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/****************************************************************************
*
* Copyright (c) 2014 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @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 <systemlib/uthash/utlist.h>
#include <drivers/drv_hrt.h>
class MavlinkOrbSubscription
{
public:
MavlinkOrbSubscription *next; ///< pointer to next subscription in list
MavlinkOrbSubscription(const orb_id_t topic, int instance);
~MavlinkOrbSubscription();
/**
* Check if subscription updated and get data.
*
* @return true only if topic was updated and data 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 zeroes.
*/
bool update(uint64_t *time, void* data);
/**
* Copy topic data to given buffer.
*
* @return true only if topic data copied successfully.
*/
bool update(void* 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.
*/
bool is_published();
orb_id_t get_topic() const;
int get_instance() const;
private:
const orb_id_t _topic; ///< topic metadata
const int _instance; ///< get topic instance
int _fd; ///< subscription handle
bool _published; ///< topic was ever published
/* do not allow copying this class */
MavlinkOrbSubscription(const MavlinkOrbSubscription&);
MavlinkOrbSubscription operator=(const MavlinkOrbSubscription&);
};
#endif /* MAVLINK_ORB_SUBSCRIPTION_H_ */
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