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'
The thredds-test server now has some password protected datasets
that can be used to test DAP2 authorization support.
The general location is
````
https://thredds.ucar.edu/thredds/tdscapabilities/authTest.html
````
and specifically:
````
https://thredds.ucar.edu/thredds/dodsC/test3/testData.nc.html
````
This PR replaces old testcases with ncdap_test/testauth.sh.
This testcase allows us to test use of the .dodsrc file and .netrc file
and embedded user+pwd.
As part of this, I had to create a program (ncdap_test/pathcvt.c)
that is essentially the equivalent to cygpath. Given a path in
windows, unix, msys or cygwin format, it converts it to the
equivalent format in one of those four cases. So it can be used
to convert a cygwin path to a windows path, for example. This is
needed in testpathcvt and testauth to make sure that the paths
in .daprc (e.g. the reference to .netrc) are of the proper
format.
Misc. Other Changes:
1. Fix some memory leaks in libdap2
2. Setting the env variable CURLOPT_VERBOSE allows tracking of curl
operations.
3. Make tst_charvlenbug be conditional on NC_VLEN_NOTEST.
re: https://github.com/Unidata/netcdf-c/issues/1827
The issue is partly resolved by this PR. The proximate problem appears to be that the semantics of mkstemp in **nix is different than the semantics of _mktemp_s in Windows. I had thought they were the same but that is incorrect. The _mktemp_s function will only produce 26 different files and so the netcdf temp file code will fail after about that many iterations.
So, to solve this, I created my own version of mkstemp for windows that uses a random number generator. This appears to solve the reported issue. I also added the testcase ncdap_test/test_manyurls but made it conditional on --enable-dap-long-tests because it is very slow.
I did note that the provided test program now fails after some 800 iterations with a libcurl error claiming it cannot resolve the host name. My belief is that the library is just running out of resources at this point: too many open curl handles or some such. I doubt if this failure is fixable.
So bottom line is that it is really important to do nc_close when you are finished with a file.
Misc. Other Changes:
1. I took the opportunity to clean up some bad string hacks in the code. Specifically
* change all uses of strncat to strlcat
* remove old string hacks: occoncat and occopycat
2. Add heck to see if test.opendap.org is running and if not, then skip test
3. Make CYGWIN use TEMP environment variable
Re: GH Issue https://github.com/Unidata/netcdf-c/issues/1900
Apparently the clock_gettime() function is not always available.
It is used in unit_test/tst_exhash.c and unit_test/tst_xcache.c.
To solve this, a number of things were changed:
* Move the timing code to a new file unit_tests/timer_utils.[ch]
* Modify the timing code to choose one of several timing methods
depending on availability. The prioritized order is as follows:
1. If Windows, use the QueryPerformanceCounter mechanism else
2. Use clock_gettime if available else
3. Use gettimeofday if available else
4. Use getrusage if available
Note that the resolution of 3 and 4 is less than 1 or 2.
Misc. Other Changes:
* Move the test in CMakeLists.txt that disables unit tests for WIN32 to unit_test/CMakeLists.txt since some unit tests actually work under Visual Studio.
* Fix some of the unit tests to work under visual studio
* Fix problem with using remove() in zmap_nzf.c
* Remove some warning about use of EXTERNL
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.
re: https://github.com/Unidata/netcdf-c/issues/1451
The situation with the various DAP (and other) remote test
servers is currently in a state of flux. For example, Unidata
admin is planning to forcibly shift the remote test server to
remotetest.unidata.ucar.edu soon. In addition, the server
test.opendap.org has shown some recent instability.
The result is that various DAP (and byterange) tests can fail
unexpectedly. This is an irritant to users and reveals nothing
about test sucess or failure.
Solve by modifying tests to report server inaccessibility and
otherwise pretend to succeed.
This puts an onus on Unidata to detect such server failures, but
will not cause users to see spurious failures. [Note. Do similar
fix for netcdf-java]. The check is:
1. export SETX=1 to cause all the shell scripts to trace
2. search the log files for the phrase "WARNING" (in upper case)
and see if it is complaining about not finding a server.
Misc. Changes
-------------
1. Added a pingurl program to see if a server was up.
2. modified some test case url targets
re: issue https://github.com/Unidata/netcdf-c/issues/1151
Modify DAP2 and DAP4 code to handle case when _FillValue type is not
same as the parent variable type.
Specifically:
1. Define a parameter [fillmismatch] to allow this mismatch;
default is to disallow.
2. If allowed, forcibly change the type of the _FillValue to match
the parent variable.
3. If allowed Convert the values to match new type
4. Generate a log message
5. if not allowed, then fail
Implementing this required some changes to ncdap_test/dapcvt.c
Also added test cases.
Minor Unrelated Changes:
1. There were a number of warnings about e.g.
assigning a const char* to a char*. Fix these
2. In nccopy.1, replace .NP with .IP "n"
(re PR https://github.com/Unidata/netcdf-c/pull/1144)
3. fix minor error in ncdump/ocprint
re: github issue https://github.com/Unidata/netcdf-c/issues/1111
One of the less common use cases for the in-memory feature is
apparently failing with HDF5-1.10.x. The fix is complicated and
requires significant changes to libhdf5/nc4memcb.c. The current
setup is detailed in the file docs/inmeminternal.dox.
Additionally, it was discovered that the program
nc_test/tst_inmemory.c, which is invoked by
nc_test/run_inmemory.sh, actually was failing because of the
above problem. But the failure is not detected since the script
does not return non-zero value.
Other Changes:
1. Fix nc_test_tst_inmemory to return errors correctly.
2. Make ncdap_tests/findtestserver.c and dap4_tests/findtestserver4.c
be generated from ncdap_test/findtestserver.c.in.
3. Make LOG() print output to stderr instead of stdout to
avoid contaminating e.g. ncdump output.
4. Modify the handling of NC_INMEMORY and NC_DISKLESS flags
to properly handle that NC_DISKLESS => NC_INMEMORY. This
affects a number of code pieces, especially memio.c.
to remove cruft and to remove unused site tests
and make the tests somewhat more understandable.
Also did a fix to libdispatch/dwinpath to convert
relative paths to absolute paths. This will, I hope,
take care of some windows path problems when using
$srcdir in shell scripts.
Specific changes:
1. Add dap4 code: libdap4 and dap4_test.
Note that until the d4ts server problem is solved, dap4 is turned off.
2. Modify various files to support dap4 flags:
configure.ac, Makefile.am, CMakeLists.txt, etc.
3. Add nc_test/test_common.sh. This centralizes
the handling of the locations of various
things in the build tree: e.g. where is
ncgen.exe located. See nc_test/test_common.sh
for details.
4. Modify .sh files to use test_common.sh
5. Obsolete separate oc2 by moving it to be part of
netcdf-c. This means replacing code with netcdf-c
equivalents.
5. Add --with-testserver to configure.ac to allow
override of the servers to be used for --enable-dap-remote-tests.
6. There were multiple versions of nctypealignment code. Try to
centralize in libdispatch/doffset.c and include/ncoffsets.h
7. Add a unit test for the ncuri code because of its complexity.
8. Move the findserver code out of libdispatch and into
a separate, self contained program in ncdap_test and dap4_test.
9. Move the dispatch header files (nc{3,4}dispatch.h) to
.../include because they are now shared by modules.
10. Revamp the handling of TOPSRCDIR and TOPBUILDDIR for shell scripts.
11. Make use of MREMAP if available
12. Misc. minor changes e.g.
- #include <config.h> -> #include "config.h"
- Add some no-install headers to /include
- extern -> EXTERNL and vice versa as needed
- misc header cleanup
- clean up checking for misc. unix vs microsoft functions
13. Change copyright decls in some files to point to LICENSE file.
14. Add notes to RELEASENOTES.md
should be under ENABLE_DAP_REMOTE_TESTS.
Fixed to make sure that this is so.
Also attempted to fix ncdap_test/CMakeLists.txt,
but probably got it wrong.
HT to Nico Schlomer.
2. Attempted to reduce the number of conversion errors
when -Wconversion is set. Fixed oc2, but
rest of netcdf remains to be done.
HT to Nico Schlomer.
3. When doing #2, I discovered an error in ncgen.y
that has remained hidden. This required some other
test case fixes.
times, but returning the same ncid.
2. Separate out the dap auth tests
and make them disabled by default.
3. turn of ncdap_test/test_varm3 until
we can find a copy of coads_climatology.nc
The code that tests if a path is a url is
faulting when the url does not end in a slash
(e.g. http://thredds-tests.ucar.edu).
The code that tests if a path is a url is
faulting when the url does not end in a slash
(e.g. http://thredds-tests.ucar.edu).
CF-273]/HZY-708311
Solution was to do a null pointer test.
Added a test (tst_misc).
