text: /* -*- mode: C++; indent-tabs-mode: nil; -*-
   *
   * This file is a part of LEMON, a generic C++ optimization library.
   *
   * Copyright (C) 2003-2013
   * 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 GraphType;
      // 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 map type.
      typedef ArrayMap Map;
  
      // The notifier type.
      typedef typename ItemSetTraits<_Graph, _Item>::ItemNotifier Notifier;
  
    private:
  
      // The MapBase of the Map which imlements the core regisitry function.
      typedef typename Notifier::ObserverBase Parent;
  
      typedef std::allocator<Value> Allocator;
  
    public:
  
      // \brief Graph initialized map constructor.
      //
      // Graph initialized map constructor.
      explicit ArrayMap(const GraphType& 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 GraphType& 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
  