RecordRep.h

Classes

RecordRep -- The representation of a Record (full description)

class RecordRep

Interface

Public Members

RecordRep()

RecordRep (const RecordDesc& description)

RecordRep (const RecordRep& other)

RecordRep& operator= (const RecordRep& other)

virtual ~RecordRep()

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 RecordRep& other) const

void copyData (const RecordRep& other)

void copyDataField (DataType type, Int whichField, const void* that) const

void removeField (Int whichField)

void renameField (const String& newName, Int whichField)

void addDataField (const String& name, DataType type, const IPosition& shape, Bool fixedShape, const void* data)

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

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

void putRecord (AipsIO& os, int recordType) const

void getRecord (AipsIO& os, int& recordType)

void putData (AipsIO& os) const

void getData (AipsIO& os, uInt version)

void* get_pointer (Int whichField, DataType type) const

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

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

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

Protected Members

void delete_myself (uInt nfields)

void copy_other (const RecordRep& other)

virtual Int fieldNumber (const String& name) const

void addDataPtr (void* ptr)

void removeDataPtr (Int index)

void checkShape (DataType type, const IPosition& shape, const void* value, const IPosition& fieldName)

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* createDataField (DataType type, const IPosition& shape)

void deleteDataField (DataType type, void* ptr, void* vecptr)

void copyDataField (DataType type, void* ptr, const void* that) const

void putDataField (AipsIO& os, DataType type, const void* ptr) const

void getDataField (AipsIO& os, DataType type, void* ptr)

void makeDataVec (Int whichField, DataType type)

void getKeySet (AipsIO& os, uInt version, uInt type)

void getKeyDesc (AipsIO& os, RecordDesc& desc)

void getScalarKeys (AipsIO& os)

void getArrayKeys (AipsIO& os)

Description

Review Status

Reviewed By:

Mark Wieringa

Date Reviewed:

1996/04/15

Programs:

Tests:

tRecord

Prerequisite

Record.

Etymology

RecordRep is the REPresentation of a Record.

Synopsis

RecordRep is the actual implementation of a Record 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 RecordRep does not know anything about RecordFieldPtr objects pointing to its data. Only its mother class Record knows about them and handles all cases where the RecordFieldPtr's have to be notified.

Example

RecordRep mirrors all functions in Record.

Motivation

Having a separate RecordRep class makes copy-on-write possible. It also allows derivation of other RecordRep classes (like TableRecordRep), while their mother classes are not derived from each other.

To Do

An implementation where arrays are stored as T*'s would cut down on instantiations (the Arrayness would come back through the creation of the RecordFieldPtr<Array<T> >).

Member Description

RecordRep()

Create a record with no fields.

RecordRep (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).

RecordRep (const RecordRep& other)

Create a copy of other using copy semantics.

RecordRep& operator= (const RecordRep& other)

Copy all the data over.

virtual ~RecordRep()

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 RecordRep& 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).

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 copyData (const RecordRep& other)

Copy all data of the Record.

void copyDataField (DataType type, Int whichField, const void* that) const

Copy a data field. This can only handle scalars and arrays.

void removeField (Int whichField)

Remove a field from the record.

void renameField (const String& newName, Int whichField)

Rename the given field.

void addDataField (const String& name, DataType type, const IPosition& shape, Bool fixedShape, const void* data)
void addField (const String& name, const Record& 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. For arrays it is possible to define if the shape is fixed.

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 putRecord (AipsIO& os, int recordType) 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)

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

void putData (AipsIO& os) 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)

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

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 RecordRep& other, Int whichFieldFromOther, RecordInterface::DuplicatesFlag)

Merge a field from another record into this record.

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

Merge all fields from the other record into this record.

void delete_myself (uInt nfields)
void copy_other (const RecordRep& other)

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

virtual Int fieldNumber (const String& name) const

Get the field number for a given name.

void addDataPtr (void* ptr)

Add the data pointer to the data block. The block is extended when needed.

void removeDataPtr (Int index)

Remove a data pointer add the given index.

void checkShape (DataType type, const IPosition& shape, const void* value, const IPosition& fieldName)

Check if the shape of the data array matches the shape of a fixed-shaped array in the description.

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* createDataField (DataType type, const IPosition& shape)

Create a data field for the given type and shape. This can only handle scalars and arrays.

void deleteDataField (DataType type, void* ptr, void* vecptr)

Delete a data field. This can only handle scalars and arrays.

void copyDataField (DataType type, void* ptr, const void* that) const

Copy a data field. This can only handle scalars and arrays.

void putDataField (AipsIO& os, DataType type, const void* ptr) const

Put a data field. This can only handle scalars and arrays.

void getDataField (AipsIO& os, DataType type, void* ptr)

Get a data field. This can only handle scalars and arrays.

void makeDataVec (Int whichField, DataType type)

Make an array for a scalar data field. It shares the data, so a change in the data is reflected in the array. It is used to be able to access a scalar as an 1D array.

void getKeySet (AipsIO& os, uInt version, uInt type)

Get a Scalar/ArrayKeywordSet object as a Record. (type 0 = ScalarKeywordSet; type 1 = ArrayKeywordSet).

void getKeyDesc (AipsIO& os, RecordDesc& desc)

Get the description of a keyword set as a RecordDesc.

void getScalarKeys (AipsIO& os)

Get the scalar values of a keyword set.

void getArrayKeys (AipsIO& os)

Get the array values of a keyword set.