/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library.

  *

  * Copyright (C) 2003-2009

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #ifndef LEMON_BITS_ARRAY_MAP_H

 #define LEMON_BITS_ARRAY_MAP_H

 #include <memory>

 #include <lemon/bits/traits.h>

 #include <lemon/bits/alteration_notifier.h>

 #include <lemon/concept_check.h>

 #include <lemon/concepts/maps.h>

 // \ingroup graphbits

 // \file

 // \brief Graph map based on the array storage.

 namespace lemon {

   // \ingroup graphbits

   //

   // \brief Graph map based on the array storage.

   //

   // The ArrayMap template class is graph map structure that automatically

   // updates the map when a key is added to or erased from the graph.

   // This map uses the allocators to implement the container functionality.

   //

   // The template parameters are the Graph, the current Item type and

   // the Value type of the map.

   template <typename _Graph, typename _Item, typename _Value>

   class ArrayMap

     : public ItemSetTraits<_Graph, _Item>::ItemNotifier::ObserverBase {

   public:

     // The graph type.

     typedef _Graph Graph;

     // The item type.

     typedef _Item Item;

     // The reference map tag.

     typedef True ReferenceMapTag;

     // The key type of the map.

     typedef _Item Key;

     // The value type of the map.

     typedef _Value Value;

     // The const reference type of the map.

     typedef const _Value& ConstReference;

     // The reference type of the map.

     typedef _Value& Reference;

     // The notifier type.

     typedef typename ItemSetTraits<_Graph, _Item>::ItemNotifier Notifier;

     // The MapBase of the Map which imlements the core regisitry function.

     typedef typename Notifier::ObserverBase Parent;

   private:

     typedef std::allocator<Value> Allocator;

   public:

     // \brief Graph initialized map constructor.

     //

     // Graph initialized map constructor.

     explicit ArrayMap(const Graph& graph) {

       Parent::attach(graph.notifier(Item()));

       allocate_memory();

       Notifier* nf = Parent::notifier();

       Item it;

       for (nf->first(it); it != INVALID; nf->next(it)) {

         int id = nf->id(it);;

         allocator.construct(&(values[id]), Value());

       }

     }

     // \brief Constructor to use default value to initialize the map.

     //

     // It constructs a map and initialize all of the the map.

     ArrayMap(const Graph& graph, const Value& value) {

       Parent::attach(graph.notifier(Item()));

       allocate_memory();

       Notifier* nf = Parent::notifier();

       Item it;

       for (nf->first(it); it != INVALID; nf->next(it)) {

         int id = nf->id(it);;

         allocator.construct(&(values[id]), value);

       }

     }

   private:

     // \brief Constructor to copy a map of the same map type.

     //

     // Constructor to copy a map of the same map type.

     ArrayMap(const ArrayMap& copy) : Parent() {

       if (copy.attached()) {

         attach(*copy.notifier());

       }

       capacity = copy.capacity;

       if (capacity == 0) return;

       values = allocator.allocate(capacity);

       Notifier* nf = Parent::notifier();

       Item it;

       for (nf->first(it); it != INVALID; nf->next(it)) {

         int id = nf->id(it);;

         allocator.construct(&(values[id]), copy.values[id]);

       }

     }

     // \brief Assign operator.

     //

     // This operator assigns for each item in the map the

     // value mapped to the same item in the copied map.

     // The parameter map should be indiced with the same

     // itemset because this assign operator does not change

     // the container of the map.

     ArrayMap& operator=(const ArrayMap& cmap) {

       return operator=<ArrayMap>(cmap);

     }

     // \brief Template assign operator.

     //

     // The given parameter should conform to the ReadMap

     // concecpt and could be indiced by the current item set of

     // the NodeMap. In this case the value for each item

     // is assigned by the value of the given ReadMap.

     template <typename CMap>

     ArrayMap& operator=(const CMap& cmap) {

       checkConcept<concepts::ReadMap<Key, _Value>, CMap>();

       const typename Parent::Notifier* nf = Parent::notifier();

       Item it;

       for (nf->first(it); it != INVALID; nf->next(it)) {

         set(it, cmap[it]);

       }

       return *this;

     }

   public:

     // \brief The destructor of the map.

     //

     // The destructor of the map.

     virtual ~ArrayMap() {

       if (attached()) {

         clear();

         detach();

       }

     }

   protected:

     using Parent::attach;

     using Parent::detach;

     using Parent::attached;

   public:

     // \brief The subscript operator.

     //

     // The subscript operator. The map can be subscripted by the

     // actual keys of the graph.

     Value& operator[](const Key& key) {

       int id = Parent::notifier()->id(key);

       return values[id];

     }

     // \brief The const subscript operator.

     //

     // The const subscript operator. The map can be subscripted by the

     // actual keys of the graph.

     const Value& operator[](const Key& key) const {

       int id = Parent::notifier()->id(key);

       return values[id];

     }

     // \brief Setter function of the map.

     //

     // Setter function of the map. Equivalent with map[key] = val.

     // This is a compatibility feature with the not dereferable maps.

     void set(const Key& key, const Value& val) {

       (*this)[key] = val;

     }

   protected:

     // \brief Adds a new key to the map.

     //

     // It adds a new key to the map. It is called by the observer notifier

     // and it overrides the add() member function of the observer base.

     virtual void add(const Key& key) {

       Notifier* nf = Parent::notifier();

       int id = nf->id(key);

       if (id >= capacity) {

         int new_capacity = (capacity == 0 ? 1 : capacity);

         while (new_capacity <= id) {

           new_capacity <<= 1;

         }

         Value* new_values = allocator.allocate(new_capacity);

         Item it;

         for (nf->first(it); it != INVALID; nf->next(it)) {

           int jd = nf->id(it);;

           if (id != jd) {

             allocator.construct(&(new_values[jd]), values[jd]);

             allocator.destroy(&(values[jd]));

           }

         }

         if (capacity != 0) allocator.deallocate(values, capacity);

         values = new_values;

         capacity = new_capacity;

       }

       allocator.construct(&(values[id]), Value());

     }

     // \brief Adds more new keys to the map.

     //

     // It adds more new keys to the map. It is called by the observer notifier

     // and it overrides the add() member function of the observer base.

     virtual void add(const std::vector<Key>& keys) {

       Notifier* nf = Parent::notifier();

       int max_id = -1;

       for (int i = 0; i < int(keys.size()); ++i) {

         int id = nf->id(keys[i]);

         if (id > max_id) {

           max_id = id;

         }

       }

       if (max_id >= capacity) {

         int new_capacity = (capacity == 0 ? 1 : capacity);

         while (new_capacity <= max_id) {

           new_capacity <<= 1;

         }

         Value* new_values = allocator.allocate(new_capacity);

         Item it;

         for (nf->first(it); it != INVALID; nf->next(it)) {

           int id = nf->id(it);

           bool found = false;

           for (int i = 0; i < int(keys.size()); ++i) {

             int jd = nf->id(keys[i]);

             if (id == jd) {

               found = true;

               break;

             }

           }

           if (found) continue;

           allocator.construct(&(new_values[id]), values[id]);

           allocator.destroy(&(values[id]));

         }

         if (capacity != 0) allocator.deallocate(values, capacity);

         values = new_values;

         capacity = new_capacity;

       }

       for (int i = 0; i < int(keys.size()); ++i) {

         int id = nf->id(keys[i]);

         allocator.construct(&(values[id]), Value());

       }

     }

     // \brief Erase a key from the map.

     //

     // Erase a key from the map. It is called by the observer notifier

     // and it overrides the erase() member function of the observer base.

     virtual void erase(const Key& key) {

       int id = Parent::notifier()->id(key);

       allocator.destroy(&(values[id]));

     }

     // \brief Erase more keys from the map.

     //

     // Erase more keys from the map. It is called by the observer notifier

     // and it overrides the erase() member function of the observer base.

     virtual void erase(const std::vector<Key>& keys) {

       for (int i = 0; i < int(keys.size()); ++i) {

         int id = Parent::notifier()->id(keys[i]);

         allocator.destroy(&(values[id]));

       }

     }

     // \brief Builds the map.

     //

     // It builds the map. It is called by the observer notifier

     // and it overrides the build() member function of the observer base.

     virtual void build() {

       Notifier* nf = Parent::notifier();

       allocate_memory();

       Item it;

       for (nf->first(it); it != INVALID; nf->next(it)) {

         int id = nf->id(it);;

         allocator.construct(&(values[id]), Value());

       }

     }

     // \brief Clear the map.

     //

     // It erase all items from the map. It is called by the observer notifier

     // and it overrides the clear() member function of the observer base.

     virtual void clear() {

       Notifier* nf = Parent::notifier();

       if (capacity != 0) {

         Item it;

         for (nf->first(it); it != INVALID; nf->next(it)) {

           int id = nf->id(it);

           allocator.destroy(&(values[id]));

         }

         allocator.deallocate(values, capacity);

         capacity = 0;

       }

     }

   private:

     void allocate_memory() {

       int max_id = Parent::notifier()->maxId();

       if (max_id == -1) {

         capacity = 0;

         values = 0;

         return;

       }

       capacity = 1;

       while (capacity <= max_id) {

         capacity <<= 1;

       }

       values = allocator.allocate(capacity);

     }

     int capacity;

     Value* values;

     Allocator allocator;

   };

 }

 #endif