Page tree

 

JAVA

FORTRAN

C++

C

 

Link

H5L_ITERATE_BY_NAME

Iterates through links in a group

Procedure:

H5L_ITERATE_BY_NAME(loc_id, group_name, index_type, order, idx, op, op_data, lapl_id)

Signature:

herr_t H5Literate_by_name( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, hsize_t *idx, H5L_iterate_t op, void *op_data, hid_t lapl_id )

Fortran2003:

  SUBROUTINE h5literate_by_name_f(loc_id, group_name, index_type, &
            order, idx, op, op_data, return_value, hdferr, lapl_id)
    INTEGER(HID_T), INTENT(IN) :: loc_id
    CHARACTER(LEN=*) :: group_name 
    INTEGER, INTENT(IN) :: index_type
    INTEGER, INTENT(IN) :: order
    INTEGER(HSIZE_T), INTENT(INOUT) :: idx

    TYPE(C_FUNPTR):: op  
    TYPE(C_PTR)   :: op_data

    INTEGER, INTENT(OUT) :: return_value

    INTEGER, INTENT(OUT) :: hdferr
    INTEGER(HID_T), OPTIONAL, INTENT(IN) :: lapl_id

Programming Note for Fortran Developers:

The integer type of the callback function must match the C integer type. Therefore, for portability, all Fortran callback functions used by h5literate_by_name_f should be declared as INTEGER(KIND=C_INT).

Parameters:
hid_t loc_idIN: Location identifier of subject group; may be a file, group, dataset, named datatype or attribute identifier
const char *group_name    IN: Name of subject group
H5_index_t index_typeIN: Type of index which determines the order
H5_iter_order_t orderIN: Order within index
hsize_t *idxIN: Iteration position at which to start 
OUT: Position at which an interrupted iteration may be restarted
H5L_iterate_t opIN: Callback function passing data regarding the link to the calling application
void *op_dataIN: User-defined pointer to data required by the application for its processing of the link
hid_t lapl_idIN: Link access property list

Description:

H5L_ITERATE_BY_NAME iterates through the links in a group, specified by loc_id and group_name, in the order of the specified index, index_type, using a user-defined callback routine opH5L_ITERATE_BY_NAME does not recursively follow links into subgroups of the specified group.

index_type specifies the index to be used. If the links have not been indexed by the index type, they will first be sorted by that index then the iteration will begin; if the links have been so indexed, the sorting step will be unnecessary, so the iteration may begin more quickly. Valid values include the following:

H5_INDEX_NAMEAlpha-numeric index on name
H5_INDEX_CRT_ORDER    Index on creation order

 

order specifies the order in which objects are to be inspected along the index specified in index_type. Valid values include the following:

H5_ITER_INCIncreasing order
H5_ITER_DECDecreasing order
H5_ITER_NATIVE    Fastest available order

 

idx allows an interrupted iteration to be resumed; it is passed in by the application with a starting point and returned by the library with the point at which the iteration stopped.

H5L_ITERATE_BY_NAME is not recursive. In particular, if a member of group_name is found to be a group, call it subgroup_a, H5L_ITERATE_BY_NAME does not examine the members of subgroup_a. When recursive iteration is required, the application must handle the recursion, explicitly calling H5L_ITERATE_BY_NAME on discovered subgroups.

H5L_ITERATE_BY_NAME assumes that the membership of the group being iterated over remains unchanged through the iteration; if any of the links in the group change during the iteration, the function’s behavior is undefined. Note, however, that objects pointed to by the links can be modified.

H5L_ITERATE_BY_NAME is the same as H5G_ITERATE, except that H5G_ITERATE always proceeds in alphanumeric order.

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 H5P_SET_ELINK_CB and H5P_SET_TYPE_CONV_CB and functions such as H5T_CONVERT and H5E_WALK2.

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.

Returns:

On success, returns the return value of the first operator that returns a positive value, or zero if all members were processed with no operator returning non-zero.

On failure, returns a negative value if something goes wrong within the library, or the first negative value returned by an operator.

Example:

Coming Soon!

History:
Release    Change
1.8.8Fortran subroutine added.
1.8.0C function introduced.

--- Last Modified: September 13, 2018 | 03:29 PM