NOTE: This PR should not be included in 4.9.1 since additional
DAP4 related PRs will be forthcoming.
This PR makes major changes to libdap4 and dap4_test driven by changes to TDS.
* Enable DAP4
* Clean up the test input files and the test baseline comparison files. This entails:
* Remove a multitude of unused test input and baseline data files; among them are dap4_test/: daptestfiles, dmrtestfiles, nctestfiles, and misctestfiles.
* Define a canonical set of test input files and record in dap4_test/cdltestfiles.
* Use the cdltestfiles to generate the .nc test inputs. This set of .nc files is then moved to the d4ts (DAP4 test server) war file in the tds repository. This set then becomes the canonical set of DAP4 test sources.
* Scrape d4ts to obtain copies of the raw streams of DAP4 encoded data. The .dmr and .dap streams are then stored in dap4_test/rawtestfiles.
* Disable some remote server tests until those servers are fixed.
* Add an option to ncdump (-XF) that forces the type of the _FillValue attribute; this is primarily to simplify testing of fill mismatch.
* Minor bug fixes to ncgen.
* Changes to libdap4:
* Replace old checksum hack with the dap4.checksum flag.
* Support the dap4.XXX controls.
* Cleanup _FillValue handling, especially var-attribute type mismatches.
* Fix enum handling based on changes to netcdf-java.
* Changes to dap4_test:
* Add getopt support to various test support programs.
* Remove unneeded shell scripts.
* Add new scripts: test_curlopt.sh
re: Issue https://github.com/Unidata/netcdf-c/issues/2458
The above Github Issue revealed some bugs in the file netcdf-c/plugins/H5Zblosc.c. Fixed and added a testcase. Also discovered that the Blosc LZ sub-compressors do not work well with small datasets.
Misc. Other Change(s): I noticed that the file "dap4_test/baselinethredds/GOES16_CONUS_20170821_020218_0.47_1km_33.3N_91.4W.nc4.thredds" is still causing tar errors during "make distcheck", so I made some changes to do rename at test-time.
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'
re: https://github.com/Unidata/netcdf-c/pull/2075
The long file name fix fails when the build is manually repeated
because the source file has already been renamed. Solution is to
test if the dest file exists or not before doing the rename.
re: e-support EOT-483791
* Add a new set of remote tests based on using the thredds-test server.
* Improve error reporting when server requests fail.
* Fix handing of _NCProperties attribute
