Common/KWCommon/vtkHashMap.h

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/*=========================================================================

  Module:    $RCSfile: vtkHashMap.h,v $

  Copyright (c) Kitware, Inc.
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkAbstractMap.h"
#include "vtkWindows.h" // used for windows.h
#ifndef __vtkHashMap_h
#define __vtkHashMap_h

template<class DataType> class vtkVector;
template<class KeyType, class DataType> class vtkHashMapIterator;

template<class KeyType, class DataType>
class vtkHashMap : public vtkAbstractMap<KeyType,DataType>
{
  friend class vtkHashMapIterator<KeyType,DataType>;
  virtual const char* GetClassNameInternal() const {return "vtkHashMap";}
public:
  typedef vtkAbstractMap<KeyType,DataType> Superclass;
  typedef vtkHashMapIterator<KeyType,DataType> IteratorType;
  
  // Cannot use this macro because of the comma in the type name.
  // The CPP splits that in two and we ae in trouble.
  //vtkContainerTypeMacro((vtkHashMap<KeyType,DataType>), vtkContainer);

  void PrintSelf(ostream& os, vtkIndent indent);
  static vtkHashMap<KeyType,DataType>* New(); 
  
  vtkHashMapIterator<KeyType,DataType>* NewIterator();
  
  int SetItem(const KeyType& key, const DataType& data);
  
  int RemoveItem(const KeyType& key);
  
  void RemoveAllItems();
  
  int GetItem(const KeyType& key, DataType& data);

  vtkIdType GetNumberOfItems() const;
  

  void SetMaximumLoadFactor(float factor);
  float GetMaximumLoadFactor() const;
  

  void SetNumberOfBuckets(vtkIdType n);
  vtkIdType GetNumberOfBuckets() const;  
  
protected:
  vtkHashMap();
  virtual ~vtkHashMap();
  
  typedef vtkAbstractMapItem<KeyType,DataType> ItemType;
  typedef vtkVector<ItemType> BucketType;
  
  // Check if the load factor is okay.  Increase number of buckets and
  // re-hash if necessary.
  void CheckLoadFactor();
  
  // Change the number of buckets to the given number and re-hash the
  // items.
  void RehashItems(vtkIdType newNumberOfBuckets);

  vtkIdType HashKey(const KeyType& key, vtkIdType nbuckets);
  
  float MaximumLoadFactor;
  vtkIdType NumberOfItems;
  vtkIdType NumberOfBuckets;
  BucketType** Buckets;
  
private:
  vtkHashMap(const vtkHashMap<KeyType,DataType>&); // Not implemented
  void operator=(const vtkHashMap<KeyType,DataType>&); // Not implemented
};

static inline unsigned long vtkHashMapHashMethod(int x) 
{ return static_cast<unsigned long>(x); }
static inline unsigned long vtkHashMapHashMethod(const char* s)
{
  unsigned long h = 0;
  for(;*s;++s)
    {
    h = 5*h + *s;
    }
  return h;
}

static inline unsigned long vtkHashMapHashMethod(vtkObjectBase* o) 
{ 
#if defined ( _MSC_VER )
  return PtrToUlong(o);
#else
  return reinterpret_cast<unsigned long>(o); 
#endif
}

#ifdef VTK_NO_EXPLICIT_TEMPLATE_INSTANTIATION
#include "vtkHashMap.txx"
#endif 

#endif

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