2 Commits

Author	SHA1	Message	Date
Dennis Heimbigner	aeb3ac2809	Mostly revert the filter code to reduce its complexity of use. ... re: https://github.com/Unidata/netcdf-c/issues/1836 Revert the internal filter code to simplify it. From the user's point of view, the only visible changes should be: 1. The functions that convert text to filter specs have had their signature reverted and have been moved to netcdf_aux.h 2. Some filter API functions now return NC_ENOFILTER when inquiry is made about some filter. Internally,the dispatch table has been modified to get rid of the filter_actions entry and associated complex structures. It has been replaced with inq_var_filter_ids and inq_var_filter_info entries and the dispatch table version has been bumped to 3. Corresponding NOOP and NOTNC4 functions were added to libdispatch/dnotnc4.c. Also, the filter_action entries in dispatch tables were replaced for all dispatch code bases (HDF5, DAP2, etc). This should only impact UDF users. In the process, it became clear that the form of the filters field in NC_VAR_INFO_T was format dependent, so I converted it to be of type void* and pushed its management into the various dispatch code bases. Specifically libhdf5 and libnczarr now manage the filters field in their own way. The auxilliary functions for parsing textual filter specifications were moved to netcdf_aux.h and were renamed to the following: * ncaux_h5filterspec_parse * ncaux_h5filterspec_parselist * ncaux_h5filterspec_free * ncaux_h5filter_fix8 Misc. Other Changes: 1. Document NUG/filters.md updated to reflect the changes above. 2. All the old data types (structs and enums) used by filter_actions actions were deleted. The exception is the NC_H5_Filterspec because it is needed by ncaux_h5filterspec_parselist. 3. Clientside filters were removed -- another enhancement for which no-one ever asked. 4. The ability to remove filters was itself removed. 5. Some functionality needed by nczarr was moved from libhdf5 to libsrc4 e.g. nc4_find_default_chunksizes 6. All the filterx code was removed 7. ncfilter.h and nc4filter.c no longer used Misc. Unrelated Changes: 1. The nczarr_test makefile clean was leaving some directories; so add clean-local to take care of them.	2020-09-27 12:43:46 -06:00
Dennis Heimbigner	59e04ae071	This PR adds EXPERIMENTAL support for accessing data in the ... cloud using a variant of the Zarr protocol and storage format. This enhancement is generically referred to as "NCZarr". The data model supported by NCZarr is netcdf-4 minus the user-defined types and the String type. In this sense it is similar to the CDF-5 data model. More detailed information about enabling and using NCZarr is described in the document NUG/nczarr.md and in a [Unidata Developer's blog entry](https://www.unidata.ucar.edu/blogs/developer/en/entry/overview-of-zarr-support-in). WARNING: this code has had limited testing, so do use this version for production work. Also, performance improvements are ongoing. Note especially the following platform matrix of successful tests: Platform | Build System | S3 support ------------------------------------ Linux+gcc | Automake | yes Linux+gcc | CMake | yes Visual Studio | CMake | no Additionally, and as a consequence of the addition of NCZarr, major changes have been made to the Filter API. NOTE: NCZarr does not yet support filters, but these changes are enablers for that support in the future. Note that it is possible (probable?) that there will be some accidental reversions if the changes here did not correctly mimic the existing filter testing. In any case, previously filter ids and parameters were of type unsigned int. In order to support the more general zarr filter model, this was all converted to char*. The old HDF5-specific, unsigned int operations are still supported but they are wrappers around the new, char* based nc_filterx_XXX functions. This entailed at least the following changes: 1. Added the files libdispatch/dfilterx.c and include/ncfilter.h 2. Some filterx utilities have been moved to libdispatch/daux.c 3. A new entry, "filter_actions" was added to the NCDispatch table and the version bumped. 4. An overly complex set of structs was created to support funnelling all of the filterx operations thru a single dispatch "filter_actions" entry. 5. Move common code to from libhdf5 to libsrc4 so that it is accessible to nczarr. Changes directly related to Zarr: 1. Modified CMakeList.txt and configure.ac to support both C and C++ -- this is in support of S3 support via the awd-sdk libraries. 2. Define a size64_t type to support nczarr. 3. More reworking of libdispatch/dinfermodel.c to support zarr and to regularize the structure of the fragments section of a URL. Changes not directly related to Zarr: 1. Make client-side filter registration be conditional, with default off. 2. Hack include/nc4internal.h to make some flags added by Ed be unique: e.g. NC_CREAT, NC_INDEF, etc. 3. cleanup include/nchttp.h and libdispatch/dhttp.c. 4. Misc. changes to support compiling under Visual Studio including: * Better testing under windows for dirent.h and opendir and closedir. 5. Misc. changes to the oc2 code to support various libcurl CURLOPT flags and to centralize error reporting. 6. By default, suppress the vlen tests that have unfixed memory leaks; add option to enable them. 7. Make part of the nc_test/test_byterange.sh test be contingent on remotetest.unidata.ucar.edu being accessible. Changes Left TO-DO: 1. fix provenance code, it is too HDF5 specific.	2020-06-28 18:02:47 -06:00