Open CASCADE Technology  6.5.4
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Public Member Functions
TDF_Data Class Reference

This class is used to manipulate a complete
independant, self sufficient data structure and
its services:

Access to the root label;

Opens, aborts, commits a transaction;

Generation and use of Delta, depending on the time.
This class uses a special allocator
(see LabelNodeAllocator() method)
for more efficient allocation of
objects in memory.

#include <TDF_Data.hxx>

Inheritance diagram for TDF_Data:
Inheritance graph
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Public Member Functions

 TDF_Data ()
 A new and empty Data structure.

const TDF_Label Root () const
 Returns the root label of the Data structure.


Standard_Integer Transaction () const
 Returns the current transaction number.

Standard_Integer Time () const
 Returns the current tick. It is incremented each Commit.


Standard_Boolean IsApplicable (const Handle< TDF_Delta > &aDelta) const
 Returns true if <aDelta> is applicable HERE and NOW.

Handle_TDF_Delta Undo (const Handle< TDF_Delta > &aDelta, const Standard_Boolean withDelta=Standard_False)
 Apply <aDelta> to undo a set of attribute
modifications.

Optionnal <withDelta> set to True indiquates a
Delta Set must be generated. (See above)

void Destroy ()
 ~TDF_Data ()
Standard_Boolean NotUndoMode () const
 Returns the undo mode status.


Standard_OStreamDump (Standard_OStream &anOS) const
 Dumps the Data on <aStream>.


Standard_OStreamoperator<< (Standard_OStream &anOS) const
void AllowModification (const Standard_Boolean isAllowed)
 Sets modification mode.


Standard_Boolean IsModificationAllowed () const
 returns modification mode.


const TDF_HAllocatorLabelNodeAllocator () const
 Returns TDF_HAllocator, which is an
incremental allocator used by
TDF_LabelNode.
This allocator is used to
manage TDF_LabelNode objects,
but it can also be used for
allocating memory to
application-specific data (be
careful because this
allocator does not release
the memory).
The benefits of this
allocation scheme are
noticeable when dealing with
large OCAF documents, due to:


Constructor & Destructor Documentation

TDF_Data::~TDF_Data ( ) [inline]

Member Function Documentation

  1. Very quick allocation of
    objects (memory heap is not
    used, the algorithm that
    replaces it is very simple).
  2. Very quick destruction of
    objects (memory is released not
    by destructors of TDF_LabelNode,
    but rather by the destructor of
    TDF_Data).
  3. TDF_LabelNode objects do not
    fragmentize the memory; they are
    kept compactly in a number of
    arrays of 16K each.
  4. Swapping is reduced on large
    data, because each document now
    occupies a smaller number of
    memory pages.
Standard_OStream& TDF_Data::operator<< ( Standard_OStream anOS) const [inline]
Handle_TDF_Delta TDF_Data::Undo ( const Handle< TDF_Delta > &  aDelta,
const Standard_Boolean  withDelta = Standard_False 
)

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