Handles converting buffers to and from disk. More...

#include <CubeIoHandler.h>

Inheritance diagram for Isis::CubeIoHandler:

Collaboration diagram for Isis::CubeIoHandler:

Public Member Functions
	CubeIoHandler (QFile dataFile, const QList< int > virtualBandList, const Pvl &label, bool alreadyOnDisk)
	Creates a new CubeIoHandler using a RegionalCachingAlgorithm.

virtual	~CubeIoHandler ()
	Cleans up all allocated memory.

void	read (Buffer &bufferToFill) const
	Read cube data from disk into the buffer.

void	write (const Buffer &bufferToWrite)
	Write buffer data into the cube data on disk.

void	addCachingAlgorithm (CubeCachingAlgorithm *algorithm)
	This will add the given caching algorithm to the list of attempted caching algorithms.

void	clearCache (bool blockForWriteCache=true) const
	Free all cube chunks (cached cube data) from memory and write them to disk.

BigInt	getDataSize () const

void	setVirtualBands (const QList< int > *virtualBandList)
	This changes the virtual band list.

virtual void	updateLabels (Pvl &labels)=0
	Function to update the labels with a Pvl object.

QMutex *	dataFileMutex ()
	Get the mutex that this IO handler is using around I/Os on the given data file.

Protected Member Functions
int	bandCount () const

int	getBandCountInChunk () const

BigInt	getBytesPerChunk () const

int	getChunkCountInBandDimension () const

int	getChunkCountInLineDimension () const

int	getChunkCountInSampleDimension () const

int	getChunkIndex (const RawCubeChunk &) const
	Given a chunk, what's its index in the file.

BigInt	getDataStartByte () const

QFile *	getDataFile ()

int	lineCount () const

int	getLineCountInChunk () const

PixelType	pixelType () const

int	sampleCount () const

int	getSampleCountInChunk () const

void	setChunkSizes (int numSamples, int numLines, int numBands)
	This should be called once from the child constructor.

virtual void	readRaw (RawCubeChunk &chunkToFill)=0
	This needs to populate the chunkToFill with unswapped raw bytes from the disk.

virtual void	writeRaw (const RawCubeChunk &chunkToWrite)=0
	This needs to write the chunkToWrite directly to disk with no modifications to the data itself.

Detailed Description

Handles converting buffers to and from disk.

This class handles converting buffers to and from disk. This class holds the cube chunks in memory and is capable of reading and writing them. It asks the caching algorithms to recommend cube chunks to not keep in memory. Children need to call setChunkSizes() in their constructor.

This class handles all of the virtual band conversions. This class also guarantees that unwritten cube data ends up read and written as NULLs. The default caching algorithm is a RegionalCachingAlgorithm.

Author: 2011-??-?? Jai Rideout and Steven Lambright

Constructor & Destructor Documentation

◆ CubeIoHandler()

Isis::CubeIoHandler::CubeIoHandler	(	QFile *	dataFile,
		const QList< int > *	virtualBandList,
		const Pvl &	label,
		bool	alreadyOnDisk )

Creates a new CubeIoHandler using a RegionalCachingAlgorithm.

The chunk sizes must be set by a child in its constructor.

Parameters

dataFile	The file that contains cube data. This should be a valid, opened QFile and may not be NULL. The file should have at least read permissions.
virtualBandList	A list where the indices are the vbands and the values are the physical bands. The values are 1-based. This can be specified as NULL, in which case the vbands are the physical bands. The virtual band list is copied (the pointer provided isn't remembered).
label	The label which contains the "Pixels" and "Core" groups.
alreadyOnDisk	True if the cube exists; false ensures all NULLs are initialized into the file before this object is destructed.

References _FILEINFO_, Isis::PvlContainer::findKeyword(), Isis::PvlObject::findObject(), Isis::PixelTypeEnumeration(), Isis::Preference::Preferences(), Isis::IException::Programmer, setVirtualBands(), and Isis::EndianSwapper::willSwap().

◆ ~CubeIoHandler()

Isis::CubeIoHandler::~CubeIoHandler ( )

virtual

Cleans up all allocated memory.

Child destructors must call clearCache() because we can no longer do IO by the time this destructor is called.

Member Function Documentation

◆ addCachingAlgorithm()

void Isis::CubeIoHandler::addCachingAlgorithm ( CubeCachingAlgorithm * algorithm )

This will add the given caching algorithm to the list of attempted caching algorithms.

The algorithms are tried in the opposite order that they were added - the first algorithm added is the last algorithm tried.

This method takes ownership of algorithm.

Parameters

algorithm The caching algorithm to add to the Cube for I/O

Referenced by Isis::Cube::addCachingAlgorithm().

◆ bandCount()

int Isis::CubeIoHandler::bandCount ( ) const

protected

Returns: the number of physical bands in the cube.

◆ clearCache()

void Isis::CubeIoHandler::clearCache ( bool blockForWriteCache = true ) const

Free all cube chunks (cached cube data) from memory and write them to disk.

Child destructors need to call this method.

This method should only be called otherwise when lots of cubes are in memory and the many caches cause problems with system RAM limitations.

Parameters

blockForWriteCache This should be true unless this method is called from the write thread.

Referenced by Isis::Cube::clearIoCache(), Isis::Cube::copy(), Isis::CubeBsqHandler::~CubeBsqHandler(), and Isis::CubeTileHandler::~CubeTileHandler().

◆ dataFileMutex()

QMutex * Isis::CubeIoHandler::dataFileMutex ( )

Get the mutex that this IO handler is using around I/Os on the given data file.

A lock should be acquired before doing any reads/writes on the data file externally.

Returns: A mutex that can guarantee exclusive access to the data file

Referenced by Isis::Cube::read(), and Isis::Cube::write().

◆ getBandCountInChunk()

int Isis::CubeIoHandler::getBandCountInChunk ( ) const

protected

Returns: the number of bands per chunk for this cube.

Referenced by getChunkIndex(), and read().

◆ getBytesPerChunk()

BigInt Isis::CubeIoHandler::getBytesPerChunk ( ) const

protected

Returns: the byte size of each chunk in the cube. Currently they must be constant size, but this is planned to be changed at some point in time.; Number of bytes in a cube chunk

References Isis::SizeOf().

Referenced by getDataSize().

◆ getChunkCountInBandDimension()

int Isis::CubeIoHandler::getChunkCountInBandDimension ( ) const

protected

Returns: the total number of chunks in the band (Z) dimension. This is always enough to contain every band in the cube.

Referenced by getDataSize().

◆ getChunkCountInLineDimension()

int Isis::CubeIoHandler::getChunkCountInLineDimension ( ) const

protected

Returns: the total number of chunks in the line (Y) dimension. This is always enough to contain every line in the cube.

Referenced by getChunkIndex(), getDataSize(), and read().

◆ getChunkCountInSampleDimension()

int Isis::CubeIoHandler::getChunkCountInSampleDimension ( ) const

protected

Returns: the total number of chunks in the sample (X) dimension. This is always enough to contain every sample in the cube.

Referenced by getChunkIndex(), getDataSize(), and read().

◆ getChunkIndex()

int Isis::CubeIoHandler::getChunkIndex ( const RawCubeChunk & chunk ) const

protected

Given a chunk, what's its index in the file.

Chunks are ordered from left to right, then top to bottom, then front to back (BSQ). The first chunk is at the top left of band 1 and is index 0, for example. In other words, this is going from the value of m_rawData to the key.

Chunks which sit outside of the cube entirely must not be passed into this method; the results will be wrong.

Returns: The chunk's index into the file

References getBandCountInChunk(), getChunkCountInLineDimension(), getChunkCountInSampleDimension(), getLineCountInChunk(), and getSampleCountInChunk().

◆ getDataFile()

QFile * Isis::CubeIoHandler::getDataFile ( )

protected

Returns: the QFile containing cube data. This is what should be read from and written to.; The data file for I/O

Referenced by Isis::CubeBsqHandler::readRaw(), Isis::CubeTileHandler::readRaw(), Isis::CubeBsqHandler::writeRaw(), and Isis::CubeTileHandler::writeRaw().

◆ getDataSize()

BigInt Isis::CubeIoHandler::getDataSize ( ) const

Returns: the number of bytes that the cube DNs will take up. This includes padding caused by the cube chunks not aligning with the cube dimensions.

References getBytesPerChunk(), getChunkCountInBandDimension(), getChunkCountInLineDimension(), and getChunkCountInSampleDimension().

Referenced by setChunkSizes(), and Isis::Cube::write().

◆ getDataStartByte()

BigInt Isis::CubeIoHandler::getDataStartByte ( ) const

protected

Returns: the byte offset to the beginning of the cube data.

Referenced by setChunkSizes().

◆ getLineCountInChunk()

int Isis::CubeIoHandler::getLineCountInChunk ( ) const

protected

Returns: the number of lines in each chunk of the cube.

Referenced by getChunkIndex(), read(), and Isis::CubeTileHandler::updateLabels().

◆ getSampleCountInChunk()

int Isis::CubeIoHandler::getSampleCountInChunk ( ) const

protected

Returns: the number of samples in each chunk of the cube.

Referenced by getChunkIndex(), read(), and Isis::CubeTileHandler::updateLabels().

◆ lineCount()

int Isis::CubeIoHandler::lineCount ( ) const

protected

Returns: the number of lines in the cube. This does not include lines created by the chunk overflowing the line dimension.

Referenced by Isis::CubeBsqHandler::CubeBsqHandler(), and Isis::CubeTileHandler::CubeTileHandler().

◆ pixelType()

PixelType Isis::CubeIoHandler::pixelType ( ) const

protected

Returns: the physical cube DN format.

Referenced by Isis::CubeBsqHandler::CubeBsqHandler(), and Isis::CubeTileHandler::CubeTileHandler().

◆ read()

void Isis::CubeIoHandler::read ( Buffer & bufferToFill ) const

Read cube data from disk into the buffer.

This is not const because it caches the read cube chunks from the disk.

Parameters

bufferToFill The buffer to populate with cube data.

References getBandCountInChunk(), getChunkCountInLineDimension(), getChunkCountInSampleDimension(), getLineCountInChunk(), getSampleCountInChunk(), and Isis::Null.

Referenced by Isis::Cube::read().

◆ readRaw()

virtual void Isis::CubeIoHandler::readRaw ( RawCubeChunk & chunkToFill )

protectedpure virtual

This needs to populate the chunkToFill with unswapped raw bytes from the disk.

See also: CubeTileHandler::readRaw()

Parameters

chunkToFill The container that needs to be filled with cube data.

Implemented in Isis::CubeBsqHandler, and Isis::CubeTileHandler.

◆ sampleCount()

int Isis::CubeIoHandler::sampleCount ( ) const

protected

Returns: the number of samples in the cube. This does not include samples created by the chunk overflowing the sample dimension.

Referenced by Isis::CubeBsqHandler::CubeBsqHandler(), and Isis::CubeTileHandler::CubeTileHandler().

◆ setChunkSizes()

void Isis::CubeIoHandler::setChunkSizes	(	int	numSamples,
		int	numLines,
		int	numBands )

protected

This should be called once from the child constructor.

This determines the chunk sizes used for the cube and often should remain constant for a particular cube (BSQ, for example, doesn't need it to be constant but Tile does). These being large can cause excessive use of disk space that stores no cube data. These being large can also drastically increase the amount of RAM consumed.

Parameters

numSamples	The chunk size in the sample dimension
numLines	The chunk size in the line dimension
numBands	The chunk size in the band dimension

References _FILEINFO_, getDataSize(), getDataStartByte(), and Isis::IException::Programmer.

Referenced by Isis::CubeBsqHandler::CubeBsqHandler(), and Isis::CubeTileHandler::CubeTileHandler().

◆ setVirtualBands()

void Isis::CubeIoHandler::setVirtualBands ( const QList< int > * virtualBandList )

This changes the virtual band list.

Parameters

virtualBandList A list where the indices are the vbands and the values are the physical bands. The values are 1-based. This can be specified as NULL, in which case the vbands are the physical bands. The virtual band list is copied (the pointer provided isn't remembered).

Referenced by CubeIoHandler(), and Isis::Cube::setVirtualBands().

◆ updateLabels()

virtual void Isis::CubeIoHandler::updateLabels ( Pvl & labels )

pure virtual

Function to update the labels with a Pvl object.

Parameters

labels Pvl object to update with

Implemented in Isis::CubeTileHandler, and Isis::CubeBsqHandler.

Referenced by Isis::Cube::create().

◆ write()

void Isis::CubeIoHandler::write ( const Buffer & bufferToWrite )

Write buffer data into the cube data on disk.

This could do no IO if the cube chunks required are already in memory and our caching algorithms say to not free any of the cube chunks afterwards.

Parameters

bufferToWrite The buffer to get cube data from.

Referenced by Isis::Cube::write().

◆ writeRaw()

virtual void Isis::CubeIoHandler::writeRaw ( const RawCubeChunk & chunkToWrite )

protectedpure virtual

This needs to write the chunkToWrite directly to disk with no modifications to the data itself.

See also: CubeTileHandler::writeRaw()

Parameters

chunkToWrite The container that needs to be put on disk.

Implemented in Isis::CubeBsqHandler, and Isis::CubeTileHandler.

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

/Users/chkim/repos/ISIS3/isis/src/base/objs/Cube/CubeIoHandler.h
/Users/chkim/repos/ISIS3/isis/src/base/objs/Cube/CubeIoHandler.cpp

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ CubeIoHandler()

◆ ~CubeIoHandler()

Member Function Documentation

◆ addCachingAlgorithm()

◆ bandCount()

◆ clearCache()

◆ dataFileMutex()

◆ getBandCountInChunk()

◆ getBytesPerChunk()

◆ getChunkCountInBandDimension()

◆ getChunkCountInLineDimension()

◆ getChunkCountInSampleDimension()

◆ getChunkIndex()

◆ getDataFile()

◆ getDataSize()

◆ getDataStartByte()

◆ getLineCountInChunk()

◆ getSampleCountInChunk()

◆ lineCount()

◆ pixelType()

◆ read()

◆ readRaw()

◆ sampleCount()

◆ setChunkSizes()

◆ setVirtualBands()

◆ updateLabels()

◆ write()

◆ writeRaw()