netcdf-c/cmake/modules/FindBz2.cmake
Dennis Heimbigner 3ffe7be446 Enhance/Fix filter support
re: Discussion https://github.com/Unidata/netcdf-c/discussions/2214

The primary change is to support so-called "standard filters".
A standard filter is one that is defined by the following
netcdf-c API:
````
int nc_def_var_XXX(int ncid, int varid, size_t nparams, unsigned* params);
int nc_inq_var_XXXX(int ncid, int varid, int* usefilterp, unsigned* params);
````
So for example, zstandard would be a standard filter by defining
the functions *nc_def_var_zstandard* and *nc_inq_var_zstandard*.

In order to define these functions, we need a new dispatch function:
````
int nc_inq_filter_avail(int ncid, unsigned filterid);
````
This function, combined with the existing filter API can be used
to implement arbitrary standard filters using a simple code pattern.
Note that I would have preferred that this function return a list
of all available filters, but HDF5 does not support that functionality.

So this PR implements the dispatch function and implements
the following standard functions:
    + bzip2
    + zstandard
    + blosc
Specific test cases are also provided for HDF5 and NCZarr.
Over time, other specific standard filters will be defined.

## Primary Changes
* Add nc_inq_filter_avail() to netcdf-c API.
* Add standard filter implementations to test use of *nc_inq_filter_avail*.
* Bump the dispatch table version number and add to all the relevant
   dispatch tables (libsrc, libsrcp, etc).
* Create a program to invoke nc_inq_filter_avail so that it is accessible
  to shell scripts.
* Cleanup szip support to properly support szip
  when HDF5 is disabled. This involves detecting
  libsz separately from testing if HDF5 supports szip.
* Integrate shuffle and fletcher32 into the existing
  filter API. This means that, for example, nc_def_var_fletcher32
  is now a wrapper around nc_def_var_filter.
* Extend the Codec defaulting to allow multiple default shared libraries.

## Misc. Changes
* Modify configure.ac/CMakeLists.txt to look for the relevant
  libraries implementing standard filters.
* Modify libnetcdf.settings to list available standard filters
  (including deflate and szip).
* Add CMake test modules to locate libbz2 and libzstd.
* Cleanup the HDF5 memory manager function use in the plugins.
* remove unused file include//ncfilter.h
* remove tests for the HDF5 memory operations e.g. H5allocate_memory.
* Add flag to ncdump to force use of _Filter instead of _Deflate
  or _Shuffle or _Fletcher32. Used for testing.
2022-03-14 12:39:37 -06:00

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2.5 KiB
CMake

# Searches for an installation of the bz2 library. On success, it sets the following variables:
#
# Bz2_FOUND Set to true to indicate the bz2 library was found
# Bz2_INCLUDE_DIRS The directory containing the header file bz2/bz2.h
# Bz2_LIBRARIES The libraries needed to use the bz2 library
#
# To specify an additional directory to search, set Bz2_ROOT.
#
# Author: Siddhartha Chaudhuri, 2009
#
# Look for the header, first in the user-specified location and then in the system locations
SET(Bz2_INCLUDE_DOC "The directory containing the header file bz2.h")
FIND_PATH(Bz2_INCLUDE_DIRS NAMES bz2.h bz2/bz2.h PATHS ${Bz2_ROOT} ${Bz2_ROOT}/include DOC ${Bz2_INCLUDE_DOC} NO_DEFAULT_PATH)
IF(NOT Bz2_INCLUDE_DIRS) # now look in system locations
FIND_PATH(Bz2_INCLUDE_DIRS NAMES bzlib.h DOC ${Bz2_INCLUDE_DOC})
ENDIF(NOT Bz2_INCLUDE_DIRS)
SET(Bz2_FOUND FALSE)
IF(Bz2_INCLUDE_DIRS)
SET(Bz2_LIBRARY_DIRS ${Bz2_INCLUDE_DIRS})
IF("${Bz2_LIBRARY_DIRS}" MATCHES "/include$")
# Strip off the trailing "/include" in the path.
GET_FILENAME_COMPONENT(Bz2_LIBRARY_DIRS ${Bz2_LIBRARY_DIRS} PATH)
ENDIF("${Bz2_LIBRARY_DIRS}" MATCHES "/include$")
IF(EXISTS "${Bz2_LIBRARY_DIRS}/lib")
SET(Bz2_LIBRARY_DIRS ${Bz2_LIBRARY_DIRS}/lib)
ENDIF(EXISTS "${Bz2_LIBRARY_DIRS}/lib")
# Find Bz2 libraries
FIND_LIBRARY(Bz2_DEBUG_LIBRARY NAMES bz2d bz2_d libbz2d libbz2_d libbz2
PATH_SUFFIXES Debug ${CMAKE_LIBRARY_ARCHITECTURE} ${CMAKE_LIBRARY_ARCHITECTURE}/Debug
PATHS ${Bz2_LIBRARY_DIRS} NO_DEFAULT_PATH)
FIND_LIBRARY(Bz2_RELEASE_LIBRARY NAMES bz2 libbz2
PATH_SUFFIXES Release ${CMAKE_LIBRARY_ARCHITECTURE} ${CMAKE_LIBRARY_ARCHITECTURE}/Release
PATHS ${Bz2_LIBRARY_DIRS} NO_DEFAULT_PATH)
SET(Bz2_LIBRARIES )
IF(Bz2_DEBUG_LIBRARY AND Bz2_RELEASE_LIBRARY)
SET(Bz2_LIBRARIES debug ${Bz2_DEBUG_LIBRARY} optimized ${Bz2_RELEASE_LIBRARY})
ELSEIF(Bz2_DEBUG_LIBRARY)
SET(Bz2_LIBRARIES ${Bz2_DEBUG_LIBRARY})
ELSEIF(Bz2_RELEASE_LIBRARY)
SET(Bz2_LIBRARIES ${Bz2_RELEASE_LIBRARY})
ENDIF(Bz2_DEBUG_LIBRARY AND Bz2_RELEASE_LIBRARY)
IF(Bz2_LIBRARIES)
SET(Bz2_FOUND TRUE)
ENDIF(Bz2_LIBRARIES)
ENDIF(Bz2_INCLUDE_DIRS)
IF(Bz2_FOUND)
# IF(NOT Bz2_FIND_QUIETLY)
MESSAGE(STATUS "Found Bz2: headers at ${Bz2_INCLUDE_DIRS}, libraries at ${Bz2_LIBRARY_DIRS}")
MESSAGE(STATUS " library is ${Bz2_LIBRARIES}")
# ENDIF(NOT Bz2_FIND_QUIETLY)
ELSE(Bz2_FOUND)
IF(Bz2_FIND_REQUIRED)
MESSAGE(FATAL_ERROR "Bz2 library not found")
ENDIF(Bz2_FIND_REQUIRED)
ENDIF(Bz2_FOUND)