Name: H5Pget_link_phase_change
Signature:
herr_t H5Pget_link_phase_change( hid_t gcpl_id, unsigned *max_compact, unsigned *min_dense )

Purpose:
Queries the settings for conversion between compact and dense groups.

Description:
H5Pget_link_phase_change queries the maximum number of entries for a compact group and the minimum number links to require before converting a group to a dense form.

In the compact format, links are stored as messages in the group’s header. In the dense format, links are stored in a fractal heap and indexed with a version 2 B-tree.

max_compact is the maximum number of links to store as header messages in the group header before converting the group to the dense format. Groups that are in the compact format and exceed this number of links are automatically converted to the dense format.

min_dense is the minimum number of links to store in the dense format. Groups which are in dense format and in which the number of links falls below this number are automatically converted back to the compact format.

In the compact format, links are stored as messages in the group’s header. In the dense format, links are stored in a fractal heap and indexed with a version 2 B-tree.

See H5Pset_link_phase_change for a discussion of traditional, compact, and dense group storage.

Parameters:
hid_t gcpl_id IN: Group creation property list identifier
unsigned *max_compact     OUT: Maximum number of links for compact storage
unsigned *min_dense OUT: Minimum number of links for dense storage
Returns:
Returns a non-negative value if successful; otherwise returns a negative value.

Fortran90 Interface:
SUBROUTINE h5pset_link_phase_change_f(gcpl_id, max_compact, min_dense, hdferr)
  IMPLICIT NONE
  INTEGER(HID_T), INTENT(IN) :: gcpl_id 
                                  ! Group creation property list identifier
  INTEGER, INTENT(IN) :: max_compact  
                                  ! Maximum number of attributes to be stored 
                                  ! in compact storage
  INTEGER, INTENT(IN) :: min_dense  
                                  ! Minimum number of attributes to be stored 
                                  ! in dense storage
  INTEGER, INTENT(OUT) :: hdferr  ! Error code
                                  ! 0 on success and -1 on failure
END SUBROUTINE h5pset_link_phase_change_f 
    

History:
Release     C
1.8.0 Function introduced in this release.