Implement recursionCheck using observer pattern

Change-Id: Ic404c098f316106abe1918c3cd100ae047f4f555
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

4 files changed, 47 insertions, 108 deletions

diff --git a/signal-composer-binding/observer-pattern.hpp b/signal-composer-binding/observer-pattern.hpp
index aba2847..940a80b 100644
--- a/signal-composer-binding/observer-pattern.hpp
+++ b/signal-composer-binding/observer-pattern.hpp
@@ -63,31 +63,11 @@ public:
 		if(it != observableList_.end())
 			{observableList_.erase(it);}
 	}
-/*
-	void recursionCheck(T* obs)
-	{
-		for (const auto& obs: observersList_)
-		{
-			if( id_ == obs->id())
-				{return -1;}
-			if( origId == obs->id())
-				{return -1;}
-			if(! obs->recursionCheck(origId))
-				{return -1;}
-		}
-		return 0;
-	}
-*/
 };
 
 template <class T>
 class Observable
 {
-private:
-	std::list<Observer<T>*> observerList_;
-	typedef typename std::list<Observer<T>*>::iterator iterator_;
-	typedef typename std::list<Observer<T>*>::const_iterator const_iterator_;
-
 public:
 	void addObserver(Observer<T>* observer)
 	{
@@ -101,19 +81,10 @@ public:
 		if(it != observerList_.end())
 			{observerList_.erase(it);}
 	}
-/*
-	int recursionCheck()
-	{
-		for (auto& obs: observerList_)
-		{
-			if( static_cast<T*>(obs) == static_cast<T*>(this))
-				{return -1;}
-			if( obs->recursionCheck(id_))
-				{return -1;}
-		}
-		return 0;
-	}
-*/
+
+	virtual int initialRecursionCheck() = 0;
+	virtual int recursionCheck(T* obs) = 0;
+
 	virtual ~Observable()
 	{
 		iterator_ itb = observerList_.begin();
@@ -126,6 +97,10 @@ public:
 	}
 
 protected:
+	std::list<Observer<T>*> observerList_;
+	typedef typename std::list<Observer<T>*>::iterator iterator_;
+	typedef typename std::list<Observer<T>*>::const_iterator const_iterator_;
+
 	void notify()
 	{
 		iterator_ itb=observerList_.begin();
diff --git a/signal-composer-binding/signal-composer-binding.cpp b/signal-composer-binding/signal-composer-binding.cpp
index d4236a0..44b644c 100644
--- a/signal-composer-binding/signal-composer-binding.cpp
+++ b/signal-composer-binding/signal-composer-binding.cpp
@@ -217,16 +217,16 @@ int execConf()
 	{
 		sig->attachToSourceSignals(composer);
 	}
-/*
+
 	for(auto& sig: allSignals)
 	{
-		if( (err += sig->recursionCheck()) )
+		if( (err += sig->initialRecursionCheck()) )
 		{
 			AFB_ERROR("There is an infinite recursion loop in your signals definition. Root coming from signal: %s", sig->id().c_str());
 			return err;
 		}
 	}
-*/
+
 	composer.execSignalsSubscription();
 
 	AFB_DEBUG("Signal Composer Control configuration Done.\n signals=%d", (int)sigCount);
diff --git a/signal-composer-binding/signal.cpp b/signal-composer-binding/signal.cpp
index 2dcc552..a74889d 100644
--- a/signal-composer-binding/signal.cpp
+++ b/signal-composer-binding/signal.cpp
@@ -184,52 +184,6 @@ void Signal::attachToSourceSignals(Composer& composer)
 	}
 }
 
-/// @brief Call update() method on observer Signal with
-/// current Signal timestamp and value
-/*void Signal::notify() const
-{
-	for (int i = 0; i < Observers_.size(); ++i)
-	  Observers_[i]->update(timestamp_, value_);
-}
-
-/// @brief Inner recursion check. Argument is the Signal id coming
-/// from the original Signal that made a recursion check.
-///
-/// @param[in] origId - name of the origine of the recursion check
-///
-/// @return 0 if no infinite loop detected, -1 if not.
-int Signal::recursionCheck(const std::string& origId) const
-{
-	for (const auto& obs: observersList_)
-	{
-		if( id_ == obs->id())
-			{return -1;}
-		if( origId == obs->id())
-			{return -1;}
-		if(! obs->recursionCheck(origId))
-			{return -1;}
-	}
-	return 0;
-}
-
-/// @brief Recursion check to ensure that there is no infinite loop
-/// in the Observers/Observables structure.
-/// This will check that observer signal is not the same than itself
-/// then trigger the check against the following eventuals observers
-///
-/// @return 0 if no infinite loop detected, -1 if not.
-int Signal::recursionCheck() const
-{
-	for (const auto& obs: observersList_)
-	{
-		if( id_ == obs->id())
-			{return -1;}
-		if( obs->recursionCheck(id_))
-			{return -1;}
-	}
-	return 0;
-}*/
-
 /// @brief Make an average over the last X 'seconds'
 ///
 /// @param[in] seconds - period to calculate the average
@@ -339,39 +293,40 @@ struct SignalValue Signal::last() const
 	return history_.rbegin()->second;
 }
 
-/*
-template<class Signal>
-Observable<Signal>::~Observable()
-{
-	iterator_ itb = observerList_.begin();
-	const_iterator_ ite = observerList_.end();
-
-	for(;itb!=ite;++itb)
-	{
-		(*itb)->delObservable(this);
-	}
-}
 
-template <class Signal>
-Observer<Signal>::~Observer()
+/// @brief Recursion check to ensure that there is no infinite loop
+/// in the Observers/Observables structure.
+/// This will check that observer signal is not the same than itself
+/// then trigger the check against the following eventuals observers
+///
+/// @return 0 if no infinite loop detected, -1 if not.
+int Signal::initialRecursionCheck()
 {
-	const_iterator_ ite = observableList_.end();
-
-	for(iterator_ itb=observableList_.begin();itb!=ite;++itb)
+	for (auto& obs: observerList_)
 	{
-			(*itb)->delObserver(this);
+		if(obs == this)
+			{return -1;}
+		if(static_cast<Signal*>(obs)->recursionCheck(static_cast<Signal*>(obs)))
+			{return -1;}
 	}
+	return 0;
 }
 
-template <class Signal>
-void Observable<Signal>::notify()
+/// @brief Inner recursion check. Argument is the Signal id coming
+/// from the original Signal that made a recursion check.
+///
+/// @param[in] origId - name of the origine of the recursion check
+///
+/// @return 0 if no infinite loop detected, -1 if not.
+int Signal::recursionCheck(Signal* parentSig)
 {
-	iterator_ itb=observerList_.begin();
-	const_iterator_ ite=observerList_.end();
-
-	for(;itb!=ite;++itb)
+	for (const auto& obs: observerList_)
 	{
-		(*itb)->update(static_cast<Signal*>(this));
+		Signal* obsSig = static_cast<Signal*>(obs);
+		if(parentSig->id() == static_cast<Signal*>(obsSig)->id())
+			{return -1;}
+		if(! obsSig->recursionCheck(obsSig))
+			{return -1;}
 	}
+	return 0;
 }
-*/
diff --git a/signal-composer-binding/signal.hpp b/signal-composer-binding/signal.hpp
index 8d0d1ab..46caa23 100644
--- a/signal-composer-binding/signal.hpp
+++ b/signal-composer-binding/signal.hpp
@@ -40,6 +40,12 @@ struct SignalValue {
 	std::string strVal;
 };
 
+/// @brief Holds a signal (raw or virtual) definition. Value could be of
+///  different types, so an intermediate structure is use to store them.
+///  A signal could also be a subject or an observer at the same time, this
+///  is the behavior retained to compose virtual signals based on raw signals.
+///  And this is the way that is used to update and reacts to an underlaying
+///  signal change.
 class Signal: public Observable<Signal>, public Observer<Signal>
 {
 private:
@@ -76,4 +82,7 @@ public:
 	double maximum(int seconds = 0) const;
 	struct SignalValue last() const;
 	//int recursionCheck() const;
+
+	int initialRecursionCheck();
+	int recursionCheck(Signal* obs);
 };