H5Pset_cache
(
hid_t plist_id
,
int mdc_nelmts
,
size_t rdcc_nelmts
,
size_t rdcc_nbytes
,
double rdcc_w0
)
H5Pset_cache
sets
the number of elements, the total number of bytes, and
the preemption policy value in the raw data chunk cache.
The plist_id is a file access property list.
The number of elements (objects) in the raw data chunk cache is rdcc_nelmts. The total size of the raw data chunk cache and the preemption policy are rdcc_nbytes and rdcc_w0, respectively.
Any (or all) of the H5Pget_cache
pointer arguments
may be null pointers.
The rdcc_w0 value should be between 0 and 1 inclusive and indicates how much chunks that have been fully read are favored for preemption. A value of zero means fully read chunks are treated no differently than other chunks (the preemption is strictly LRU) while a value of one means fully read chunks are always preempted before other chunks.
The *mdc_nelmts
parameter is no longer used;
any value passed in that parameter is ignored.
H5Pset_fapl_mpio
and
H5Pset_fapl_mpiposix
,
respectively.
When using one of these file drivers, all calls to H5Dread
and H5Dwrite
will access the disk directly,
and H5Pset_cache
will have no effect on performance.
Raw dataset chunk caching is supported when these drivers are used in read-only mode.
hid_t plist_id |
IN: Identifier of the file access property list. |
int mdc_nelmts |
IN: No longer used; any value passed is ignored. |
size_t rdcc_nelmts |
IN: Number of elements (objects) in the raw data chunk cache. |
size_t rdcc_nbytes |
IN: Total size of the raw data chunk cache, in bytes. |
double rdcc_w0 |
IN: Preemption policy. |
SUBROUTINE h5pset_cache_f(prp_id, mdc_nelmts,rdcc_nelmts, rdcc_nbytes, rdcc_w0, hdferr) IMPLICIT NONE INTEGER(HID_T), INTENT(IN) :: prp_id ! Property list identifier INTEGER, INTENT(IN) :: mdc_nelmts ! Number of elements (objects) ! in the meta data cache INTEGER(SIZE_T), INTENT(IN) :: rdcc_nelmts ! Number of elements (objects) ! in the meta data cache INTEGER(SIZE_T), INTENT(IN) :: rdcc_nbytes ! Total size of the raw data ! chunk cache, in bytes REAL, INTENT(IN) :: rdcc_w0 ! Preemption policy INTEGER, INTENT(OUT) :: hdferr ! Error code ! 0 on success and -1 on failure END SUBROUTINE h5pset_cache_f
Release | Change | ||
1.8.0 |
In C, use of the mdc_nelmts parameter discontinued.
Metadata cache configuration is managed with H5Pset_mdc_config
and
H5Pget_mdc_config .
| ||
1.6.1 | Fortran rdcc_nbytes parameter type
changed to INTEGER(SIZE_T) . | ||
1.6.0 | In C, the rdcc_nbytes
and rdcc_nelmts parameters changed from type
int to size_t. |