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, 16 insertions, 5 deletions

diff --git a/src/H5VLnative_dataset.c b/src/H5VLnative_dataset.c
index 399c19f..f9065c1 100644
--- a/src/H5VLnative_dataset.c
+++ b/src/H5VLnative_dataset.c
@@ -203,7 +203,7 @@ H5VL__native_dataset_write(void *obj, hid_t mem_type_id, hid_t mem_space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from file_space_id")
 
     /* Write the data */
-    if(H5D__write(dset, mem_type_id, mem_space, file_space, buf) < 0) 
+    if(H5D__write(dset, mem_type_id, mem_space, file_space, buf) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write data")
 
 done:
@@ -309,6 +309,18 @@ H5VL__native_dataset_get(void *obj, H5VL_dataset_get_t get_type,
                 break;
             }
 
+        /* H5Dvlen_get_buf_size */
+        case H5VL_DATASET_GET_VLEN_BUF_SIZE:
+            {
+                hid_t type_id = HDva_arg(arguments, hid_t);
+                hid_t space_id = HDva_arg(arguments, hid_t);
+                hsize_t *size = HDva_arg(arguments, hsize_t *);
+
+                if(H5D__vlen_get_buf_size(dset, type_id, space_id, size) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get size of vlen buf needed")
+                break;
+            }
+
         default:
             HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from dataset")
     } /* end switch */
@@ -388,11 +400,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL__native_dataset_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req, va_list arguments)
+H5VL__native_dataset_optional(void *obj, H5VL_dataset_optional_t optional_type,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
 {
     H5D_t *dset = NULL;             /* Dataset */
-    H5VL_native_dataset_optional_t optional_type = HDva_arg(arguments, H5VL_native_dataset_optional_t);
     herr_t ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_PACKAGE
@@ -426,7 +437,7 @@ H5VL__native_dataset_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
                     case H5D_NLAYOUTS:
                         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset layout type")
 
-                    default: 
+                    default:
                         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown dataset layout type")
                 } /* end switch */