Merge branch 'master' of /home/lavaux/Dropbox/gitRoot/CosmoToolbox

sample/CMakeLists.txt

@@ -22,6 +22,9 @@ target_link_libraries(testDelaunay ${tolink})
 add_executable(testNewton testNewton.cpp)
 target_link_libraries(testNewton ${tolink})
 
+add_executable(testPool testPool.cpp)
+target_link_libraries(testPool ${tolink})
+
 if (HDF5_FOUND)
 	  add_executable(testReadFlash testReadFlash.cpp)
 	  target_link_libraries(testReadFlash ${tolink})
@@ -29,4 +32,7 @@ endif (HDF5_FOUND)
 
 
 add_executable(testEskow testEskow.cpp)
-target_link_libraries(testEskow ${tolink})
+target_link_libraries(testEskow ${tolink})
+
+add_executable(testAlgo testAlgo.cpp)
+target_link_libraries(testAlgo ${tolink})

sample/testAlgo.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+#include <stdio.h>
+#include "algo.hpp"
+
+using namespace CosmoTool;
+using namespace std;
+
+int main(int argc, char **argv)
+{
+  cout << square(2) << endl;
+  cout << cube(2) << endl;
+  cout << square(2.1f) << endl;
+  cout << cube(2.1f) << endl;
+  
+  cout << spower<2>(2.1f) << endl;
+  cout << spower<3>(2.1f) << endl;
+  cout << spower<4>(2.1f) << endl;
+  cout << spower<5>(2.1f) << endl;
+  return 0;
+}

sample/testPool.cpp

@@ -0,0 +1,19 @@
+#include "pool.hpp"
+
+using namespace CosmoTool;
+
+int main(int argc, char **argv)
+{
+  MemoryPool<int> pool(1024);
+  int **j = new int *[3000];
+
+  for (int i = 0; i < 3000; i++)
+    {
+      j[i] = pool.alloc();
+      j[i][0] = i;
+    }
+
+  pool.free_all();
+
+  return 0;
+}

sample/testkd2.cpp

@@ -5,14 +5,16 @@
 #include <fstream>
 #define __KD_TREE_NUMNODES
 #include "mykdtree.hpp"
+#include "kdtree_splitters.hpp"
 
-#define NTRY 100 
+#define NTRY 10
 #define ND 3
 
 using namespace std;
 using namespace CosmoTool;
 
-typedef KDTree<ND,char> MyTree;
+typedef KDTree<ND,char,ComputePrecision,KD_homogeneous_cell_splitter<ND, char> > MyTree;
+//typedef KDTree<ND,char,ComputePrecision > MyTree;
 typedef KDCell<ND,char> MyCell;
 
 MyCell *findNearest(MyTree::coords& xc, MyCell *cells, uint32_t Ncells)
@@ -38,7 +40,7 @@ MyCell *findNearest(MyTree::coords& xc, MyCell *cells, uint32_t Ncells)
 
 int main()
 {
-  uint32_t Ncells = 100000;
+  uint32_t Ncells = 10000000;
   MyCell *cells = new MyCell[Ncells];
   
   for (int i = 0; i < Ncells; i++)
@@ -48,8 +50,16 @@ int main()
 	cells[i].coord[l] = drand48();
     }
   
+  // Check timing
+  clock_t startTimer = clock();
   MyTree tree(cells, Ncells);
-  
+  clock_t endTimer = clock();
+
+  clock_t delta = endTimer-startTimer;
+  double myTime = delta*1.0/CLOCKS_PER_SEC * 1.0;
+
+  cout << "KDTree build = " << myTime << " s" << endl;
+
   MyTree::coords *xc = new MyTree::coords[NTRY];
 
   cout << "Generating seeds..." << endl;
@@ -68,31 +78,39 @@ int main()
   for (int k = 0; k < NTRY; k++) {
     cout << "Seed = " << xc[k][0] << " " << xc[k][1] << " " << xc[k][2] << endl;
     tree.getNearestNeighbours(xc[k], 12, ngb, distances);
+    int last = -1;
 
     for (uint32_t i = 0; i < 12; i++)
       {
+	if (ngb[i] == 0)
+	  continue;
+
+	last = i;
+
 	double d2 = 0;
 	for (int l = 0; l < 3; l++)
 	  d2 += ({double delta = xc[k][l] - ngb[i]->coord[l]; delta*delta;});
 	fngb << ngb[i]->coord[0] << " " << ngb[i]->coord[1] << " " << ngb[i]->coord[2] << " " << sqrt(d2) << endl;
       }
-	fngb << endl << endl;
+    fngb << endl << endl;
-    double farther_dist = distances[11];
+    double farther_dist = distances[last];
     for (uint32_t i = 0; i < Ncells; i++)
       {
          bool found = false;
-         // If the points is not in the list, it means it is farther than the farther point
+         // If the points is not in the list, it means it is farther than the farthest  point
-        for (int j =0; j < 12; j++)
+	 for (int j =0; j < 12; j++)
           {
              if (&cells[i] == ngb[j]) {
                found = true;
                break;
              }
           } 
-            double dist_to_seed = 0;
+	 double dist_to_seed = 0;
-            for (int l = 0; l < 3; l++)
+	 for (int l = 0; l < 3; l++)
-		{ double delta = xc[k][l]-cells[i].coord[l];
+	   {
-              dist_to_seed += delta*delta; }
+	     double delta = xc[k][l]-cells[i].coord[l];
+	     dist_to_seed += delta*delta; 
+	   }
         if (!found) 
           { 
 	    if (dist_to_seed <= farther_dist)

src/algo.hpp

@@ -0,0 +1,59 @@
+#ifndef __COSMOTOOL_ALGO_HPP
+#define __COSMOTOOL_ALGO_HPP
+
+#include "config.hpp"
+
+namespace  CosmoTool
+{
+
+  template<typename T>
+  T cube(T a)
+  {
+    return a*a*a;
+  }
+
+  template<typename T>
+  T square(T a)
+  {
+    return a*a;
+  }
+
+  template<int N>
+  class SPowerBase
+  {
+  public:
+    template<typename T>
+    static T spower(T a)
+    {
+      if ((N%2)==0)
+	{
+	  T b = SPowerBase<N/2>::spower(a);
+	  return b*b;
+	}
+      T b = SPowerBase<(N-1)/2>::spower(a);
+      return a*b*b;
+    }
+  };
+
+  template<>
+  class SPowerBase<0>
+  {
+  public:
+    template<typename T>
+    static T spower(T a)
+    {
+      return T(1);
+    }
+  };
+
+  template<int N, typename T>
+  T spower(T a)
+  {
+    return SPowerBase<N>::spower(a);
+  }
+
+
+
+};
+
+#endif

src/dinterpolate.tcc

@@ -217,7 +217,7 @@ namespace CosmoTool {
        kdc[i] = c[i];
 
     // It may happen that we are unlucky and have to iterate to farther
-    // neighbors. It should happen, especially on the boundaries.
+    // neighbors. It is bound to happen, especially on the boundaries.
     do
       {
 	uint32_t i;

src/kdtree_splitters.hpp

@@ -0,0 +1,134 @@
+#ifndef __KDTREE_SPLITTERS_HPP
+#define __KDTREE_SPLITTERS_HPP
+
+#include <algorithm>
+
+namespace CosmoTool
+{
+
+  template<int N, typename ValType, typename CType = ComputePrecision> 
+  struct KD_homogeneous_cell_splitter
+  {
+    typedef typename KDDef<N,CType>::KDCoordinates coords; 
+    typedef typename KDDef<N,CType>::CoordType ctype; 
+
+
+    void check_splitting(KDCell<N,ValType,CType> **cells, uint32_t Ncells, int axis, uint32_t split_index, ctype midCoord)
+    {
+      ctype delta = std::numeric_limits<ctype>::max();
+      assert(split_index < Ncells);
+      assert(axis < N);
+      for (uint32_t i = 0; i < split_index; i++)
+	{
+	  assert(cells[i]->coord[axis] <= midCoord);
+	  delta = min(midCoord-cells[i]->coord[axis], delta);
+	}
+      for (uint32_t i = split_index+1; i < Ncells; i++)
+	{
+	  assert(cells[i]->coord[axis] > midCoord);
+	  delta = min(cells[i]->coord[axis]-midCoord, delta);
+	}
+      assert(delta >= 0);
+      assert (std::abs(cells[split_index]->coord[axis]-midCoord) <= delta);
+    } 
+    
+    void operator()(KDCell<N,ValType,CType> **cells, uint32_t Ncells, uint32_t& split_index, int axis, coords minBound, coords maxBound)
+    {
+      if (Ncells == 1)
+	{
+	  split_index = 0;
+	  return;
+	}
+
+      ctype midCoord = 0.5*(maxBound[axis]+minBound[axis]);
+      uint32_t below = 0, above = Ncells-1;
+      ctype delta_min = std::numeric_limits<ctype>::max();
+      uint32_t idx_min = std::numeric_limits<uint32_t>::max();     
+
+      while (below < above)
+	{
+          ctype delta = cells[below]->coord[axis]-midCoord;
+	  if (delta > 0)
+            {
+              if (delta < delta_min)
+                {
+                  delta_min = delta;
+                  idx_min = above;
+                }
+	      std::swap(cells[below], cells[above--]);
+            }
+	  else
+            {
+              if (-delta < delta_min)
+                {
+                  delta_min = -delta;
+                  idx_min = below;
+                }
+	      below++;
+            }
+	}
+      // Last iteration
+      {
+	ctype delta = cells[below]->coord[axis]-midCoord;	
+	if (delta > 0)
+	  {
+	    if (delta < delta_min)
+	      {
+		delta_min = delta;
+		idx_min = above;
+	      }
+	  }
+	else
+	  {
+	    if (-delta < delta_min)
+	      {
+		delta_min = -delta;
+		idx_min = above;
+	      }
+	  }
+      }
+
+      if (idx_min != above)
+        {
+          bool cond1 = cells[idx_min]->coord[axis] > midCoord;
+          bool cond2 = cells[above]->coord[axis] > midCoord;
+          if ((cond1 && cond2) || (!cond1 && !cond2))
+            {
+              split_index = above;
+              std::swap(cells[above], cells[idx_min]);
+            }
+          else if (cond2)
+            {
+              if (above >= 1)
+		{
+		  split_index = above-1;
+		  std::swap(cells[above-1], cells[idx_min]);
+		}
+	      else
+		split_index = 0;
+	      assert(split_index >= 0);
+            }
+          else
+            {
+	      if (above+1 < Ncells)
+		{
+		  split_index = above+1;
+		  std::swap(cells[above+1], cells[idx_min]);
+		}
+	      else
+		split_index = Ncells-1;
+
+	      assert(split_index < Ncells);
+            }
+         }
+       else split_index = above;
+
+
+      //      check_splitting(cells, Ncells, axis, split_index, midCoord);
+    }
+  };
+
+
+};
+
+#endif

src/mykdtree.hpp

@@ -59,6 +59,7 @@ namespace CosmoTool {
     uint32_t currentRank;
     uint32_t numCells;
   };
+  
 
   template<int N, typename ValType, typename CType = ComputePrecision>
   class RecursionMultipleInfo
@@ -76,7 +77,13 @@ namespace CosmoTool {
     }
   };
 
-  template<int N, typename ValType, typename CType = ComputePrecision>
+  template<int N, typename ValType, typename CType = ComputePrecision> 
+  struct KD_default_cell_splitter
+  {
+    void operator()(KDCell<N,ValType,CType> **cells, uint32_t Ncells, uint32_t& split_index, int axis, typename KDDef<N,CType>::KDCoordinates minBound, typename KDDef<N,CType>::KDCoordinates maxBound);
+  };
+
+  template<int N, typename ValType, typename CType = ComputePrecision, typename CellSplitter = KD_default_cell_splitter<N,ValType,CType> >
   class KDTree
   {
   public:
@@ -84,6 +91,8 @@ namespace CosmoTool {
     typedef typename KDDef<N>::KDCoordinates coords;
     typedef KDCell<N,ValType,CType> Cell;
     typedef KDTreeNode<N,ValType,CType> Node;
+    
+    CellSplitter splitter;
 
     KDTree(Cell *cells, uint32_t Ncells);
     ~KDTree();

src/mykdtree.tcc

@@ -23,13 +23,13 @@ namespace CosmoTool {
     int rank;
   };
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  KDTree<N,ValType,CType>::~KDTree()
+  KDTree<N,ValType,CType,CellSplitter>::~KDTree()
   {
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  KDTree<N,ValType,CType>::KDTree(Cell *cells, uint32_t Ncells)
+  KDTree<N,ValType,CType,CellSplitter>::KDTree(Cell *cells, uint32_t Ncells)
   {
     
     base_cell = cells;
@@ -43,8 +43,8 @@ namespace CosmoTool {
     optimize();
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  void KDTree<N,ValType,CType>::optimize()
+  void KDTree<N,ValType,CType,CellSplitter>::optimize()
   {
     coords absoluteMin, absoluteMax;
 
@@ -76,9 +76,9 @@ namespace CosmoTool {
     std::cout << "   done." << std::endl;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  uint32_t KDTree<N,ValType,CType>::getIntersection(const coords& x, CoordType r, 
+  uint32_t KDTree<N,ValType,CType,CellSplitter>::getIntersection(const coords& x, CoordType r, 
-						    KDTree<N,ValType,CType>::Cell **cells,
+						    KDTree<N,ValType,CType,CellSplitter>::Cell **cells,
 						    uint32_t numCells)
     throw (NotEnoughCells)
   {
@@ -96,8 +96,8 @@ namespace CosmoTool {
     return info.currentRank;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  uint32_t KDTree<N,ValType,CType>::getIntersection(const coords& x, CoordType r, 
+  uint32_t KDTree<N,ValType,CType,CellSplitter>::getIntersection(const coords& x, CoordType r, 
 						    Cell **cells,
 						    CoordType *distances,
 						    uint32_t numCells)
@@ -117,8 +117,8 @@ namespace CosmoTool {
     return info.currentRank;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  uint32_t KDTree<N,ValType,CType>::countCells(const coords& x, CoordType r)
+  uint32_t KDTree<N,ValType,CType,CellSplitter>::countCells(const coords& x, CoordType r)
   {
     RecursionInfoCells<N,ValType> info;
 
@@ -134,9 +134,9 @@ namespace CosmoTool {
     return info.currentRank;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
   template<bool justCount>
-  void KDTree<N,ValType,CType>::recursiveIntersectionCells(RecursionInfoCells<N,ValType,CType>& info, 
+  void KDTree<N,ValType,CType,CellSplitter>::recursiveIntersectionCells(RecursionInfoCells<N,ValType,CType>& info, 
 							   Node *node,
 							   int level)
     throw (NotEnoughCells)
@@ -208,25 +208,31 @@ namespace CosmoTool {
   }
 
   template<int N, typename ValType, typename CType>
-  KDTreeNode<N,ValType,CType> *KDTree<N,ValType,CType>::buildTree(Cell **cell0,
+  void  KD_default_cell_splitter<N,ValType,CType>::operator()(KDCell<N,ValType,CType> **cells, uint32_t Ncells, uint32_t& split_index, int axis, typename KDDef<N,CType>::KDCoordinates minBound, typename KDDef<N,CType>::KDCoordinates maxBound)
-								    uint32_t Ncells,
+  {
-								    uint32_t depth,
+    CellCompare<N,ValType,CType> compare(axis);
-								    coords minBound,
+    std::sort(cells, cells+Ncells, compare);
-								    coords maxBound)
+    split_index = Ncells/2;
+  }
+
+
+  template<int N, typename ValType, typename CType, typename CellSplitter>
+  KDTreeNode<N,ValType,CType> *KDTree<N,ValType,CType,CellSplitter>::buildTree(Cell **cell0,
+								  uint32_t Ncells,
+								  uint32_t depth,
+								  coords minBound,
+								  coords maxBound)
   {
     if (Ncells == 0)
       return 0;
 
     int axis = depth % N;
     Node *node = &nodes[lastNode++];
-    uint32_t mid = Ncells/2;
+    uint32_t mid;
     coords tmpBound;
     
     // Isolate the environment
-    {
+    splitter(cell0, Ncells, mid, axis, minBound, maxBound);
-      CellCompare<N,ValType,CType> compare(axis);
-      std::sort(cell0, cell0+Ncells, compare);
-    }
 
     node->value = *(cell0+mid);
     memcpy(&node->minBound[0], &minBound[0], sizeof(coords));
@@ -252,8 +258,8 @@ namespace CosmoTool {
     return node;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  uint32_t KDTree<N,ValType,CType>::countActives() const
+  uint32_t KDTree<N,ValType,CType,CellSplitter>::countActives() const
   {
     uint32_t numActive = 0;
     for (uint32_t i = 0; i < lastNode; i++)
@@ -264,9 +270,9 @@ namespace CosmoTool {
     return numActive;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
   typename KDDef<N,CType>::CoordType
-  KDTree<N,ValType,CType>::computeDistance(const Cell *cell, const coords& x) const
+  KDTree<N,ValType,CType,CellSplitter>::computeDistance(const Cell *cell, const coords& x) const
   {
     CoordType d2 = 0;
 
@@ -278,9 +284,9 @@ namespace CosmoTool {
     return d2;
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
   void
-  KDTree<N,ValType,CType>::recursiveNearest(
+  KDTree<N,ValType,CType,CellSplitter>::recursiveNearest(
 				       Node *node,
 				       int level,
 				       const coords& x,
@@ -352,9 +358,9 @@ namespace CosmoTool {
       }
   }
 
- template<int N, typename ValType, typename CType>
+ template<int N, typename ValType, typename CType, typename CellSplitter>
  KDCell<N,ValType,CType> *
- KDTree<N,ValType,CType>::getNearestNeighbour(const coords& x)
+ KDTree<N,ValType,CType,CellSplitter>::getNearestNeighbour(const coords& x)
  {
    CoordType R2 = INFINITY;
    Cell *best = 0;
@@ -364,9 +370,9 @@ namespace CosmoTool {
    return best;
  }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
   void
-  KDTree<N,ValType,CType>::recursiveMultipleNearest(RecursionMultipleInfo<N,ValType,CType>& info, Node *node,
+  KDTree<N,ValType,CType,CellSplitter>::recursiveMultipleNearest(RecursionMultipleInfo<N,ValType,CType>& info, Node *node,
 					       int level)
   {
     CoordType d2 = 0;
@@ -384,11 +390,11 @@ namespace CosmoTool {
 	// If not it is in 1.
 	go = node->children[1];
 	other = node->children[0];
-	if (go == 0)
+	//	if (go == 0)
-	  {
+	//	  {
-	    go = other;
+	//	go = other;
-	    other = 0;
+	//other = 0;
-	  }
+	//}
       }
 
     if (go != 0)
@@ -401,8 +407,8 @@ namespace CosmoTool {
       computeDistance(node->value, info.x);
     info.queue.push(node->value, thisR2);
     info.traversed++;
-    if (go == 0)
+    //    if (go == 0)
-      return;
+    //      return;
     
     // Now we found the best. We check whether the hypersphere
     // intersect the hyperplane of the other branch
@@ -421,8 +427,8 @@ namespace CosmoTool {
       }    
   }
 
- template<int N, typename ValType, typename CType>
+ template<int N, typename ValType, typename CType, typename CellSplitter>
- void KDTree<N,ValType,CType>::getNearestNeighbours(const coords& x, uint32_t N2,
+ void KDTree<N,ValType,CType,CellSplitter>::getNearestNeighbours(const coords& x, uint32_t N2,
 						    Cell **cells)
  {
    RecursionMultipleInfo<N,ValType> info(x, cells, N2);
@@ -435,8 +441,8 @@ namespace CosmoTool {
    //   std::cout << "Traversed = " << info.traversed << std::endl;
  }
 
- template<int N, typename ValType, typename CType>
+ template<int N, typename ValType, typename CType, typename CellSplitter>
- void KDTree<N,ValType,CType>::getNearestNeighbours(const coords& x, uint32_t N2,
+ void KDTree<N,ValType,CType,CellSplitter>::getNearestNeighbours(const coords& x, uint32_t N2,
 						    Cell **cells,
 						    CoordType *distances)
  {
@@ -470,8 +476,8 @@ namespace CosmoTool {
     long rootId;
   };
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  void KDTree<N,ValType,CType>::saveTree(std::ostream& o) const
+  void KDTree<N,ValType,CType,CellSplitter>::saveTree(std::ostream& o) const
   {
     KDTreeHeader h;
 
@@ -505,8 +511,8 @@ namespace CosmoTool {
       }
   }
 
-  template<int N, typename ValType, typename CType>
+  template<int N, typename ValType, typename CType, typename CellSplitter>
-  KDTree<N,ValType,CType>::KDTree(std::istream& in, Cell *cells, uint32_t Ncells)
+  KDTree<N,ValType,CType,CellSplitter>::KDTree(std::istream& in, Cell *cells, uint32_t Ncells)
     throw (InvalidOnDiskKDTree)
   {
     KDTreeHeader h;

src/pool.hpp

@@ -0,0 +1,166 @@
+#ifndef __COSMO_POOL_HPP
+#define __COSMO_POOL_HPP
+
+#include <list>
+#include "config.hpp"
+
+namespace CosmoTool
+{
+
+  template<typename T>
+  struct PoolNode
+  {
+    T *data;
+    uint32_t last_free, size;
+    PoolNode<T> *next;
+  };
+
+  template<typename T> class MemoryPool;
+
+  template<typename T>
+  class MemoryIterator
+  {
+  private:
+    friend  class MemoryPool<T>;
+
+    PoolNode<T> *cur, *previous;
+    uint32_t in_node;
+
+    MemoryIterator(PoolNode<T> *h) 
+    {
+      cur = h; 
+      previous = h; 
+      in_node = 0;
+    }
+  public:
+    MemoryIterator() { cur = 0; }
+    ~MemoryIterator() {}
+
+    const MemoryIterator& operator=(const MemoryIterator& i)
+    {
+      cur = i.cur;
+      previous = i.previous;
+      in_node = i.in_node;
+    }
+    
+    bool operator==(const MemoryIterator& i) const
+    {
+      return (cur == i.cur) && (in_node == i.in_node);
+    }
+
+    MemoryIterator& operator++()
+    {
+      if (cur == 0)
+	return *this;
+
+      in_node++;
+      if (in_node == cur->size)
+	{
+	  in_node = 0;
+	  previous = cur;
+	  cur = cur->next;
+	}
+      return *this;
+    }
+
+    T& operator*()
+    {
+      return cur->data[in_node];
+    }
+
+    T& operator->()
+    {
+      return cur->data[in_node];
+    }
+
+    
+    
+  };
+
+  // This is bare simple memory pools
+  template<typename T>
+  class MemoryPool
+  {
+  private:
+    uint32_t m_allocSize;
+    PoolNode<T> *head, *current;
+    typedef MemoryIterator<T> iterator;
+  public:
+    MemoryPool(uint32_t allocSize)
+      : m_allocSize(allocSize), head(0), current(0) {}
+
+    ~MemoryPool()
+    {
+      free_all();
+    }
+
+    void free_all()
+    {
+      PoolNode<T> *node = head;
+
+      while (node != 0)
+	{
+	  PoolNode<T> *next = node->next;
+	  	  
+	  delete[] node->data;
+	  delete node;
+	  node = next;
+	}
+      current = head = 0;
+    }
+
+    T *alloc()
+    {
+      T *ret = alloc_in_node();
+      return (ret == 0) ? alloc_new_in_node() : ret;
+    }
+    
+    iterator begin()
+    {
+      return iterator(head);
+    }
+    
+    iterator end()
+    {
+      return iterator(0);
+    }    
+
+  protected:
+    T *alloc_in_node()
+    {
+      if (current == 0 || current->last_free == current->size)
+	return 0;
+      return &current->data[current->last_free++];
+    }
+
+    T *alloc_new_in_node()
+    {
+      PoolNode<T> *newNode = new PoolNode<T>;
+      if (newNode == 0)
+	return 0;
+
+      newNode->last_free = 1;
+      newNode->size = m_allocSize;
+      newNode->data = new T[m_allocSize];
+      if (newNode->data == 0)
+	{
+	  delete newNode;
+	  return 0;
+	}
+      newNode->next = 0;
+
+      if (current == 0)
+	current = head = newNode;
+      else
+	{
+	  current->next = newNode;
+	  current = newNode;
+	}
+      return &newNode->data[0];
+    }
+
+  };
+  
+};
+
+#endif