HDF5 C++ API Reference Manual

 

 

 

H5::DataType Class Reference

#include <H5DataType.h>

Inheritance diagram for H5::DataType:

List of all members.

Public Member Functions
	DataType (const H5T_class_t type_class, size_t size)
	Creates a object given its class and size.
	DataType (const DataType &original)
	Copy constructor: makes a copy of the original DataType object.
virtual void	close ()
	Closes the datatype if it is not a predefined type.
void	copy (const DataType &like_type)
	Copies an existing datatype to this datatype object.
H5T_class_t	getClass () const
	Returns the datatype class identifier.
void	commit (CommonFG &loc, const char *name) const
	Commits a transient datatype to a file, creating a new named datatype.
void	commit (CommonFG &loc, const string &name) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.
bool	committed () const
	Determines whether a datatype is a named type or a transient type.
H5T_conv_t	find (const DataType &dest, H5T_cdata_t **pcdata) const
	Finds a conversion function that can handle a conversion from this datatype to the specified datatype, dest.
void	convert (const DataType &dest, size_t nelmts, void *buf, void *background, PropList &plist) const
	Converts data from this datatype to the specified datatypes.
DataType &	operator= (const DataType &rhs)
	Assignment operator.
bool	operator== (const DataType &compared_type) const
	Compares this DataType against the given one to determines whether the two objects refer to the same actual datatype.
void	lock () const
	Locks a datatype, making it read-only and non-destructible.
H5T_overflow_t	getOverflow (void) const
	Returns a pointer to the current global overflow function.
void	setOverflow (H5T_overflow_t func) const
	Sets the overflow handler to a specified function.
size_t	getSize () const
	Returns the size of a datatype.
DataType	getSuper () const
	Returns the base datatype from which a datatype is derived.
void	registerFunc (H5T_pers_t pers, const char *name, const DataType &dest, H5T_conv_t func) const
	Registers the specified conversion function.
void	registerFunc (H5T_pers_t pers, const string &name, const DataType &dest, H5T_conv_t func) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.
void	unregister (H5T_pers_t pers, const char *name, const DataType &dest, H5T_conv_t func) const
	Removes a conversion function from all conversion paths.
void	unregister (H5T_pers_t pers, const string &name, const DataType &dest, H5T_conv_t func) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.
void	setTag (const char *tag) const
	Tags an opaque datatype.
void	setTag (const string &tag) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.
string	getTag () const
	Gets the tag associated with an opaque datatype.
bool	detectClass (H5T_class_t cls) const
	Checks whether a datatype contains (or is) a certain type of datatype.
bool	isVariableStr () const
	Check whether this datatype is a variable-length string.
void *	Reference (const char *name) const
	This is an overloaded function, provided for your convenience. It differs from the above function in that it only creates a reference to an HDF5 object, not to a dataset region.
void *	Reference (const string &name) const
	This is an overloaded function, provided for your convenience. It differs from the above function in that it takes an std::string for the object's name.
void *	Reference (const char *name, DataSpace &dataspace, H5R_type_t ref_type=H5R_DATASET_REGION) const
	Creates a reference to an HDF5 object or a dataset region.
H5G_obj_t	getObjType (void *ref, H5R_type_t ref_type) const
	Retrieves the type of object that an object reference points to.
DataSpace	getRegion (void *ref, H5R_type_t ref_type=H5R_DATASET_REGION) const
	Retrieves a dataspace with the region pointed to selected.
virtual string	fromClass () const
	DataType (const hid_t type_id, bool predtype=false)
	Creates a datatype using an existing datatype's id.
	DataType ()
	Default constructor: Creates a stub datatype.
virtual	~DataType ()
	Properly terminates access to this datatype.
Protected Attributes
bool	is_predtype

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Constructor & Destructor Documentation

H5::DataType::DataType (  const H5T_class_t  type_class, size_t  size )

Creates a object given its class and size. Parameters: type_class  - IN: Class of datatype to create size  - IN: Number of bytes in the datatype to create Exceptions: H5::DataTypeIException

H5::DataType::DataType (  const DataType &  original  )

Copy constructor: makes a copy of the original DataType object.

H5::DataType::DataType (  const hid_t  existing_id, bool  predefined = false )

Creates a datatype using an existing datatype's id. Parameters: existing_id  - IN: Id of the existing datatype predefined  - IN: Indicates whether or not this datatype is a predefined datatype; default to false

H5::DataType::DataType (   )

Default constructor: Creates a stub datatype.

H5::DataType::~DataType (   )  [virtual]

Properly terminates access to this datatype.

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Member Function Documentation

void H5::DataType::close (   )  [virtual]

Closes the datatype if it is not a predefined type. Exceptions: H5::DataTypeIException

void H5::DataType::copy (  const DataType &  like_type  )

Copies an existing datatype to this datatype object. Parameters: like_type  - IN: Datatype to be copied Exceptions: H5::DataTypeIException

H5T_class_t H5::DataType::getClass (   )  const

Returns the datatype class identifier. Returns: Datatype class identifier Exceptions: H5::DataTypeIException

void H5::DataType::commit (  CommonFG &  loc, const char *  name )  const

Commits a transient datatype to a file, creating a new named datatype. Parameters: loc  - IN: Either a file or a group name  - IN: Name of the datatype Exceptions: H5::DataTypeIException

void H5::DataType::commit (  CommonFG &  loc, const string &  name )  const

This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.

bool H5::DataType::committed (   )  const

Determines whether a datatype is a named type or a transient type. Returns: true if the datatype is a named type, and false, otherwise. Exceptions: H5::DataTypeIException

H5T_conv_t H5::DataType::find (  const DataType &  dest, H5T_cdata_t **  pcdata )  const

Finds a conversion function that can handle a conversion from this datatype to the specified datatype, dest. Parameters: dest  - IN: Destination datatype pcdata  - IN: Pointer to type conversion data Returns: Pointer to a suitable conversion function Exceptions: H5::DataTypeIException

void H5::DataType::convert (  const DataType &  dest, size_t  nelmts, void *  buf, void *  background, PropList &  plist )  const

Converts data from this datatype to the specified datatypes. Parameters: dest  - IN: Destination datatype nelmts  - IN: Size of array buf buf  - IN/OUT: Array containing pre- and post-conversion values background  - IN: Optional backgroud buffer plist  - IN: Dataset transfer property list Returns: Pointer to a suitable conversion function Exceptions: H5::DataTypeIException

DataType & H5::DataType::operator= (  const DataType &  rhs  )

Assignment operator. Parameters: rhs  - IN: Reference to the existing datatype Returns: Reference to DataType instance Exceptions: H5::DataTypeIException

bool H5::DataType::operator== (  const DataType &  compared_type  )  const

Compares this DataType against the given one to determines whether the two objects refer to the same actual datatype. Parameters: compared_type  - IN: Reference to the datatype to compare Returns: true if the datatypes are equal, and false, otherwise. Exceptions: H5::DataTypeIException

void H5::DataType::lock (   )  const

Locks a datatype, making it read-only and non-destructible. Exceptions: H5::DataTypeIException  Descrition This is normally done by the library for predefined data types so the application doesn't inadvertently change or delete a predefined type. Once a data type is locked it can never be unlocked unless the entire library is closed.

H5T_overflow_t H5::DataType::getOverflow (  void   )  const

Returns a pointer to the current global overflow function. Returns: Pointer to an application-defined function if successful; otherwise returns NULL; this can happen if no overflow handling function is registered. Exceptions: H5::DataTypeIException

void H5::DataType::setOverflow (  H5T_overflow_t  func  )  const

Sets the overflow handler to a specified function. Parameters: func  - IN: Function to be called when overflow occurs Returns: Pointer to a suitable conversion function Exceptions: H5::DataTypeIException  Description The function specified by func will be called for all data type conversions that result in an overflow. For more information, please see: http://hdf.ncsa.uiuc.edu/HDF5/doc/RM_H5T.html#Datatype-SetOverflow

size_t H5::DataType::getSize (   )  const

Returns the size of a datatype. Returns: Datatype size in bytes Exceptions: H5::DataTypeIException

DataType H5::DataType::getSuper (   )  const

Returns the base datatype from which a datatype is derived. Returns: DataType object Exceptions: H5::DataTypeIException

void H5::DataType::registerFunc (  H5T_pers_t  pers, const char *  name, const DataType &  dest, H5T_conv_t  func )  const

Registers the specified conversion function. Parameters: pers  - IN: Conversion option H5T_PERS_HARD for hard conversion functions H5T_PERS_SOFT for soft conversion functions. name  - IN: Name displayed in diagnostic output. dest  - IN: Destination datatype. func  - IN: Function to convert between source and destination datatypes. Exceptions: H5::DataTypeIException  Description For more information, please see: http://hdf.ncsa.uiuc.edu/HDF5/doc/RM_H5T.html#Datatype-Register

void H5::DataType::registerFunc (  H5T_pers_t  pers, const string &  name, const DataType &  dest, H5T_conv_t  func )  const

This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.

void H5::DataType::unregister (  H5T_pers_t  pers, const char *  name, const DataType &  dest, H5T_conv_t  func )  const

Removes a conversion function from all conversion paths. Parameters: pers  - IN: Conversion option H5T_PERS_HARD for hard conversion functions H5T_PERS_SOFT for soft conversion functions. name  - IN: Name displayed in diagnostic output. dest  - IN: Destination datatype. func  - IN: Function to convert between source and destination datatypes. Exceptions: H5::DataTypeIException

void H5::DataType::unregister (  H5T_pers_t  pers, const string &  name, const DataType &  dest, H5T_conv_t  func )  const

This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.

void H5::DataType::setTag (  const char *  tag  )  const

Tags an opaque datatype. Parameters: tag  - IN: Descriptive ASCII string with which the opaque datatype is to be tagged. Exceptions: H5::DataTypeIException

void H5::DataType::setTag (  const string &  tag  )  const

This is an overloaded member function, provided for convenience. It differs from the above function only in the type of the argument name.

string H5::DataType::getTag (   )  const

Gets the tag associated with an opaque datatype. Returns: Tag associated with the opaque datatype Exceptions: H5::DataTypeIException

bool H5::DataType::detectClass (  H5T_class_t  cls  )  const

Checks whether a datatype contains (or is) a certain type of datatype. Returns: true if this datatype contains or is the specified type, and false, otherwise. Exceptions: H5::DataTypeIException

bool H5::DataType::isVariableStr (   )  const

Check whether this datatype is a variable-length string. Returns: true if this datatype is a variable-length string, and false, otherwise. Exceptions: H5::DataTypeIException

void * H5::DataType::Reference (  const char *  name  )  const

This is an overloaded function, provided for your convenience. It differs from the above function in that it only creates a reference to an HDF5 object, not to a dataset region. Parameters: name  - IN: Name of the object to be referenced Returns: A reference Exceptions: H5::IdComponentException  Description

void * H5::DataType::Reference (  const string &  name  )  const

This is an overloaded function, provided for your convenience. It differs from the above function in that it takes an std::string for the object's name. Parameters: name  - IN: Name of the object to be referenced - std::string

void * H5::DataType::Reference (  const char *  name, DataSpace &  dataspace, H5R_type_t  ref_type = H5R_DATASET_REGION )  const

Creates a reference to an HDF5 object or a dataset region. Parameters: name  - IN: Name of the object to be referenced dataspace  - IN: Dataspace with selection ref_type  - IN: Type of reference; default to H5R_DATASET_REGION Returns: A reference Exceptions: H5::IdComponentException

H5G_obj_t H5::DataType::getObjType (  void *  ref, H5R_type_t  ref_type )  const

Retrieves the type of object that an object reference points to. Parameters: ref  - IN: Reference to query ref_type  - IN: Type of reference to query Returns: Object type, which can be one of the following: H5G_LINK Object is a symbolic link. H5G_GROUP Object is a group. H5G_DATASET Object is a dataset. H5G_TYPE Object is a named datatype Exceptions: H5::IdComponentException

DataSpace H5::DataType::getRegion (  void *  ref, H5R_type_t  ref_type = H5R_DATASET_REGION )  const

Retrieves a dataspace with the region pointed to selected. Parameters: ref  - IN: Reference to get region of ref_type  - IN: Type of reference to get region of - default Returns: DataSpace instance Exceptions: H5::IdComponentException

virtual string H5::DataType::fromClass (   )  const [inline, virtual]

Reimplemented from H5::IdComponent. Reimplemented in H5::ArrayType, H5::AtomType, H5::CompType, H5::EnumType, H5::FloatType, H5::IntType, H5::PredType, H5::StrType, and H5::VarLenType.

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Member Data Documentation

bool H5::DataType::is_predtype [protected]

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