trivalize data structure

BGL/include/CGAL/boost/graph/Euler_operations.h

@@ -783,7 +783,7 @@ void add_faces(const RangeofVertexRange& faces_to_add, PolygonMesh& pm)
   typedef boost::container::small_vector<halfedge_descriptor,8> Halfedges;
 #else
   //typedef boost::unordered_map<vertex_descriptor, halfedge_descriptor, boost::hash<vertex_descriptor> > Halfedges;
-  typedef Small_unordered_mapV2<vertex_descriptor, halfedge_descriptor, boost::hash<vertex_descriptor>,8,1> Halfedges;
+  typedef Small_unordered_mapV2<vertex_descriptor, halfedge_descriptor, 8> Halfedges;
 #endif  
 
   typedef typename CGAL::GetInitializedVertexIndexMap<PolygonMesh>::type Vid_map;

STL_Extension/include/CGAL/Small_unordered_mapV2.h

@@ -21,95 +21,46 @@
 namespace CGAL {
 
 
-template <typename K, typename T, typename H, unsigned int M, unsigned int Factor>
+template <typename K, typename T, int M>
 class Small_unordered_mapV2 {
-#ifdef    CGAL_SMALL_UNORDERED_MAP_STATS
-  std::array<int, 20> collisions = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-#endif
-  static constexpr int B = M * Factor ; // the number of bins
-  int head = B;
-  // mutable std::array<boost::int8_t, B> occupied {}; // all 0
-  mutable std::bitset<B> occupied;
-  std::array<std::pair<K, T>, B> data;
-  const H hash = {};
+
+  std::array<std::pair<K, T>, M> data;
+
   boost::unordered_map<K, T> * big = nullptr;
-  std::size_t N = 0; // the number of stored elements
+  int N = 0; // the number of stored elements
 public:
 
   Small_unordered_mapV2()
   {}
 
-#ifdef CGAL_SMALL_UNORDERED_MAP_STATS
-  ~Small_unordered_mapV2()
-  {
-    std::cout << "N = "<< N << std::endl;
-    int total = 0;
-    std::cout << "0 " << collisions[0] << std::endl;
-    for (int i = 1; i < 20; i++) {
-      total += collisions[i];
-      if (collisions[i] != 0) {
-        std::cout << i << " " << collisions[i] << std::endl;
-      }
-    }
-    std::cout << "Total: " << total << " " << 100 * (double(total) / double(total + collisions[0])) << "%" << std::endl;
-  }
-#else
+
   ~Small_unordered_mapV2()
   {
     if(big != nullptr){
       delete big;
     }
   }
-#endif
+
 
   /// Set only once for a key
   void set(const K& k, const T& t)
   {
     if (N < M) {
-      unsigned int h = hash(k) % B;
-      unsigned i = h;
-#ifdef CGAL_SMALL_UNORDERED_MAP_STATS
-      int collision = 0;
-#endif
-      do {
-        if (occupied[i] == false) {
-          occupied[i] = true;
-          data[i].first = k;
-          data[i].second = t;
-          if(i < head){
-            head = i;
-          }
-#ifdef  CGAL_SMALL_UNORDERED_MAP_STATS
-          if (collision > 19) {
-            std::cerr << collision << " collisions" << std::endl;
-          }
-          else {
-            ++collisions[collision];
-          }
-#endif
-          ++N;
-          return;
-        }
-        i = (i + 1) % B;
-#ifdef CGAL_SMALL_UNORDERED_MAP_STATS
-        ++collision;
-#endif
-      } while (i != h);
-      CGAL_error();
-    }
-    else if (N == M) {
-      big = new boost::unordered_map<K, T>(); 
-      for(int pos = head; pos < B; ++pos){
-        if(occupied[pos]){
+      data[N].first = k;
+      data[N].second = t;
+      ++N;
+    }else{
+      if (N == M) {
+        big = new boost::unordered_map<K, T>(); 
+        for(int pos = 0; pos < M; ++pos){
           big->insert(data[pos]);
         }
+        (*big)[k] = t;
+      }else{
+        (*big)[k] = t;
       }
-      (*big)[k] = t;
+      ++N;
     }
-    else {
-      (*big)[k] = t;
-    }
-    ++N;
   }
 
   
@@ -119,44 +70,19 @@ public:
   }
   
 
-  const T& at(const K& k) const
-  {
-    if (N <= M) {
-      unsigned int h = hash(k) % B;
-      unsigned int i = h;
-      do {
-        if ((occupied[i]) && (data[i].first == k)) {
-          return data[i].second;
-        }
-        i = (i + 1) % B;
-      } while (i != h);
-      CGAL_error();
-    }
-    else {
-      return big.at(k);
-    }
-  }
-
+  
   struct const_iterator;
 
   const_iterator find(const K& k) const
   {
-     if (N <= M) {
-       unsigned int h = hash(k) % B;
-      unsigned int i = h;
-      do {
-        if(! occupied[i]){
-          // the element is not in the map
-          return end();
-        }
+    if (N <= M) {
+      for(int i =0; i < M; ++i){
         if (data[i].first == k) {
           return const_iterator(*this,i);
         }
-        i = (i + 1) % B;
-      } while (i != h);
-      CGAL_error();
-    }
-    else {
+      }
+      return end();
+    }else{
       return const_iterator(*this, big->find(k));
     }
   }
@@ -170,18 +96,6 @@ public:
     return N;
   }
 
-  /*
-  void clear()
-  {
-    head = B;
-    // occupied.fill(0);
-    if(big != nullptr){
-      delete big;
-      big = nullptr;
-    }
-    N = 0;
-  }
-  */
 
   struct const_iterator {
     typedef std::pair<K, T>           value_type;
@@ -198,7 +112,7 @@ public:
     bool big = false;
 
     const_iterator(const Small_unordered_mapV2& map)
-      : map(map), pos(B), big(map.N > M)
+      : map(map), pos(M), big(map.N > M)
     {
       if(big){
         bigit = map.big->end();
@@ -214,7 +128,7 @@ public:
     }
 
     const_iterator(const Small_unordered_mapV2& map, const Bigit& bigit)
-      : map(map), pos(B), bigit(bigit), big(true)
+      : map(map), pos(M), bigit(bigit), big(true)
     {}
     
     bool operator==(const const_iterator& other) const
@@ -234,12 +148,11 @@ public:
     {
       if (big) {
         ++bigit;
-      } else {
-        if(pos != B){
-          do {
-            ++pos;
-          }while((pos !=B) && (! map.occupied[pos]));
-        }
+      } else if(pos < map.N-1){
+        ++pos;
+      }else {
+          CGAL_assertion((pos == map.N-1) || (pos = M));
+          pos = M;
       }
       return *this;
     }
@@ -258,7 +171,10 @@ public:
 
   const_iterator begin() const
   {
-    return const_iterator(*this, head);
+    if(N==0){
+      return const_iterator(*this);
+    }
+    return const_iterator(*this, 0);
   }
 
   const_iterator end() const