Envelope class for the description of a table column. More...

#include <ColumnDesc.h>

Public Types
enum	Option { Direct, Undefined, FixedShape }
	Enumerate the possible column options. More...
typedef BaseColumnDesc *	ColumnDescCtor (const String &className)
	Define the type of a XXColumnDesc construction function.
Public Member Functions
	ColumnDesc (const BaseColumnDesc &)
	Construct from a column description.
	ColumnDesc (const ColumnDesc &that)
	Copy constructor (copy semantics).
	ColumnDesc ()
	Default constructor (needed for ColumnDescSet).
	~ColumnDesc ()
ColumnDesc &	operator= (const ColumnDesc &that)
	Assignment (copy semantics).
Bool	operator== (const ColumnDesc &) const
	Comparison.
Bool	operator!= (const ColumnDesc &) const
TableRecord &	rwKeywordSet ()
	Get access to the set of keywords.
const TableRecord &	keywordSet () const
const String &	name () const
	Get the name of the column.
DataType	dataType () const
	Get the data type of the column.
DataType	trueDataType () const
	Get the true data type of the column.
const String &	dataTypeId () const
	Get the type id for non-standard data types (i.e.
const String &	dataManagerType () const
	Get the type name of the default data manager.
String &	dataManagerType ()
	Get the type name of the default data manager (allowing it to be changed).
const String &	dataManagerGroup () const
	Get the data manager group.
String &	dataManagerGroup ()
	Get the data manager group.
void	setDefaultDataManager (Bool always=True)
	If `always==True` they are always set, otherwise only if empty.
const String &	comment () const
	Get comment string.
String &	comment ()
	Get comment string (allowing it to be changed).
int	options () const
	Get the options.
Bool	isFixedShape () const
	Check if the column is defined with a fixed shape.
Bool	isScalar () const
	Test if column is a scalar.
Bool	isArray () const
	Test if column is an array.
Bool	isTable () const
	Test if column is a table.
Int	ndim () const
	Get the number of dimensions.
const IPosition &	shape () const
	Get the predefined shape.
void	setNdim (uInt ndim)
	Set the number of dimensions.
void	setShape (const IPosition &shape)
	Set the predefined shape.
void	setShape (const IPosition &shape, Bool directOption)
void	setOptions (int options)
	Set the options to the given value.
uInt	maxLength () const
	Get the maximum value length.
void	setMaxLength (uInt maxLength)
	Set the maximum value length.
const TableDesc *	tableDesc () const
	Get table description (in case column contains subtables).
TableDesc *	tableDesc ()
void	show () const
	Show the column on cout.
void	show (ostream &os) const
	Show the column.
void	setName (const String &name)
	Set the name of the column.
RefColumn *	makeRefColumn (RefTable rtp, BaseColumn bcp) const
	Create a RefColumn column object out of this column description.
ConcatColumn *	makeConcatColumn (ConcatTable *rtp) const
	Create a ConcatColumn column object out of this column description.
Static Public Member Functions
static ColumnDescCtor *	getCtor (const String &name)
	Get a construction function for a XXColumnDesc object (thread-safe).
static void	registerCtor (const String &name, ColumnDescCtor *)
	Register a "XXColumnDesc" constructor (thread-safe).
static void	registerMainCtor ()
	Register the main data managers (if not done yet).
Protected Attributes
BaseColumnDesc *	colPtr_p
Bool	allocated_p
Private Member Functions
	ColumnDesc (BaseColumnDesc *)
	Construct from a pointer (for class BaseColumn).
void	checkAdd (const ColumnDescSet &cds) const
	Check if a column can be handled by ColumnDescSet.
void	checkRename (const ColumnDescSet &cds, const String &newName) const
	Check when a column gets renamed in a table description.
void	handleAdd (ColumnDescSet &cds)
	Take action after a column has been handled by ColumnDescSet.
void	handleRename (ColumnDescSet &cds, const String &oldName)
void	handleRemove (ColumnDescSet &cds)
void	renameAction (const String &newName, const String &oldName)
	This function allows each column to act upon a rename of another column.
PlainColumn *	makeColumn (ColumnSet *csp) const
	Create a PlainColumn column object out of this column description.
void	putFile (AipsIO &ios, const TableAttr &) const
	Store the object in AipsIO.
void	getFile (AipsIO &, const TableAttr &)
	Get the object from AipsIO.
Static Private Member Functions
static void	unlockedRegisterCtor (const String &type, ColumnDescCtor *func)
	Register a constructor without doing a mutex lock.
static BaseColumnDesc *	unknownColumnDesc (const String &name)
	Serve as default function for theirRegisterMap (see below), which catches all unknown XXColumnDesc class names.
static void	doRegisterMainCtor (void *)
	Do the actual (thread-safe) registration of the main data managers.
Static Private Attributes
static MutexedInit	theirMutexedInit
	Define a map which maps the name of the various XXColumnDesc classes to a static function constructing them.
static SimpleOrderedMap < String, BaseColumnDesc ()(const String &)>	theirRegisterMap
Friends
class	ColumnDescSet
class	ColumnSet
class	BaseColumn
AipsIO &	operator<< (AipsIO &ios, const ColumnDesc &cd)
	Write into AipsIO.
AipsIO &	operator>> (AipsIO &ios, ColumnDesc &cd)
	Read from AipsIO.
ostream &	operator<< (ostream &ios, const ColumnDesc &cd)
	Show on ostream.

Detailed Description

Envelope class for the description of a table column.

Intended use:

Public interface

Review Status

Reviewed By:: Paul Shannon
Date Reviewed:: 1994/08/11
Test programs:: none

Prerequisite

Tables module (see especially Tables.h, the module header file)
Envelope/Letter class design (see J. Coplien, Advanced C++)

Synopsis

Class ColumnDesc is an envelope for the letter class BaseColDesc and its derivations like ScalarColumnDesc ,

ScalarRecordColumnDesc . ArrayColumnDesc , and SubTableDesc . ColumnDesc is meant to examine or slightly modify already existing column descriptions. It allows the retrieval of attributes like name, data type, etc.. For non-const ColumnDesc objects it is possible to modify the attributes comment and keyword set.

Since there are several types of columns, the class ColumnDesc cannot handle all details of those column types. Therefore, to create a column description, an instance of the specialized classes ArrayColumnDesc<T>, etc. has to be constructed. In there column type dependent things like array shape and default value can be defined.

This class also enumerates the possible options which can be used when defining a column via classes like ScalarColumnDesc<T>. These options are:

FixedShape: This is only useful for columns containing arrays and tables. FixedShape means that the shape of the array or table must be the same in each cell of the column. If not given, the array or table shape may vary. Option Direct forces FixedShape.
Direct: This is only useful for columns containing arrays and tables. Direct means that the data is directly stored in the table. Direct forces option FixedShape. If not given, the array or table is indirect, which implies that the data will be stored in a separate file.
Undefined: Undefined is only useful for scalars. If not given, all possible values of the scalar have a meaning. If given, a value equal to the default value in the column description is an undefined value. The function TableColumn::isDefined will return False for such values.

Example

     TableDesc tableDesc("theTableDesc", TableDesc::New);
     // Add a float scalar column.
     tableDesc.addColumn (ScalarColumnDesc<float> ("NAME");
     // Get the description of a column and change the comments.
     // In order to change the comments, a reference must be used
     // (because the ColumnDesc copy constructor and assign have copy
     // semantics).
     ColumnDesc& myColDesc = tableDesc.columnDesc ("aName");
     myColDesc.comment() += "some more comments";

Motivation

When getting the description of an arbitrary column, a pointer to that description is needed to allow proper execution of virtual functions. An envelope class is needed to hide this from the user.

Definition at line 131 of file ColumnDesc.h.

Member Typedef Documentation

typedef BaseColumnDesc* casa::ColumnDesc::ColumnDescCtor(const String &className)

Define the type of a XXColumnDesc construction function.

Definition at line 351 of file ColumnDesc.h.

Member Enumeration Documentation

enum casa::ColumnDesc::Option

Enumerate the possible column options.

They can be combined by adding (logical or-ing) them.

Enumerator:

Direct	direct table or array
Undefined	undefined values are possible
FixedShape	fixed array/table shape

Definition at line 141 of file ColumnDesc.h.

Constructor & Destructor Documentation

casa::ColumnDesc::ColumnDesc ( const BaseColumnDesc & )

Construct from a column description.

This constructor is merely for the purpose of the automatic conversion of an object like ScalarColumnDesc<T> to ColumnDesc when adding a column to the table description using the function TableDesc::addColumn.

casa::ColumnDesc::ColumnDesc ( const ColumnDesc & that )

Copy constructor (copy semantics).

casa::ColumnDesc::ColumnDesc ( ) [inline]

Default constructor (needed for ColumnDescSet).

Definition at line 161 of file ColumnDesc.h.

casa::ColumnDesc::~ColumnDesc ( )

casa::ColumnDesc::ColumnDesc ( BaseColumnDesc * ) [private]

Construct from a pointer (for class BaseColumn).

Member Function Documentation

void casa::ColumnDesc::checkAdd ( const ColumnDescSet & cds ) const [inline, private]

Check if a column can be handled by ColumnDescSet.

It is called before the column gets actually added, etc..

Check if the column can be added to the table description. It is implemented for a virtual column to check if the columns it uses really exist.

Definition at line 400 of file ColumnDesc.h.

References casa::BaseColumnDesc::checkAdd(), and colPtr_p.

void casa::ColumnDesc::checkRename	(	const ColumnDescSet &	cds,
		const String &	newName
	)		const `[inline, private]`

Check when a column gets renamed in a table description.

It is not used.

Definition at line 404 of file ColumnDesc.h.

References casa::BaseColumnDesc::checkRename(), and colPtr_p.

const String& casa::ColumnDesc::comment ( ) const [inline]

Get comment string.

Definition at line 230 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::comment().

String& casa::ColumnDesc::comment ( ) [inline]

Get comment string (allowing it to be changed).

Definition at line 234 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::comment().

const String& casa::ColumnDesc::dataManagerGroup ( ) const [inline]

Get the data manager group.

Definition at line 217 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::dataManagerGroup().

String& casa::ColumnDesc::dataManagerGroup ( ) [inline]

Get the data manager group.

(allowing it to be changed).

Definition at line 222 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::dataManagerGroup().

const String& casa::ColumnDesc::dataManagerType ( ) const [inline]

Get the type name of the default data manager.

Definition at line 208 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::dataManagerType().

String& casa::ColumnDesc::dataManagerType ( ) [inline]

Get the type name of the default data manager (allowing it to be changed).

Definition at line 213 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::dataManagerType().

DataType casa::ColumnDesc::dataType ( ) const [inline]

Get the data type of the column.

This always returns the type of a scalar, even when the column contains arrays.

Definition at line 194 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::dataType().

const String& casa::ColumnDesc::dataTypeId ( ) const [inline]

Get the type id for non-standard data types (i.e.

for TpOther). For standard data types the returned string is empty.

Definition at line 204 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::dataTypeId().

static void casa::ColumnDesc::doRegisterMainCtor ( void * ) [static, private]

Do the actual (thread-safe) registration of the main data managers.

static ColumnDescCtor* casa::ColumnDesc::getCtor ( const String & name ) [static]

Get a construction function for a XXColumnDesc object (thread-safe).

void casa::ColumnDesc::getFile	(	AipsIO &	,
		const TableAttr &
	)		`[private]`

Get the object from AipsIO.

void casa::ColumnDesc::handleAdd ( ColumnDescSet & cds ) [inline, private]

Take action after a column has been handled by ColumnDescSet.

It is called after the column has been actually added, etc.. This gives, for instance, the virtual column class the opportunity to update the virtual column list.

Definition at line 413 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::handleAdd().

void casa::ColumnDesc::handleRemove ( ColumnDescSet & cds ) [inline, private]

Definition at line 417 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::handleRemove().

void casa::ColumnDesc::handleRename	(	ColumnDescSet &	cds,
		const String &	oldName
	)		`[inline, private]`

Definition at line 415 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::handleRename().

Bool casa::ColumnDesc::isArray ( ) const [inline]

Test if column is an array.

Definition at line 257 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::isArray().

Bool casa::ColumnDesc::isFixedShape ( ) const

Check if the column is defined with a fixed shape.

This is always true for scalars. For arrays it is true when the FixedShape flag was set when the column was defined.

Bool casa::ColumnDesc::isScalar ( ) const [inline]

Test if column is a scalar.

Definition at line 254 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::isScalar().

Bool casa::ColumnDesc::isTable ( ) const [inline]

Test if column is a table.

Definition at line 260 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::isTable().

const TableRecord& casa::ColumnDesc::keywordSet ( ) const [inline]

Definition at line 183 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::keywordSet().

PlainColumn* casa::ColumnDesc::makeColumn ( ColumnSet * csp ) const [inline, private]

Create a PlainColumn column object out of this column description.

Definition at line 428 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::makeColumn().

ConcatColumn* casa::ColumnDesc::makeConcatColumn ( ConcatTable * rtp ) const [inline]

Create a ConcatColumn column object out of this column description.

Definition at line 346 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::makeConcatColumn().

RefColumn* casa::ColumnDesc::makeRefColumn	(	RefTable *	rtp,
		BaseColumn *	bcp
	)		const `[inline]`

Create a RefColumn column object out of this column description.

Definition at line 342 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::makeRefColumn().

uInt casa::ColumnDesc::maxLength ( ) const [inline]

Get the maximum value length.

Definition at line 303 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::maxLength().

const String& casa::ColumnDesc::name ( ) const

Get the name of the column.

Int casa::ColumnDesc::ndim ( ) const [inline]

Get the number of dimensions.

Definition at line 264 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::ndim().

Bool casa::ColumnDesc::operator!= ( const ColumnDesc & ) const

ColumnDesc& casa::ColumnDesc::operator= ( const ColumnDesc & that )

Assignment (copy semantics).

Bool casa::ColumnDesc::operator== ( const ColumnDesc & ) const

Comparison.

Two descriptions are equal when their data types, value types (scalar, array or table) and possible dimensionalities are equal.

int casa::ColumnDesc::options ( ) const [inline]

Get the options.

The possible options are defined by the enum Option. E.g.

           const ColumnDesc& coldesc = tableDesc.getColumn ("column_name");
           if (coldesc.option() & ColumnDesc::Direct  ==  ColumnDesc::Direct) {
                   // the column has the Direct flag set
           }

Definition at line 245 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::options().

void casa::ColumnDesc::putFile	(	AipsIO &	ios,
		const TableAttr &
	)		const `[private]`

Store the object in AipsIO.

static void casa::ColumnDesc::registerCtor	(	const String &	name,
		ColumnDescCtor *
	)		`[static]`

Register a "XXColumnDesc" constructor (thread-safe).

static void casa::ColumnDesc::registerMainCtor ( ) [inline, static]

Register the main data managers (if not done yet).

It is fully thread-safe.

Definition at line 361 of file ColumnDesc.h.

References casa::MutexedInit::exec(), and theirMutexedInit.

void casa::ColumnDesc::renameAction	(	const String &	newName,
		const String &	oldName
	)		`[inline, private]`

This function allows each column to act upon a rename of another column.

If the old name is used internally, the column can update itself. It is called after handleRename has been called.

Definition at line 424 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::renameAction().

TableRecord& casa::ColumnDesc::rwKeywordSet ( ) [inline]

Get access to the set of keywords.

Definition at line 181 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::rwKeywordSet().

void casa::ColumnDesc::setDefaultDataManager ( Bool always = True ) [inline]

If always==True they are always set, otherwise only if empty.

Definition at line 226 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setDefaultDataManager().

void casa::ColumnDesc::setMaxLength ( uInt maxLength ) [inline]

Set the maximum value length.

So far, this is only possible for columns containing String values. An exception is thrown if the column data type is not TpString. Some storage managers support fixed length strings and can store them more efficiently than variable length strings.

Definition at line 311 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setMaxLength().

void casa::ColumnDesc::setName ( const String & name ) [inline]

Set the name of the column.

Definition at line 338 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setName().

void casa::ColumnDesc::setNdim ( uInt ndim ) [inline]

Set the number of dimensions.

This is only allowed for arrays. ndim can be zero to clear the number of dimensions and the shape. Otherwise it can only be used if the dimensionality has not been defined yet.

Definition at line 278 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setNdim().

void casa::ColumnDesc::setOptions ( int options ) [inline]

Set the options to the given value.

Option ColumnDesc::Direct forces FixedShape. If FixedShape is not given (implicitly or explicitly), the column can have no shape, so its shape is cleared.

Definition at line 299 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setOptions().

void casa::ColumnDesc::setShape ( const IPosition & shape ) [inline]

Set the predefined shape.

This is only allowed for arrays, for which the shape has not been defined yet. If the dimensionality has already been defined, it must match. It will set the option FixedShape if not set yet.
The first version leaves the Direct option as is. The second version sets the Direct option as given.

Definition at line 289 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setShape().

void casa::ColumnDesc::setShape	(	const IPosition &	shape,
		Bool	directOption
	)		`[inline]`

Definition at line 291 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::setShape().

const IPosition& casa::ColumnDesc::shape ( ) const [inline]

Get the predefined shape.

If not defined, a zero shape will be returned.

Definition at line 269 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::shape().

void casa::ColumnDesc::show ( ) const

Show the column on cout.

void casa::ColumnDesc::show ( ostream & os ) const

Show the column.

const TableDesc* casa::ColumnDesc::tableDesc ( ) const [inline]

Get table description (in case column contains subtables).

Definition at line 316 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::tableDesc().

TableDesc* casa::ColumnDesc::tableDesc ( ) [inline]

Definition at line 318 of file ColumnDesc.h.

References colPtr_p, and casa::BaseColumnDesc::tableDesc().

DataType casa::ColumnDesc::trueDataType ( ) const

Get the true data type of the column.

Unlike dataType, it returns an array data type (e.g. TpArrayInt) when the column contains arrays.

static BaseColumnDesc* casa::ColumnDesc::unknownColumnDesc ( const String & name ) [static, private]

Serve as default function for theirRegisterMap (see below), which catches all unknown XXColumnDesc class names.

Thrown Exceptions

TableUnknownDesc

static void casa::ColumnDesc::unlockedRegisterCtor	(	const String &	type,
		ColumnDescCtor *	func
	)		`[inline, static, private]`

Register a constructor without doing a mutex lock.

Definition at line 366 of file ColumnDesc.h.

References casa::SimpleOrderedMap< K, V >::define(), and theirRegisterMap.

Friends And Related Function Documentation

friend class BaseColumn [friend]

Definition at line 135 of file ColumnDesc.h.

friend class ColumnDescSet [friend]

Definition at line 133 of file ColumnDesc.h.

friend class ColumnSet [friend]

Definition at line 134 of file ColumnDesc.h.

AipsIO& operator<<	(	AipsIO &	ios,
		const ColumnDesc &	cd
	)		`[friend]`

Write into AipsIO.

ostream& operator<<	(	ostream &	ios,
		const ColumnDesc &	cd
	)		`[friend]`

Show on ostream.

AipsIO& operator>>	(	AipsIO &	ios,
		ColumnDesc &	cd
	)		`[friend]`

Read from AipsIO.

Member Data Documentation

Bool casa::ColumnDesc::allocated_p [protected]

Definition at line 440 of file ColumnDesc.h.

BaseColumnDesc* casa::ColumnDesc::colPtr_p [protected]

Definition at line 439 of file ColumnDesc.h.

Referenced by checkAdd(), checkRename(), comment(), dataManagerGroup(), dataManagerType(), dataType(), dataTypeId(), handleAdd(), handleRemove(), handleRename(), isArray(), isScalar(), isTable(), keywordSet(), makeColumn(), makeConcatColumn(), makeRefColumn(), maxLength(), ndim(), options(), renameAction(), rwKeywordSet(), setDefaultDataManager(), setMaxLength(), setName(), setNdim(), setOptions(), setShape(), shape(), and tableDesc().

MutexedInit casa::ColumnDesc::theirMutexedInit [static, private]

Define a map which maps the name of the various XXColumnDesc classes to a static function constructing them.

This is used when reading a column description back; it in fact determines the exact column type and is an easier thing to do than an enormous switch statement. The map is filled with the main XXColumnDesc construction functions by the function registerColumnDesc upon the first call of ColumnDesc::getFile.

Definition at line 377 of file ColumnDesc.h.

Referenced by registerMainCtor().

SimpleOrderedMap<String, BaseColumnDesc* (*)(const String&)> casa::ColumnDesc::theirRegisterMap [static, private]

Definition at line 378 of file ColumnDesc.h.

Referenced by unlockedRegisterCtor().

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

casacore/tables/Tables/ColumnDesc.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Attributes

Private Member Functions

Static Private Member Functions

Static Private Attributes

Friends