visad.data.hdf5.hdf5objects

Class HDF5Datatype

java.lang.Object

visad.data.hdf5.hdf5objects.HDF5Object

visad.data.hdf5.hdf5objects.HDF5Datatype

All Implemented Interfaces:

java.io.Serializable

public class HDF5Datatype
extends HDF5Object

This class provides a mechanism to describe the storage format of individual data points of a data set.

A data type is a collection of data type properties, all of which can be stored on disk, and which when taken as a whole, provide complete information for data conversion to or from that data type. The interface provides functions to set and query properties of a data type.

A data point is an instance of a data type, which is an instance of a type class. We have defined a set of type classes and properties which can be extended at a later time. The atomic type classes are those which describe types which cannot be decomposed at the data type interface level; all other classes are compound.

For details of the HDF5 libraries, see the HDF5 Documentation at: http://hdf.ncsa.uiuc.edu/HDF5/doc/

See Also:

Serialized Form

Field Summary

Fields inherited from class visad.data.hdf5.hdf5objects.HDF5Object

ATTRIBUTE, DATASET, DATASPACE, DATATYPE, GROUP, HDF5FILE, LINK, UNKNOWN

Constructor Summary

Constructors

Constructor and Description
HDF5Datatype() Construct an HDF5Datatype
HDF5Datatype(int datatype_class, int size) Creates a new HDF5Datatype
HDF5Datatype(int loc_id, java.lang.String type_name) Opens a named HDF5Datatype

Method Summary

Modifier and Type	Method and Description
java.lang.Object	defineData(long[] count) define the data with specified data type.
int	get_class() Returns the datatype class identifier
int	get_size() Returns the size of a datatype in bytes
static java.lang.String	getDatatype(int data_type) Gets the string representation of the data type
int	H5Tcommit(int loc_id, java.lang.String type_name) H5Tcommit commits a transient datatype to a file, turned it into a named datatype.

Methods inherited from class visad.data.hdf5.hdf5objects.HDF5Object

getDescription, getID, getName, getShortName, getType, init, setID, setShortName, setType, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

HDF5Datatype

public HDF5Datatype()

Construct an HDF5Datatype

HDF5Datatype

public HDF5Datatype(int datatype_class,
                    int size)

Creates a new HDF5Datatype

Parameters:

datatype_class - Class of datatype to create.

size - The number of bytes in the datatype to create.

HDF5Datatype

public HDF5Datatype(int loc_id,
                    java.lang.String type_name)

Opens a named HDF5Datatype

Parameters:

loc_id - A file, group, or datatype identifier.

type_name - A datatype name.

Method Detail

H5Tcommit

public int H5Tcommit(int loc_id,
                     java.lang.String type_name)
              throws ncsa.hdf.hdf5lib.exceptions.HDF5LibraryException,
                     java.lang.NullPointerException

H5Tcommit commits a transient datatype to a file, turned it into a named datatype.

Parameters:

loc_id - A file or group identifier.

type_name - A datatype name.

Returns:

a non-negative value if successful; otherwise returns a negative value.

Throws:

ncsa.hdf.hdf5lib.exceptions.HDF5LibraryException

java.lang.NullPointerException

get_class

public int get_class()
              throws ncsa.hdf.hdf5lib.exceptions.HDF5LibraryException

Returns the datatype class identifier

Throws:

ncsa.hdf.hdf5lib.exceptions.HDF5LibraryException

get_size

public int get_size()
             throws ncsa.hdf.hdf5lib.exceptions.HDF5LibraryException

Returns the size of a datatype in bytes

Throws:

ncsa.hdf.hdf5lib.exceptions.HDF5LibraryException

defineData

public java.lang.Object defineData(long[] count)
                            throws ncsa.hdf.hdf5lib.exceptions.HDF5Exception

define the data with specified data type. The maximum selected data size is limited to Integer.MAX_VALUE, which is 2,147,483,647 bytes

Parameters:

count - the number of points of data

Throws:

ncsa.hdf.hdf5lib.exceptions.HDF5Exception

getDatatype

public static java.lang.String getDatatype(int data_type)

Gets the string representation of the data type

Parameters:

data_type - the type of the data.

Returns:

the string of the data type