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*
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*
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/**
* @file Subscription.h
*
*/
#pragma once
#include <assert.h>
#include <uORB/uORB.h>
#include <containers/List.hpp>
namespace uORB
{
/**
* Base subscription warapper class, used in list traversal
* of various subscriptions.
*/
class __EXPORT SubscriptionBase
{
public:
// methods
/**
* Constructor
*
* @param meta The uORB metadata (usually from the ORB_ID()
* macro) for the topic.
*
* @param interval The minimum interval in milliseconds
* between updates
*/
SubscriptionBase(const struct orb_metadata *meta,
unsigned interval=0) :
_meta(meta),
_handle() {
setHandle(orb_subscribe(getMeta()));
orb_set_interval(getHandle(), interval);
}
/**
* Check if there is a new update.
* */
bool updated() {
bool isUpdated = false;
orb_check(_handle, &isUpdated);
return isUpdated;
}
/**
* Update the struct
* @param data The uORB message struct we are updating.
*/
void update(void * data) {
if (updated()) {
orb_copy(_meta, _handle, data);
}
}
/**
* Deconstructor
*/
virtual ~SubscriptionBase() {
orb_unsubscribe(_handle);
}
// accessors
const struct orb_metadata *getMeta() { return _meta; }
int getHandle() { return _handle; }
protected:
// accessors
void setHandle(int handle) { _handle = handle; }
// attributes
const struct orb_metadata *_meta;
int _handle;
};
/**
* alias class name so it is clear that the base class
*/
typedef SubscriptionBase SubscriptionTiny;
/**
* The publication base class as a list node.
*/
class __EXPORT SubscriptionNode :
public SubscriptionBase,
public ListNode<SubscriptionNode *>
{
public:
/**
* Constructor
*
*
* @param meta The uORB metadata (usually from the ORB_ID()
* macro) for the topic.
* @param interval The minimum interval in milliseconds
* between updates
* @param list A pointer to a list of subscriptions
* that this should be appended to.
*/
SubscriptionNode(const struct orb_metadata *meta,
unsigned interval=0,
List<SubscriptionNode *> * list=nullptr) :
SubscriptionBase(meta, interval),
_interval(interval) {
if (list != nullptr) list->add(this);
}
/**
* This function is the callback for list traversal
* updates, a child class must implement it.
*/
virtual void update() = 0;
// accessors
unsigned getInterval() { return _interval; }
protected:
// attributes
unsigned _interval;
};
/**
* Subscription wrapper class
*/
template<class T>
class __EXPORT Subscription :
public T, // this must be first!
public SubscriptionNode
{
public:
/**
* Constructor
*
* @param meta The uORB metadata (usually from
* the ORB_ID() macro) for the topic.
* @param interval The minimum interval in milliseconds
* between updates
* @param list A list interface for adding to
* list during construction
*/
Subscription(const struct orb_metadata *meta,
unsigned interval=0,
List<SubscriptionNode *> * list=nullptr);
/**
* Deconstructor
*/
virtual ~Subscription();
/**
* Create an update function that uses the embedded struct.
*/
void update() {
SubscriptionBase::update(getDataVoidPtr());
}
/*
* XXX
* This function gets the T struct, assuming
* the struct is the first base class, this
* should use dynamic cast, but doesn't
* seem to be available
*/
void *getDataVoidPtr();
T getData();
};
} // namespace uORB
