Major plugin refactor and cleanup.

Switched to POCO library for unified platform/library interface.
Deprecated the external module API. It was creating more problems than solving.
Removed most built-in libraries in favor of system libraries for easier maintenance.
Cleaned and secured code with help from static analyzers.

vendor/POCO/Foundation/include/Poco/UniqueAccessExpireStrategy.h

@@ -0,0 +1,156 @@
+//
+// UniqueAccessExpireStrategy.h
+//
+// Library: Foundation
+// Package: Cache
+// Module:  UniqueAccessExpireStrategy
+//
+// Definition of the UniqueAccessExpireStrategy class.
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Foundation_UniqueAccessExpireStrategy_INCLUDED
+#define Foundation_UniqueAccessExpireStrategy_INCLUDED
+
+
+#include "Poco/KeyValueArgs.h"
+#include "Poco/ValidArgs.h"
+#include "Poco/AbstractStrategy.h"
+#include "Poco/Bugcheck.h"
+#include "Poco/Timestamp.h"
+#include "Poco/Timespan.h"
+#include "Poco/EventArgs.h"
+#include "Poco/UniqueExpireStrategy.h"
+#include <set>
+#include <map>
+
+
+namespace Poco {
+
+
+template < 
+	class TKey,
+	class TValue
+>
+class UniqueAccessExpireStrategy: public AbstractStrategy<TKey, TValue>
+	/// An UniqueExpireStrategy implements time based expiration of cache entries. In contrast
+	/// to ExpireStrategy which only allows to set a per cache expiration value, it allows to define 
+	/// expiration per CacheEntry.
+	/// Each TValue object must thus offer the following method:
+	///    
+	///    const Poco::Timestamp& getTimeout() const;
+	///    
+	/// which returns the timespan for how long an object will be valid without being accessed.
+{
+public:
+	typedef std::pair<TKey, Timespan>           KeyExpire;
+	typedef std::multimap<Timestamp, KeyExpire> TimeIndex;
+	typedef typename TimeIndex::iterator        IndexIterator;
+	typedef typename TimeIndex::const_iterator  ConstIndexIterator;
+	typedef std::map<TKey, IndexIterator>       Keys;
+	typedef typename Keys::iterator             Iterator;
+
+public:
+	UniqueAccessExpireStrategy()
+		/// Create an unique expire strategy.
+	{
+	}
+
+	~UniqueAccessExpireStrategy()
+	{
+	}
+
+	void onAdd(const void*, const KeyValueArgs <TKey, TValue>& args)
+	{
+		// the expire value defines how many millisecs in the future the
+		// value will expire, even insert negative values!
+		Timestamp expire;
+		expire += args.value().getTimeout().totalMicroseconds();
+		
+		IndexIterator it = _keyIndex.insert(std::make_pair(expire, std::make_pair(args.key(), args.value().getTimeout())));
+		std::pair<Iterator, bool> stat = _keys.insert(std::make_pair(args.key(), it));
+		if (!stat.second)
+		{
+			_keyIndex.erase(stat.first->second);
+			stat.first->second = it;
+		}
+	}
+
+	void onRemove(const void*, const TKey& key)
+	{
+		Iterator it = _keys.find(key);
+		if (it != _keys.end())
+		{
+			_keyIndex.erase(it->second);
+			_keys.erase(it);
+		}
+	}
+
+	void onGet(const void*, const TKey& key)
+	{
+		// get updates the expiration time stamp
+		Iterator it = _keys.find(key);
+		if (it != _keys.end())
+		{
+			KeyExpire ke = it->second->second;
+			// gen new absolute expire value
+			Timestamp expire;
+			expire += ke.second.totalMicroseconds();
+			// delete old index
+			_keyIndex.erase(it->second);
+			IndexIterator itt = _keyIndex.insert(std::make_pair(expire, ke));
+			// update iterator
+			it->second = itt;
+		}
+	}
+
+	void onClear(const void*, const EventArgs& args)
+	{
+		_keys.clear();
+		_keyIndex.clear();
+	}
+
+	void onIsValid(const void*, ValidArgs<TKey>& args)
+	{
+		Iterator it = _keys.find(args.key());
+		if (it != _keys.end())
+		{
+			Timestamp now;
+			if (it->second->first <= now)
+			{
+				args.invalidate();
+			}
+		}
+		else //not found: probably removed by onReplace
+			args.invalidate();
+	}
+
+	void onReplace(const void*, std::set<TKey>& elemsToRemove)
+	{
+		// Note: replace only informs the cache which elements
+		// it would like to remove!
+		// it does not remove them on its own!
+		IndexIterator it = _keyIndex.begin();
+		Timestamp now;
+		while (it != _keyIndex.end() && it->first < now)
+		{
+			elemsToRemove.insert(it->second.first);
+			++it;
+		}
+	}
+
+protected:
+	Keys      _keys;     /// For faster replacement of keys, the iterator points to the _keyIndex map
+	TimeIndex _keyIndex; /// Maps time to key value
+};
+
+
+} // namespace Poco
+
+
+#endif // Foundation_UniqueAccessExpireStrategy_INCLUDED