TableRecordRep.h

Classes

TableRecordRep -- The representation of a TableRecord (full description)

class TableRecordRep : public RecordRep

Interface

Public Members
TableRecordRep()
TableRecordRep (const RecordDesc& description)
TableRecordRep (const TableRecordRep& other)
TableRecordRep& operator= (const TableRecordRep& other)
~TableRecordRep()
const String& comment (Int whichField) const
void setComment (Int whichField, const String& comment)
const RecordDesc& description() const
void restructure (const RecordDesc& newDescription, Bool recursive)
Bool conform (const TableRecordRep& other) const
void renameField (const String& newName, Int whichField)
void copyData (const TableRecordRep& other)
void addField (const String& name, const TableRecord& value, RecordInterface::RecordType type)
void addField (const String& name, const Table& value, RecordInterface::RecordType type)
void defineDataField (Int whichField, DataType type, const void* value)
void closeTable (Int whichField) const
void closeTables() const
void flushTables (Bool fsync) const
void renameTables (const String& newParentName, const String& oldParentName)
Bool areTablesMultiUsed() const
void putRecord (AipsIO& os, int recordType, const TableAttr&) const
void getRecord (AipsIO& os, int& recordType, const TableAttr&)
void putData (AipsIO& os, const TableAttr&) const
void getData (AipsIO& os, uInt version, const TableAttr&)
void reopenRW()
void* get_pointer (Int whichField, DataType type) const
void* get_pointer (Int whichField, DataType type, const String& recordType) const
void mergeField (const TableRecordRep& other, Int whichFieldFromOther, RecordInterface::DuplicatesFlag)
void merge (const TableRecordRep& other, RecordInterface::DuplicatesFlag)
Protected Members
void copy_other (const TableRecordRep& other)
virtual Int fieldNumber (const String& name) const
virtual void addFieldToDesc (const String& name, DataType type, const IPosition& shape, Bool fixedShape)
virtual void removeData (Int whichField, void* ptr, void* vecptr)
virtual void removeFieldFromDesc (Int whichField)
void getTableKeySet (AipsIO& os, uInt version, const TableAttr&, uInt type)

Description

Review Status

Reviewed By:
Mark Wieringa
Date Reviewed:
1996/04/15
Programs:
Tests:

Prerequisite

Etymology

TableRecordRep is the REPresentation of a TableRecord.

Synopsis

TableRecordRep is the actual implementation of a TableRecord object. It contains the description and the data. The data is stored as a collection of void* pointers to the actual data. By storing it in this indirect way, it is easier to extend the data block. It also means that RecordFieldPtr objects always have the correct pointer and do not need to be adjusted when the data block is extended.

Despite the fact that the data pointers have type void*, the functions are completely type safe. This is done by passing the type around using the DataType enumeration. The downpart is that only types from that enumeration are supported (but that is also required by the RecordDesc mechanics).

Note that TableRecordRep does not know anything about RecordFieldPtr objects pointing to its data. Only its mother class TableRecord knows about them and handles all cases where the RecordFieldPtr's have to be notified.

Fields containing tables are not directly handled using class Table. Instead the class TableKeyword is used to map a table name to a table and to take care of opening a table on demand.

Example

TableRecordRep mirrors all functions in TableRecord.

Motivation

Having a separate TableRecordRep class makes copy-on-write possible. It also allows derivation from RecordRep.

Member Description

TableRecordRep()

Create a record with no fields.

TableRecordRep (const RecordDesc& description)

Create a record with the given description. If it is not possible to create all fields (for example, if a field of an unsupported type is requested), an exception is thrown. All fields are checked by the field checking function (if defined).

TableRecordRep (const TableRecordRep& other)

Create a copy of other using copy semantics.

TableRecordRep& operator= (const TableRecordRep& other)

Copy all the data over.

~TableRecordRep()

Delete all data.

const String& comment (Int whichField) const

Get the comment for this field.

void setComment (Int whichField, const String& comment)

Set the comment for this field.

const RecordDesc& description() const

Describes the current structure of this Record.

void restructure (const RecordDesc& newDescription, Bool recursive)

Change the structure of this Record to contain the fields in newDescription. After calling restructure, description() == newDescription.

Bool conform (const TableRecordRep& other) const

Returns True if this and other have the same RecordDesc, other than different names for the fields. That is, the number, type and the order of the fields must be identical (recursively for fixed structured sub-Records in this).

Caution thisRecord.conform(thatRecord) == True does not imply
thatRecord.conform(thisRecord) == True, because a variable record in one conforms a fixed record in that, but not vice-versa.

void renameField (const String& newName, Int whichField)

Rename the given field.

void copyData (const TableRecordRep& other)

Copy all data of the TableRecord.

void addField (const String& name, const TableRecord& value, RecordInterface::RecordType type)
void addField (const String& name, const Table& value, RecordInterface::RecordType type)

Add a field with the given name and value to the record. The data type of the field is determined by the data type of the value.

void defineDataField (Int whichField, DataType type, const void* value)

Define a value for the given field. Array conformance rules will not be applied for variable shaped arrays. When the field and value data type mismatch, type promotion of scalars will be done if possible. If not possible, an exception is thrown.

void closeTable (Int whichField) const

Close the table in the given field. When accessed again, it will be opened automatically. This can be useful to save memory usage.

void closeTables() const

Close all open tables. When accessed again, it will be opened automatically. This can be useful to save memory usage.

void flushTables (Bool fsync) const

Flush all open subtables.

void renameTables (const String& newParentName, const String& oldParentName)

Rename the subtables with a path containing the old parent table name.

Bool areTablesMultiUsed() const

Are subtables used in other processes.

void putRecord (AipsIO& os, int recordType, const TableAttr&) const

Put the description and data of the Record. It also puts the fixedFlag attribute (of the mother object).

void getRecord (AipsIO& os, int& recordType, const TableAttr&)

Get the description and data of the Record. It also gets the fixedFlag attribute (of the mother object).

void putData (AipsIO& os, const TableAttr&) const

Put the data of a record. This is used to write a subrecord, whose description has already been written.

void getData (AipsIO& os, uInt version, const TableAttr&)

Read the data of a record. This is used to read a subrecord, whose description has already been read.

void reopenRW()

Reopen possible tables in keywords as read/write. Tables are not reopened if they are not writable.

void* get_pointer (Int whichField, DataType type) const
void* get_pointer (Int whichField, DataType type, const String& recordType) const

Used by the RecordFieldPtr classes to attach in a type-safe way to the correct field.

void mergeField (const TableRecordRep& other, Int whichFieldFromOther, RecordInterface::DuplicatesFlag)

Merge a field from another record into this record.

void merge (const TableRecordRep& other, RecordInterface::DuplicatesFlag)

Merge all fields from the other record into this record.

void copy_other (const TableRecordRep& other)

Utility function to avoid code duplication in the public member functions.

virtual Int fieldNumber (const String& name) const

Get the field number for a given name.

virtual void addFieldToDesc (const String& name, DataType type, const IPosition& shape, Bool fixedShape)

Add a field to the description.

virtual void removeData (Int whichField, void* ptr, void* vecptr)

Remove a data field.

virtual void removeFieldFromDesc (Int whichField)

Remove a field from the description.

void getTableKeySet (AipsIO& os, uInt version, const TableAttr&, uInt type)

Get a KeywordSet object as a TableRecord. (type: 0=ScalarKeywordSet, 1=ArrayKeywordSet, 2=TableKeywordSet)