6.7 Get the HDF5 Chunk Cache Settings for a variable: NF_GET_VAR_CHUNK_CACHE
This function gets the current chunk cache settings for a variable in
a netCDF-4/HDF5 file.
For more information, see the documentation for the H5Pget_cache()
function in the HDF5 library at the HDF5 website:
http://hdfgroup.org/HDF5/.
Usage
INTEGER NF_GET_VAR_CHUNK_CACHE(INTEGER NCID, INTEGER VARID, INTEGER SIZE, INTEGER NELEMS,
INTEGER PREEMPTION);
ncid- NetCDF ID, from a previous call to NF_OPEN or NF_CREATE.
varid- Variable ID.
sizep- The total size of the raw data chunk cache, in megabytes, will be put
here.
nelemsp- The number of chunk slots in the raw data chunk cache hash table will
be put here.
preemptionp- The preemption will be put here. The preemtion value is between 0 and
100 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 100 means fully read chunks are always
preempted before other chunks.
Return Codes
NC_NOERR- No error.
Example
This example is from nf_test/ftst_vars2.c:
include 'netcdf.inc'
...
C These will be used to set the per-variable chunk cache.
integer CACHE_SIZE, CACHE_NELEMS, CACHE_PREEMPTION
parameter (CACHE_SIZE = 8, CACHE_NELEMS = 571)
parameter (CACHE_PREEMPTION = 42)
C These will be used to check the setting of the per-variable chunk
C cache.
integer cache_size_in, cache_nelems_in, cache_preemption_in
...
retval = nf_get_var_chunk_cache(ncid, varid(i), cache_size_in,
& cache_nelems_in, cache_preemption_in)
if (retval .ne. nf_noerr) call handle_err(retval)
if (cache_size_in .ne. CACHE_SIZE .or. cache_nelems_in .ne.
& CACHE_NELEMS .or. cache_preemption .ne. CACHE_PREEMPTION)
& stop 8
