Sets estimated number of links and length of link names in a group

Procedure:

H5P_SET_EST_LINK_INFO ( gcpl_id,  est_num_entries, est_name_len )

Signature:

<pre><code class="language-c">herr_t H5Pset_est_link_info(
        hid_t gcpl_id,
        unsigned est_num_entries,
        unsigned est_name_len
    )
  </code></pre>

<pre><code class="language-fortran">Fortran90 Interface: h5pset_est_link_info_f 
    
SUBROUTINE h5pset_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 identifier
  INTEGER, INTENT(IN) :: est_num_entries 
                                    ! Estimated number of links to be  
                                    ! inserted into group
  INTEGER, INTENT(IN) :: est_name_len    
                                    ! Estimated average length of link names
  INTEGER, INTENT(OUT) :: hdferr    ! Error code
                                    ! 0 on success and -1 on failure
END SUBROUTINE H5Pset_est_link_info_f
    </code></pre>

Parameters:
hid_t gcpl_idIN: Group creation property list identifier
unsigned est_num_entries    IN: Estimated number of links to be inserted into group
unsigned est_name_lenIN: Estimated average length of link names

Description:

H5P_SET_EST_LINK_INFO inserts two settings into the group creation property list gcpl_id: the estimated number of links that are expected to be inserted into a group created with the property list and the estimated average length of those link names.

The estimated number of links is passed in est_num_entries.

The estimated average length of the anticipated link names is passed 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.

If a group is expected to have many links and to be stored in dense format, set est_num_entries to 0 (zero) for maximum efficiency. This will prevent the 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.

Returns:

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

Example:

Coming Soon!

History:
Release    Change
1.8.0Function introduced in this release.