vtk9/IO/MPIImage/vtkMPIImageReader.h

136 lines
4.7 KiB
C++

// -*- c++ -*-
/*=========================================================================
Program: Visualization Toolkit
Module: vtkMPIImageReader.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.
=========================================================================*/
/*----------------------------------------------------------------------------
Copyright (c) Sandia Corporation
See Copyright.txt or http://www.paraview.org/HTML/Copyright.html for details.
----------------------------------------------------------------------------*/
/**
* @class vtkMPIImageReader
*
*
*
* vtkMPIImageReader provides the mechanism to read a brick of bytes (or shorts,
* or ints, or floats, or doubles, ...) from a file or series of files. You can
* use it to read raw image data from files. You may also be able to subclass
* this to read simple file formats.
*
* What distinguishes this class from vtkImageReader and vtkImageReader2 is that
* it performs synchronized parallel I/O using the MPIIO layer. This can make a
* huge difference in file read times, especially when reading in parallel from
* a parallel file system.
*
* Despite the name of this class, vtkMPIImageReader will work even if MPI is
* not available. If MPI is not available or MPIIO is not available or the
* given Controller is not a vtkMPIController (or nullptr), then this class will
* silently work exactly like its superclass. The point is that you can safely
* use this class in applications that may or may not be compiled with MPI (or
* may or may not actually be run with MPI).
*
* @sa
* vtkMultiProcessController, vtkImageReader, vtkImageReader2
*
*/
#ifndef vtkMPIImageReader_h
#define vtkMPIImageReader_h
#include "vtkIOMPIImageModule.h" // For export macro
#include "vtkImageReader.h"
class vtkMPIOpaqueFileHandle;
class vtkMultiProcessController;
class VTKIOMPIIMAGE_EXPORT vtkMPIImageReader : public vtkImageReader
{
public:
vtkTypeMacro(vtkMPIImageReader, vtkImageReader);
static vtkMPIImageReader* New();
void PrintSelf(ostream& os, vtkIndent indent) override;
///@{
/**
* Get/set the multi process controller to use for coordinated reads. By
* default, set to the global controller.
*/
vtkGetObjectMacro(Controller, vtkMultiProcessController);
virtual void SetController(vtkMultiProcessController*);
///@}
protected:
vtkMPIImageReader();
~vtkMPIImageReader() override;
vtkMultiProcessController* Controller;
/**
* Returns the size, in bytes of the scalar data type (GetDataScalarType).
*/
int GetDataScalarTypeSize();
/**
* Break up the controller based on the files each process reads. Each group
* comprises the processes that read the same files in the same order.
* this->GroupedController is set to the group for the current process.
*/
virtual void PartitionController(const int extent[6]);
/**
* Get the header size of the given open file. This should be used in liu of
* the GetHeaderSize methods of the superclass.
*/
virtual unsigned long GetHeaderSize(vtkMPIOpaqueFileHandle& file);
/**
* Set up a "view" on the open file that will allow you to read the 2D or 3D
* subarray from the file in one read. Once you call this method, the file
* will look as if it contains only the data the local process needs to read
* in.
*/
virtual void SetupFileView(vtkMPIOpaqueFileHandle& file, const int extent[6]);
/**
* Given a slice of the data, open the appropriate file, read the data into
* given buffer, and close the file. For three dimensional data, always
* use "slice" 0. Make sure the GroupedController is properly created before
* calling this using the PartitionController method.
*/
virtual void ReadSlice(int slice, const int extent[6], void* buffer);
/**
* Transform the data from the order read from a file to the order to place
* in the output data (as defined by the transform).
*/
virtual void TransformData(vtkImageData* data);
///@{
/**
* A group of processes that are reading the same file (as determined by
* PartitionController.
*/
void SetGroupedController(vtkMultiProcessController*);
vtkMultiProcessController* GroupedController;
///@}
void ExecuteDataWithInformation(vtkDataObject* data, vtkInformation* outInfo) override;
private:
vtkMPIImageReader(const vtkMPIImageReader&) = delete;
void operator=(const vtkMPIImageReader&) = delete;
};
#endif // vtkMPIImageReader_h