Name: H5Pget_est_link_info
Signature:
herr_t H5Pget_est_link_info( hid_t gcpl_id, unsigned *est_num_entries, unsigned *est_name_len )

Purpose:
Queries data required to estimate required local heap or object header size.

Description:
H5Pget_est_link_info queries a group creation property list, gcpl_id, for its “estimated number of links” and “estimated average name length” settings.

The estimated number of links anticipated to be inserted into a group created with this property list is returned in est_num_entries.

The estimated average length of the anticipated link names is returned in est_name_len.

The values for these two settings are multiplied to compute the initial local heap size (for old-style groups, if the local heap size hint is not set) or the initial object header size for (new-style compact groups; see “Group implementations in HDF5”). Accurately setting these parameters will help reduce wasted file space.

A value of 0 (zero) in est_num_entries will prevent a group from being created in the compact format.

See “Group implementations in HDF5” in the H5G API introduction for a discussion of the available types of HDF5 group structures.

Parameters:
hid_t gcpl_id IN: Group creation property list identifier
unsigned *est_num_entries     OUT: Estimated number of links to be inserted into group
unsigned *est_name_len OUT: Estimated average length of link names
Returns:
Returns a non-negative value if successful; otherwise returns a negative value.

Fortran90 Interface: h5pget_est_link_info_f
SUBROUTINE h5pget_est_link_info_f(gcpl_id,est_num_entries, est_name_len,hdferr)

  IMPLICIT NONE
  INTEGER(HID_T), INTENT(IN) :: gcpl_id   ! Group creation property list id
  INTEGER, INTENT(OUT) :: est_num_entries ! Estimated number of links to be 
                                          ! inserted into group
  INTEGER, INTENT(OUT) :: est_name_len    ! Estimated average length of link 
                                          ! names
  INTEGER, INTENT(OUT) :: hdferr          ! Error code
                                          ! 0 on success and -1 on failure
END SUBROUTINE h5pget_est_link_info_f 
        

History:
Release     C
1.8.0 Function introduced in this release.