PX4-Autopilot/src/lib/FlightTasks/SubscriptionArray.hpp
2018-04-05 07:30:12 +02:00

112 lines
3.6 KiB
C++

/****************************************************************************
*
* Copyright (c) 2017 PX4 Development Team. All rights reserved.
*
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* modification, are permitted provided that the following conditions
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*
* 1. Redistributions of source code must retain the above copyright
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/**
* @file SubscriptionArray.hpp
*
* Simple array that contains a dynamic amount of Subscription<T> instances
*
* @author Beat Küng <beat-kueng@gmx.net>
*/
#pragma once
#include <uORB/Subscription.hpp>
class SubscriptionArray
{
public:
SubscriptionArray() = default;
~SubscriptionArray();
/**
* Get a subscription
* @param meta ORB_ID(topic)
* @param subscription returned subscription (output parameter)
* @param instance topic instance
* @return true on success, false otherwise (subscription set to nullptr)
*/
template<class T>
bool get(const struct orb_metadata *meta, uORB::Subscription<T> *&subscription, unsigned instance = 0);
/**
* update all subscriptions (if new data is available)
*/
void update();
/**
* update all subscriptions
*/
void forcedUpdate();
private:
void cleanup();
bool resizeSubscriptions();
uORB::SubscriptionNode **_subscriptions{nullptr};
int _subscriptions_count{0}; ///< number of valid subscriptions
int _subscriptions_size{0}; ///< actual size of the _subscriptions array
};
template<class T>
bool SubscriptionArray::get(const struct orb_metadata *meta, uORB::Subscription<T> *&subscription, unsigned instance)
{
// does it already exist?
for (int i = 0; i < _subscriptions_count; ++i) {
if (_subscriptions[i]->getMeta() == meta && _subscriptions[i]->getInstance() == instance) {
// we know the type must be correct, so we can use reinterpret_cast (dynamic_cast is not available)
subscription = reinterpret_cast<uORB::Subscription<T>*>(_subscriptions[i]);
return true;
}
}
// resize if needed
if (_subscriptions_count >= _subscriptions_size) {
if (!resizeSubscriptions()) {
subscription = nullptr;
return false;
}
}
subscription = new uORB::Subscription<T>(meta, 0, instance);
if (!subscription) {
return false;
}
_subscriptions[_subscriptions_count++] = subscription;
return true;
}