Last modified: 22 August 2012
Name: H5Pset_type_conv_cb
Signature:
herr_t H5Pset_type_conv_cb( hid_t plist, H5T_conv_except_func_t func, void *op_data)

Purpose:
Sets user-defined datatype conversion callback function.

Description:
H5Pset_type_conv_cb sets the user-defined datatype conversion callback function func in the dataset transfer property list plist.

The parameter op_data is a pointer to user-defined input data for the callback function and will be passed through to the callback function.

The callback function func defines the actions an application is to take when there is an exception during datatype conversion. The function prototype is as follows:

where except_type indicates what kind of exception has happened, src_id and dst_id are the source and destination datatype identifiers, src_buf and dst_buf are the source and destination data buffer, and op_data is the required input data for this callback function.

Valid values for except_type are as follows:

H5T_CONV_EXCEPT_RANGE_HI
Source value is positive and is too big to the destination. Overflow happens.
H5T_CONV_EXCEPT_RANGE_LOW
Source value is negative and its magnitude is too big to the destination. Overflow happens.
H5T_CONV_EXCEPT_TRUNCATE
Source is floating-point type and destination is integer. The floating-point number has fractional part.
H5T_CONV_EXCEPT_PRECISION
Source is integer and destination is floating-point type. The mantissa of floating-point type is not big enough to hold all the digits of the integer.
H5T_CONV_EXCEPT_PINF
Source is floating-point type and the value is positive infinity.
H5T_CONV_EXCEPT_NINF
Source is floating-point type and the value is negative infinity.
H5T_CONV_EXCEPT_NAN
Source is floating-point type and the value is NaN (not a number, including QNaN and SNaN).

Valid callback function return values are H5T_CONV_ABORT, H5T_CONV_UNHANDLED and H5T_CONV_HANDLED.

Programming Note for C++ Developers Using C Functions:

If a C routine that takes a function pointer as an argument is called from within C++ code, the C routine should be returned from normally.

Examples of this kind of routine include callbacks such as H5Pset_elink_cb and H5Pset_type_conv_cb and functions such as H5Tconvert and H5Ewalk2.

Exiting the routine in its normal fashion allows the HDF5 C Library to clean up its work properly. In other words, if the C++ application jumps out of the routine back to the C++ “catch” statement, the library is not given the opportunity to close any temporary data structures that were set up when the routine was called. The C++ application should save some state as the routine is started so that any problem that occurs might be diagnosed.

Parameters:
hid_t plist IN: Dataset transfer property list identifier.
H5T_conv_except_func_t func     IN: User-defined type conversion callback function.< /td>
void *op_data IN: User-defined input data for the callback function.

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

Fortran90 Interface:
None.