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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.
39 lines
1.5 KiB
C
39 lines
1.5 KiB
C
/*********************************************************************
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* Copyright 2018, UCAR/Unidata
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* See netcdf/COPYRIGHT file for copying and redistribution conditions.
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*********************************************************************/
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#ifndef ZCACHE_H
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#define ZCACHE_H
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typedef struct NCZCacheEntry {
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int modified;
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size64_t indices[NC_MAX_VAR_DIMS];
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char* key; /* as string */
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void* data;
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} NCZCacheEntry;
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typedef struct NCZChunkCache {
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const NC_VAR_INFO_T* var; /* backlink */
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size64_t chunksize;
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void* fillchunk; /* enough fillvalues to fill a chunk */
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size_t maxentries; /* Max number of entries allowed */
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NClist* entries; /* in LRU order */
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} NCZChunkCache;
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/**************************************************/
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extern int NCZ_set_var_chunk_cache(int ncid, int varid, size_t size, size_t nelems, float preemption);
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extern int NCZ_adjust_var_cache(NC_GRP_INFO_T *grp, NC_VAR_INFO_T *var);
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extern int NCZ_create_chunk_cache(NC_VAR_INFO_T* var, size64_t, NCZChunkCache** cachep);
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extern void NCZ_free_chunk_cache(NCZChunkCache* cache);
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extern int NCZ_read_cache_chunk(NCZChunkCache* cache, const size64_t* indices, void** datap);
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extern int NCZ_flush_chunk_cache(NCZChunkCache* cache);
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extern size64_t NCZ_cache_entrysize(NCZChunkCache* cache);
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extern NCZCacheEntry* NCZ_cache_entry(NCZChunkCache* cache, const size64_t* indices);
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extern size64_t NCZ_cache_size(NCZChunkCache* cache);
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extern int NCZ_buildchunkpath(NCZChunkCache* cache, const size64_t* chunkindices, char** keyp);
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#endif /*ZCACHE_H*/
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