casa::VirtualTaQLColumn Class Reference
[Tables]

#include <VirtualTaQLColumn.h>

Inheritance diagram for casa::VirtualTaQLColumn:

[legend]Collaboration diagram for casa::VirtualTaQLColumn:

[legend]List of all members.

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Detailed Description

Virtual scalar column using TaQL.

Review Status

Reviewed By:

GvD

Date Reviewed:

2004/07/09

Prerequisite

• VirtualColumnColumn
• VirtualScalarColumn
• VirtualArrayColumn

Synopsis

DummyVirtualScalar is an example of how to implement a virtual column class handling a scalar. This class scales the data in table column "DATA1" from Int to double and back using a scale factor given at construction time. This class is used by DummyVirtualColumn which is the engine for handling this scalar column and another column.

Motivation

This class is an example for writers of real virtual column classes. It is tested by tVirtColEng.cc.

Definition at line 66 of file VirtualTaQLColumn.h.

Public Member Functions
	VirtualTaQLColumn (const String &expr)
	Construct it with the given TaQL expression.
	VirtualTaQLColumn (const Record &spec)
	Construct it with the given specification.
virtual	~VirtualTaQLColumn ()
	Destructor is mandatory.
virtual DataManager *	clone () const
	Clone the engine object.
virtual Record	dataManagerSpec () const
	Get the data manager specification.
virtual String	dataManagerType () const
	Return the type name of the engine.
const String &	expression () const
	Return the TaQL expression used.
virtual int	dataType () const
	Functions to return column info.
virtual Bool	isWritable () const
	Test if data can be put into this column.
virtual uInt	ndim (uInt rownr)
	Get the dimensionality of the item in the given row.
virtual IPosition	shape (uInt rownr)
	Get the shape of the item in the given row.
virtual Bool	isShapeDefined (uInt rownr)
	Is the value shape defined in the given row? By default it returns True.
Static Public Member Functions
static void	registerClass ()
	Register the class name and the static makeObject "constructor".
Private Member Functions
	VirtualTaQLColumn (const VirtualTaQLColumn &)
	Copy is not needed and therefore forbidden (so it is made private).
VirtualTaQLColumn &	operator= (const VirtualTaQLColumn &)
	Assignment is not needed and therefore forbidden (so it is made private).
virtual DataManagerColumn *	makeScalarColumn (const String &columnName, int dataType, const String &)
	Create the column object for the scalar column in this engine.
virtual DataManagerColumn *	makeIndArrColumn (const String &columnName, int dataType, const String &dataTypeId)
	Create the column object for the indirect array column in this engine.
virtual void	create (uInt)
	Let the engine initialize the object for a new table.
virtual void	prepare ()
	Prepare compiles the expression.
virtual void	getArrayV (uInt rownr, void *dataPtr)
	Get the array value in the given row.
IPosition	getResult (uInt rownr, void *dataPtr)
	Get the result.
void	clearCurResult ()
	Clear the result cache.
virtual void	getBoolV (uInt rownr, Bool *dataPtr)
	Get the scalar value in the given row.
virtual void	getuCharV (uInt rownr, uChar *dataPtr)
virtual void	getShortV (uInt rownr, Short *dataPtr)
virtual void	getuShortV (uInt rownr, uShort *dataPtr)
virtual void	getIntV (uInt rownr, Int *dataPtr)
virtual void	getuIntV (uInt rownr, uInt *dataPtr)
virtual void	getfloatV (uInt rownr, float *dataPtr)
virtual void	getdoubleV (uInt rownr, double *dataPtr)
virtual void	getComplexV (uInt rownr, Complex *dataPtr)
virtual void	getDComplexV (uInt rownr, DComplex *dataPtr)
virtual void	getStringV (uInt rownr, String *dataPtr)
Static Private Member Functions
static DataManager *	makeObject (const String &dataManagerName, const Record &spec)
	Define the "constructor" to construct this engine when a table is read back.
Private Attributes
int	itsDataType
Bool	itsIsArray
String	itsColumnName
String	itsExpr
TableExprNode *	itsNode
Bool	itsTempWritable
Int	itsCurRow
void *	itsCurResult
IPosition	itsCurShape

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Constructor & Destructor Documentation

casa::VirtualTaQLColumn::VirtualTaQLColumn

(

const String &

expr

)

Construct it with the given TaQL expression.

casa::VirtualTaQLColumn::VirtualTaQLColumn

(

const Record &

spec

)

Construct it with the given specification.

virtual casa::VirtualTaQLColumn::~VirtualTaQLColumn

(

)

[virtual]

Destructor is mandatory.

casa::VirtualTaQLColumn::VirtualTaQLColumn

(

const VirtualTaQLColumn &

)

[private]

Copy is not needed and therefore forbidden (so it is made private).

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Member Function Documentation

virtual DataManager* casa::VirtualTaQLColumn::clone

(

)

const [virtual]

Clone the engine object.

Implements casa::DataManager.

virtual Record casa::VirtualTaQLColumn::dataManagerSpec

(

)

const [virtual]

Get the data manager specification.

Reimplemented from casa::DataManager.

virtual String casa::VirtualTaQLColumn::dataManagerType

(

)

const [virtual]

Return the type name of the engine.

(i.e. its class name VirtualTaQLColumn).

Implements casa::DataManager.

static void casa::VirtualTaQLColumn::registerClass

(

)

[static]

Register the class name and the static makeObject "constructor".

This will make the engine known to the table system.

const String& casa::VirtualTaQLColumn::expression

(

)

const [inline]

Return the TaQL expression used.

Definition at line 94 of file VirtualTaQLColumn.h.

References itsExpr.

virtual int casa::VirtualTaQLColumn::dataType

(

)

const [virtual]

Functions to return column info.

Implements casa::DataManagerColumn.

virtual Bool casa::VirtualTaQLColumn::isWritable

(

)

const [virtual]

Test if data can be put into this column.

This does not test if the data file is writable, only if it is in principle allowed to store data into the column. (It may not be allowed for virtual columns). The default is True.

Reimplemented from casa::DataManagerColumn.

virtual uInt casa::VirtualTaQLColumn::ndim

(

uInt

rownr

)

[virtual]

Get the dimensionality of the item in the given row.

By default it returns shape(rownr).nelements().

Reimplemented from casa::DataManagerColumn.

virtual IPosition casa::VirtualTaQLColumn::shape

(

uInt

rownr

)

[virtual]

Get the shape of the item in the given row.

By default it returns a zero-length IPosition (for a scalar value).

Reimplemented from casa::DataManagerColumn.

virtual Bool casa::VirtualTaQLColumn::isShapeDefined

(

uInt

rownr

)

[virtual]

Is the value shape defined in the given row? By default it returns True.

Reimplemented from casa::DataManagerColumn.

VirtualTaQLColumn& casa::VirtualTaQLColumn::operator=

(

const VirtualTaQLColumn &

)

[private]

Assignment is not needed and therefore forbidden (so it is made private).

virtual DataManagerColumn* casa::VirtualTaQLColumn::makeScalarColumn	(	const String &	columnName,
		int	dataType,
		const String &
	)			[private, virtual]

Create the column object for the scalar column in this engine.

Reimplemented from casa::VirtualColumnEngine.

virtual DataManagerColumn* casa::VirtualTaQLColumn::makeIndArrColumn	(	const String &	columnName,
		int	dataType,
		const String &	dataTypeId
	)			[private, virtual]

Create the column object for the indirect array column in this engine.

Reimplemented from casa::VirtualColumnEngine.

virtual void casa::VirtualTaQLColumn::create

(

uInt

)

[private, virtual]

Let the engine initialize the object for a new table.

It defines a column keyword holding the expression.

Reimplemented from casa::VirtualColumnEngine.

virtual void casa::VirtualTaQLColumn::prepare

(

)

[private, virtual]

Prepare compiles the expression.

Reimplemented from casa::VirtualColumnEngine.

static DataManager* casa::VirtualTaQLColumn::makeObject	(	const String &	dataManagerName,
		const Record &	spec
	)			[static, private]

Define the "constructor" to construct this engine when a table is read back.

This "constructor" has to be registered by the user of the engine. If the engine is commonly used, its registration can be added into the registerAllCtor function in DataManReg.cc. This function gets automatically invoked by the table system.

virtual void casa::VirtualTaQLColumn::getBoolV	(	uInt	rownr,
		Bool *	dataPtr
	)			[private, virtual]

Get the scalar value in the given row.

The default implementation throws an "invalid operation" exception.

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getuCharV	(	uInt	rownr,
		uChar *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getShortV	(	uInt	rownr,
		Short *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getuShortV	(	uInt	rownr,
		uShort *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getIntV	(	uInt	rownr,
		Int *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getuIntV	(	uInt	rownr,
		uInt *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getfloatV	(	uInt	rownr,
		float *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getdoubleV	(	uInt	rownr,
		double *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getComplexV	(	uInt	rownr,
		Complex *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getDComplexV	(	uInt	rownr,
		DComplex *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getStringV	(	uInt	rownr,
		String *	dataPtr
	)			[private, virtual]

Reimplemented from casa::DataManagerColumn.

virtual void casa::VirtualTaQLColumn::getArrayV	(	uInt	rownr,
		void *	dataPtr
	)			[private, virtual]

Get the array value in the given row.

The argument dataPtr is in fact an Array<T>*, but a void* is needed to be generic. The array pointed to by dataPtr has to have the correct shape (which is guaranteed by the ArrayColumn get function). The default implementation throws an "invalid operation" exception.

Reimplemented from casa::DataManagerColumn.

IPosition casa::VirtualTaQLColumn::getResult	(	uInt	rownr,
		void *	dataPtr
	)			[private]

Get the result.

void casa::VirtualTaQLColumn::clearCurResult

(

)

[private]

Clear the result cache.

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Member Data Documentation

int casa::VirtualTaQLColumn::itsDataType [private]

Definition at line 176 of file VirtualTaQLColumn.h.

Bool casa::VirtualTaQLColumn::itsIsArray [private]

Definition at line 177 of file VirtualTaQLColumn.h.

String casa::VirtualTaQLColumn::itsColumnName [private]

Definition at line 178 of file VirtualTaQLColumn.h.

String casa::VirtualTaQLColumn::itsExpr [private]

Definition at line 179 of file VirtualTaQLColumn.h.

Referenced by expression().

TableExprNode* casa::VirtualTaQLColumn::itsNode [private]

Definition at line 180 of file VirtualTaQLColumn.h.

Bool casa::VirtualTaQLColumn::itsTempWritable [private]

Definition at line 181 of file VirtualTaQLColumn.h.

Int casa::VirtualTaQLColumn::itsCurRow [private]

Definition at line 182 of file VirtualTaQLColumn.h.

void* casa::VirtualTaQLColumn::itsCurResult [private]

Definition at line 183 of file VirtualTaQLColumn.h.

IPosition casa::VirtualTaQLColumn::itsCurShape [private]

Definition at line 184 of file VirtualTaQLColumn.h.

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

• tables/implement/Tables/VirtualTaQLColumn.h

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