Integration of OCCT 6.5.0 from SVN

src/NCollection/NCollection_UBTreeFiller.hxx

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+// File:      NCollection_UBTreeFiller.hxx
+// Created:   18.10.02 10:34:57
+// Author:    Michael SAZONOV
+// Copyright: Open CASCADE 2002
+
+#ifndef NCollection_UBTreeFiller_HeaderFile
+#define NCollection_UBTreeFiller_HeaderFile
+
+#include <NCollection_UBTree.hxx>
+#include <NCollection_Vector.hxx>
+#include <stdlib.h>
+#include <stdio.h>
+
+/**
+ * This class is used to fill an UBTree in a random order.
+ * The quality of a tree is much better (from the point of view of
+ * the search time) if objects are added to it in a random order to
+ * avoid adding a chain of neerby objects one following each other.
+ *
+ * This class collects objects to be added, and then add them to the tree
+ * in a random order.
+ */
+template <class TheObjType, class TheBndType> class NCollection_UBTreeFiller
+{
+ public:
+  // ---------- PUBLIC TYPES ----------
+
+  //! Structure of pair (object, bnd box)
+  struct ObjBnd
+  {
+    TheObjType  myObj;
+    TheBndType  myBnd;
+    ObjBnd (const TheObjType& theObj, const TheBndType& theBnd)
+      : myObj(theObj), myBnd(theBnd) {}
+    ObjBnd ()
+      : myObj(TheObjType()), myBnd(TheBndType()) {}
+  };
+
+  //! UBTree algorithm
+  typedef NCollection_UBTree<TheObjType, TheBndType>    UBTree;
+  typedef TYPENAME UBTree::TreeNode                     UBTreeNode;
+
+
+  // ---------- PUBLIC METHODS ----------
+
+  /**
+   * Constructor.
+   * @param theTree
+   *   Tree instance that is to be filled.
+   * @param isFullRandom
+   *   Takes effect when the number of items is large (order of 50,000). When
+   *   it is True, the code uses the maximal randomization allowing a better
+   *   balanced tree. If False, the randomization/tree balance are worse but
+   *   the tree filling is faster due to better utilisation of CPU L1/L2 cache.
+   */ 
+  NCollection_UBTreeFiller (UBTree& theTree,
+                            const Standard_Boolean isFullRandom = Standard_True)
+    : myTree(theTree), mySeed(1), myIsFullRandom (isFullRandom)
+    {
+#ifndef _REENTRANT
+      // We use srand/rand for a single threaded application
+      // and rand_r for a multi threaded one.
+      // _REENTRANT must be defined for a multi threaded application.
+      srand (mySeed);
+#endif
+    }
+
+  //! Adds a pair (theObj, theBnd) to my sequence
+  void Add (const TheObjType& theObj, const TheBndType& theBnd)
+  { mySeqPtr.Append (ObjBnd (theObj, theBnd)); }
+
+  /**
+   * Fills the tree with the objects from my sequence. This method clears
+   * the internal buffer of added items making sure that no item would be added
+   * twice.
+   * @return
+   *   the number of objects added to the tree.
+   */
+  Standard_EXPORT Standard_Integer Fill ();
+
+  /**
+   * Check the filled tree for the total number of items and the balance
+   * outputting these results to ostream.
+   * @return
+   *   the tree size (the same value is returned by method Fill()).
+   */ 
+  Standard_EXPORT Standard_Integer CheckTree (Standard_OStream& theStream);
+
+  /**
+   * Destructor. Fills the tree with accumulated items if they have not been
+   * passed by a previous call of method Fill().
+   */
+  ~NCollection_UBTreeFiller ()
+  {
+    if (mySeqPtr.Length() > 0)
+#ifdef DEB_UBTREE
+      cout << "~NCollection_UBTreeFiller: " << Fill()
+           << " objects added to the tree" << endl;
+#else
+      Fill();
+#endif
+  }
+
+ private:
+
+  // Assignment operator is made empty and private in order to
+  // avoid warning on MSVC (C4512)
+  void operator = (const NCollection_UBTreeFiller&) {}
+  
+  static Standard_Real    checkNode     (const UBTreeNode&      theNode,
+                                         const Standard_Integer theLength,
+                                         Standard_Integer&      theNumber);
+
+
+ private:
+  // ---------- PRIVATE FIELDS ----------
+
+  UBTree&                               myTree;
+  NCollection_Vector<ObjBnd>            mySeqPtr;
+  int                                   mySeed;         //!< seed for rand
+  Standard_Boolean                      myIsFullRandom;
+};
+
+#ifdef _REENTRANT
+inline int take_random (int * theSeed)
+{
+  return rand_r ((unsigned *) theSeed);
+}
+#else
+inline int take_random (int *)
+{
+  return rand();
+}
+#endif
+
+//=======================================================================
+//function : Fill
+//purpose  : 
+//=======================================================================
+
+template <class TheObjType, class TheBndType>
+Standard_Integer NCollection_UBTreeFiller<TheObjType,TheBndType>::Fill ()
+{
+  Standard_Integer i, nbAdd = mySeqPtr.Length();
+  // Fisher-Yates randomization
+  if (myIsFullRandom)
+    for (i = nbAdd; i > 0; i--) { 
+      unsigned int ind = take_random(&mySeed);
+      if (i > RAND_MAX) {
+        const unsigned int ind1 = take_random(&mySeed);
+        ind += (ind1 << 15);
+      }
+      ind = ind % i;
+      const ObjBnd& aObjBnd = mySeqPtr(ind);
+      myTree.Add (aObjBnd.myObj, aObjBnd.myBnd);
+      mySeqPtr(ind) = mySeqPtr(i-1);
+    }
+  else
+    for (i = nbAdd; i > 0; i--) { 
+      unsigned int ind = take_random(&mySeed);
+      ind = i - (ind % i) - 1;
+      const ObjBnd& aObjBnd = mySeqPtr(ind);
+      myTree.Add (aObjBnd.myObj, aObjBnd.myBnd);
+      mySeqPtr(ind) = mySeqPtr(i-1);
+    }
+  mySeqPtr.Clear();
+  return nbAdd;
+}
+
+//=======================================================================
+//function : CheckTree
+//purpose  : 
+//=======================================================================
+
+template <class TheObjType, class TheBndType>
+Standard_Integer NCollection_UBTreeFiller<TheObjType,TheBndType>::CheckTree
+                                        (Standard_OStream& theStream)
+{
+  Standard_Integer aNumber(0);
+  const Standard_Real aLen = checkNode (myTree.Root(), 0, aNumber);
+  const Standard_Real num = (double) aNumber;
+  const Standard_Real aLen1 = sqrt (aLen / num);
+  const Standard_Real aLen0 = log(num) / log(2.);
+  char buf[128];
+  sprintf (buf,  "Checking UBTree:%8d leaves, balance =%7.2f",
+           aNumber, aLen1 / aLen0);
+  theStream << buf << endl;
+  return aNumber;
+}
+
+//=======================================================================
+//function : checkNode
+//purpose  : 
+//=======================================================================
+
+template <class TheObjType, class TheBndType>
+Standard_Real NCollection_UBTreeFiller<TheObjType,TheBndType>::checkNode
+  (const TYPENAME NCollection_UBTree<TheObjType, TheBndType>::TreeNode& theNode,
+   const Standard_Integer theLength,
+   Standard_Integer&      theNumber)
+{
+  Standard_Real aLength;
+  if (!theNode.IsLeaf())
+    aLength = (checkNode (theNode.Child(0), theLength+1, theNumber) +
+               checkNode (theNode.Child(1), theLength+1, theNumber));
+  else {
+    theNumber++;
+    aLength = theLength * theLength;
+  }
+  return aLength;
+}
+
+#endif