SubscriptionInterval.hpp

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/**
 * @file SubscriptionInterval.hpp
 *
 */

#pragma once

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

#include "uORBDeviceNode.hpp"
#include "uORBManager.hpp"
#include "uORBUtils.hpp"

#include "Subscription.hpp"

namespace uORB
{

// Base subscription wrapper class
class SubscriptionInterval
{
public:

    /**
     * Constructor
     *
     * @param meta The uORB metadata (usually from the ORB_ID() macro) for the topic.
     * @param interval The requested maximum update interval in microseconds.
     * @param instance The instance for multi sub.
     */
    SubscriptionInterval(const orb_metadata *meta, uint32_t interval_us = 0, uint8_t instance = 0) :
        _subscription{meta, instance},
        _interval_us(interval_us)
    {}

    SubscriptionInterval() : _subscription{nullptr} {}

    ~SubscriptionInterval() = default;

    bool subscribe() { return _subscription.subscribe(); }

    bool advertised() { return _subscription.advertised(); }

    /**
     * Check if there is a new update.
     * */
    bool updated()
    {
        if (advertised() && (hrt_elapsed_time(&_last_update) >= _interval_us)) {
            return _subscription.updated();
        }

        return false;
    }

    /**
     * Copy the struct if updated.
     * @param dst The destination pointer where the struct will be copied.
     * @return true only if topic was updated and copied successfully.
     */
    bool update(void *dst)
    {
        if (updated()) {
            return copy(dst);
        }

        return false;
    }

    /**
     * Copy the struct
     * @param dst The destination pointer where the struct will be copied.
     * @return true only if topic was copied successfully.
     */
    bool copy(void *dst)
    {
        if (_subscription.copy(dst)) {
            _last_update = hrt_absolute_time();
            return true;
        }

        return false;
    }

    bool        valid() const { return _subscription.valid(); }

    uint8_t     get_instance() const { return _subscription.get_instance(); }
    orb_id_t    get_topic() const { return _subscription.get_topic(); }

    /**
     * Set the interval in microseconds
     * @param interval The interval in microseconds.
     */
    void        set_interval_us(uint32_t interval) { _interval_us = interval; }

    /**
     * Set the interval in milliseconds
     * @param interval The interval in milliseconds.
     */
    void        set_interval_ms(uint32_t interval) { _interval_us = interval * 1000; }

protected:

    Subscription    _subscription;
    uint64_t    _last_update{0};    // last update in microseconds
    uint32_t    _interval_us{0};    // maximum update interval in microseconds

};

} // namespace uORB