H5Pget_shared_mesg_phase_change
(
hid_t fcpl_id
,
unsigned *max_list
,
unsigned *min_btree
)
H5Pget_shared_mesg_phase_change
retrieves the
threshold values for storage of shared object header message
indexes in a file. These phase change thresholds determine the
point at which the index storage mechanism changes
from a more compact list format
to a more performance-oriented B-tree format, and vice-versa.
By default, a shared object header message index is initially
stored as a compact list.
When the number of messages in an index exceeds the specified
max_list
threshold, storage switches to a B-tree
format for improved performance.
If the number of messages subsequently falls below the
min_btree
threshold, the index will revert to the
list format.
If max_list
is set to 0
(zero),
shared object header message indexes in the file will always
be stored as B-trees.
fcpl_id
specifies the file creation property list.
hid_t fcpl_id
|
IN: File creation property list identifier |
unsigned *max_list
|
OUT: Threshold above which storage of a shared object header message index shifts from list to B-tree |
unsigned *min_btree
|
OUT: Threshold below which storage of a shared object header message index reverts to list format |
Release | C |
1.8.0 | Function introduced in this release. |