netcdf-c/docs
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
..
images Updating files to refer to the top-level COPYRIGHT file. 2018-12-04 15:52:43 -07:00
obsolete Misc. source comment typos 2018-04-26 23:04:01 -04:00
old Spelling fixes 2019-09-18 08:03:01 -06:00
static-pages Updated one of the static software pages. 2019-11-21 14:18:10 -07:00
.gitignore Fix up documentation to replace old auth documentation 2017-08-20 18:27:48 -06:00
all-error-codes.md introduce error code NC_EPNETCDF for errors at PnetCDF level 2018-07-29 15:33:08 -05:00
architecture.dox Use PnetCDF instead of parallel-netcdf to avoid confusion with 2018-09-17 17:18:48 -05:00
attribute_conventions.md There was a request to extend the provenance information 2018-08-25 21:44:41 -06:00
auth.html Misc. source comment typos 2018-04-26 23:04:01 -04:00
auth.md The pr does some cleanup on the internal documentation 2018-06-29 15:06:27 -06:00
building-with-cmake.md Updated documentation to reflect minimum cmake version of 2.8.12. 2014-07-29 14:53:12 -06:00
byterange.dox changed/removed references to jetstream remotetest instance. 2020-01-03 13:12:58 -07:00
cdl.dox Misc. source comment typos 2018-04-26 23:04:01 -04:00
CMakeLists.txt Provide byte-range reading of remote datasets 2019-01-01 18:27:36 -07:00
COPYRIGHT.md Updating files to refer to the top-level COPYRIGHT file. 2018-12-04 15:52:43 -07:00
credits.md Spelling fixes 2019-09-18 08:03:01 -06:00
dispatch.dox Spelling fixes 2019-09-18 08:03:01 -06:00
docmap.pdf The 'Credits' page is now a generated document distributed with netcdf, even though the contents are static. It is currently included as a subpage underneath the NetCDF Overview page. Also, renamed 'Credits' on the Overview page to 'About NetCDF'. 2014-12-10 11:14:43 -07:00
Doxyfile.developer Updated soversion, bump to next development version in preparation of upstream merge back into master from 4.7.4 wellspring. 2020-03-26 11:31:43 -06:00
Doxyfile.in Tweaked docs to fix dead references introduced as part of separating out NUG from netCDF-C. 2020-03-27 14:21:25 -06:00
Doxyfile.user Added a stand-alone user level doxygen configuration file. It must be used from the top-level netcdf-c directory, e.g. doxygen docs/Doxyfile.user. 2020-05-07 16:23:43 -06:00
DoxygenLayout.xml Further reorganization. Figured out how subpage works with different files. Renamed some of the header cells. 2014-12-09 16:36:15 -07:00
esg.md More doxygen tweaks. 2016-01-15 12:23:56 -07:00
FAQ.md Update FAQ.md 2020-05-29 11:58:38 -04:00
file_format_specifications.md This PR adds EXPERIMENTAL support for accessing data in the 2020-06-28 18:02:47 -06:00
footer.html Ensure that the nav-tree extends to the full height of the content area. The footer must be enclosed in a div element with the id="nav-path" for this to work. 2020-05-13 16:45:35 -06:00
groups.dox Renamed man4 directory to docs. 2014-05-21 14:40:39 -06:00
header.html Renamed man4 directory to docs. 2014-05-21 14:40:39 -06:00
indexing.dox Spelling fixes 2019-09-18 08:03:01 -06:00
inmeminternal.dox Spelling fixes 2019-09-18 08:03:01 -06:00
inmemory.md Spelling fixes 2019-09-18 08:03:01 -06:00
install-fortran.md Fix doxygen list 2015-06-08 10:20:50 -06:00
internal.dox Change (again), and hopefully simplify, the file model inference algorithm. 2019-09-29 12:59:28 -06:00
known_problems.md Spelling fixes 2019-09-18 08:03:01 -06:00
mainpage.dox Tweaked docs to fix dead references introduced as part of separating out NUG from netCDF-C. 2020-03-27 14:21:25 -06:00
Makefile.am Cleaning up distcheck. 2020-02-07 13:47:45 -07:00
netcdf-50x50.png Renamed man4 directory to docs. 2014-05-21 14:40:39 -06:00
netcdf.m4 Spelling fixes 2019-09-18 08:03:01 -06:00
notes.md More document reorganization. 2015-03-15 15:29:58 -06:00
release_header.html Added release to release header. 2016-11-21 11:23:02 -07:00
release.css Tweaks to css 2016-01-21 11:19:23 -07:00
tests.md Added a document to catalog what the various tests are. 2016-06-06 14:51:57 -06:00
testserver.dox changed/removed references to jetstream remotetest instance. 2020-01-03 13:12:58 -07:00
tutorial.dox updated tutorial 2019-11-14 08:14:53 -07:00
unidata_logo_cmyk.png Renamed man4 directory to docs. 2014-05-21 14:40:39 -06:00
windows-binaries.md Corrected mistake regarding which version of Visual Studio is being used to build the libraries. 2019-06-17 14:41:50 -06:00