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'
This is a follow-on to pull request
````https://github.com/Unidata/netcdf-c/pull/1959````,
which fixed up type scoping.
The primary changes are to _nc\_inq\_dimid()_ and to ncdump.
The _nc\_inq\_dimid()_ function is supposed to allow the name to be
and FQN, but this apparently never got implemented. So if was modified
to support FQNs.
The ncdump program is supposed to output fully qualified dimension names
in its generated CDL file under certain conditions.
Suppose ncdump has a netcdf-4 file F with variable V, and V's parent group
is G. For each dimension id D referenced by V, ncdump needs to determine
whether to print its name as a simple name or as a fully qualified name (FQN).
The algorithm is as follows:
1. Search up the tree of ancestor groups.
2. If one of those ancestor groups contains the dimid, then call it dimgrp.
3. If one of those ancestor groups contains a dim with the same name as the dimid, but with a different dimid, then record that as duplicate=true.
4. If dimgrp is defined and duplicate == false, then we do not need an fqn.
5. If dimgrp is defined and duplicate == true, then we do need an fqn to avoid incorrectly using the duplicate.
6. If dimgrp is undefined, then do a preorder breadth-first search of all the groups looking for the dimid.
7. If found, then use the fqn of the first found such dimension location.
8. If not found, then fail.
Test case ncdump/test_scope.sh was modified to test the proper
operation of ncdump and _nc\_inq\_dimid()_.
Misc. Other Changes:
* Fix nc_inq_ncid (NC4_inq_ncid actually) to return root group id if the name argument is NULL.
* Modify _ncdump/printfqn_ to print out a dimid FQN; this supports verification that the resulting .nc files were properly created.
Re: https://github.com/zarr-developers/zarr-python/pull/716
The Zarr version 2 spec has been extended to include the ability
to choose the dimension separator in chunk name keys. The legal
separators has been extended from {'.'} to {'.' '/'}. So now it
is possible to use a key like "0/1/2/0" for chunk names.
This PR implements this for NCZarr. The V2 spec now says that
this separator can be set on a per-variable basis. For now, I
have chosen to allow this be set only globally by adding a key
named "ZARR.DIMENSION_SEPARATOR=<char>" in the
.daprc/.dodsrc/ncrc file. Currently, the only legal separator
characters are '.' (the default) and '/'. On writing, this key
will only be written if its value is different than the default.
This change caused problems because supporting a separator of '/'
is difficult to parse when keys/paths use '/' as the path separator.
A test case was added for this.
Additionally, make nczarr be enabled default by default. This required
some additional changes so that if zip and/or AWS S3 sdk are unavailable,
then they are disabled for NCZarr.
In addition the following unrelated changes were made.
1. Tested that pure-zarr mode could read an nczarr formatted store.
1. The .rc file handling now merges all known .rc files (.ncrc,.daprc, and .dodsrc) in that order and using those in HOME first, then in current directory. For duplicate entries, the later ones override the earlier ones. This change is to remove some of the conflicts inherent in the current .rc file load process. A set of test cases was also added.
1. Re-order tests in configure.ac and CMakeLists.txt so that if libcurl
is not found then the other options that depend upon it properly
are disabled.
1. I decided that xarray support should be enabled by default for pure
zarr. In order to allow disabling, I added a new mode flag "noxarray".
1. Certain test in nczarr_test depend on use of .dodsrc. In order for these
to work when testing in parallel, some inter-test dependencies needed to
be added.
1. Improved authorization testing to use changes in thredds.ucar.edu
re: https://github.com/Unidata/netcdf-c/issues/1977
PR https://github.com/Unidata/netcdf-c/pull/1753, changed ncgen
to allows certain type names to be used as identifiers in
selected situations.
An unwanted side effect was that existing type aliases no longer
were accepted by ncgen. Specifically, using the "long" type
caused an error.
I was able to figure out a better solution to the original
problem (https://github.com/Unidata/netcdf-c/issues/1750)
that also fixes this problem as well.
This PR fixes that problem in ncgen/ncgen.l,
and adds tests to ncdump/test_keywords.sh
re: Github issue https://github.com/Unidata/netcdf-c/issues/1956
The function NC_compare_nc_types in libdispatch/dcopy.c uses an
incorrect algorithm to search for types. The core of this is the
function NC_rec_find_nc_type in libdispatch/dcopy.c. Currently
it searchs the current group and its subtree.
Additionally, the function NC4_inq_typeid in libsrc4/nc4internal.c
has been extended to handle fully qualified names. It was originally
designed to do this, but for some reason never completed.
The NC_rec_find_nc_type algorithm has been altered to match the
algorithm used by NC4_inq_typeid. It operates as follows.
Given a file F, group G and a type T. It searches file F2, group
G2, for another type T2 that is equivalent to T.
The search order is as follows.
1. Search G2 for a type T2 equivalent to T.
2. Search upwards in the ancestor groups of G2 for a type T2 equivalent to T.
3. Search the complete group tree of F2 in pre-order, breadth-first order to locate T2 equivalent to T.
Also add a test case to validate algorithm: ncdump/test_scope.sh.
Note, this change may cause compatibility problems, though it is
unlikely because two different equivalent type declarations in
one dataset is unlikely.
The netcdf-c code has to deal with a variety of platforms:
Windows, OSX, Linux, Cygwin, MSYS, etc. These platforms differ
significantly in the kind of file paths that they accept. So in
order to handle this, I have created a set of replacements for
the most common file system operations such as _open_ or _fopen_
or _access_ to manage the file path differences correctly.
A more limited version of this idea was already implemented via
the ncwinpath.h and dwinpath.c code. So this can be viewed as a
replacement for that code. And in path in many cases, the only
change that was required was to replace '#include <ncwinpath.h>'
with '#include <ncpathmgt.h>' and then replace file operation
calls with the NCxxx equivalent from ncpathmgr.h Note that
recently, the ncwinpath.h was renamed ncpathmgmt.h, so this pull
request should not require dealing with winpath.
The heart of the change is include/ncpathmgmt.h, which provides
alternate operations such as NCfopen or NCaccess and which properly
parse and rebuild path arguments to work for the platform on which
the code is executing. This mostly matters for Windows because of the
way that it uses backslash and drive letters, as compared to *nix*.
One important feature is that the user can do string manipulations
on a file path without having to worry too much about the platform
because the path management code will properly handle most mixed cases.
So one can for example concatenate a path suffix that uses forward
slashes to a Windows path and have it work correctly.
The conversion code is in libdispatch/dpathmgr.c, and the
important function there is NCpathcvt which does the proper
conversions to the local path format.
As a rule, most code should just replace their file operations with
the corresponding NCxxx ones defined in include/ncpathmgmt.h. These
NCxxx functions all call NCpathcvt on their path arguments before
executing the actual file operation.
In some rare cases, the client may need to directly use NCpathcvt,
but this should be avoided as much as possible. If there is a need
for supporting a new file operation not already in ncpathmgmt.h, then
use the code in dpathmgr.c as a template. Also please notify Unidata
so we can include it as a formal part or our supported operations.
Also, if you see an operation in the library that is not using the
NCxxx form, then please submit an issue so we can fix it.
Misc. Changes:
* Clean up the utf8 testing code; it is impossible to get some
tests to work under windows using shell scripts; the args do
not pass as utf8 but as some other encoding.
* Added an extra utf8 test case: test_unicode_path.sh
* Add a true test for HDF5 1.10.6 or later because as noted in
PR https://github.com/Unidata/netcdf-c/pull/1794,
HDF5 changed its Windows file path handling.
re: Issue https://github.com/Unidata/netcdf-c/issues/1936
The algorithm controlling interaction of -d 0 -F and -c / options
is incorrect.
The fix:
1. make -d 0 => no deflation
2. make -F properly use the filter specs to decide.
Also added a test case to ncdump/tst_nccopy4.sh.
Primary Fixes:
* Add a whole variable optimization -- used in the rare case that nc_get/put_vara covers the whole of a variable and the variable has a single chunk.
* Fix chunking error when stride causes whole chunks to be skipped.
* Fix some memory leaks
* Add test cases
* Add one performance test to nczarr_test/. This uses the timer utils from unit_test: timer_utils.[ch].
* Move ncdumpchunks utility from ncdump to nczarr_test
Misc. Other Changes:
* Make check for aws libraries conditional on --enable-nczarr-s3
* Remove all but one bm tests from nczarr_test until they are working.
* Remove another dependency on HDF5 from supposedly non-HDF5 specific code; specifically hdf5_log_hdf5.
* Make the BAIL2 macro be hdf5 specific and replace elsewhere with an HDF5 independent equivalent.
* Move hdf5cache.c to libsrc4/nc4cache.c because it is used by nczarr.
* Modify unit_tests so that some of them are run even if using Windows.
* Misc. small bug fixes and refactors and memory leaks.
* Rename some conflicting tests for cmake.
* Attempted to make nc_perf work with cmake and failed.
Primary changes:
* Add an improved cache system to speed up performance.
* Fix NCZarr to properly handle scalar variables.
Misc. Related Changes:
* Added unit tests for extendible hash and for the generic cache.
* Add config parameter to set size of the NCZarr cache.
* Add initial performance tests but leave them unused.
* Add CRC64 support.
* Move location of ncdumpchunks utility from /ncgen to /ncdump.
* Refactor auth support.
Misc. Unrelated Changes:
* More cleanup of the S3 support
* Add support for S3 authentication in .rc files: HTTP.S3.ACCESSID and HTTP.S3.SECRETKEY.
* Remove the hashkey from the struct OBJHDR since it is never used.
re: Issue https://github.com/Unidata/netcdf-c/issues/1848
The existing Virtual File Driver built to support byte-range
read-only file access is quite old. It turns out to be extremely
slow (reason unknown at the moment).
Starting with HDF5 1.10.6, the HDF5 library has its own version
of such a file driver. The HDF5 developers have better knowledge
about building such a driver and what incantations are needed to
get good performance.
This PR modifies the byte-range code in hdf5open.c so
that if the HDF5 file driver is available, then it is used
in preference to the one written by the Netcdf group.
Misc. Other Changes:
1. Moved all of nc4print code to ncdump to keep appveyor quiet.
As it was, nccopy -c dim/x was sometimes being ignored. So
modify nccopy to properly take into account. This also required
a change to the nczarr code because it was not applying default
chunking in the same way as libhdf5.
Modify ncdump/tst_nccopy4.sh to test this feature properly.
Also add a similar test to nczarr_test.
Additionally, fix some other things that were causing Visual
Studio builds with testing to not work.
* fix curl testing under CMake to properly handle case
where DAP is disabled, but byterange support is enabled.
* properly test and/or define uintptr_t
* Convert _O_XXX to O_XXX flags used by open();
disengagement of enable-netcdf4 from enable-hdf5.
That is, with the advent of nczarr, it is possible
to turn off hdf5 but still need netcdf-4 enabled
because nczarr uses libsrc4, but not libhdf5.
This change involves a bunch of things:
1. Modify configure.ac and CMakelist to make enable_hdf5
control if hdf5 support is provided. For back compatibility,
disable-netcdf4 is treated as disable-hdf5. But internally,
netcdf4 support is controlled only by the enabling of formats
that require it.
2. In support of #1, modify .travis.yml to use enable/disable-hdf5
instead of enable/disable-netcdf4.
3. test_common.in is modified to track selected features,
including enable-hdf5 and enable-s3-tests. This is used in
selected tests that mix netcdf-3 and netcdf4 tests.
4. The conflation of USE_HDF5 and USE_NETCDF4 is common in
code, tests, and build files, so all of those had to be weeded out.
5. It turns out that some of the NC4_dim functions really are HDF5 specific,
but are not treated as such. So they are moved from nc4dim.c to
hdf5dim.c or hdf5dispatch.c
6. Some generic functions in libhdf5 can be (and were) moved to libsrc4.
The primary fix is to improve CMake build support.
Specific changes include:
* CMake: Provide a better soln to locating the AWS SDK
libraries; the new way is the preferred method as described in
the aws-cpp-sdk documentation.
* CMake (and Automake): allow -DENABLE_S3_SDK (default off) to suppress
looking for AWS libraries.
* CMake: add the complete set of nczarr tests
* CMake: add EXTERNL as needed to various .h files.
* Improve support for windows drive letters in paths.
* Add nczarr and s3 flags to nc-config
* For VisualStudio X nczarr, cleanup the NAN+INFINITY handling
* Convert _MSC_VER -> _WIN32 and vice versa as needed
* NCZarr - support multiple platform paths including windows, cygwin.
mingw, etc.
* NCZarr - sort the test outputs because different platforms
produce directory contents in different orders.
One big change concerns netcdf-c/CMakeLists.txt and netcdf-c/configure.ac.
In the current versions, it was the case that --disable-hdf5
disabled netcdf-4 (libsrc4). With nczarr, this can no longer
be the case because nczarr requires libsrc4 even if libhdf5
is disabled. So, I modified the above files to move the
format options (HDF5, NCZarr, HDF4, etc) to a single place
near the front of the files. Now it is the case that:
* Enabling any of the formats that require libsrc4
also does an implicit --enable-netcdf4.
* --disable-netcdf4 | --disable-netcdf-4 now becomes
and alias for --disable-hdf5.
There are probably some bugs in this change in terms of
dependencies between format options.
Problems:
* CMake S3 support is still not working for Visual Studio
* A recent issue points out that there is work to do on handling
UTF8 filenames, but that will be addressed in a separate fix.
Notes:
* Consider converting all of our includes/.h files to use 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.
Built-in type-name keywords are currently flagged when used as
identifiers in formats that do not support that type. So if a
user declares a dimension named "string" in a classic .cdl file,
it causes an error.
This PR modifies ncgen to allow those format-specific type keywords
to be used as identifiers when compiling to formats that do not
support that type. Also added a test for this.
Also a couple of misc. changes to conditionalize some debug output.
Fix Issue https://github.com/Unidata/netcdf-c/issues/1725.
Replace PR https://github.com/Unidata/netcdf-c/pull/1726
Also replace PR https://github.com/Unidata/netcdf-c/pull/1694
The general problem is that under Visual Studio, we are seeing
a number of undefined reference and other scoping errors.
The reason is that the code is not properly using Visual Studio
_declspec() declarations.
The basic solution is to ensure that when compiling the code itself
one needs to ensure that _declspec(dllexport) is used. There
are several sets of macros to handle this, but they all rely
on the flag DLL_EXPORT being define when the code is compiled,
but not being defined when the code is used via a .h file.
As a test, I modified XGetOpt.c to build properly. I also
fixed the oc2 library to properly _declspec things like ocdebug.
I also made some misc. changes to get all the tests to run
if cygwin is installed (to get bash, sed, etc).
Misc. Changes:
* Put XGetOpt.c into libsrc and copy at build time
to the other directories where it is needed.
Add Wei-King Liao's ncvalidator program (with his permission) as
an uninstalled (for now) tool in the ncdump directory. It has in
the past been useful for debugging netcdf-3 files.
re: Issue https://github.com/Unidata/netcdf-c/issues/1365
At some point (4.6.1) we changed the diskless handling of flags
and added a new NC_PERSIST flag. Looks like we did not fix all
occurrences of the old flag set, specifically for 'nccopy -w' command.
Also added some tests (tst_nccopy_w{3,4}.sh) for this situation.
re: https://github.com/Unidata/netcdf-c/issues/1352
When nc4info.c encounters an _NCProperties attribute
with a version number it does not recognize, it does not
show it correctly.
Solution chosen is to arrange so that accessing the attribute
returns the raw value of the Attribute from the file. This way,
even if the version is unrecognized, it will return something
usable.
The changes were primarily to never attempt to parse the value
of _NCProperties until actually required. Which since they
are currently not used means that parsing never occurs.
Also modified ncdump/tst_fileinfo.sh to include some extra testing
I tested the original failure by changing the value of NCPROPS to 3.
However, there is no way to test this at build time.
Misc. Changes
* Inlined the provenance info in the NC_FILE_INFO_T structure
* Centralized stuff from elsewhere into include/nc_provenance.h
Misc. Unrelated Changes
* Removed/turned off some misc debug output left on by accident
* Fix CPPFLAGS name error in libhdf5/Makefile.am
re: https://github.com/Unidata/netcdf-c/issues/1330
The ncgen utility is documented to accept octal integer constants
if the leading digit is zero. This was not implemented. Fix ncgen.l
to properly handle such constants. Also add a test to c0.cdl.
