netcdf-c/nc_test4
Dennis Heimbigner 231ae96c4b Add support for Zarr string type to NCZarr
* re: https://github.com/Unidata/netcdf-c/pull/2278
* re: https://github.com/Unidata/netcdf-c/issues/2485
* re: https://github.com/Unidata/netcdf-c/issues/2474

This PR subsumes PR https://github.com/Unidata/netcdf-c/pull/2278.
Actually is a bit an omnibus covering several issues.

## PR https://github.com/Unidata/netcdf-c/pull/2278
Add support for the Zarr string type.
Zarr strings are restricted currently to be of fixed size.
The primary issue to be addressed is to provide a way for user to
specify the size of the fixed length strings. This is handled by providing
the following new attributes special:
1. **_nczarr_default_maxstrlen** —
This is an attribute of the root group. It specifies the default
maximum string length for string types. If not specified, then
it has the value of 64 characters.
2. **_nczarr_maxstrlen** —
This is a per-variable attribute. It specifies the maximum
string length for the string type associated with the variable.
If not specified, then it is assigned the value of
**_nczarr_default_maxstrlen**.

This PR also requires some hacking to handle the existing netcdf-c NC_CHAR
type, which does not exist in zarr. The goal was to choose numpy types for
both the netcdf-c NC_STRING type and the netcdf-c NC_CHAR type such that
if a pure zarr implementation read them, it would still work and an
NC_CHAR type would be handled by zarr as a string of length 1.

For writing variables and NCZarr attributes, the type mapping is as follows:
* "|S1" for NC_CHAR.
* ">S1" for NC_STRING && MAXSTRLEN==1
* ">Sn" for NC_STRING && MAXSTRLEN==n

Note that it is a bit of a hack to use endianness, but it should be ok since for
string/char, the endianness has no meaning.

For reading attributes with pure zarr (i.e. with no nczarr
atribute types defined), they will always be interpreted as of
type NC_CHAR.

## Issue: https://github.com/Unidata/netcdf-c/issues/2474
This PR partly fixes this issue because it provided more
comprehensive support for Zarr attributes that are JSON valued expressions.
This PR still does not address the problem in that issue where the
_ARRAY_DIMENSION attribute is incorrectly set. Than can only be
fixed by the creator of the datasets.

## Issue: https://github.com/Unidata/netcdf-c/issues/2485
This PR also fixes the scalar failure shown in this issue.
It generally cleans up scalar handling.
It also adds a note to the documentation describing that
NCZarr supports scalars while Zarr does not and also how
scalar interoperability is achieved.

## Misc. Other Changes
1. Convert the nczarr special attributes and keys to be all lower case. So "_NCZARR_ATTR" now used "_nczarr_attr. Support back compatibility for the upper case names.
2. Cleanup my too-clever-by-half handling of scalars in libnczarr.
2022-08-27 20:21:13 -06:00
..
bm_chunking.c
bm_radar.c
build_fixedstring.c Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
bzip2.cdl
cdm_sea_soundings.c
clear_cache.sh
CMakeLists.txt Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
findplugin.in I made a major update to this PR with the following changes: 2022-05-19 22:00:40 -06:00
h5testszip.c Fix for use with szip and also 1.8.21 2021-04-28 15:42:02 -06:00
Makefile.am Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
noop1.cdl Improve filter installation process to avoid use of an extra shell script 2022-05-14 16:05:48 -06:00
noop.cdl Enhance/Fix filter support 2022-03-14 12:39:37 -06:00
ref_any.cdl Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
ref_bzip2.c This PR adds EXPERIMENTAL support for accessing data in the 2020-06-28 18:02:47 -06:00
ref_fillonly.cdl Fix error where not converting fill data 2020-09-12 14:49:59 -06:00
ref_filter_order_create.txt Add tests for filter order on read and write cases 2020-12-29 20:12:35 -07:00
ref_filter_order_read.txt Add tests for filter order on read and write cases 2020-12-29 20:12:35 -07:00
ref_filter_repeat.txt Add tests for filter order on read and write cases 2020-12-29 20:12:35 -07:00
ref_filtered.cdl Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
ref_filteredvv.cdl Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
ref_filterx_hdf5.txt Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
ref_fixedstring.cdl Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
ref_fixedstring.h5 Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
ref_hdf5_compat1.nc
ref_hdf5_compat2.nc
ref_hdf5_compat3.nc
ref_multi.cdl Add support for multiple filters per variable. 2020-02-16 12:59:33 -07:00
ref_nccopyF.cdl Add support for multiple filters per variable. 2020-02-16 12:59:33 -07:00
ref_ncgenF.cdl Add support for multiple filters per variable. 2020-02-16 12:59:33 -07:00
ref_szip.cdl
ref_szip.h5
ref_tst_compounds.nc
ref_tst_dims.nc
ref_tst_interops4.nc
ref_tst_xplatform2_1.nc
ref_tst_xplatform2_2.nc
ref_unfiltered.cdl
ref_unfilteredvv.cdl
renamegroup.c
run_empty_vlen_test.sh
run_grp_rename.sh
run_par_test.sh.in no longer run tst_parallel_zlib with 1 processor in testing 2022-04-30 07:42:01 -06:00
t_type.c
tdset.h5
test_fillonly.sh Fix error where not converting fill data 2020-09-12 14:49:59 -06:00
test_filter_misc.c Explicitly disallow variable length type compression 2022-02-19 16:47:31 -07:00
test_filter_order.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
test_filter_reg.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
test_filter_repeat.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
test_filter_vlen.c Enhance/Fix filter support 2022-03-14 12:39:37 -06:00
test_filter.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
test_filterx_hdf5.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
test_szip.c Add support for multiple filters per variable. 2020-02-16 12:59:33 -07:00
test_wrapper.in
tst_alignment.c Add support for setting HDF5 alignment property when creating a file 2022-01-29 15:27:52 -07:00
tst_atts1.c
tst_atts2.c
tst_atts3.c
tst_atts_string_rewrite.c
tst_atts.c
tst_broken_files.c Merge branch 'main' into jsonconvention.dmh 2022-05-17 13:24:53 -06:00
tst_bug324.c
tst_bug1442.c
tst_camrun.c Improve UTF8 Support On Windows 2022-02-08 20:53:30 -07:00
tst_charvlenbug.c Fix various problem around VLEN's 2022-01-08 18:30:00 -07:00
tst_chunks2.c
tst_chunks.c
tst_compounds2.c
tst_compounds3.c
tst_compounds.c
tst_converts2.c
tst_converts.c Revert "Revert "Fix nczarr-experimental: improve build support, disengage hdf5 vs netcdf4 flags, and find AWS libraries"" 2020-08-17 19:15:47 -06:00
tst_coords2.c
tst_coords3.c
tst_coords.c
tst_dims2.c Fix undefined references when using Visual Studio 2020-05-18 19:36:28 -06:00
tst_dims3.c Make public a limited API for programmatic access to internal .rc tables 2022-06-17 14:35:12 -06:00
tst_dims.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
tst_elatefill.c
tst_empty_vlen_unlim.c
tst_endian_fill.c
tst_enums.c
tst_files4.c
tst_files5.c
tst_files6.c
tst_files.c now dont return error on second redef call for netcdf/HDF5 files 2020-07-08 11:10:15 -06:00
tst_fill_attr_vanish.c Fix in support of https://github.com/Unidata/netcdf-c/issues/2027 2021-07-06 11:34:30 -06:00
tst_fillbug.c
tst_fillonly.c Mostly revert the filter code to reduce its complexity of use. 2020-09-27 12:43:46 -06:00
tst_fills2.c
tst_fills.c Fix undefined references when using Visual Studio 2020-05-18 19:36:28 -06:00
tst_filter_avail.c Enhance/Fix filter support 2022-03-14 12:39:37 -06:00
tst_filter.sh Improve filter installation process to avoid use of an extra shell script 2022-05-14 16:05:48 -06:00
tst_filterinstall.sh Update to default --with-plugin-dir to yes 2022-05-24 20:05:19 -06:00
tst_filterparser.c Mostly revert the filter code to reduce its complexity of use. 2020-09-27 12:43:46 -06:00
tst_fixedstring.sh Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
tst_grps2.c
tst_grps.c
tst_h5_endians.c
tst_h_converts.c Remove need for HDF5-1.6 API being defined 2021-04-28 13:59:24 -06:00
tst_h_refs.c
tst_h_scalar.c
tst_h_strbug.c Remove need for HDF5-1.6 API being defined 2021-04-28 13:59:24 -06:00
tst_h_strings3.c
tst_h_vl2.c Merge branch 'virtual_datasets' of https://github.com/d70-t/netcdf-c into gh1983.wif 2021-07-19 09:44:35 -07:00
tst_hdf5_file_compat.c
tst_interops4.c
tst_interops5.c Enhance/Fix filter support 2022-03-14 12:39:37 -06:00
tst_interops6.c Remove need for HDF5-1.6 API being defined 2021-04-28 13:59:24 -06:00
tst_interops_dims.c
tst_interops.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
tst_large2.c
tst_large3.c
tst_large5.c
tst_large.c
tst_misc.sh Fix various problem around VLEN's 2022-01-08 18:30:00 -07:00
tst_mode.c fixed tst_mode to not attempt to set filters on scalars 2020-03-03 07:44:37 -07:00
tst_mpi_parallel.c
tst_multifilter.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
tst_nc4perf.c
tst_nc_converts.c
tst_opaques.c
tst_parallel3.c
tst_parallel4.c
tst_parallel5.c Enhance/Fix filter support 2022-03-14 12:39:37 -06:00
tst_parallel6.c undoing unintended change 2022-04-30 07:48:03 -06:00
tst_parallel_compress.c fixed problem setting szip on var with unlimited dim and added test 2020-07-02 10:55:34 -06:00
tst_parallel_zlib.c Added error message. 2022-05-02 09:55:08 -06:00
tst_parallel.c
tst_put_vars_two_unlim_dim.c
tst_put_vars.c
tst_quantize_par.c added parallel I/O quantize test 2021-09-02 10:21:44 -06:00
tst_quantize.c more testing of quantize 2022-07-08 14:58:52 -06:00
tst_rehash.c
tst_rename2.c
tst_rename3.c
tst_rename.c
tst_simplerw_coll_r.c
tst_specific_filters.sh Add support for Zarr string type to NCZarr 2022-08-27 20:21:13 -06:00
tst_strings2.c
tst_strings.c
tst_sync.c
tst_szip.sh Regularize the scoping of dimensions 2021-05-31 15:51:12 -06:00
tst_types.c
tst_udf.c Merge branch 'winutf8.dmh' of https://github.com/DennisHeimbigner/netcdf-c into gh2222.wif 2022-04-05 10:46:22 -06:00
tst_unknown.sh I made a major update to this PR with the following changes: 2022-05-19 22:00:40 -06:00
tst_unlim_vars.c more checking in 3D test 2020-02-12 08:21:52 -07:00
tst_utf8.c
tst_v2.c
tst_varms.c
tst_vars2.c Disable varible rename test 2021-08-12 10:56:39 -06:00
tst_vars3.c Fix support for reading arrays of HDF5 fixed size strings 2022-07-29 14:47:07 -06:00
tst_vars4.c Enhance/Fix filter support 2022-03-14 12:39:37 -06:00
tst_vars.c more test development 2021-12-03 06:41:20 -07:00
tst_varsperf.c
tst_virtual_datasets.c tst_virtual_datasets: add missing hdf5 close calls 2020-09-02 16:11:43 +02:00
tst_vl.c
tst_vlenstr.c Rename GranularBitGroom to GranularBitRound 2022-01-28 13:04:16 -07:00
tst_xplatform2.c Remove need for HDF5-1.6 API being defined 2021-04-28 13:59:24 -06:00
tst_xplatform.c
unknown.cdl Improve filter installation process to avoid use of an extra shell script 2022-05-14 16:05:48 -06:00