Use the degeneralization unicity_table in more places.

* src/tgbaalgos/degen.cc (unicity_table): Move and rename as...
* src/tgba/state.hh (state_unicity_table): ... this.
* src/tgbaalgos/cutscc.cc, src/tgbaalgos/cycles.cc,
src/tgbaalgos/cycles.hh, src/tgbaalgos/minimize.cc,
src/tgbaalgos/powerset.cc, src/tgbaalgos/powerset.hh,
src/tgbaalgos/safety.cc: Use it to simplify existing code.

src/tgba/state.hh

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2009, 2011, 2013 Laboratoire de Recherche et
+// Copyright (C) 2009, 2011, 2013, 2014 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE).
 // Copyright (C) 2003, 2004 Laboratoire d'Informatique de Paris 6
 // (LIP6), département Systèmes Répartis Coopératifs (SRC), Université
@@ -176,6 +176,64 @@ namespace spot
 			     state_ptr_hash, state_ptr_equal> state_set;
 
 
+  /// \ingroup tgba_essentials
+  /// \brief Render state pointers unique via a hash table.
+  class SPOT_API state_unicity_table
+  {
+    state_set m;
+  public:
+
+    /// \brief Canonicalize state pointer.
+    ///
+    /// If this is the first time a state is seen, this return the
+    /// state pointer as-is, otherwise it frees the state and returns
+    /// a point to the previously seen copy.
+    ///
+    /// States are owned by the table and will be freed on
+    /// destruction.
+    const state* operator()(const state* s)
+    {
+      auto p = m.insert(s);
+      if (!p.second)
+	s->destroy();
+      return *p.first;
+    }
+
+    /// \brief Canonicalize state pointer.
+    ///
+    /// Same as operator(), except that a nullptr
+    /// is returned if the state is not new.
+    const state* is_new(const state* s)
+    {
+      auto p = m.insert(s);
+      if (!p.second)
+	{
+	  s->destroy();
+	  return nullptr;
+	}
+      return *p.first;
+    }
+
+    ~state_unicity_table()
+    {
+      for (state_set::iterator i = m.begin(); i != m.end();)
+	{
+	  // Advance the iterator before destroying its key.  This
+	  // avoid issues with old g++ implementations.
+	  state_set::iterator old = i++;
+	  (*old)->destroy();
+	}
+    }
+
+    size_t
+    size()
+    {
+      return m.size();
+    }
+  };
+
+
+
   // Functions related to shared_ptr.
   //////////////////////////////////////////////////
 

src/tgbaalgos/cutscc.cc

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2009, 2011, 2012, 2013 Laboratoire de Recherche et
+// Copyright (C) 2009, 2011, 2012, 2013, 2014 Laboratoire de Recherche
-// Developpement de l'Epita (LRDE).
+// et Developpement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -33,12 +33,10 @@ namespace spot
 	    const std::set<unsigned>& s)
     {
       tgba_explicit_string* sub_a = new tgba_explicit_string(a->get_dict());
-      state* cur = a->get_init_state();
+      const state* cur = a->get_init_state();
-      std::queue<state*> tovisit;
+      std::queue<const state*> tovisit;
-      typedef std::unordered_set<const state*,
-				 state_ptr_hash, state_ptr_equal> hash_type;
       // Setup
-      hash_type seen;
+      state_unicity_table seen;
       unsigned scc_number;
       std::string cur_format = a->format_state(cur);
       std::set<unsigned>::iterator it;
@@ -46,8 +44,7 @@ namespace spot
       for (it = s.begin(); it != s.end() && !m.accepting(*it); ++it)
 	continue;
       assert(it != s.end());
-      tovisit.push(cur);
+      tovisit.push(seen(cur));
-      seen.insert(cur);
       sub_a->add_state(cur_format);
       sub_a->copy_acceptance_conditions_of(a);
       // If the initial is not part of one of the desired SCC, exit
@@ -68,15 +65,8 @@ namespace spot
 	      // Is the successor included in one of the desired SCC ?
 	      if (s.find(scc_number) != s.end())
 		{
-		  if (seen.find(dst) == seen.end())
+		  if (seen.is_new(dst))
-		    {
+		    tovisit.push(dst);
-		      tovisit.push(dst);
-		      seen.insert(dst); // has_state?
-		    }
-		  else
-		    {
-		      dst->destroy();
-		    }
 		  state_explicit_string::transition* t =
 		    sub_a->create_transition(cur_format, dst_format);
 		  sub_a->add_conditions(t, sit->current_condition());
@@ -90,11 +80,6 @@ namespace spot
 	    }
 	  delete sit;
 	}
-
-      hash_type::iterator it2;
-      // Free visited states.
-      for (it2 = seen.begin(); it2 != seen.end(); ++it2)
-	(*it2)->destroy();
       return sub_a;
     }
 

src/tgbaalgos/cycles.cc

@@ -1,4 +1,5 @@
-// Copyright (C) 2012 Laboratoire de Recherche et Developpement de
+// -*- coding: utf-8 -*-
+// Copyright (C) 2012, 2014 Laboratoire de Recherche et Developpement de
 // l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
@@ -47,14 +48,12 @@ namespace spot
 	q.pop_back();
 
 	y->second.mark = false;
-	for (set_type::iterator i = y->second.b.begin();
+	for (auto s: y->second.b)
-	     i != y->second.b.end(); ++i)
 	  {
-	    tagged_state x = tags_.find(*i);
+	    tagged_state x = tags_.find(s);
 	    assert(x != tags_.end());
 	    // insert y in A(x)
 	    x->second.del.erase(y->first);
-
 	    // unmark x recursively if marked
 	    if (x->second.mark)
 	      q.push_back(x);

src/tgbaalgos/cycles.hh

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2012, 2013 Laboratoire de Recherche et Développement
+// Copyright (C) 2012, 2013, 2014 Laboratoire de Recherche et
-// de l'Epita (LRDE).
+// Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -79,9 +79,6 @@ namespace spot
   class SPOT_API enumerate_cycles
   {
   protected:
-    typedef std::unordered_set<const state*,
-			       state_ptr_hash, state_ptr_equal> set_type;
-
     // Extra information required for the algorithm for each state.
     struct state_info
     {
@@ -98,10 +95,10 @@ namespace spot
       // that a contributed to a contributed to a cycle.
       bool mark;
       // Deleted successors (in the paper, states deleted from A(x))
-      set_type del;
+      state_set del;
       // Predecessors of the current states, that could not yet
       // contribute to a cycle.
-      set_type b;
+      state_set b;
     };
 
     // Store the state_info for all visited states.

src/tgbaalgos/degen.cc

@@ -67,37 +67,6 @@ namespace spot
     // Queue of state to be processed.
     typedef std::deque<degen_state> queue_t;
 
-    // Memory management for the input states.
-    class unicity_table
-    {
-      state_set m;
-    public:
-      const state* operator()(const state* s)
-      {
-	auto p = m.insert(s);
-	if (!p.second)
-	  s->destroy();
-	return *p.first;
-      }
-
-      ~unicity_table()
-      {
-	for (state_set::iterator i = m.begin(); i != m.end();)
-	  {
-	    // Advance the iterator before destroying its key.  This
-	    // avoid issues with old g++ implementations.
-	    state_set::iterator old = i++;
-	    (*old)->destroy();
-	  }
-      }
-
-      size_t
-      size()
-      {
-        return m.size();
-      }
-    };
-
     // Acceptance set common to all outgoing transitions (of the same
     // SCC -- we do not care about the other) of some state.
     class outgoing_acc
@@ -165,10 +134,10 @@ namespace spot
       typedef std::unordered_map<const state*, bool,
 				 state_ptr_hash, state_ptr_equal> cache_t;
       cache_t cache_;
-      unicity_table& uniq_;
+      state_unicity_table& uniq_;
 
     public:
-      has_acc_loop(const tgba* a, unicity_table& uniq):
+      has_acc_loop(const tgba* a, state_unicity_table& uniq):
 	a_(a),
 	uniq_(uniq)
       {
@@ -329,7 +298,7 @@ namespace spot
 
     // Make sure we always use the same pointer for identical states
     // from the input automaton.
-    unicity_table uniq;
+    state_unicity_table uniq;
 
     // Accepting loop checker, for some heuristics.
     has_acc_loop acc_loop(a, uniq);

src/tgbaalgos/minimize.cc

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2010, 2011, 2012, 2013 Laboratoire de Recherche et
+// Copyright (C) 2010, 2011, 2012, 2013, 2014 Laboratoire de Recherche
-// Développement de l'Epita (LRDE).
+// et Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -52,6 +52,8 @@
 
 namespace spot
 {
+  // FIXME: do we really want to use unordered_set instead of set here?
+  // This calls for benchmarking.
   typedef std::unordered_set<const state*,
 			     state_ptr_hash, state_ptr_equal> hash_set;
   typedef std::unordered_map<const state*, unsigned,
@@ -184,36 +186,13 @@ namespace spot
 			   power_map& pm, const state* dest)
 	: bfs_steps(det_a), scc_n(scc_n), sm(sm), pm(pm), dest(dest)
       {
-	seen.insert(dest);
+	seen(dest);
-      }
-
-      virtual
-      ~wdba_search_acc_loop()
-      {
-	hash_set::const_iterator i = seen.begin();
-	while (i != seen.end())
-	  {
-	    hash_set::const_iterator old = i;
-	    ++i;
-	    (*old)->destroy();
-	  }
       }
 
       virtual const state*
       filter(const state* s)
       {
-	// Use the state from seen.
+	s = seen(s);
-	hash_set::const_iterator i = seen.find(s);
-	if (i == seen.end())
-	  {
-	    seen.insert(s);
-	  }
-	else
-	  {
-	    s->destroy();
-	    s = *i;
-	  }
-	// Ignore states outside SCC #n.
 	if (sm.scc_of_state(s) != scc_n)
 	  return 0;
 	return s;
@@ -229,7 +208,7 @@ namespace spot
       scc_map& sm;
       power_map& pm;
       const state* dest;
-      hash_set seen;
+      state_unicity_table seen;
     };
 
 

src/tgbaalgos/powerset.cc

@@ -1,7 +1,8 @@
-// Copyright (C) 2009, 2010, 2011, 2013 Laboratoire de Recherche et
+// -*- coding: utf-8 -*-
-// Développement de l'Epita (LRDE).
+// Copyright (C) 2009, 2010, 2011, 2013, 2014 Laboratoire de Recherche
+// et Développement de l'Epita (LRDE).
 // Copyright (C) 2004 Laboratoire d'Informatique de Paris 6 (LIP6),
-// département Systèmes Répartis Coopératifs (SRC), Université Pierre
+// département Systèmes Répartis Coopératifs (SRC), Université Pierre
 // et Marie Curie.
 //
 // This file is part of Spot, a model checking library.
@@ -54,8 +55,7 @@ namespace spot
 
     {
       power_state ps;
-      state* s = aut->get_init_state();
+      const state* s = pm.canonicalize(aut->get_init_state());
-      pm.states.insert(s);
       ps.insert(s);
       todo.push_back(ps);
       seen[ps] = 1;
@@ -325,7 +325,7 @@ namespace spot
     tgba_explicit_number* det = tgba_powerset(aut, pm, false);
 
     if ((threshold_states > 0)
-	&& (pm.map_.size() > pm.states.size() * threshold_states))
+	&& (pm.map_.size() > pm.states_.size() * threshold_states))
       {
 	delete det;
 	return 0;

src/tgbaalgos/powerset.hh

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2011, 2013 Laboratoire de Recherche et Développement
+// Copyright (C) 2011, 2013, 2014 Laboratoire de Recherche et
-// de l'Epita.
+// Développement de l'Epita.
 // Copyright (C) 2004 Laboratoire d'Informatique de Paris 6 (LIP6),
 // département Systèmes Répartis Coopératifs (SRC), Université Pierre
 // et Marie Curie.
@@ -34,21 +34,6 @@ namespace spot
   {
     typedef std::set<const state*, state_ptr_less_than> power_state;
     typedef std::map<int, power_state> power_map_data;
-    typedef std::unordered_set<const state*, state_ptr_hash,
-			       state_ptr_equal> state_set;
-
-    ~power_map()
-    {
-      // Release all states.
-      state_set::const_iterator i = states.begin();
-      while (i != states.end())
-	{
-	  // Advance the iterator before deleting the key.
-	  const state* s = *i;
-	  ++i;
-	  s->destroy();
-	}
-    }
 
     const power_state&
     states_of(int s) const
@@ -59,21 +44,11 @@ namespace spot
     const state*
     canonicalize(const state* s)
     {
-      state_set::const_iterator i = states.find(s);
+      return states_(s);
-      if (i != states.end())
-	{
-	  s->destroy();
-	  s = *i;
-	}
-      else
-	{
-	  states.insert(s);
-	}
-      return s;
     }
 
     power_map_data map_;
-    state_set states;
+    state_unicity_table states_;
   };
 
 

src/tgbaalgos/safety.cc

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2010, 2011, 2013 Laboratoire de Recherche et
+// Copyright (C) 2010, 2011, 2013, 2014 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE)
 //
 // This file is part of Spot, a model checking library.
@@ -72,16 +72,10 @@ namespace spot
 
   bool is_safety_mwdba(const tgba* aut)
   {
-    typedef std::unordered_set<const state*,
+    state_unicity_table seen;	   // States already seen.
-			       state_ptr_hash, state_ptr_equal> seen_map;
-    seen_map seen;		   // States already seen.
     std::deque<const state*> todo; // A queue of states yet to explore.
 
-    {
+    todo.push_back(seen(aut->get_init_state()));
-      state* s = aut->get_init_state();
-      todo.push_back(s);
-      seen.insert(s);
-    }
 
     bdd all_acc = aut->all_acceptance_conditions();
 
@@ -100,28 +94,11 @@ namespace spot
 		all_accepting = false;
 		break;
 	      }
-	    state* d = it->current_state();
+	    if (const state* d = seen.is_new(it->current_state()))
-	    if (seen.find(d) != seen.end())
+	      todo.push_back(d);
-	      {
-		d->destroy();
-	      }
-	    else
-	      {
-		seen.insert(d);
-		todo.push_back(d);
-	      }
 	  }
 	delete it;
       }
-
-    seen_map::const_iterator it = seen.begin();
-    while (it != seen.end())
-      {
-	seen_map::const_iterator old = it;
-	++it;
-	(*old)->destroy();
-      }
-
     return all_accepting;
   }