#ifndef GUIDMAP_H
#define GUIDMAP_H

#include <boost/thread/shared_mutex.hpp>
#include <boost/thread/locks.hpp>
#include <boost/foreach.hpp>
#include <map>

class GUIDMap {
	public:
		class NotFound : public std::exception { };
	protected:
		GUIDMap(int16_t s) : seed(int32_t(s) << 16) {
		}
		virtual ~GUIDMap() {
		}
		mutable boost::shared_mutex lock;
		int32_t seed;
		int16_t key;
};
template<class Value, int ValueDeleter(Value)>
class GUIDMapImpl : public GUIDMap {
	public:
		typedef std::map<int32_t, const Value> Storage;
		GUIDMapImpl(int16_t s) : GUIDMap(s) {
		}
		~GUIDMapImpl() {
			BOOST_FOREACH(typename Storage::value_type v, storage) {
				ValueDeleter(v.second);
			}
		}

		int32_t store(const Value & value) {
			boost::unique_lock<boost::shared_mutex> l(lock);
			int32_t newKey = (seed + ++key);
			while (storage.find(newKey) != storage.end()) {
				newKey = (seed + ++key);
			}
			storage.insert(std::pair<int32_t, const Value>(newKey, value));
			return newKey;
		}
		void remove(int32_t key) {
			boost::unique_lock<boost::shared_mutex> l(lock);
			storage.erase(key);
		}
		Value get(int32_t key) const {
			boost::shared_lock<boost::shared_mutex> l(lock);
			typename Storage::const_iterator i = storage.find(key);
			if (i != storage.end()) {
				return i->second;
			}
			throw NotFound();
		}
		bool contains(int32_t key) const {
			boost::shared_lock<boost::shared_mutex> l(lock);
			return (storage.find(key) != storage.end());
		}

	private:
		Storage storage;
};

#endif