Support no-op dispatch functions

re: Unidata#1693

1. Add functions to libdispatch/dnotnc4.c to support
   dispatch table operations that should work for any
   dispatch table, even if they do not do anything.
   Functions such as nc_inq_var_filter.
2. Modify selected dispatch tables to utilize
   the noop functions.
3. Extend nc_test/tst_formats.c to test.

This is an extension of Ed's work to do this for
chunking and deflate and szip. See PRs
Unidata#1697
and
Unidata#1692

As a side effect, elide libdispatch/dnotnc3.c since
it is no longer used.

include/netcdf_dispatch.h

@@ -180,16 +180,6 @@ extern "C" {
     EXTERNL int NC_RO_rename_dim(int ncid, int dimid, const char *name);
     EXTERNL int NC_RO_set_fill(int ncid, int fillmode, int *old_modep);
 
-    /* These functions are for dispatch layers that don't implement
-     * these legacy functions. They return NC_ENOTNC3. */
-    EXTERNL int NC_NOTNC3_put_varm(int ncid, int varid, const size_t * start,
-                                   const size_t *edges, const ptrdiff_t *stride,
-                                   const ptrdiff_t *imapp, const void *value0,
-                                   nc_type memtype);
-    EXTERNL int NC_NOTNC3_get_varm(int ncid, int varid, const size_t *start,
-                                   const size_t *edges, const ptrdiff_t *stride,
-                                   const ptrdiff_t *imapp, void *value0, nc_type memtype);
-
     /* These functions are for dispatch layers that don't implement
      * the enhanced model. They return NC_ENOTNC4. */
     EXTERNL int NC_NOTNC4_def_var_filter(int, int, unsigned int, size_t,
@@ -230,9 +220,16 @@ extern "C" {
     EXTERNL int NC_NOTNC4_inq_typeids(int, int *, int *);
     EXTERNL int NC_NOTNC4_inq_user_type(int, nc_type, char *, size_t *,
                                         nc_type *, size_t *, int *);
-    EXTERNL int NC_NOTNC4_inq_typeid(int, const char *, nc_type *);
     EXTERNL int NC_NOTNC4_filter_actions(int, int, int, struct NC_Filterobject*);
 
+    /* These functions are for dispatch layers that don't implement
+     * the enhanced model, but want to succeed anyway.
+     * They return NC_NOERR plus properly set the out parameters.
+     * In some cases (filter actions), some cases may succeed and some
+     * will fail.
+     */
+    EXTERNL int NC_NOOP_filter_actions(int, int, int, struct NC_Filterobject*);
+
 #if defined(__cplusplus)
 }
 #endif

libdap2/ncd2dispatch.c

@@ -175,7 +175,7 @@ NCD2_def_var_filter,
 NCD2_set_var_chunk_cache,
 NCD2_get_var_chunk_cache,
 
-NC_NOTNC4_filter_actions,
+NC_NOOP_filter_actions,
 
 };
 

libdap4/ncd4dispatch.c

@@ -241,14 +241,6 @@ NCD4_set_var_chunk_cache(int ncid, int p2, size_t p3, size_t p4, float p5)
     return (NC_EPERM);
 }
 
-struct NC_FILTER_ACTION;
-
-static int
-NCD4_filter_actions(int ncid, int varid, int action, struct NC_Filterobject* spec)
-{
-    return (NC_EPERM);
-}
-
 /**************************************************/
 /*
 Following functions basically return the netcdf-4 value WRT to the nc4id.
@@ -870,7 +862,7 @@ NCD4_def_var_filter,
 NCD4_set_var_chunk_cache,
 NCD4_get_var_chunk_cache,
 
-NCD4_filter_actions,
+NC_NOOP_filter_actions,
 };
 
 

libdispatch/Makefile.am

@@ -19,7 +19,7 @@ libdispatch_la_SOURCES = dparallel.c dcopy.c dfile.c ddim.c datt.c	\
 dattinq.c dattput.c dattget.c derror.c dvar.c dvarget.c dvarput.c	\
 dvarinq.c dinternal.c ddispatch.c dutf8.c nclog.c dstring.c ncuri.c	\
 nclist.c ncbytes.c nchashmap.c nctime.c nc.c nclistmgr.c		\
-dauth.c doffsets.c dwinpath.c dutil.c dreadonly.c dnotnc4.c dnotnc3.c	\
+dauth.c doffsets.c dwinpath.c dutil.c dreadonly.c dnotnc4.c \
 crc32.c crc32.h daux.c dinfermodel.c
 
 # Add the utf8 codebase