
     * Check if the topic has been published.
     *
     * This call will return true if the topic was ever published.
     * @return true if the topic has been published at least once.
     * If no data is available the buffer will be filled with zeros.
     */
    bool is_published();

    void subscribe_from_beginning(bool from_beginning) { _subscribe_from_beginning = from_beginning; }

    orb_id_t get_topic() const { return _sub.get_topic(); }
    int get_instance() const { return _sub.get_instance(); }

private:

    uORB::Subscription  _sub;

    bool _subscribe_from_beginning{false}; ///< we need to subscribe from the beginning, e.g. for vehicle_command_acks
};


#endif /* MAVLINK_ORB_SUBSCRIPTION_H_ */