netcdf-c/oc2
Dennis Heimbigner 11fe00ea05 Add filter support to NCZarr
Filter support has three goals:

1. Use the existing HDF5 filter implementations,
2. Allow filter metadata to be stored in the NumCodecs metadata format used by Zarr,
3. Allow filters to be used even when HDF5 is disabled

Detailed usage directions are define in docs/filters.md.

For now, the existing filter API is left in place. So filters
are defined using ''nc_def_var_filter'' using the HDF5 style
where the id and parameters are unsigned integers.

This is a big change since filters affect many parts of the code.

In the following, the terms "compressor" and "filter" and "codec" are generally
used synonomously.

### Filter-Related Changes:
* In order to support dynamic loading of shared filter libraries, a new library was added in the libncpoco directory; it helps to isolate dynamic loading across multiple platforms.
* Provide a json parsing library for use by plugins; this is created by merging libdispatch/ncjson.c with include/ncjson.h.
* Add a new _Codecs attribute to allow clients to see what codecs are being used; let ncdump -s print it out.
* Provide special headers to help support compilation of HDF5 filters when HDF5 is not enabled: netcdf_filter_hdf5_build.h and netcdf_filter_build.h.
* Add a number of new test to test the new nczarr filters.
* Let ncgen parse _Codecs attribute, although it is ignored.

### Plugin directory changes:
* Add support for the Blosc compressor; this is essential because it is the most common compressor used in Zarr datasets. This also necessitated adding a CMake FindBlosc.cmake file
* Add NCZarr support for the big-four filters provided by HDF5: shuffle, fletcher32, deflate (zlib), and szip
* Add a Codec defaulter (see docs/filters.md) for the big four filters.
* Make plugins work with windows by properly adding __declspec declaration.

### Misc. Non-Filter Changes
* Replace most uses of USE_NETCDF4 (deprecated) with USE_HDF5.
* Improve support for caching
* More fixes for path conversion code
* Fix misc. memory leaks
* Add new utility -- ncdump/ncpathcvt -- that does more or less the same thing as cygpath.
* Add a number of new test to test the non-filter fixes.
* Update the parsers
* Convert most instances of '#ifdef _MSC_VER' to '#ifdef _WIN32'
2021-09-02 17:04:26 -06:00
..
auth.html.in Misc. source comment typos 2018-04-26 23:04:01 -04:00
CMakeLists.txt nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
dap.y Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
daplex.c Fix undefined references when using Visual Studio 2020-05-18 19:36:28 -06:00
dapparse.c Fix LGTM errors 2020-06-28 19:07:08 -06:00
dapparselex.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
dapy.c Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
dapy.h Fix for Github issue 314. 2016-09-01 22:06:07 -06:00
dodsrc.example
Makefile.am Add filter support to NCZarr 2021-09-02 17:04:26 -06:00
oc.c LGTM cleanup 2021-04-24 21:44:57 -06:00
oc.css Github issue 152: https://github.com/Unidata/netcdf-c/issues/152 2015-11-29 20:38:12 -07:00
oc.h LGTM cleanup 2021-04-24 21:44:57 -06:00
occompile.c This PR adds EXPERIMENTAL support for accessing data in the 2020-06-28 18:02:47 -06:00
occompile.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
occonstraints.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
occurlflags.c Add support for CURLOPT_CONNECTTIMEOUT 2020-01-09 11:48:04 -07:00
occurlfunctions.c Re-enable DAP2 authorization tests 2021-05-29 21:30:33 -06:00
occurlfunctions.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocdata.c nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocdata.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocdatatypes.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocdebug.c Fix undefined references when using Visual Studio 2020-05-18 19:36:28 -06:00
ocdebug.h Fix undefined references when using Visual Studio 2020-05-18 19:36:28 -06:00
ocdump.c Regularize the semantics of mkstemp. 2021-05-14 11:33:03 -06:00
ocdump.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ochttp.c This PR adds EXPERIMENTAL support for accessing data in the 2020-06-28 18:02:47 -06:00
ochttp.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocinternal.c Regularize the semantics of mkstemp. 2021-05-14 11:33:03 -06:00
ocinternal.h Provide a Number of fixes/improvements to NCZarr 2020-11-19 17:01:04 -07:00
ocnode.c nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocnode.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
ocread.c Regularize the semantics of mkstemp. 2021-05-14 11:33:03 -06:00
ocread.h Yet another fix for DAP2 double URL encoding. 2020-11-05 11:04:56 -07:00
ocutil.c Regularize the semantics of mkstemp. 2021-05-14 11:33:03 -06:00
ocutil.h Thread safety: step 1: cleanup 2019-03-30 14:06:20 -06:00
ocx.h nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
xxdr.c nctest, oc2 files updated. 2018-12-06 15:47:47 -07:00
xxdr.h Spelling fixes 2019-09-18 08:03:01 -06:00