Publication.hpp

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/**
 * @file Publication.hpp
 *
 */

#pragma once

#include <px4_platform_common/defines.h>
#include <systemlib/err.h>
#include <uORB/uORB.h>

namespace uORB
{

/**
 * Base publication wrapper class
 */
template<typename T>
class Publication
{
public:

    /**
     * Constructor
     *
     * @param meta The uORB metadata (usually from the ORB_ID() macro) for the topic.
     */
    Publication(const orb_metadata *meta) : _meta(meta) {}
    ~Publication() { orb_unadvertise(_handle); }

    /**
     * Publish the struct
     * @param data The uORB message struct we are updating.
     */
    bool publish(const T &data)
    {
        if (_handle != nullptr) {
            return (orb_publish(_meta, _handle, &data) == PX4_OK);

        } else {
            orb_advert_t handle = orb_advertise(_meta, &data);

            if (handle != nullptr) {
                _handle = handle;
                return true;
            }
        }

        return false;
    }

protected:
    const orb_metadata *_meta;

    orb_advert_t _handle{nullptr};
};

/**
 * The publication class with data embedded.
 */
template<typename T>
class PublicationData : public Publication<T>
{
public:
    /**
     * Constructor
     *
     * @param meta The uORB metadata (usually from the ORB_ID() macro) for the topic.
     */
    PublicationData(const orb_metadata *meta) : Publication<T>(meta) {}
    ~PublicationData() = default;

    T   &get() { return _data; }
    void    set(const T &data) { _data = data; }

    // Publishes the embedded struct.
    bool    update() { return Publication<T>::publish(_data); }
    bool    update(const T &data)
    {
        _data = data;
        return Publication<T>::publish(_data);
    }

private:
    T _data{};
};

} // namespace uORB