text: /****************************************************************************
   *
   *   Copyright (c) 2012-2017 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 Subscription.cpp
   *
   */
  
  #include "Subscription.hpp"
  #include <px4_defines.h>
  
  namespace uORB
  {
  
  SubscriptionBase::SubscriptionBase(const struct orb_metadata *meta, unsigned interval, unsigned instance) :
  	_meta(meta),
  	_instance(instance)
  {
  	if (instance > 0) {
  		_handle = orb_subscribe_multi(_meta, instance);
  
  	} else {
  		_handle = orb_subscribe(_meta);
  	}
  
  	if (_handle < 0) {
  		PX4_ERR("%s sub failed", _meta->o_name);
  	}
  
  	if (interval > 0) {
  		orb_set_interval(_handle, interval);
  	}
  }
  
  bool SubscriptionBase::updated()
  {
  	bool isUpdated = false;
  
  	if (orb_check(_handle, &isUpdated) != PX4_OK) {
  		PX4_ERR("%s check failed", _meta->o_name);
  	}
  
  	return isUpdated;
  }
  
  bool SubscriptionBase::update(void *data)
  {
  	bool orb_updated = false;
  
  	if (updated()) {
  		if (orb_copy(_meta, _handle, data) != PX4_OK) {
  			PX4_ERR("%s copy failed", _meta->o_name);
  
  		} else {
  			orb_updated = true;
  		}
  	}
  
  	return orb_updated;
  }
  
  SubscriptionBase::~SubscriptionBase()
  {
  	if (orb_unsubscribe(_handle) != PX4_OK) {
  		PX4_ERR("%s unsubscribe failed", _meta->o_name);
  	}
  }
  
  SubscriptionNode::SubscriptionNode(const struct orb_metadata *meta, unsigned interval, unsigned instance,
  				   List<SubscriptionNode *> *list)
  	: SubscriptionBase(meta, interval, instance)
  {
  	if (list != nullptr) {
  		list->add(this);
  	}
  }
  
  } // namespace uORB
  