casa::VirtualScalarColumn< T > Class Template Reference
[Tables_internal_classes]

#include <VirtScaCol.h>

Inheritance diagram for casa::VirtualScalarColumn< T >:

[legend]Collaboration diagram for casa::VirtualScalarColumn< T >:

[legend]List of all members.

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Detailed Description

template<class T>
class casa::VirtualScalarColumn< T >

Templated base class for virtual scalar column.

Intended use:

Internal

Review Status

Reviewed By:

Gareth Hunt

Date Reviewed:

94Nov17

Prerequisite

• DataManagerColumn
• VirtualColumnEngine

Etymology

VirtualScalarColumn handles a virtual column containing a scalar.

Synopsis

VirtualScalarColumn is the abstract base class to handle a scalar column for a virtual column engine. It is derived from DataManagerColumn and reimplements some virtual functions to make life easier for the derived classes. It does the following:

• It implements the dataType function, so it is not needed to implement that in derived classes.
• It has a default implementation of False for function isWritable. Thus by default virtual scalar columns are not writable, which will often be the case. Only if a virtual scalar column can be writable, it has to be implemented in the derived class.
• Declare a get/put function with the template parameter as its argument. The virtual functions get/putBoolV, etc. (defined in DataManagerColumn) are by default implemented using this (templated) get/put function. This allows for the default implementation of get/putBlock and makes life easier for the implementor of a derived class. However, the disadvantage of this is an extra virtual function call. (E.g. for a Bool value the first one is getBoolV and the second one get(T&), where T is Bool). If efficiency is really necessary, getBoolV, etc. should also be implemented in the derived class.
• In DataManagerColumn the functions get/putBlockV and get/putColumnV are defined, which have a void* data argument. This is necessary to handle arbitrary data types in the non-templated base class DataManagerColumn. In this templated VirtualScalarColumn class, virtual functions get/putBlock and get/putColumn have been defined. They cast the void* data argument to T&, so in a derived class no care has to be taken for that cast. Furthermore a default implementation of them has been made.
  • getBlock gets one value using function get.
  • putBlock puts one value at the time using function put.
  • getColumn uses function getBlock.
  • putColumn uses function putBlock.
  If efficiency is an issue, these functions should be implemented in the derived class.

Motivation

This class reimplements some virtual functions implemented by DataManagerColumn and types the data argument. In that way they are easier to implement in derived classes. Furthermore they allow default implementations.

Template Type Argument Requirements (T)

• default constructor
• copy constructor
• assignment operator
• static String dataTypeId(); // unique name of the class

To Do

Definition at line 126 of file VirtScaCol.h.

Public Member Functions
	VirtualScalarColumn ()
	Create a column.
virtual	~VirtualScalarColumn ()
	Frees up the storage.
int	dataType () const
	Return the data type of the column.
String	dataTypeId () const
	Return the data type Id of the column.
virtual Bool	isWritable () const
	By default no data can be put in a virtual column.
Protected Member Functions
Bool	canAccessScalarColumn (Bool &reask) const
	The class can handle a get/putScalarColumn.
virtual void	get (uInt rownr, T &data)=0
	Get the scalar value in the given row.
virtual void	put (uInt rownr, const T &data)
	Put the scalar value into the given row.
virtual void	getScalarColumn (Vector< T > &data)
	Get all scalar values in the column.
virtual void	putScalarColumn (const Vector< T > &data)
	Put all scalar values in the column.
virtual uInt	getBlock (uInt rownr, uInt nrmax, T *dataPtr)
	Get scalars from the given row on with a maximum of nrmax values.
virtual void	putBlock (uInt rownr, uInt nrmax, const T *dataPtr)
	Put nrmax scalars from the given row on.
Private Member Functions
void	getScalarColumnV (void *dataPtr)
	Implement the virtual functions defined in DataManagerColumn.
void	putScalarColumnV (const void *dataPtr)
	Implement the virtual functions defined in DataManagerColumn.
uInt	getBlockV (uInt rownr, uInt nrmax, void *dataPtr)
	Implement the virtual functions defined in DataManagerColumn.
void	putBlockV (uInt rownr, uInt nrmax, const void *dataPtr)
	Implement the virtual functions defined in DataManagerColumn.
	VirtualScalarColumn (const VirtualScalarColumn< T > &)
	The object cannot be copied.
VirtualScalarColumn< T > &	operator= (const VirtualScalarColumn< T > &)
	The object cannot be assigned to.
void	getBoolV (uInt rownr, Bool *dataPtr)
	Implement the virtual functions defined in DataManagerColumn.
void	getuCharV (uInt rownr, uChar *dataPtr)
void	getShortV (uInt rownr, Short *dataPtr)
void	getuShortV (uInt rownr, uShort *dataPtr)
void	getIntV (uInt rownr, Int *dataPtr)
void	getuIntV (uInt rownr, uInt *dataPtr)
void	getfloatV (uInt rownr, float *dataPtr)
void	getdoubleV (uInt rownr, double *dataPtr)
void	getComplexV (uInt rownr, Complex *dataPtr)
void	getDComplexV (uInt rownr, DComplex *dataPtr)
void	getStringV (uInt rownr, String *dataPtr)
void	getOtherV (uInt rownr, void *dataPtr)
	This function is the get for all non-standard data types.
void	putBoolV (uInt rownr, const Bool *dataPtr)
	Implement the virtual functions defined in DataManagerColumn.
void	putuCharV (uInt rownr, const uChar *dataPtr)
void	putShortV (uInt rownr, const Short *dataPtr)
void	putuShortV (uInt rownr, const uShort *dataPtr)
void	putIntV (uInt rownr, const Int *dataPtr)
void	putuIntV (uInt rownr, const uInt *dataPtr)
void	putfloatV (uInt rownr, const float *dataPtr)
void	putdoubleV (uInt rownr, const double *dataPtr)
void	putComplexV (uInt rownr, const Complex *dataPtr)
void	putDComplexV (uInt rownr, const DComplex *dataPtr)
void	putStringV (uInt rownr, const String *dataPtr)
void	putOtherV (uInt rownr, const void *dataPtr)
	This function is the put for all non-standard data types.

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Constructor & Destructor Documentation

template<class T>

casa::VirtualScalarColumn< T >::VirtualScalarColumn

(

)

[inline]

Create a column.

Definition at line 131 of file VirtScaCol.h.

template<class T>

virtual casa::VirtualScalarColumn< T >::~VirtualScalarColumn

(

)

[virtual]

Frees up the storage.

template<class T>

casa::VirtualScalarColumn< T >::VirtualScalarColumn

(

const VirtualScalarColumn< T > &

)

[private]

The object cannot be copied.

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Member Function Documentation

template<class T>

int casa::VirtualScalarColumn< T >::dataType

(

)

const [virtual]

Return the data type of the column.

Implements casa::DataManagerColumn.

template<class T>

String casa::VirtualScalarColumn< T >::dataTypeId

(

)

const [virtual]

Return the data type Id of the column.

Reimplemented from casa::DataManagerColumn.

template<class T>

virtual Bool casa::VirtualScalarColumn< T >::isWritable

(

)

const [virtual]

By default no data can be put in a virtual column.

Reimplemented from casa::DataManagerColumn.

template<class T>

Bool casa::VirtualScalarColumn< T >::canAccessScalarColumn

(

Bool &

reask

)

const [protected, virtual]

The class can handle a get/putScalarColumn.

Reimplemented from casa::DataManagerColumn.

template<class T>

virtual void casa::VirtualScalarColumn< T >::get	(	uInt	rownr,
		T &	data
	)			[protected, pure virtual]

Get the scalar value in the given row.

template<class T>

virtual void casa::VirtualScalarColumn< T >::put	(	uInt	rownr,
		const T &	data
	)			[protected, virtual]

Put the scalar value into the given row.

The default implementation throws an exception.

template<class T>

virtual void casa::VirtualScalarColumn< T >::getScalarColumn

(

Vector< T > &

data

)

[protected, virtual]

Get all scalar values in the column.

The argument dataPtr is in fact a Vector<T>*, but a void* is needed to be generic. The vector pointed to by dataPtr has to have the correct length (which is guaranteed by the ScalarColumn getColumn function).

template<class T>

virtual void casa::VirtualScalarColumn< T >::putScalarColumn

(

const Vector< T > &

data

)

[protected, virtual]

Put all scalar values in the column.

The argument dataPtr is in fact a const Vector<T>*, but a const void* is needed to be generic. The vector pointed to by dataPtr has to have the correct length (which is guaranteed by the ScalarColumn putColumn function).

template<class T>

virtual uInt casa::VirtualScalarColumn< T >::getBlock	(	uInt	rownr,
		uInt	nrmax,
		T *	dataPtr
	)			[protected, virtual]

Get scalars from the given row on with a maximum of nrmax values.

It returns the actual number of values got. This can be used to get an entire column of scalars or to get a part of a column (for a cache for example). The argument dataPtr is in fact a T*, but a void* is needed to be generic. It must have length nrmax.

template<class T>

virtual void casa::VirtualScalarColumn< T >::putBlock	(	uInt	rownr,
		uInt	nrmax,
		const T *	dataPtr
	)			[protected, virtual]

Put nrmax scalars from the given row on.

It returns the actual number of values put. This can be used to put an entire column of scalars or to put a part of a column (for a cache for example). The argument dataPtr is in fact a const T*, but a const void* is needed to be generic. It must have length nrmax.

template<class T>

void casa::VirtualScalarColumn< T >::getBoolV	(	uInt	rownr,
		Bool *	dataPtr
	)			[private, virtual]

Implement the virtual functions defined in DataManagerColumn.

Get the scalar value in the given row.

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getuCharV	(	uInt	rownr,
		uChar *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getShortV	(	uInt	rownr,
		Short *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getuShortV	(	uInt	rownr,
		uShort *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getIntV	(	uInt	rownr,
		Int *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getuIntV	(	uInt	rownr,
		uInt *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getfloatV	(	uInt	rownr,
		float *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getdoubleV	(	uInt	rownr,
		double *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getComplexV	(	uInt	rownr,
		Complex *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getDComplexV	(	uInt	rownr,
		DComplex *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getStringV	(	uInt	rownr,
		String *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getOtherV	(	uInt	rownr,
		void *	dataPtr
	)			[private, virtual]

This function is the get for all non-standard data types.

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putBoolV	(	uInt	rownr,
		const Bool *	dataPtr
	)			[private, virtual]

Implement the virtual functions defined in DataManagerColumn.

Put the scalar value into the given row.

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putuCharV	(	uInt	rownr,
		const uChar *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putShortV	(	uInt	rownr,
		const Short *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putuShortV	(	uInt	rownr,
		const uShort *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putIntV	(	uInt	rownr,
		const Int *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putuIntV	(	uInt	rownr,
		const uInt *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putfloatV	(	uInt	rownr,
		const float *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putdoubleV	(	uInt	rownr,
		const double *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putComplexV	(	uInt	rownr,
		const Complex *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putDComplexV	(	uInt	rownr,
		const DComplex *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putStringV	(	uInt	rownr,
		const String *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putOtherV	(	uInt	rownr,
		const void *	dataPtr
	)			[private, virtual]

This function is the put for all non-standard data types.

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::getScalarColumnV

(

void *

dataPtr

)

[private, virtual]

Implement the virtual functions defined in DataManagerColumn.

Get all scalar values in the column.

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putScalarColumnV

(

const void *

dataPtr

)

[private, virtual]

Implement the virtual functions defined in DataManagerColumn.

Put all scalar values in the column.

Reimplemented from casa::DataManagerColumn.

template<class T>

uInt casa::VirtualScalarColumn< T >::getBlockV	(	uInt	rownr,
		uInt	nrmax,
		void *	dataPtr
	)			[private, virtual]

Implement the virtual functions defined in DataManagerColumn.

Get scalars from the given row on with a maximum of nrmax values.

Reimplemented from casa::DataManagerColumn.

template<class T>

void casa::VirtualScalarColumn< T >::putBlockV	(	uInt	rownr,
		uInt	nrmax,
		const void *	dataPtr
	)			[private, virtual]

Implement the virtual functions defined in DataManagerColumn.

Put nrmax scalars from the given row on.

Reimplemented from casa::DataManagerColumn.

template<class T>

VirtualScalarColumn<T>& casa::VirtualScalarColumn< T >::operator=

(

const VirtualScalarColumn< T > &

)

[private]

The object cannot be assigned to.

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

• tables/implement/Tables/VirtScaCol.h

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