---

vtkPriorityQueue Class Reference

an list of ids arranged in priority order. More...

#include <vtkPriorityQueue.h>

Inheritance diagram for vtkPriorityQueue:

[legend]Collaboration diagram for vtkPriorityQueue:

[legend]List of all members.

Public Methods
virtual const char *	GetClassName ()
virtual int	IsA (const char *type)
void	PrintSelf (ostream &os, vtkIndent indent)
void	Allocate (const int sz, const int ext=1000)
void	Insert (float priority, int id)
int	Pop (float &priority, int location=0)
int	Pop (int location=0)
int	Peek (float &priority, int location=0)
int	Peek (int location=0)
float	DeleteId (int id)
float	GetPriority (int id)
int	GetNumberOfItems ()
void	Reset ()
Static Public Methods
vtkPriorityQueue *	New ()
int	IsTypeOf (const char *type)
vtkPriorityQueue *	SafeDownCast (vtkObject *o)
Protected Methods
	vtkPriorityQueue ()
	~vtkPriorityQueue ()
	vtkPriorityQueue (const vtkPriorityQueue &)
void	operator= (const vtkPriorityQueue &)
vtkPriorityItem *	Resize (const int sz)
Protected Attributes
vtkIntArray *	ItemLocation
vtkPriorityItem *	Array
int	Size
int	MaxId
int	Extend

---

Detailed Description

an list of ids arranged in priority order.

Date:

2000/12/10 20:08:16

Revision:

1.25

vtkPriorityQueue is a general object for creating and manipulating lists of object ids (e.g., point or cell ids). Object ids are sorted according to a user-specified priority, where entries at the top of the queue have the smallest values.

This implementation provides a feature beyond the usual ability to insert and retrieve (or pop) values from the queue. It is also possible to pop any item in the queue given its id number. This allows you to delete entries in the queue which can useful for reinserting an item into the queue.

Warning:

This implementation is a variation of the priority queue described in "Data Structures & Algorithms" by Aho, Hopcroft, Ullman. It creates a balanced, partially ordered binary tree implemented as an ordered array. This avoids the overhead associated with parent/child pointers, and frequent memory allocation and deallocation.

Definition at line 79 of file vtkPriorityQueue.h.

---

Constructor & Destructor Documentation

vtkPriorityQueue::vtkPriorityQueue (    )  [protected]

vtkPriorityQueue::~vtkPriorityQueue (    )  [protected]

vtkPriorityQueue::vtkPriorityQueue (  const vtkPriorityQueue &    )  [inline, protected]

Definition at line 132 of file vtkPriorityQueue.h.

---

Member Function Documentation

vtkPriorityQueue* vtkPriorityQueue::New (    )  [static]

Instantiate priority queue with default size and extension size of 1000. Reimplemented from vtkObject.

virtual const char* vtkPriorityQueue::GetClassName (    )  [virtual]

Return the class name as a string. This method is defined in all subclasses of vtkObject with the vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject.

int vtkPriorityQueue::IsTypeOf (  const char *    type )  [static]

Return 1 if this class type is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject.

virtual int vtkPriorityQueue::IsA (  const char *    type )  [virtual]

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject.

vtkPriorityQueue* vtkPriorityQueue::SafeDownCast (  vtkObject *    o )  [static]

Will cast the supplied object to vtkObject* is this is a safe operation (i.e., a safe downcast); otherwise NULL is returned. This method is defined in all subclasses of vtkObject with the vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject.

void vtkPriorityQueue::PrintSelf (  ostream &    os, vtkIndent    indent )  [virtual]

Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes. Reimplemented from vtkObject.

void vtkPriorityQueue::Allocate (  const int    sz, const int    ext = 1000 )

Allocate initial space for priority queue.

void vtkPriorityQueue::Insert (  float    priority, int    id )

Insert id with priority specified. The id is generally an index like a point id or cell id.

int vtkPriorityQueue::Pop (  float &    priority, int    location = 0 )

Removes item at specified location from tree; then reorders and balances tree. The location == 0 is the root of the tree. If queue is exhausted, then a value < 0 is returned. (Note: the location is not the same as deleting an id; id is mapped to location.) Referenced by DeleteId().

int vtkPriorityQueue::Pop (  int    location = 0 )

Same as above but simplified for easier wrapping into interpreted languages.

int vtkPriorityQueue::Peek (  float &    priority, int    location = 0 )  [inline]

Peek into the queue without actually removing anything. Returns the id and the priority. Definition at line 169 of file vtkPriorityQueue.h.

int vtkPriorityQueue::Peek (  int    location = 0 )  [inline]

Peek into the queue without actually removing anything. Returns the id. Definition at line 182 of file vtkPriorityQueue.h.

float vtkPriorityQueue::DeleteId (  int    id )  [inline]

Delete entry in queue with specified id. Returns priority value associated with that id; or VTK_LARGE_FLOAT if not in queue. Definition at line 144 of file vtkPriorityQueue.h.

float vtkPriorityQueue::GetPriority (  int    id )  [inline]

Get the priority of an entry in the queue with specified id. Returns priority value of that id or VTK_LARGE_FLOAT if not in queue. Definition at line 157 of file vtkPriorityQueue.h.

int vtkPriorityQueue::GetNumberOfItems (    )  [inline]

Return the number of items in this queue. Definition at line 123 of file vtkPriorityQueue.h.

void vtkPriorityQueue::Reset (    )

Empty the queue but without releasing memory. This avoids the overhead of memory allocation/deletion.

void vtkPriorityQueue::operator= (  const vtkPriorityQueue &    )  [inline, protected]

Definition at line 133 of file vtkPriorityQueue.h.

vtkPriorityItem* vtkPriorityQueue::Resize (  const int    sz )  [protected]

---

Member Data Documentation

vtkIntArray* vtkPriorityQueue::ItemLocation [protected]

Definition at line 137 of file vtkPriorityQueue.h.

vtkPriorityItem* vtkPriorityQueue::Array [protected]

Definition at line 138 of file vtkPriorityQueue.h.

int vtkPriorityQueue::Size [protected]

Definition at line 139 of file vtkPriorityQueue.h.

int vtkPriorityQueue::MaxId [protected]

Definition at line 140 of file vtkPriorityQueue.h.

int vtkPriorityQueue::Extend [protected]

Definition at line 141 of file vtkPriorityQueue.h.

---

The documentation for this class was generated from the following file:

• common/vtkPriorityQueue.h

---