Refactor all the 'H5VL_*_optional' callbacks to move the type of operation out

of the va_list, so it's at least possible for another connector to know what
the operation is and decide whether to implement it or not.

Added a new VOL sub-class called "introspect" where callbacks that report
information about the connector or container can be placed.  Added an
'opt_query' callback to this sub-class, for a connector to report back
to the library whether a particular optional callback operation is supported.
Also added a 'get_conn_cls' introspection callback, to retrieve the H5VL_class_t
of a connector (either the "current" connector, H5VL_GET_CONN_LVL_CURR, or
the terminal connector, H5VL_GET_CONN_LVL_TERM).

Moved the "post open" operation from a file 'specific' operation to a file
'optional' operation, now that it's possible to detect (with the 'opt_query'
introspection callback) whether a VOL connector implements an optional
operation, without just returning an error.

Added new internal VOL helper routines: H5VL_object_is_native, to determine
if an object is in (or is a) native file, and H5VL_file_is_same, to determine
if two objects are in (or are) the same terminal VOL connector's container.
(And moved the special handling for FILE_IS_EQUAL operation out of internal VOL
callback routine into H5VL_file_is_same)

Made new dataset 'get' operation for H5Dvlen_get_buf_size, aligning it better
with other 'get' operations in API.

Fixed several issues with pass-through connectors, which are now passing the
'make check-passthrough-vol' tests again.

A bunch of warning and style cleanups as well.

1 files changed, 43 insertions, 47 deletions

diff --git a/src/H5VLnative.h b/src/H5VLnative.h
index 73cec8d..b23182f 100644
--- a/src/H5VLnative.h
+++ b/src/H5VLnative.h
@@ -28,14 +28,12 @@
 #define H5VL_NATIVE_VALUE       H5_VOL_NATIVE   /* enum value */
 #define H5VL_NATIVE_VERSION     0
 
-/* Typedef and values for native VOL connector attribute optional VOL operations */
-typedef int H5VL_native_attr_optional_t;
+/* Values for VOL connector attribute optional VOL operations */
 #ifndef H5_NO_DEPRECATED_SYMBOLS
-#define H5VL_NATIVE_ATTR_ITERATE_OLD    0   /* H5Aiterate (deprecated routine) */
+#define H5VL_NATIVE_ATTR_ITERATE_OLD    0      /* H5Aiterate (deprecated routine) */
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
-/* Typedef and values for native VOL connector dataset optional VOL operations */
-typedef int H5VL_native_dataset_optional_t;
+/* Values for native VOL connector dataset optional VOL operations */
 #define H5VL_NATIVE_DATASET_FORMAT_CONVERT          0   /* H5Dformat_convert (internal) */
 #define H5VL_NATIVE_DATASET_GET_CHUNK_INDEX_TYPE    1   /* H5Dget_chunk_index_type      */
 #define H5VL_NATIVE_DATASET_GET_CHUNK_STORAGE_SIZE  2   /* H5Dget_chunk_storage_size    */
@@ -45,52 +43,50 @@ typedef int H5VL_native_dataset_optional_t;
 #define H5VL_NATIVE_DATASET_CHUNK_READ              6   /* H5Dchunk_read                */
 #define H5VL_NATIVE_DATASET_CHUNK_WRITE             7   /* H5Dchunk_write               */
 
-/* Typedef and values for native VOL connector file optional VOL operations */
-typedef int H5VL_native_file_optional_t;
-#define H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE              0   /* H5Fclear_elink_file_cache            */
-#define H5VL_NATIVE_FILE_GET_FILE_IMAGE                 1   /* H5Fget_file_image                    */
-#define H5VL_NATIVE_FILE_GET_FREE_SECTIONS              2   /* H5Fget_free_sections                 */
-#define H5VL_NATIVE_FILE_GET_FREE_SPACE                 3   /* H5Fget_freespace                     */
-#define H5VL_NATIVE_FILE_GET_INFO                       4   /* H5Fget_info1/2                       */
-#define H5VL_NATIVE_FILE_GET_MDC_CONF                   5   /* H5Fget_mdc_config                    */
-#define H5VL_NATIVE_FILE_GET_MDC_HR                     6   /* H5Fget_mdc_hit_rate                  */
-#define H5VL_NATIVE_FILE_GET_MDC_SIZE                   7   /* H5Fget_mdc_size                      */
-#define H5VL_NATIVE_FILE_GET_SIZE                       8   /* H5Fget_filesize                      */
-#define H5VL_NATIVE_FILE_GET_VFD_HANDLE                 9   /* H5Fget_vfd_handle                    */
-#define H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE             10  /* H5Freset_mdc_hit_rate_stats          */
-#define H5VL_NATIVE_FILE_SET_MDC_CONFIG                 11  /* H5Fset_mdc_config                    */
-#define H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO   12  /* H5Fget_metadata_read_retry_info      */
-#define H5VL_NATIVE_FILE_START_SWMR_WRITE               13  /* H5Fstart_swmr_write                  */
-#define H5VL_NATIVE_FILE_START_MDC_LOGGING              14  /* H5Fstart_mdc_logging                 */
-#define H5VL_NATIVE_FILE_STOP_MDC_LOGGING               15  /* H5Fstop_mdc_logging                  */
-#define H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS         16  /* H5Fget_mdc_logging_status            */
-#define H5VL_NATIVE_FILE_FORMAT_CONVERT                 17  /* H5Fformat_convert                    */
-#define H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS     18  /* H5Freset_page_buffering_stats        */
-#define H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS       19  /* H5Fget_page_buffering_stats          */
-#define H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO             20  /* H5Fget_mdc_image_info                */
-#define H5VL_NATIVE_FILE_GET_EOA                        21  /* H5Fget_eoa                           */
-#define H5VL_NATIVE_FILE_INCR_FILESIZE                  22  /* H5Fincrement_filesize                */
-#define H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS              23  /* H5Fset_latest_format/libver_bounds   */
-#define H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG         24  /* H5Fget_dset_no_attrs_hint            */
-#define H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG         25  /* H5Fset_dset_no_attrs_hint            */
-#define H5VL_NATIVE_FILE_GET_MPI_ATOMICITY              26  /* H5Fget_mpi_atomicity                 */
-#define H5VL_NATIVE_FILE_SET_MPI_ATOMICITY              27  /* H5Fset_mpi_atomicity                 */
+/* Values for native VOL connector file optional VOL operations */
+#define H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE             0   /* H5Fclear_elink_file_cache            */
+#define H5VL_NATIVE_FILE_GET_FILE_IMAGE                1   /* H5Fget_file_image                    */
+#define H5VL_NATIVE_FILE_GET_FREE_SECTIONS             2   /* H5Fget_free_sections                 */
+#define H5VL_NATIVE_FILE_GET_FREE_SPACE                3   /* H5Fget_freespace                     */
+#define H5VL_NATIVE_FILE_GET_INFO                      4   /* H5Fget_info1/2                       */
+#define H5VL_NATIVE_FILE_GET_MDC_CONF                  5   /* H5Fget_mdc_config                    */
+#define H5VL_NATIVE_FILE_GET_MDC_HR                    6   /* H5Fget_mdc_hit_rate                  */
+#define H5VL_NATIVE_FILE_GET_MDC_SIZE                  7   /* H5Fget_mdc_size                      */
+#define H5VL_NATIVE_FILE_GET_SIZE                      8   /* H5Fget_filesize                      */
+#define H5VL_NATIVE_FILE_GET_VFD_HANDLE                9   /* H5Fget_vfd_handle                    */
+#define H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE            10  /* H5Freset_mdc_hit_rate_stats          */
+#define H5VL_NATIVE_FILE_SET_MDC_CONFIG                11  /* H5Fset_mdc_config                    */
+#define H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO  12  /* H5Fget_metadata_read_retry_info      */
+#define H5VL_NATIVE_FILE_START_SWMR_WRITE              13  /* H5Fstart_swmr_write                  */
+#define H5VL_NATIVE_FILE_START_MDC_LOGGING             14  /* H5Fstart_mdc_logging                 */
+#define H5VL_NATIVE_FILE_STOP_MDC_LOGGING              15  /* H5Fstop_mdc_logging                  */
+#define H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS        16  /* H5Fget_mdc_logging_status            */
+#define H5VL_NATIVE_FILE_FORMAT_CONVERT                17  /* H5Fformat_convert                    */
+#define H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS    18  /* H5Freset_page_buffering_stats        */
+#define H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS      19  /* H5Fget_page_buffering_stats          */
+#define H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO            20  /* H5Fget_mdc_image_info                */
+#define H5VL_NATIVE_FILE_GET_EOA                       21  /* H5Fget_eoa                           */
+#define H5VL_NATIVE_FILE_INCR_FILESIZE                 22  /* H5Fincrement_filesize                */
+#define H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS             23  /* H5Fset_latest_format/libver_bounds   */
+#define H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG        24  /* H5Fget_dset_no_attrs_hint            */
+#define H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG        25  /* H5Fset_dset_no_attrs_hint            */
+#define H5VL_NATIVE_FILE_GET_MPI_ATOMICITY             26  /* H5Fget_mpi_atomicity                 */
+#define H5VL_NATIVE_FILE_SET_MPI_ATOMICITY             27  /* H5Fset_mpi_atomicity                 */
+#define H5VL_NATIVE_FILE_POST_OPEN                     28  /* Adjust file after open, with wrapping context */
 
-/* Typedef and values for native VOL connector group optional VOL operations */
-typedef int H5VL_native_group_optional_t;
+/* Values for native VOL connector group optional VOL operations */
 #ifndef H5_NO_DEPRECATED_SYMBOLS
-#define H5VL_NATIVE_GROUP_ITERATE_OLD   0   /* HG5Giterate (deprecated routine) */
-#define H5VL_NATIVE_GROUP_GET_OBJINFO   1   /* HG5Gget_objinfo (deprecated routine) */
+#define H5VL_NATIVE_GROUP_ITERATE_OLD      0   /* HG5Giterate (deprecated routine) */
+#define H5VL_NATIVE_GROUP_GET_OBJINFO      1   /* HG5Gget_objinfo (deprecated routine) */
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
-/* Typedef and values for native VOL connector object optional VOL operations */
-typedef int H5VL_native_object_optional_t;
-#define H5VL_NATIVE_OBJECT_GET_COMMENT                  0   /* H5G|H5Oget_comment, H5Oget_comment_by_name   */
-#define H5VL_NATIVE_OBJECT_GET_INFO                     1   /* H5Oget_info(_by_idx, _by_name)(2)            */
-#define H5VL_NATIVE_OBJECT_SET_COMMENT                  2   /* H5G|H5Oset_comment, H5Oset_comment_by_name   */
-#define H5VL_NATIVE_OBJECT_DISABLE_MDC_FLUSHES          3   /* H5Odisable_mdc_flushes                       */
-#define H5VL_NATIVE_OBJECT_ENABLE_MDC_FLUSHES           4   /* H5Oenable_mdc_flushes                        */
-#define H5VL_NATIVE_OBJECT_ARE_MDC_FLUSHES_DISABLED     5   /* H5Oare_mdc_flushes_disabled                  */
+/* Values for native VOL connector object optional VOL operations */
+#define H5VL_NATIVE_OBJECT_GET_COMMENT                 0   /* H5G|H5Oget_comment, H5Oget_comment_by_name   */
+#define H5VL_NATIVE_OBJECT_GET_INFO                    1   /* H5Oget_info(_by_idx, _by_name)(2)            */
+#define H5VL_NATIVE_OBJECT_SET_COMMENT                 2   /* H5G|H5Oset_comment, H5Oset_comment_by_name   */
+#define H5VL_NATIVE_OBJECT_DISABLE_MDC_FLUSHES         3   /* H5Odisable_mdc_flushes                       */
+#define H5VL_NATIVE_OBJECT_ENABLE_MDC_FLUSHES          4   /* H5Oenable_mdc_flushes                        */
+#define H5VL_NATIVE_OBJECT_ARE_MDC_FLUSHES_DISABLED    5   /* H5Oare_mdc_flushes_disabled                  */
 
 #ifdef __cplusplus
 extern "C" {