src/lib/chemistry/qc/mbptr12/registry.h

//
// registry.h
//
// Copyright (C) 2008 Edward Valeev
//
// Author: Edward Valeev <evaleev@vt.edu>
// Maintainer: EV
//
// This file is part of the SC Toolkit.
//
// The SC Toolkit is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// The SC Toolkit is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
// the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
//
// The U.S. Government is granted a limited license as per AL 91-7.
//

#ifdef __GNUG__
#pragma interface
#endif

#ifndef _mpqc_src_lib_chemistry_qc_mbptr12_registry_h
#define _mpqc_src_lib_chemistry_qc_mbptr12_registry_h

#include <map>
#include <stdexcept>
#include <util/group/thread.h>

namespace sc {

  namespace detail {
    template <typename T>
    class SingletonCreationPolicy {
      protected:
        static Ref<T> instance() {
          return instance_;
        }
        static Ref<T> instance(StateIn& si) {
          if (!instance_restored_) {
            instance_ = new T(si);
            instance_restored_ = true;
          }
          return instance_;
        }
        static void save_instance(const Ref<T>& instance, StateOut& so) {
          if (!instance_saved_) {
            instance_->save_data_state(so);
            instance_saved_ = true;
          }
        }
        static Ref<T> instance_;
        static bool instance_restored_;
        static bool instance_saved_;
    };

    template <typename T> Ref<T> SingletonCreationPolicy<T>::instance_(new T);
    template <typename T> bool SingletonCreationPolicy<T>::instance_restored_ = false;
    template <typename T> bool SingletonCreationPolicy<T>::instance_saved_ = false;

    template<typename T>
    class NonsingletonCreationPolicy {
      protected:
        static Ref<T> instance() {
          return new T;
        }
        static Ref<T> instance(StateIn& si) {
          return new T(si);
        }
        static void save_instance(const Ref<T>& instance, StateOut& so) {
          instance->save_data_state(so);
        }
    };

  } // end of namespace detail

  template <typename Key, typename Value, template <typename> class CreationPolicy,
            typename KeyEqual = std::equal_to<Key>,
            typename ValueEqual = std::equal_to<Value>
           >
    class Registry : public RefCount, public CreationPolicy< Registry<Key,Value,CreationPolicy,KeyEqual,ValueEqual> > {
      public:
        static Ref<Registry> instance();
        static void save_instance(const Ref<Registry>&, StateOut&);
        static Ref<Registry> restore_instance(StateIn&);

        bool key_exists(const Key& key) const;
        bool value_exists(const Value& value) const;
        const Value& value(const Key& key) const;
        const Key& key(const Value& obj) const;
        void add(const Key& key,
                 const Value& obj);
        void add(const std::pair<Key,Value>& keyval_pair);

        class not_found : public std::runtime_error {
          public:
            not_found(const char* what) : std::runtime_error(what) {}
        };

      private:
        // creation policy must be able to construct Registry
        friend class CreationPolicy< Registry<Key,Value,CreationPolicy,KeyEqual,ValueEqual> >;

        // access only through instance() and related methods
        Registry();
        // use restore_instance
        Registry(StateIn&);
        // use save_instance
        void save_data_state(StateOut&);

        typedef std::map<Key,Value> Map;
        typedef typename Map::const_iterator const_iterator;
        Map map_;

        // assumes that map is already locked
        const_iterator find_by_key(const Key& key) const;
        // assumes that map is already locked
        const_iterator find_by_value(const Value& value) const;

        // std::map's operations are not reentrant, hence lock the map every time
        Ref<ThreadLock> lock_;

        template <typename T1, typename T2> struct SameType {
          static const bool result = false;
        };
        template <typename T> struct SameType<T,T> {
          static const bool result = true;
        };

    };

} // end of namespace sc

#include <chemistry/qc/mbptr12/registry.timpl.h>

#endif // end of header guard


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