Improved "count" for unique associative containers. Instead of calling tree's count just use find() != end() to avoid iterations as there is only one potential key.

Fixed some typos.
2014-01-19 14:28:57 +01:00
parent caee07a643
commit 3c6f96a96a
21 changed files with 324 additions and 416 deletions
--- a/include/boost/intrusive/splaytree_algorithms.hpp
+++ b/include/boost/intrusive/splaytree_algorithms.hpp
@@ -45,33 +45,70 @@ namespace intrusive {
 namespace detail {

 template<class NodeTraits>
-struct splaydown_rollback
+struct splaydown_assemble_and_fix_header
 {
   typedef typename NodeTraits::node_ptr node_ptr;
-   splaydown_rollback( const node_ptr *pcur_subtree, const node_ptr & header
-                     , const node_ptr & leftmost           , const node_ptr & rightmost)
-      : pcur_subtree_(pcur_subtree)  , header_(header)
-      , leftmost_(leftmost)   , rightmost_(rightmost)
+
+   splaydown_assemble_and_fix_header(const node_ptr & t, const node_ptr & header, const node_ptr &leftmost, const node_ptr &rightmost)
+      : t_(t)
+      , null_node_(header)
+      , l_(null_node_)
+      , r_(null_node_)
+      , leftmost_(leftmost)
+      , rightmost_(rightmost)
   {}

-   void release()
-   {  pcur_subtree_ = 0;  }
-
-   ~splaydown_rollback()
+   ~splaydown_assemble_and_fix_header()
   {
-      if(pcur_subtree_){
-         //Exception can only be thrown by comp, but
-         //tree invariants still hold. *pcur_subtree is the current root
-         //so link it to the header.
-         NodeTraits::set_parent(*pcur_subtree_, header_);
-         NodeTraits::set_parent(header_, *pcur_subtree_);
-         //Recover leftmost/rightmost pointers
-         NodeTraits::set_left (header_, leftmost_);
-         NodeTraits::set_right(header_, rightmost_);
+      this->assemble();
+
+      //Now recover the original header except for the
+      //splayed root node.
+      //"t_" is the current root and "null_node_" is the header node
+      NodeTraits::set_parent(null_node_, t_);
+      NodeTraits::set_parent(t_, null_node_);
+      //Recover leftmost/rightmost pointers
+      NodeTraits::set_left (null_node_, leftmost_);
+      NodeTraits::set_right(null_node_, rightmost_);
+   }
+
+   private:
+
+   void assemble()
+   {
+      //procedure assemble;
+      //    left(r), right(l) := right(t), left(t);
+      //    left(t), right(t) := right(null), left(null);
+      //end assemble;
+      {  //    left(r), right(l) := right(t), left(t);
+         
+         node_ptr const old_t_left  = NodeTraits::get_left(t_);
+         node_ptr const old_t_right = NodeTraits::get_right(t_);
+         NodeTraits::set_right(l_, old_t_left);
+         NodeTraits::set_left (r_, old_t_right);
+         if(old_t_left){
+            NodeTraits::set_parent(old_t_left, l_);
+         }
+         if(old_t_right){
+            NodeTraits::set_parent(old_t_right, r_);
+         }
+      }
+      {  //    left(t), right(t) := right(null), left(null);
+         node_ptr const null_right = NodeTraits::get_right(null_node_);
+         node_ptr const null_left  = NodeTraits::get_left(null_node_);
+         NodeTraits::set_left (t_, null_right);
+         NodeTraits::set_right(t_, null_left);
+         if(null_right){
+            NodeTraits::set_parent(null_right, t_);
+         }
+         if(null_left){
+            NodeTraits::set_parent(null_left, t_);
+         }
      }
   }
-   const node_ptr *pcur_subtree_;
-   node_ptr header_, leftmost_, rightmost_;
+
+   public:
+   node_ptr t_, null_node_, l_, r_, leftmost_, rightmost_;
 };

 }  //namespace detail {
@@ -184,32 +221,28 @@ class splaytree_algorithms
   #endif   //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED

   //! @copydoc ::boost::intrusive::bstree_algorithms::erase(const node_ptr&,const node_ptr&)
-   //! Additional notes: the previous node of z is splayed. The "splay" parameter which indicated if splaying
-   //! should be performed, it's deprecated and will disappear in future versions.
-   static void erase(const node_ptr & header, const node_ptr & z, bool splay = true)
+   //! Additional notes: the previous node of z is splayed to speed up range deletions.
+   static void erase(const node_ptr & header, const node_ptr & z)
   {
      //posibility 1
-      if(splay && NodeTraits::get_left(z)){
+      if(NodeTraits::get_left(z)){
         splay_up(bstree_algo::prev_node(z), header);
      }
      /*
      //possibility 2
-      if(splay && NodeTraits::get_left(z)){
+      if(NodeTraits::get_left(z)){
         node_ptr l = NodeTraits::get_left(z);
         splay_up(l, header);
-      }*//*
-      if(splay && NodeTraits::get_left(z)){
+      }*/
+      /*
+      if(NodeTraits::get_left(z)){
         node_ptr l = bstree_algo::prev_node(z);
         splay_up_impl(l, z);
      }*/
      /*
      //possibility 4
-      if(splay){
-         splay_up(z, header);
-      }*/
-
-      //if(splay)
-         //splay_up(z, header);
+      splay_up(z, header);
+      */
      bstree_algo::erase(header, z);
   }

@@ -225,7 +258,7 @@ class splaytree_algorithms

   #endif   //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
   //! @copydoc ::boost::intrusive::bstree_algorithms::count(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
-   //! Additional notes: the first node of the range is splayed.
+   //! Additional notes: an element with key `key` is splayed.
   template<class KeyType, class KeyNodePtrCompare>
   static std::size_t count
      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp)
@@ -247,15 +280,14 @@ class splaytree_algorithms
   {  return bstree_algo::count(header, key, comp);  }

   //! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
-   //! Additional notes: the first node of the range is splayed. The "splay" parameter which indicated if splaying
-   //! should be performed, it's deprecated and will disappear in future versions.
+   //! Additional notes: the first node of the range is splayed.
   template<class KeyType, class KeyNodePtrCompare>
   static node_ptr lower_bound
-      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool splay = true)
+      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp)
   {
-      //splay_down(detail::uncast(header), key, comp);
+      splay_down(detail::uncast(header), key, comp);
      node_ptr y = bstree_algo::lower_bound(header, key, comp);
-      if(splay) splay_up(y, detail::uncast(header));
+      //splay_up(y, detail::uncast(header));
      return y;
   }

@@ -267,15 +299,14 @@ class splaytree_algorithms
   {  return bstree_algo::lower_bound(header, key, comp);  }

   //! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
-   //! Additional notes: the first node of the range is splayed. The "splay" parameter which indicated if splaying
-   //! should be performed, it's deprecated and will disappear in future versions.
+   //! Additional notes: the first node of the range is splayed.
   template<class KeyType, class KeyNodePtrCompare>
   static node_ptr upper_bound
-      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool splay = true)
+      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp)
   {
-      //splay_down(detail::uncast(header), key, comp);
+      splay_down(detail::uncast(header), key, comp);
      node_ptr y = bstree_algo::upper_bound(header, key, comp);
-      if(splay) splay_up(y, detail::uncast(header));
+      //splay_up(y, detail::uncast(header));
      return y;
   }

@@ -287,17 +318,13 @@ class splaytree_algorithms
   {  return bstree_algo::upper_bound(header, key, comp);  }

   //! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare)
-   //! Additional notes: the found node of the lower bound is splayed. The "splay" parameter which indicated if splaying
-   //! should be performed, it's deprecated and will disappear in future versions.
+   //! Additional notes: the found node of the lower bound is splayed.
   template<class KeyType, class KeyNodePtrCompare>
   static node_ptr find
-      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool splay = true)
+      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp)
   {
-      if(splay) splay_down(detail::uncast(header), key, comp);
-      node_ptr end = detail::uncast(header);
-      node_ptr y = bstree_algo::lower_bound(header, key, comp);
-      node_ptr r = (y == end || comp(key, y)) ? end : y;
-      return r;
+      splay_down(detail::uncast(header), key, comp);
+      return bstree_algo::find(header, key, comp);
   }

   //! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&, const KeyType&,KeyNodePtrCompare)
@@ -308,15 +335,14 @@ class splaytree_algorithms
   {  return bstree_algo::find(header, key, comp);  }

   //! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
-   //! Additional notes: the first node of the range is splayed. The "splay" parameter which indicated if splaying
-   //! should be performed, it's deprecated and will disappear in future versions.
+   //! Additional notes: the first node of the range is splayed.
   template<class KeyType, class KeyNodePtrCompare>
   static std::pair<node_ptr, node_ptr> equal_range
-      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool splay = true)
+      (const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp)
   {
-      //splay_down(detail::uncast(header), key, comp);
+      splay_down(detail::uncast(header), key, comp);
      std::pair<node_ptr, node_ptr> ret = bstree_algo::equal_range(header, key, comp);
-      if(splay) splay_up(ret.first, detail::uncast(header));
+      //splay_up(ret.first, detail::uncast(header));
      return ret;
   }

@@ -328,16 +354,16 @@ class splaytree_algorithms
   {  return bstree_algo::equal_range(header, key, comp);  }

   //! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const const_node_ptr&,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool)
-   //! Additional notes: the first node of the range is splayed. The "splay" parameter which indicated if splaying
-   //! should be performed, it's deprecated and will disappear in future versions.
+   //! Additional notes: the first node of the range is splayed.
   template<class KeyType, class KeyNodePtrCompare>
   static std::pair<node_ptr, node_ptr> bounded_range
      (const node_ptr & header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp
-      , bool left_closed, bool right_closed, bool splay = true)
+      , bool left_closed, bool right_closed)
   {
+      splay_down(detail::uncast(header), lower_key, comp);
      std::pair<node_ptr, node_ptr> ret =
         bstree_algo::bounded_range(header, lower_key, upper_key, comp, left_closed, right_closed);
-      if(splay) splay_up(ret.first, detail::uncast(header));
+      //splay_up(ret.first, detail::uncast(header));
      return ret;
   }

@@ -445,6 +471,20 @@ class splaytree_algorithms

   // bottom-up splay, use data_ as parent for n    | complexity : logarithmic    | exception : nothrow
   static void splay_up(const node_ptr & node, const node_ptr & header)
+   {  priv_splay_up<true>(node, header); }
+
+   // top-down splay | complexity : logarithmic    | exception : strong, note A
+   template<class KeyType, class KeyNodePtrCompare>
+   static node_ptr splay_down(const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool *pfound = 0)
+   {  return priv_splay_down<true>(header, key, comp, pfound);   }
+
+   private:
+
+   /// @cond
+
+   // bottom-up splay, use data_ as parent for n    | complexity : logarithmic    | exception : nothrow
+   template<bool SimpleSplay>
+   static void priv_splay_up(const node_ptr & node, const node_ptr & header)
   {
      // If (node == header) do a splay for the right most node instead
      // this is to boost performance of equal_range/count on equivalent containers in the case
@@ -470,20 +510,19 @@ class splaytree_algorithms
            rotate(p);
            rotate(n);
         }
-         else{
+         else {
            // zig-zag
            rotate(n);
-            rotate(n);
+            if(!SimpleSplay){
+               rotate(n);
+            }
         }
      }
   }

-   // top-down splay | complexity : logarithmic    | exception : strong, note A
-   template<class KeyType, class KeyNodePtrCompare>
-   static node_ptr splay_down(const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp)
+   template<bool SimpleSplay, class KeyType, class KeyNodePtrCompare>
+   static node_ptr priv_splay_down(const node_ptr & header, const KeyType &key, KeyNodePtrCompare comp, bool *pfound = 0)
   {
-      if(!NodeTraits::get_parent(header))
-         return header;
      //Most splay tree implementations use a dummy/null node to implement.
      //this function. This has some problems for a generic library like Intrusive:
      //
@@ -494,123 +533,87 @@ class splaytree_algorithms
      //are not changed when splaying (because the invariants of the tree don't
      //change) We can back up them, use the header as the null node and
      //reassign old values after the function has been completed.
-      node_ptr t = NodeTraits::get_parent(header);
-      //Check if tree has a single node
-      if(!NodeTraits::get_left(t) && !NodeTraits::get_right(t))
-         return t;
-      //Backup leftmost/rightmost
-      node_ptr leftmost (NodeTraits::get_left(header));
-      node_ptr rightmost(NodeTraits::get_right(header));
-      {
-         //Anti-exception rollback, recovers the original header node if an exception is thrown.
-         detail::splaydown_rollback<NodeTraits> rollback(&t, header, leftmost, rightmost);
-         node_ptr null_node = header;
-         node_ptr l = null_node;
-         node_ptr r = null_node;
+      node_ptr const old_root  = NodeTraits::get_parent(header);
+      node_ptr const leftmost  = NodeTraits::get_left(header);
+      node_ptr const rightmost = NodeTraits::get_right(header);
+      if(leftmost == rightmost){ //Empty or unique node
+         if(pfound){
+            *pfound = old_root && !comp(key, old_root) && !comp(old_root, key);
+         }
+         return old_root ? old_root : header;
+      }
+      else{
+         //Initialize "null node" (the header in our case)
+         NodeTraits::set_left (header, node_ptr());
+         NodeTraits::set_right(header, node_ptr());
+         //Class that will backup leftmost/rightmost from header, commit the assemble(),
+         //and will restore leftmost/rightmost to header even if "comp" throws
+         detail::splaydown_assemble_and_fix_header<NodeTraits> commit(old_root, header, leftmost, rightmost);
+         bool found = false;

         for( ;; ){
-            if(comp(key, t)){
-               node_ptr const t_left = NodeTraits::get_left(t);
+            if(comp(key, commit.t_)){
+               node_ptr const t_left = NodeTraits::get_left(commit.t_);
               if(!t_left)
                  break;
               if(comp(key, t_left)){
-                  t = bstree_algo::rotate_right(t);
+                  commit.t_ = bstree_algo::rotate_right(commit.t_);

-                  if( !NodeTraits::get_left(t) )
+                  if( !NodeTraits::get_left(commit.t_) )
                     break;
-                  link_right(t, r);
-               }
-               else if(comp(t_left, key)){
-                  link_right(t, r);
-
-                  if( !NodeTraits::get_right(t) )
-                     break;
-                  link_left(t, l);
+                  link_right(commit.t_, commit.r_);
               }
               else{
-                  link_right(t, r);
+                  link_right(commit.t_, commit.r_);
+                  if(!SimpleSplay && comp(t_left, key)){
+                     if( !NodeTraits::get_right(commit.t_) )
+                        break;
+                     link_left(commit.t_, commit.l_);
+                  }
               }
            }
-            else if(comp(t, key)){
-               node_ptr const t_right = NodeTraits::get_right(t);
+            else if(comp(commit.t_, key)){
+               node_ptr const t_right = NodeTraits::get_right(commit.t_);
               if(!t_right)
                  break;

               if(comp(t_right, key)){
-                     t = bstree_algo::rotate_left( t );
+                     commit.t_ = bstree_algo::rotate_left( commit.t_ );

-                     if( !NodeTraits::get_right(t) )
+                     if( !NodeTraits::get_right(commit.t_) )
                        break;
-                     link_left(t, l);
-               }
-               else if(comp(key, t_right)){
-                  link_left(t, l);
-
-                  if( !NodeTraits::get_left(t) )
-                     break;
-
-                  link_right(t, r);
+                     link_left(commit.t_, commit.l_);
               }
               else{
-                  link_left(t, l);
+                  link_left(commit.t_, commit.l_);
+                  if(!SimpleSplay && comp(key, t_right)){
+                     if( !NodeTraits::get_left(commit.t_) )
+                        break;
+                     link_right(commit.t_, commit.r_);
+                  }
               }
            }
            else{
+               found = true;
               break;
            }
         }

-         assemble(t, l, r, null_node);
-         rollback.release();
-      }
-
-      //Now recover the original header except for the
-      //splayed root node.
-      //t is the current root
-      NodeTraits::set_parent(header, t);
-      NodeTraits::set_parent(t, header);
-      //Recover leftmost/rightmost pointers
-      NodeTraits::set_left (header, leftmost);
-      NodeTraits::set_right(header, rightmost);
-      return t;
-   }
-
-   private:
-
-   /// @cond
-
-   // assemble the three sub-trees into new tree pointed to by t    | complexity : constant        | exception : nothrow
-   static void assemble(const node_ptr &t, const node_ptr & l, const node_ptr & r, const const_node_ptr & null_node )
-   {
-      node_ptr const new_l_right = NodeTraits::get_left(t);
-      node_ptr const new_r_left  = NodeTraits::get_right(t);
-      NodeTraits::set_right(l, new_l_right);
-      NodeTraits::set_left (r, new_r_left);
-
-      if(new_l_right){
-         NodeTraits::set_parent(new_l_right, l);
-      }
-      if(new_r_left){
-         NodeTraits::set_parent(new_r_left, r);
-      }
-
-      node_ptr const t_new_left  = NodeTraits::get_right(null_node);
-      node_ptr const t_new_right = NodeTraits::get_left(null_node);
-      NodeTraits::set_left (t, t_new_left);
-      NodeTraits::set_right(t, t_new_right);
-
-      if(t_new_left){
-         NodeTraits::set_parent(t_new_left, t);
-      }
-
-      if(t_new_right){
-         NodeTraits::set_parent(t_new_right, t);
+         //commit.~splaydown_assemble_and_fix_header<NodeTraits>() will first
+         //"assemble()" + link the new root & recover header's leftmost & rightmost
+         if(pfound){
+            *pfound = found;
+         }
+         return commit.t_;
      }
   }

   // break link to left child node and attach it to left tree pointed to by l   | complexity : constant | exception : nothrow
   static void link_left(node_ptr & t, node_ptr & l)
   {
+      //procedure link_left;
+      //    t, l, right(l) := right(t), t, t
+      //end link_left
      NodeTraits::set_right(l, t);
      NodeTraits::set_parent(t, l);
      l = t;
@@ -620,6 +623,9 @@ class splaytree_algorithms
   // break link to right child node and attach it to right tree pointed to by r | complexity : constant | exception : nothrow
   static void link_right(node_ptr & t, node_ptr & r)
   {
+      //procedure link_right;
+      //    t, r, left(r) := left(t), t, t
+      //end link_right;
      NodeTraits::set_left(r, t);
      NodeTraits::set_parent(t, r);
      r = t;
@@ -629,6 +635,9 @@ class splaytree_algorithms
   // rotate n with its parent                     | complexity : constant    | exception : nothrow
   static void rotate(const node_ptr & n)
   {
+      //procedure rotate_left;
+      //    t, right(t), left(right(t)) := right(t), left(right(t)), t
+      //end rotate_left;
      node_ptr p = NodeTraits::get_parent(n);
      node_ptr g = NodeTraits::get_parent(p);
      //Test if g is header before breaking tree