preserve/restore session features/properties within the pool

Data/include/Poco/Data/SessionPool.h

@@ -114,7 +114,28 @@ public:
 		/// If the maximum number of sessions for this pool has
 		/// already been created, a SessionPoolExhaustedException
 		/// is thrown.
-		
+	
+	template <typename T>
+	Session get(const std::string& name, const T& value)
+		/// Returns a Session with requested property set.
+		/// The property can be diferent from the default pool
+		/// value, in which case it is reset back to the pool 
+		/// value when the session is reclaimed by the pool.
+	{
+		Session& s = get();
+		_addPropertyMap.insert(AddPropertyMap::value_type(s.impl(),
+			std::make_pair(name, s.getProperty(name))));
+		s.setProperty(name, value);
+
+		return s;
+	}
+
+	Session get(const std::string& name, bool value);
+		/// Returns a Session with requested feature set.
+		/// The feature can be diferent from the default pool
+		/// value, in which case it is reset back to the pool 
+		/// value when the session is reclaimed by the pool.
+
 	int capacity() const;
 		/// Returns the maximum number of sessions the SessionPool will manage.
 		
@@ -163,27 +184,35 @@ protected:
 
 	void purgeDeadSessions();
 	int deadImpl(SessionList& rSessions);
+	void applySettings(SessionImpl* pImpl);
 	void putBack(PooledSessionHolderPtr pHolder);
 	void onJanitorTimer(Poco::Timer&);
 
 private:
+	typedef std::pair<std::string, Poco::Any> PropertyPair; 
+	typedef std::pair<std::string, bool> FeaturePair; 
+	typedef std::map<SessionImpl*, PropertyPair> AddPropertyMap;
+	typedef std::map<SessionImpl*, FeaturePair> AddFeatureMap;
+
 	SessionPool(const SessionPool&);
 	SessionPool& operator = (const SessionPool&);
 		
 	void closeAll(SessionList& sessionList);
 
-	std::string _connector;
-	std::string _connectionString;
-	int         _minSessions;
-	int         _maxSessions;
-	int         _idleTime;
-	int         _nSessions;
-	SessionList _idleSessions;
-	SessionList _activeSessions;
-	Poco::Timer _janitorTimer;
-	FeatureMap  _featureMap;
-	PropertyMap _propertyMap;
-	bool        _shutdown;
+	std::string    _connector;
+	std::string    _connectionString;
+	int            _minSessions;
+	int            _maxSessions;
+	int            _idleTime;
+	int            _nSessions;
+	SessionList    _idleSessions;
+	SessionList    _activeSessions;
+	Poco::Timer    _janitorTimer;
+	FeatureMap     _featureMap;
+	PropertyMap    _propertyMap;
+	bool           _shutdown;
+	AddPropertyMap _addPropertyMap;
+	AddFeatureMap  _addFeatureMap;
 	mutable
 	Poco::Mutex _mutex;
 	

Data/src/SessionPool.cpp

@@ -65,6 +65,17 @@ SessionPool::~SessionPool()
 }
 
 
+Session SessionPool::get(const std::string& name, bool value)
+{
+	Session& s = get();
+	_addFeatureMap.insert(AddFeatureMap::value_type(s.impl(),
+		std::make_pair(name, s.getFeature(name))));
+	s.setFeature(name, value);
+
+	return s;
+}
+
+
 Session SessionPool::get()
 {
 	Poco::Mutex::ScopedLock lock(_mutex);
@@ -77,14 +88,7 @@ Session SessionPool::get()
 		if (_nSessions < _maxSessions)
 		{
 			Session newSession(SessionFactory::instance().create(_connector, _connectionString));
-
-			FeatureMap::Iterator fmIt = _featureMap.begin();
-			FeatureMap::Iterator fmEnd = _featureMap.end();
-			for (; fmIt != fmEnd; ++fmIt) newSession.setFeature(fmIt->first, fmIt->second);
-
-			PropertyMap::Iterator pmIt = _propertyMap.begin();
-			PropertyMap::Iterator pmEnd = _propertyMap.end();
-			for (; pmIt != pmEnd; ++pmIt) newSession.setProperty(pmIt->first, pmIt->second);
+			applySettings(newSession.impl());
 
 			PooledSessionHolderPtr pHolder(new PooledSessionHolder(*this, newSession.impl()));
 			_idleSessions.push_front(pHolder);
@@ -218,16 +222,40 @@ Poco::Any SessionPool::getProperty(const std::string& name)
 }
 
 
+void SessionPool::applySettings(SessionImpl* pImpl)
+{
+	FeatureMap::Iterator fmIt = _featureMap.begin();
+	FeatureMap::Iterator fmEnd = _featureMap.end();
+	for (; fmIt != fmEnd; ++fmIt) pImpl->setFeature(fmIt->first, fmIt->second);
+
+	PropertyMap::Iterator pmIt = _propertyMap.begin();
+	PropertyMap::Iterator pmEnd = _propertyMap.end();
+	for (; pmIt != pmEnd; ++pmIt) pImpl->setProperty(pmIt->first, pmIt->second);
+}
+
+
 void SessionPool::putBack(PooledSessionHolderPtr pHolder)
 {
 	Poco::Mutex::ScopedLock lock(_mutex);
 	if (_shutdown) return;
-	
+
 	SessionList::iterator it = std::find(_activeSessions.begin(), _activeSessions.end(), pHolder);
 	if (it != _activeSessions.end())
 	{
 		if (pHolder->session()->isConnected())
 		{
+			// reverse settings applied at acquisition time, if any
+			AddPropertyMap::iterator pIt = _addPropertyMap.find(pHolder->session());
+			if (pIt != _addPropertyMap.end())
+				pHolder->session()->setProperty(pIt->second.first, pIt->second.second);
+
+			AddFeatureMap::iterator fIt = _addFeatureMap.find(pHolder->session());
+			if (fIt != _addFeatureMap.end())
+				pHolder->session()->setFeature(fIt->second.first, fIt->second.second);
+
+			// re-apply the default pool settings
+			applySettings(pHolder->session());
+
 			pHolder->access();
 			_idleSessions.push_front(pHolder);
 		}

Data/testsuite/src/SessionPoolTest.cpp

@@ -88,6 +88,9 @@ void SessionPoolTest::testSessionPool()
 	assert (pool.allocated() == pool.used() + pool.idle());
 	Session s1(pool.get());
 	
+	assert (s1.getFeature("f1"));
+	assert (1 == Poco::AnyCast<int>(s1.getProperty("p1")));
+
 	try { pool.setFeature("f1", true); fail ("must fail"); }
 	catch ( Poco::InvalidAccessException& ) { }
 	
@@ -101,7 +104,9 @@ void SessionPoolTest::testSessionPool()
 	assert (pool.dead() == 0);
 	assert (pool.allocated() == pool.used() + pool.idle());
 
-	Session s2(pool.get());
+	Session s2(pool.get("f1", false));
+	assert (!s2.getFeature("f1"));
+	assert (1 == Poco::AnyCast<int>(s2.getProperty("p1")));
 
 	assert (pool.capacity() == 4);
 	assert (pool.allocated() == 2);
@@ -111,7 +116,9 @@ void SessionPoolTest::testSessionPool()
 	assert (pool.allocated() == pool.used() + pool.idle());
 	
 	{
-		Session s3(pool.get());
+		Session s3(pool.get("p1", 2));
+		assert (s3.getFeature("f1"));
+		assert (2 == Poco::AnyCast<int>(s3.getProperty("p1")));
 
 		assert (pool.capacity() == 4);
 		assert (pool.allocated() == 3);
@@ -129,6 +136,8 @@ void SessionPoolTest::testSessionPool()
 	assert (pool.allocated() == pool.used() + pool.idle());
 
 	Session s4(pool.get());
+	assert (s4.getFeature("f1"));
+	assert (1 == Poco::AnyCast<int>(s4.getProperty("p1")));
 
 	assert (pool.capacity() == 4);
 	assert (pool.allocated() == 3);