vtkPriorityQueue.h

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

  Program:   Visualization Toolkit
  Module:    vtkPriorityQueue.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  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.

=========================================================================*/
#ifndef vtkPriorityQueue_h
#define vtkPriorityQueue_h

#include "vtkCommonCoreModule.h" // For export macro
#include "vtkObject.h"

#include "vtkIdTypeArray.h" // Needed for inline methods

class VTKCOMMONCORE_EXPORT vtkPriorityQueue : public vtkObject
{
public:
  class Item
  {
  public:
    double priority;
    vtkIdType id;
  };

  static vtkPriorityQueue* New();

  vtkTypeMacro(vtkPriorityQueue, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  void Allocate(vtkIdType sz, vtkIdType ext = 1000);

  void Insert(double priority, vtkIdType id);

  vtkIdType Pop(vtkIdType location, double& priority);

  vtkIdType Pop(vtkIdType location = 0);

  vtkIdType Peek(vtkIdType location, double& priority);

  vtkIdType Peek(vtkIdType location = 0);

  double DeleteId(vtkIdType id);

  double GetPriority(vtkIdType id);

  vtkIdType GetNumberOfItems() { return this->MaxId + 1; }

  void Reset();

protected:
  vtkPriorityQueue();
  ~vtkPriorityQueue() override;

  Item* Resize(const vtkIdType sz);

  vtkIdTypeArray* ItemLocation;
  Item* Array;
  vtkIdType Size;
  vtkIdType MaxId;
  vtkIdType Extend;

private:
  vtkPriorityQueue(const vtkPriorityQueue&) = delete;
  void operator=(const vtkPriorityQueue&) = delete;
};

inline double vtkPriorityQueue::DeleteId(vtkIdType id)
{
  double priority = VTK_DOUBLE_MAX;
  vtkIdType loc;

  if (id <= this->ItemLocation->GetMaxId() && (loc = this->ItemLocation->GetValue(id)) != -1)
  {
    this->Pop(loc, priority);
  }
  return priority;
}

inline double vtkPriorityQueue::GetPriority(vtkIdType id)
{
  vtkIdType loc;

  if (id <= this->ItemLocation->GetMaxId() && (loc = this->ItemLocation->GetValue(id)) != -1)
  {
    return this->Array[loc].priority;
  }
  return VTK_DOUBLE_MAX;
}

inline vtkIdType vtkPriorityQueue::Peek(vtkIdType location, double& priority)
{
  if (this->MaxId < 0)
  {
    return -1;
  }
  else
  {
    priority = this->Array[location].priority;
    return this->Array[location].id;
  }
}

inline vtkIdType vtkPriorityQueue::Peek(vtkIdType location)
{
  if (this->MaxId < 0)
  {
    return -1;
  }
  else
  {
    return this->Array[location].id;
  }
}

#endif