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, 62 insertions, 31 deletions

diff --git a/src/H5Rint.c b/src/H5Rint.c
index 2a21179..566c656 100644
--- a/src/H5Rint.c
+++ b/src/H5Rint.c
@@ -319,12 +319,12 @@ H5R__create_region(const H5VL_token_t *obj_token, size_t token_size,
         ref->encode_size);
 
 done:
-    if(ret_value < 0) {
+    if(ret_value < 0)
         if(ref->ref.reg.space) {
             H5S_close(ref->ref.reg.space);
             ref->ref.reg.space = NULL;
-        }
-    }
+        } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5R__create_region */
 
@@ -374,8 +374,11 @@ H5R__create_attr(const H5VL_token_t *obj_token, size_t token_size,
         ref->ref.attr.name, ref->encode_size);
 
 done:
-    if(ret_value < 0)
-        ref->ref.attr.name = H5MM_xfree(ref->ref.attr.name);
+    if(ret_value < 0) {
+        H5MM_xfree(ref->ref.attr.name);
+        ref->ref.attr.name = NULL;
+    } /* end if */
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5R__create_attr */
 
@@ -398,19 +401,24 @@ H5R__destroy(H5R_ref_priv_t *ref)
 
     HDassert(ref != NULL);
 
-    ref->ref.obj.filename = H5MM_xfree(ref->ref.obj.filename);
+    H5MM_xfree(ref->ref.obj.filename);
+    ref->ref.obj.filename = NULL;
 
     switch(ref->type) {
         case H5R_OBJECT2:
             break;
+
         case H5R_DATASET_REGION2:
             if(H5S_close(ref->ref.reg.space) < 0)
                 HGOTO_ERROR(H5E_REFERENCE, H5E_CANTFREE, FAIL, "Cannot close dataspace")
             ref->ref.reg.space = NULL;
             break;
+
         case H5R_ATTR:
-            ref->ref.attr.name = H5MM_xfree(ref->ref.attr.name);
+            H5MM_xfree(ref->ref.attr.name);
+            ref->ref.attr.name = NULL;
             break;
+
         case H5R_OBJECT1:
         case H5R_DATASET_REGION1:
             break;
@@ -418,6 +426,7 @@ H5R__destroy(H5R_ref_priv_t *ref)
         case H5R_MAXTYPE:
             HDassert("invalid reference type" && 0);
             HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (invalid reference type)")
+
         default:
             HDassert("unknown reference type" && 0);
             HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
@@ -501,11 +510,11 @@ H5R__get_loc_id(const H5R_ref_priv_t *ref)
 hid_t
 H5R__reopen_file(H5R_ref_priv_t *ref, hid_t fapl_id)
 {
-    void *new_file = NULL;
-    H5VL_connector_prop_t connector_prop;
-    unsigned flags = H5F_ACC_RDWR; /* Must open file read-write to allow for object modifications */
-    H5P_genplist_t *plist;
-    H5VL_object_t *vol_obj = NULL; /* VOL object for file */
+    H5P_genplist_t *plist;              /* Property list for FAPL */
+    void *new_file = NULL;              /* File object opened */
+    H5VL_connector_prop_t connector_prop;  /* Property for VOL connector ID & info     */
+    H5VL_object_t *vol_obj = NULL;      /* VOL object for file */
+    hbool_t supported;                  /* Whether 'post open' operation is supported by VOL connector */
     hid_t ret_value = H5I_INVALID_HID;
 
     FUNC_ENTER_PACKAGE
@@ -529,7 +538,8 @@ H5R__reopen_file(H5R_ref_priv_t *ref, hid_t fapl_id)
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, H5I_INVALID_HID, "can't set VOL connector info in API context")
 
     /* Open the file */
-    if(NULL == (new_file = H5VL_file_open(&connector_prop, H5R_REF_FILENAME(ref), flags, fapl_id, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
+    /* (Must open file read-write to allow for object modifications) */
+    if(NULL == (new_file = H5VL_file_open(&connector_prop, H5R_REF_FILENAME(ref), H5F_ACC_RDWR, fapl_id, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, H5I_INVALID_HID, "unable to open file")
 
     /* Get an ID for the file */
@@ -540,9 +550,13 @@ H5R__reopen_file(H5R_ref_priv_t *ref, hid_t fapl_id)
     if(NULL == (vol_obj = H5VL_vol_object(ret_value)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, H5I_INVALID_HID, "invalid object identifier")
 
-    /* Make the post open callback */
-    if(H5VL_file_specific(vol_obj, H5VL_FILE_POST_OPEN, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to make file post open callback")
+    /* Make the 'post open' callback */
+    supported = FALSE;
+    if(H5VL_introspect_opt_query(vol_obj, H5VL_SUBCLS_FILE, H5VL_NATIVE_FILE_POST_OPEN, &supported) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, H5I_INVALID_HID, "can't check for 'post open' operation")
+    if(supported)
+        if(H5VL_file_optional(vol_obj, H5VL_NATIVE_FILE_POST_OPEN, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
+            HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, H5I_INVALID_HID, "unable to make file 'post open' callback")
 
     /* Attach loc_id to reference */
     if(H5R__set_loc_id((H5R_ref_priv_t *)ref, ret_value, FALSE) < 0)
@@ -570,7 +584,7 @@ H5R__get_type(const H5R_ref_priv_t *ref)
     FUNC_ENTER_PACKAGE_NOERR
 
     HDassert(ref != NULL);
-    ret_value = ref->type;
+    ret_value = (H5R_type_t)ref->type;
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5R__get_type() */
@@ -762,7 +776,7 @@ H5R__set_obj_token(H5R_ref_priv_t *ref, const H5VL_token_t *obj_token,
     HDassert(token_size <= H5VL_MAX_TOKEN_SIZE);
 
     H5MM_memcpy(&ref->ref.obj.token, obj_token, ref->token_size);
-    ref->token_size = token_size;
+    ref->token_size = (uint8_t)token_size;
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5R__set_obj_token() */
@@ -922,7 +936,7 @@ H5R__encode(const char *filename, const H5R_ref_priv_t *ref, unsigned char *buf,
         *p++ = (uint8_t)flags;
 
         buf_size = *nalloc - H5R_ENCODE_HEADER_SIZE;
-    }
+    } /* end if */
     encode_size += H5R_ENCODE_HEADER_SIZE;
 
     /* Encode object token */
@@ -937,31 +951,34 @@ H5R__encode(const char *filename, const H5R_ref_priv_t *ref, unsigned char *buf,
      *   - avoid duplicating VOL info on each reference
      *   - must query terminal VOL connector to avoid passthrough confusion
      */
-    if(flags & H5R_IS_EXTERNAL) {
+    if(flags & H5R_IS_EXTERNAL)
         /* Encode file name */
         H5R_ENCODE(H5R__encode_string, filename, p, buf_size, encode_size,
             "Cannot encode filename");
-    }
 
     switch(ref->type) {
         case H5R_OBJECT2:
             break;
+
         case H5R_DATASET_REGION2:
             /* Encode dataspace */
             H5R_ENCODE(H5R__encode_region, ref->ref.reg.space, p, buf_size,
                 encode_size, "Cannot encode region");
             break;
+
         case H5R_ATTR:
             /* Encode attribute name */
             H5R_ENCODE(H5R__encode_string, ref->ref.attr.name, p, buf_size,
                 encode_size, "Cannot encode attribute name");
             break;
+
         case H5R_OBJECT1:
         case H5R_DATASET_REGION1:
         case H5R_BADTYPE:
         case H5R_MAXTYPE:
             HDassert("invalid reference type" && 0);
             HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (invalid reference type)")
+
         default:
             HDassert("unknown reference type" && 0);
             HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
@@ -1053,7 +1070,7 @@ H5R__decode(const unsigned char *buf, size_t *nbytes, H5R_ref_priv_t *ref)
     ref->loc_id = H5I_INVALID_HID;
 
     /* Set encoding size */
-    ref->encode_size = decode_size;
+    ref->encode_size = (uint32_t)decode_size;
 
     H5R_LOG_DEBUG("Decoded reference, filename=%s, obj_addr=%s, encode size=%u",
         ref->ref.obj.filename, H5R__print_token(ref->ref.obj.token),
@@ -1136,7 +1153,7 @@ H5R__decode_obj_token(const unsigned char *buf, size_t *nbytes,
     /* Decode token */
     H5MM_memcpy(obj_token, p, *token_size);
 
-    *nbytes = *token_size + H5_SIZEOF_UINT8_T;
+    *nbytes = (size_t)*token_size + H5_SIZEOF_UINT8_T;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1184,7 +1201,7 @@ H5R__encode_region(H5S_t *space, unsigned char *buf, size_t *nalloc)
         /* Serialize the selection */
         if(H5S_SELECT_SERIALIZE(space, (unsigned char **)&p) < 0)
             HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, FAIL, "can't serialize selection")
-    }
+    } /* end if */
     *nalloc = (size_t)buf_size + 2 * H5_SIZEOF_UINT32_T;
 
 done:
@@ -1322,7 +1339,7 @@ H5R__decode_string(const unsigned char *buf, size_t *nbytes, char **string_ptr)
     HDassert(string_len <= H5R_MAX_STRING_LEN);
 
     /* Allocate the string */
-    if(NULL == (string = H5MM_malloc(string_len + 1)))
+    if(NULL == (string = (char *)H5MM_malloc(string_len + 1)))
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTALLOC, FAIL, "Cannot allocate string")
 
      /* Copy the string */
@@ -1364,13 +1381,13 @@ H5R__encode_heap(H5F_t *f, unsigned char *buf, size_t *nalloc,
         uint8_t *p = (uint8_t *)buf;
 
         /* Write the reference information to disk (allocates space also) */
-        if(H5HG_insert(f, data_size, (void *)data, &hobjid) < 0)
+        if(H5HG_insert(f, data_size, data, &hobjid) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "Unable to write reference information")
 
         /* Encode the heap information */
         H5F_addr_encode(f, &p, hobjid.addr);
         UINT32ENCODE(p, hobjid.idx);
-    }
+    } /* end if */
     *nalloc = buf_size;
 
 done:
@@ -1490,6 +1507,19 @@ H5R__decode_token_compat(H5VL_object_t *vol_obj, H5I_type_t type, H5R_type_t ref
 
     FUNC_ENTER_PACKAGE
 
+#ifndef NDEBUG
+{
+    hbool_t is_native = FALSE;  /* Whether the src file is using the native VOL connector */
+
+    /* Check if using native VOL connector */
+    if(H5VL_object_is_native(vol_obj, &is_native) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't query if file uses native VOL connector")
+
+    /* Must use native VOL connector for this operation */
+    HDassert(is_native);
+}
+#endif /* NDEBUG */
+
     /* Get the file for the object */
     if((file_id = H5F_get_file_id(vol_obj, type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
@@ -1499,7 +1529,7 @@ H5R__decode_token_compat(H5VL_object_t *vol_obj, H5I_type_t type, H5R_type_t ref
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Get container info */
-    if(H5VL_file_get(vol_obj_file, H5VL_FILE_GET_CONT_INFO, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &cont_info) < 0)
+    if(H5VL_file_get((const H5VL_object_t *)vol_obj_file, H5VL_FILE_GET_CONT_INFO, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &cont_info) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to get container info")
 
     if(ref_type == H5R_OBJECT1) {
@@ -1508,18 +1538,19 @@ H5R__decode_token_compat(H5VL_object_t *vol_obj, H5I_type_t type, H5R_type_t ref
         /* Get object address */
         if(H5R__decode_token_obj_compat(buf, &buf_size, obj_token, cont_info.token_size) < 0)
             HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "unable to get object token")
-    } else {
+    } /* end if */
+    else {
         size_t buf_size = H5R_DSET_REG_REF_BUF_SIZE;
         H5F_t *f = NULL;
 
         /* Retrieve file from VOL object */
-        if(NULL == (f = (H5F_t *)H5VL_object_data(vol_obj_file)))
+        if(NULL == (f = (H5F_t *)H5VL_object_data((const H5VL_object_t *)vol_obj_file)))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
 
         /* Get object address */
         if(H5R__decode_token_region_compat(f, buf, &buf_size, obj_token, cont_info.token_size, NULL) < 0)
             HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "unable to get object address")
-    }
+    } /* end else */
 
 done:
     if(file_id != H5I_INVALID_HID && H5I_dec_ref(file_id) < 0)