lemon/bits/alteration_notifier.h
changeset 212 1ae84dea7d09
parent 157 2ccc1afc2c52
child 220 a5d8c039f218
equal deleted inserted replaced
2:75bbb975ba75 3:a337fcd686af
     1 /* -*- C++ -*-
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     4  *
     5  * Copyright (C) 2003-2008
     5  * Copyright (C) 2003-2008
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     8  *
    30 
    30 
    31 namespace lemon {
    31 namespace lemon {
    32 
    32 
    33   /// \ingroup graphbits
    33   /// \ingroup graphbits
    34   ///
    34   ///
    35   /// \brief Notifier class to notify observes about alterations in 
    35   /// \brief Notifier class to notify observes about alterations in
    36   /// a container.
    36   /// a container.
    37   ///
    37   ///
    38   /// The simple graph's can be refered as two containers, one node container
    38   /// The simple graph's can be refered as two containers, one node container
    39   /// and one edge container. But they are not standard containers they
    39   /// and one edge container. But they are not standard containers they
    40   /// does not store values directly they are just key continars for more
    40   /// does not store values directly they are just key continars for more
    47   /// the current indicing key that cause a drawback in the performance
    47   /// the current indicing key that cause a drawback in the performance
    48   /// in the library. We use another solution we notify all maps about
    48   /// in the library. We use another solution we notify all maps about
    49   /// an alteration in the graph, which cause only drawback on the
    49   /// an alteration in the graph, which cause only drawback on the
    50   /// alteration of the graph.
    50   /// alteration of the graph.
    51   ///
    51   ///
    52   /// This class provides an interface to the container. The \e first() and \e 
    52   /// This class provides an interface to the container. The \e first() and \e
    53   /// next() member functions make possible to iterate on the keys of the
    53   /// next() member functions make possible to iterate on the keys of the
    54   /// container. The \e id() function returns an integer id for each key.
    54   /// container. The \e id() function returns an integer id for each key.
    55   /// The \e maxId() function gives back an upper bound of the ids.
    55   /// The \e maxId() function gives back an upper bound of the ids.
    56   ///
    56   ///
    57   /// For the proper functonality of this class, we should notify it
    57   /// For the proper functonality of this class, we should notify it
    58   /// about each alteration in the container. The alterations have four type
    58   /// about each alteration in the container. The alterations have four type
    59   /// as \e add(), \e erase(), \e build() and \e clear(). The \e add() and
    59   /// as \e add(), \e erase(), \e build() and \e clear(). The \e add() and
    60   /// \e erase() signals that only one or few items added or erased to or
    60   /// \e erase() signals that only one or few items added or erased to or
    61   /// from the graph. If all items are erased from the graph or from an empty
    61   /// from the graph. If all items are erased from the graph or from an empty
    62   /// graph a new graph is builded then it can be signaled with the
    62   /// graph a new graph is builded then it can be signaled with the
    63   /// clear() and build() members. Important rule that if we erase items 
    63   /// clear() and build() members. Important rule that if we erase items
    64   /// from graph we should first signal the alteration and after that erase
    64   /// from graph we should first signal the alteration and after that erase
    65   /// them from the container, on the other way on item addition we should
    65   /// them from the container, on the other way on item addition we should
    66   /// first extend the container and just after that signal the alteration.
    66   /// first extend the container and just after that signal the alteration.
    67   ///
    67   ///
    68   /// The alteration can be observed with a class inherited from the
    68   /// The alteration can be observed with a class inherited from the
    69   /// \e ObserverBase nested class. The signals can be handled with
    69   /// \e ObserverBase nested class. The signals can be handled with
    70   /// overriding the virtual functions defined in the base class.  The
    70   /// overriding the virtual functions defined in the base class.  The
    71   /// observer base can be attached to the notifier with the 
    71   /// observer base can be attached to the notifier with the
    72   /// \e attach() member and can be detached with detach() function. The
    72   /// \e attach() member and can be detached with detach() function. The
    73   /// alteration handlers should not call any function which signals
    73   /// alteration handlers should not call any function which signals
    74   /// an other alteration in the same notifier and should not
    74   /// an other alteration in the same notifier and should not
    75   /// detach any observer from the notifier.
    75   /// detach any observer from the notifier.
    76   ///
    76   ///
    77   /// Alteration observers try to be exception safe. If an \e add() or
    77   /// Alteration observers try to be exception safe. If an \e add() or
    78   /// a \e clear() function throws an exception then the remaining
    78   /// a \e clear() function throws an exception then the remaining
    79   /// observeres will not be notified and the fulfilled additions will
    79   /// observeres will not be notified and the fulfilled additions will
    80   /// be rolled back by calling the \e erase() or \e clear()
    80   /// be rolled back by calling the \e erase() or \e clear()
    81   /// functions. Thence the \e erase() and \e clear() should not throw
    81   /// functions. Thence the \e erase() and \e clear() should not throw
    82   /// exception. Actullay, it can be throw only 
    82   /// exception. Actullay, it can be throw only
    83   /// \ref AlterationObserver::ImmediateDetach ImmediateDetach
    83   /// \ref AlterationObserver::ImmediateDetach ImmediateDetach
    84   /// exception which detach the observer from the notifier.
    84   /// exception which detach the observer from the notifier.
    85   ///
    85   ///
    86   /// There are some place when the alteration observing is not completly
    86   /// There are some place when the alteration observing is not completly
    87   /// reliable. If we want to carry out the node degree in the graph
    87   /// reliable. If we want to carry out the node degree in the graph
    88   /// as in the \ref InDegMap and we use the reverseEdge that cause 
    88   /// as in the \ref InDegMap and we use the reverseEdge that cause
    89   /// unreliable functionality. Because the alteration observing signals
    89   /// unreliable functionality. Because the alteration observing signals
    90   /// only erasing and adding but not the reversing it will stores bad
    90   /// only erasing and adding but not the reversing it will stores bad
    91   /// degrees. The sub graph adaptors cannot signal the alterations because
    91   /// degrees. The sub graph adaptors cannot signal the alterations because
    92   /// just a setting in the filter map can modify the graph and this cannot
    92   /// just a setting in the filter map can modify the graph and this cannot
    93   /// be watched in any way.
    93   /// be watched in any way.
   102     typedef True Notifier;
   102     typedef True Notifier;
   103 
   103 
   104     typedef _Container Container;
   104     typedef _Container Container;
   105     typedef _Item Item;
   105     typedef _Item Item;
   106 
   106 
   107     /// \brief Exception which can be called from \e clear() and 
   107     /// \brief Exception which can be called from \e clear() and
   108     /// \e erase().
   108     /// \e erase().
   109     ///
   109     ///
   110     /// From the \e clear() and \e erase() function only this
   110     /// From the \e clear() and \e erase() function only this
   111     /// exception is allowed to throw. The exception immediatly
   111     /// exception is allowed to throw. The exception immediatly
   112     /// detaches the current observer from the notifier. Because the
   112     /// detaches the current observer from the notifier. Because the
   125     /// to notify the oberver when one item is added or
   125     /// to notify the oberver when one item is added or
   126     /// erased.
   126     /// erased.
   127     ///
   127     ///
   128     /// The build() and clear() members are to notify the observer
   128     /// The build() and clear() members are to notify the observer
   129     /// about the container is built from an empty container or
   129     /// about the container is built from an empty container or
   130     /// is cleared to an empty container. 
   130     /// is cleared to an empty container.
   131 
   131 
   132     class ObserverBase {
   132     class ObserverBase {
   133     protected:
   133     protected:
   134       typedef AlterationNotifier Notifier;
   134       typedef AlterationNotifier Notifier;
   135 
   135 
   136       friend class AlterationNotifier;
   136       friend class AlterationNotifier;
   137 
   137 
   138       /// \brief Default constructor.
   138       /// \brief Default constructor.
   139       ///
   139       ///
   140       /// Default constructor for ObserverBase.
   140       /// Default constructor for ObserverBase.
   141       /// 
   141       ///
   142       ObserverBase() : _notifier(0) {}
   142       ObserverBase() : _notifier(0) {}
   143 
   143 
   144       /// \brief Constructor which attach the observer into notifier.
   144       /// \brief Constructor which attach the observer into notifier.
   145       ///
   145       ///
   146       /// Constructor which attach the observer into notifier.
   146       /// Constructor which attach the observer into notifier.
   149       }
   149       }
   150 
   150 
   151       /// \brief Constructor which attach the obserever to the same notifier.
   151       /// \brief Constructor which attach the obserever to the same notifier.
   152       ///
   152       ///
   153       /// Constructor which attach the obserever to the same notifier as
   153       /// Constructor which attach the obserever to the same notifier as
   154       /// the other observer is attached to. 
   154       /// the other observer is attached to.
   155       ObserverBase(const ObserverBase& copy) {
   155       ObserverBase(const ObserverBase& copy) {
   156 	if (copy.attached()) {
   156         if (copy.attached()) {
   157           attach(*copy.notifier());
   157           attach(*copy.notifier());
   158 	}
   158         }
   159       }
   159       }
   160 	
   160 
   161       /// \brief Destructor
   161       /// \brief Destructor
   162       virtual ~ObserverBase() {
   162       virtual ~ObserverBase() {
   163         if (attached()) {
   163         if (attached()) {
   164           detach();
   164           detach();
   165         }
   165         }
   168       /// \brief Attaches the observer into an AlterationNotifier.
   168       /// \brief Attaches the observer into an AlterationNotifier.
   169       ///
   169       ///
   170       /// This member attaches the observer into an AlterationNotifier.
   170       /// This member attaches the observer into an AlterationNotifier.
   171       ///
   171       ///
   172       void attach(AlterationNotifier& nf) {
   172       void attach(AlterationNotifier& nf) {
   173 	nf.attach(*this);
   173         nf.attach(*this);
   174       }
   174       }
   175       
   175 
   176       /// \brief Detaches the observer into an AlterationNotifier.
   176       /// \brief Detaches the observer into an AlterationNotifier.
   177       ///
   177       ///
   178       /// This member detaches the observer from an AlterationNotifier.
   178       /// This member detaches the observer from an AlterationNotifier.
   179       ///
   179       ///
   180       void detach() {
   180       void detach() {
   181         _notifier->detach(*this);
   181         _notifier->detach(*this);
   182       }
   182       }
   183       
   183 
   184       /// \brief Gives back a pointer to the notifier which the map 
   184       /// \brief Gives back a pointer to the notifier which the map
   185       /// attached into.
   185       /// attached into.
   186       ///
   186       ///
   187       /// This function gives back a pointer to the notifier which the map
   187       /// This function gives back a pointer to the notifier which the map
   188       /// attached into.
   188       /// attached into.
   189       ///
   189       ///
   190       Notifier* notifier() const { return const_cast<Notifier*>(_notifier); }
   190       Notifier* notifier() const { return const_cast<Notifier*>(_notifier); }
   191       
   191 
   192       /// Gives back true when the observer is attached into a notifier.
   192       /// Gives back true when the observer is attached into a notifier.
   193       bool attached() const { return _notifier != 0; }
   193       bool attached() const { return _notifier != 0; }
   194 
   194 
   195     private:
   195     private:
   196 
   196 
   197       ObserverBase& operator=(const ObserverBase& copy);
   197       ObserverBase& operator=(const ObserverBase& copy);
   198 
   198 
   199     protected:
   199     protected:
   200       
   200 
   201       Notifier* _notifier;
   201       Notifier* _notifier;
   202       typename std::list<ObserverBase*>::iterator _index;
   202       typename std::list<ObserverBase*>::iterator _index;
   203 
   203 
   204       /// \brief The member function to notificate the observer about an
   204       /// \brief The member function to notificate the observer about an
   205       /// item is added to the container.
   205       /// item is added to the container.
   207       /// The add() member function notificates the observer about an item
   207       /// The add() member function notificates the observer about an item
   208       /// is added to the container. It have to be overrided in the
   208       /// is added to the container. It have to be overrided in the
   209       /// subclasses.
   209       /// subclasses.
   210       virtual void add(const Item&) = 0;
   210       virtual void add(const Item&) = 0;
   211 
   211 
   212       /// \brief The member function to notificate the observer about 
   212       /// \brief The member function to notificate the observer about
   213       /// more item is added to the container.
   213       /// more item is added to the container.
   214       ///
   214       ///
   215       /// The add() member function notificates the observer about more item
   215       /// The add() member function notificates the observer about more item
   216       /// is added to the container. It have to be overrided in the
   216       /// is added to the container. It have to be overrided in the
   217       /// subclasses.
   217       /// subclasses.
   220       /// \brief The member function to notificate the observer about an
   220       /// \brief The member function to notificate the observer about an
   221       /// item is erased from the container.
   221       /// item is erased from the container.
   222       ///
   222       ///
   223       /// The erase() member function notificates the observer about an
   223       /// The erase() member function notificates the observer about an
   224       /// item is erased from the container. It have to be overrided in
   224       /// item is erased from the container. It have to be overrided in
   225       /// the subclasses.	
   225       /// the subclasses.
   226       virtual void erase(const Item&) = 0;
   226       virtual void erase(const Item&) = 0;
   227 
   227 
   228       /// \brief The member function to notificate the observer about 
   228       /// \brief The member function to notificate the observer about
   229       /// more item is erased from the container.
   229       /// more item is erased from the container.
   230       ///
   230       ///
   231       /// The erase() member function notificates the observer about more item
   231       /// The erase() member function notificates the observer about more item
   232       /// is erased from the container. It have to be overrided in the
   232       /// is erased from the container. It have to be overrided in the
   233       /// subclasses.
   233       /// subclasses.
   245       /// \brief The member function to notificate the observer about all
   245       /// \brief The member function to notificate the observer about all
   246       /// items are erased from the container.
   246       /// items are erased from the container.
   247       ///
   247       ///
   248       /// The clear() member function notificates the observer about all
   248       /// The clear() member function notificates the observer about all
   249       /// items are erased from the container. It have to be overrided in
   249       /// items are erased from the container. It have to be overrided in
   250       /// the subclasses.      
   250       /// the subclasses.
   251       virtual void clear() = 0;
   251       virtual void clear() = 0;
   252 
   252 
   253     };
   253     };
   254 	
   254 
   255   protected:
   255   protected:
   256 
   256 
   257     const Container* container;
   257     const Container* container;
   258 
   258 
   259     typedef std::list<ObserverBase*> Observers; 
   259     typedef std::list<ObserverBase*> Observers;
   260     Observers _observers;
   260     Observers _observers;
   261 
   261 
   262 		
   262 
   263   public:
   263   public:
   264 
   264 
   265     /// \brief Default constructor.
   265     /// \brief Default constructor.
   266     ///
   266     ///
   267     /// The default constructor of the AlterationNotifier. 
   267     /// The default constructor of the AlterationNotifier.
   268     /// It creates an empty notifier.
   268     /// It creates an empty notifier.
   269     AlterationNotifier() 
   269     AlterationNotifier()
   270       : container(0) {}
   270       : container(0) {}
   271 
   271 
   272     /// \brief Constructor.
   272     /// \brief Constructor.
   273     ///
   273     ///
   274     /// Constructor with the observed container parameter.
   274     /// Constructor with the observed container parameter.
   275     AlterationNotifier(const Container& _container) 
   275     AlterationNotifier(const Container& _container)
   276       : container(&_container) {}
   276       : container(&_container) {}
   277 
   277 
   278     /// \brief Copy Constructor of the AlterationNotifier. 
   278     /// \brief Copy Constructor of the AlterationNotifier.
   279     ///
   279     ///
   280     /// Copy constructor of the AlterationNotifier. 
   280     /// Copy constructor of the AlterationNotifier.
   281     /// It creates only an empty notifier because the copiable
   281     /// It creates only an empty notifier because the copiable
   282     /// notifier's observers have to be registered still into that notifier.
   282     /// notifier's observers have to be registered still into that notifier.
   283     AlterationNotifier(const AlterationNotifier& _notifier) 
   283     AlterationNotifier(const AlterationNotifier& _notifier)
   284       : container(_notifier.container) {}
   284       : container(_notifier.container) {}
   285 
   285 
   286     /// \brief Destructor.
   286     /// \brief Destructor.
   287     ///		
   287     ///
   288     /// Destructor of the AlterationNotifier.
   288     /// Destructor of the AlterationNotifier.
   289     ///
   289     ///
   290     ~AlterationNotifier() {
   290     ~AlterationNotifier() {
   291       typename Observers::iterator it;
   291       typename Observers::iterator it;
   292       for (it = _observers.begin(); it != _observers.end(); ++it) {
   292       for (it = _observers.begin(); it != _observers.end(); ++it) {
   293 	(*it)->_notifier = 0;
   293         (*it)->_notifier = 0;
   294       }
   294       }
   295     }
   295     }
   296 
   296 
   297     /// \brief Sets the container.
   297     /// \brief Sets the container.
   298     ///
   298     ///
   336     ///
   336     ///
   337     /// Returns the maximum id of the container.
   337     /// Returns the maximum id of the container.
   338     int maxId() const {
   338     int maxId() const {
   339       return container->maxId(Item());
   339       return container->maxId(Item());
   340     }
   340     }
   341 		
   341 
   342   protected:
   342   protected:
   343 
   343 
   344     void attach(ObserverBase& observer) {
   344     void attach(ObserverBase& observer) {
   345       observer._index = _observers.insert(_observers.begin(), &observer);
   345       observer._index = _observers.insert(_observers.begin(), &observer);
   346       observer._notifier = this;
   346       observer._notifier = this;
   347     } 
   347     }
   348 
   348 
   349     void detach(ObserverBase& observer) {
   349     void detach(ObserverBase& observer) {
   350       _observers.erase(observer._index);
   350       _observers.erase(observer._index);
   351       observer._index = _observers.end();
   351       observer._index = _observers.end();
   352       observer._notifier = 0;
   352       observer._notifier = 0;
   353     }
   353     }
   354 
   354 
   355   public:
   355   public:
   356 	
   356 
   357     /// \brief Notifies all the registed observers about an item added to 
   357     /// \brief Notifies all the registed observers about an item added to
   358     /// the container.
   358     /// the container.
   359     ///
   359     ///
   360     /// It notifies all the registed observers about an item added to 
   360     /// It notifies all the registed observers about an item added to
   361     /// the container.
   361     /// the container.
   362     /// 
   362     ///
   363     void add(const Item& item) {
   363     void add(const Item& item) {
   364       typename Observers::reverse_iterator it;
   364       typename Observers::reverse_iterator it;
   365       try {
   365       try {
   366         for (it = _observers.rbegin(); it != _observers.rend(); ++it) {
   366         for (it = _observers.rbegin(); it != _observers.rend(); ++it) {
   367           (*it)->add(item);
   367           (*it)->add(item);
   371         for (jt = it.base(); jt != _observers.end(); ++jt) {
   371         for (jt = it.base(); jt != _observers.end(); ++jt) {
   372           (*jt)->erase(item);
   372           (*jt)->erase(item);
   373         }
   373         }
   374         throw;
   374         throw;
   375       }
   375       }
   376     }	
   376     }
   377 
   377 
   378     /// \brief Notifies all the registed observers about more item added to 
   378     /// \brief Notifies all the registed observers about more item added to
   379     /// the container.
   379     /// the container.
   380     ///
   380     ///
   381     /// It notifies all the registed observers about more item added to 
   381     /// It notifies all the registed observers about more item added to
   382     /// the container.
   382     /// the container.
   383     /// 
   383     ///
   384     void add(const std::vector<Item>& items) {
   384     void add(const std::vector<Item>& items) {
   385       typename Observers::reverse_iterator it;
   385       typename Observers::reverse_iterator it;
   386       try {
   386       try {
   387         for (it = _observers.rbegin(); it != _observers.rend(); ++it) {
   387         for (it = _observers.rbegin(); it != _observers.rend(); ++it) {
   388           (*it)->add(items);
   388           (*it)->add(items);
   392         for (jt = it.base(); jt != _observers.end(); ++jt) {
   392         for (jt = it.base(); jt != _observers.end(); ++jt) {
   393           (*jt)->erase(items);
   393           (*jt)->erase(items);
   394         }
   394         }
   395         throw;
   395         throw;
   396       }
   396       }
   397     }	
   397     }
   398 
   398 
   399     /// \brief Notifies all the registed observers about an item erased from 
   399     /// \brief Notifies all the registed observers about an item erased from
   400     /// the container.
   400     /// the container.
   401     ///	
   401     ///
   402     /// It notifies all the registed observers about an item erased from 
   402     /// It notifies all the registed observers about an item erased from
   403     /// the container.
   403     /// the container.
   404     /// 
   404     ///
   405     void erase(const Item& item) throw() {
   405     void erase(const Item& item) throw() {
   406       typename Observers::iterator it = _observers.begin();
   406       typename Observers::iterator it = _observers.begin();
   407       while (it != _observers.end()) {
   407       while (it != _observers.end()) {
   408         try {
   408         try {
   409           (*it)->erase(item);
   409           (*it)->erase(item);
   414           (*it)->_notifier = 0;
   414           (*it)->_notifier = 0;
   415         }
   415         }
   416       }
   416       }
   417     }
   417     }
   418 
   418 
   419     /// \brief Notifies all the registed observers about more item erased  
   419     /// \brief Notifies all the registed observers about more item erased
   420     /// from the container.
   420     /// from the container.
   421     ///	
   421     ///
   422     /// It notifies all the registed observers about more item erased from 
   422     /// It notifies all the registed observers about more item erased from
   423     /// the container.
   423     /// the container.
   424     /// 
   424     ///
   425     void erase(const std::vector<Item>& items) {
   425     void erase(const std::vector<Item>& items) {
   426       typename Observers::iterator it = _observers.begin();
   426       typename Observers::iterator it = _observers.begin();
   427       while (it != _observers.end()) {
   427       while (it != _observers.end()) {
   428         try {
   428         try {
   429           (*it)->erase(items);
   429           (*it)->erase(items);
   434           (*it)->_notifier = 0;
   434           (*it)->_notifier = 0;
   435         }
   435         }
   436       }
   436       }
   437     }
   437     }
   438 
   438 
   439     /// \brief Notifies all the registed observers about the container is 
   439     /// \brief Notifies all the registed observers about the container is
   440     /// built.
   440     /// built.
   441     ///		
   441     ///
   442     /// Notifies all the registed observers about the container is built
   442     /// Notifies all the registed observers about the container is built
   443     /// from an empty container.
   443     /// from an empty container.
   444     void build() {
   444     void build() {
   445       typename Observers::reverse_iterator it;
   445       typename Observers::reverse_iterator it;
   446       try {
   446       try {
   454         }
   454         }
   455         throw;
   455         throw;
   456       }
   456       }
   457     }
   457     }
   458 
   458 
   459     /// \brief Notifies all the registed observers about all items are 
   459     /// \brief Notifies all the registed observers about all items are
   460     /// erased.
   460     /// erased.
   461     ///
   461     ///
   462     /// Notifies all the registed observers about all items are erased
   462     /// Notifies all the registed observers about all items are erased
   463     /// from the container.
   463     /// from the container.
   464     void clear() {
   464     void clear() {