lemon/bits/array_map.h
author Peter Kovacs <kpeter@inf.elte.hu>
Mon, 14 Jul 2008 16:20:12 +0200
changeset 216 6d7bfcf5b48e
parent 107 31a2e6d28f61
child 263 be8a861d3bb7
permissions -rw-r--r--
Doc improvement for kruskal() (ticket #114)
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #ifndef LEMON_BITS_ARRAY_MAP_H
    20 #define LEMON_BITS_ARRAY_MAP_H
    21 
    22 #include <memory>
    23 
    24 #include <lemon/bits/traits.h>
    25 #include <lemon/bits/alteration_notifier.h>
    26 #include <lemon/concept_check.h>
    27 #include <lemon/concepts/maps.h>
    28 
    29 /// \ingroup graphbits
    30 /// \file
    31 /// \brief Graph map based on the array storage.
    32 
    33 namespace lemon {
    34 
    35   /// \ingroup graphbits
    36   ///
    37   /// \brief Graph map based on the array storage.
    38   ///
    39   /// The ArrayMap template class is graph map structure what
    40   /// automatically updates the map when a key is added to or erased from
    41   /// the map. This map uses the allocators to implement
    42   /// the container functionality.
    43   ///
    44   /// The template parameters are the Graph the current Item type and
    45   /// the Value type of the map.
    46   template <typename _Graph, typename _Item, typename _Value>
    47   class ArrayMap
    48     : public ItemSetTraits<_Graph, _Item>::ItemNotifier::ObserverBase {
    49   public:
    50     /// The graph type of the maps.
    51     typedef _Graph Graph;
    52     /// The item type of the map.
    53     typedef _Item Item;
    54     /// The reference map tag.
    55     typedef True ReferenceMapTag;
    56 
    57     /// The key type of the maps.
    58     typedef _Item Key;
    59     /// The value type of the map.
    60     typedef _Value Value;
    61 
    62     /// The const reference type of the map.
    63     typedef const _Value& ConstReference;
    64     /// The reference type of the map.
    65     typedef _Value& Reference;
    66 
    67     /// The notifier type.
    68     typedef typename ItemSetTraits<_Graph, _Item>::ItemNotifier Notifier;
    69 
    70     /// The MapBase of the Map which imlements the core regisitry function.
    71     typedef typename Notifier::ObserverBase Parent;
    72 
    73   private:
    74     typedef std::allocator<Value> Allocator;
    75 
    76   public:
    77 
    78     /// \brief Graph initialized map constructor.
    79     ///
    80     /// Graph initialized map constructor.
    81     explicit ArrayMap(const Graph& graph) {
    82       Parent::attach(graph.notifier(Item()));
    83       allocate_memory();
    84       Notifier* nf = Parent::notifier();
    85       Item it;
    86       for (nf->first(it); it != INVALID; nf->next(it)) {
    87         int id = nf->id(it);;
    88         allocator.construct(&(values[id]), Value());
    89       }
    90     }
    91 
    92     /// \brief Constructor to use default value to initialize the map.
    93     ///
    94     /// It constructs a map and initialize all of the the map.
    95     ArrayMap(const Graph& graph, const Value& value) {
    96       Parent::attach(graph.notifier(Item()));
    97       allocate_memory();
    98       Notifier* nf = Parent::notifier();
    99       Item it;
   100       for (nf->first(it); it != INVALID; nf->next(it)) {
   101         int id = nf->id(it);;
   102         allocator.construct(&(values[id]), value);
   103       }
   104     }
   105 
   106     /// \brief Constructor to copy a map of the same map type.
   107     ///
   108     /// Constructor to copy a map of the same map type.
   109     ArrayMap(const ArrayMap& copy) : Parent() {
   110       if (copy.attached()) {
   111         attach(*copy.notifier());
   112       }
   113       capacity = copy.capacity;
   114       if (capacity == 0) return;
   115       values = allocator.allocate(capacity);
   116       Notifier* nf = Parent::notifier();
   117       Item it;
   118       for (nf->first(it); it != INVALID; nf->next(it)) {
   119         int id = nf->id(it);;
   120         allocator.construct(&(values[id]), copy.values[id]);
   121       }
   122     }
   123 
   124     /// \brief Assign operator.
   125     ///
   126     /// This operator assigns for each item in the map the
   127     /// value mapped to the same item in the copied map.
   128     /// The parameter map should be indiced with the same
   129     /// itemset because this assign operator does not change
   130     /// the container of the map.
   131     ArrayMap& operator=(const ArrayMap& cmap) {
   132       return operator=<ArrayMap>(cmap);
   133     }
   134 
   135 
   136     /// \brief Template assign operator.
   137     ///
   138     /// The given parameter should be conform to the ReadMap
   139     /// concecpt and could be indiced by the current item set of
   140     /// the NodeMap. In this case the value for each item
   141     /// is assigned by the value of the given ReadMap.
   142     template <typename CMap>
   143     ArrayMap& operator=(const CMap& cmap) {
   144       checkConcept<concepts::ReadMap<Key, _Value>, CMap>();
   145       const typename Parent::Notifier* nf = Parent::notifier();
   146       Item it;
   147       for (nf->first(it); it != INVALID; nf->next(it)) {
   148         set(it, cmap[it]);
   149       }
   150       return *this;
   151     }
   152 
   153     /// \brief The destructor of the map.
   154     ///
   155     /// The destructor of the map.
   156     virtual ~ArrayMap() {
   157       if (attached()) {
   158         clear();
   159         detach();
   160       }
   161     }
   162 
   163   protected:
   164 
   165     using Parent::attach;
   166     using Parent::detach;
   167     using Parent::attached;
   168 
   169   public:
   170 
   171     /// \brief The subscript operator.
   172     ///
   173     /// The subscript operator. The map can be subscripted by the
   174     /// actual keys of the graph.
   175     Value& operator[](const Key& key) {
   176       int id = Parent::notifier()->id(key);
   177       return values[id];
   178     }
   179 
   180     /// \brief The const subscript operator.
   181     ///
   182     /// The const subscript operator. The map can be subscripted by the
   183     /// actual keys of the graph.
   184     const Value& operator[](const Key& key) const {
   185       int id = Parent::notifier()->id(key);
   186       return values[id];
   187     }
   188 
   189     /// \brief Setter function of the map.
   190     ///
   191     /// Setter function of the map. Equivalent with map[key] = val.
   192     /// This is a compatibility feature with the not dereferable maps.
   193     void set(const Key& key, const Value& val) {
   194       (*this)[key] = val;
   195     }
   196 
   197   protected:
   198 
   199     /// \brief Adds a new key to the map.
   200     ///
   201     /// It adds a new key to the map. It called by the observer notifier
   202     /// and it overrides the add() member function of the observer base.
   203     virtual void add(const Key& key) {
   204       Notifier* nf = Parent::notifier();
   205       int id = nf->id(key);
   206       if (id >= capacity) {
   207         int new_capacity = (capacity == 0 ? 1 : capacity);
   208         while (new_capacity <= id) {
   209           new_capacity <<= 1;
   210         }
   211         Value* new_values = allocator.allocate(new_capacity);
   212         Item it;
   213         for (nf->first(it); it != INVALID; nf->next(it)) {
   214           int jd = nf->id(it);;
   215           if (id != jd) {
   216             allocator.construct(&(new_values[jd]), values[jd]);
   217             allocator.destroy(&(values[jd]));
   218           }
   219         }
   220         if (capacity != 0) allocator.deallocate(values, capacity);
   221         values = new_values;
   222         capacity = new_capacity;
   223       }
   224       allocator.construct(&(values[id]), Value());
   225     }
   226 
   227     /// \brief Adds more new keys to the map.
   228     ///
   229     /// It adds more new keys to the map. It called by the observer notifier
   230     /// and it overrides the add() member function of the observer base.
   231     virtual void add(const std::vector<Key>& keys) {
   232       Notifier* nf = Parent::notifier();
   233       int max_id = -1;
   234       for (int i = 0; i < int(keys.size()); ++i) {
   235         int id = nf->id(keys[i]);
   236         if (id > max_id) {
   237           max_id = id;
   238         }
   239       }
   240       if (max_id >= capacity) {
   241         int new_capacity = (capacity == 0 ? 1 : capacity);
   242         while (new_capacity <= max_id) {
   243           new_capacity <<= 1;
   244         }
   245         Value* new_values = allocator.allocate(new_capacity);
   246         Item it;
   247         for (nf->first(it); it != INVALID; nf->next(it)) {
   248           int id = nf->id(it);
   249           bool found = false;
   250           for (int i = 0; i < int(keys.size()); ++i) {
   251             int jd = nf->id(keys[i]);
   252             if (id == jd) {
   253               found = true;
   254               break;
   255             }
   256           }
   257           if (found) continue;
   258           allocator.construct(&(new_values[id]), values[id]);
   259           allocator.destroy(&(values[id]));
   260         }
   261         if (capacity != 0) allocator.deallocate(values, capacity);
   262         values = new_values;
   263         capacity = new_capacity;
   264       }
   265       for (int i = 0; i < int(keys.size()); ++i) {
   266         int id = nf->id(keys[i]);
   267         allocator.construct(&(values[id]), Value());
   268       }
   269     }
   270 
   271     /// \brief Erase a key from the map.
   272     ///
   273     /// Erase a key from the map. It called by the observer notifier
   274     /// and it overrides the erase() member function of the observer base.
   275     virtual void erase(const Key& key) {
   276       int id = Parent::notifier()->id(key);
   277       allocator.destroy(&(values[id]));
   278     }
   279 
   280     /// \brief Erase more keys from the map.
   281     ///
   282     /// Erase more keys from the map. It called by the observer notifier
   283     /// and it overrides the erase() member function of the observer base.
   284     virtual void erase(const std::vector<Key>& keys) {
   285       for (int i = 0; i < int(keys.size()); ++i) {
   286         int id = Parent::notifier()->id(keys[i]);
   287         allocator.destroy(&(values[id]));
   288       }
   289     }
   290 
   291     /// \brief Buildes the map.
   292     ///
   293     /// It buildes the map. It called by the observer notifier
   294     /// and it overrides the build() member function of the observer base.
   295     virtual void build() {
   296       Notifier* nf = Parent::notifier();
   297       allocate_memory();
   298       Item it;
   299       for (nf->first(it); it != INVALID; nf->next(it)) {
   300         int id = nf->id(it);;
   301         allocator.construct(&(values[id]), Value());
   302       }
   303     }
   304 
   305     /// \brief Clear the map.
   306     ///
   307     /// It erase all items from the map. It called by the observer notifier
   308     /// and it overrides the clear() member function of the observer base.
   309     virtual void clear() {
   310       Notifier* nf = Parent::notifier();
   311       if (capacity != 0) {
   312         Item it;
   313         for (nf->first(it); it != INVALID; nf->next(it)) {
   314           int id = nf->id(it);
   315           allocator.destroy(&(values[id]));
   316         }
   317         allocator.deallocate(values, capacity);
   318         capacity = 0;
   319       }
   320     }
   321 
   322   private:
   323 
   324     void allocate_memory() {
   325       int max_id = Parent::notifier()->maxId();
   326       if (max_id == -1) {
   327         capacity = 0;
   328         values = 0;
   329         return;
   330       }
   331       capacity = 1;
   332       while (capacity <= max_id) {
   333         capacity <<= 1;
   334       }
   335       values = allocator.allocate(capacity);
   336     }
   337 
   338     int capacity;
   339     Value* values;
   340     Allocator allocator;
   341 
   342   };
   343 
   344 }
   345 
   346 #endif