VOL FEATURE

1 files changed, 260 insertions, 76 deletions

diff --git a/src/H5O.c b/src/H5O.c
index b33e6e2..77b9498 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -100,15 +100,16 @@
 hid_t
 H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t  *vol_obj         = NULL;                     /* Object token of loc_id */
+    H5I_type_t      opened_type;
+    void           *opened_obj  = NULL;
+    H5VL_loc_params_t loc_params;
     hid_t           ret_value   = H5I_INVALID_HID;
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "i*si", loc_id, name, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(!name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
     if(!*name)
@@ -118,10 +119,24 @@ H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Set location struct fields */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
     /* Open the object */
-    if((ret_value = H5O_open_name(&loc, name, TRUE)) < 0)
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj->data, loc_params, vol_obj->driver->cls, 
+                                              &opened_type, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object")
 
+    /* Get an atom for the object */
+    if((ret_value = H5VL_register_id(opened_type, opened_obj, vol_obj->driver, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen() */
@@ -154,15 +169,16 @@ hid_t
 H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj = NULL;        /* object token of loc_id */
+    H5I_type_t opened_type;
+    void *opened_obj = NULL;
+    H5VL_loc_params_t loc_params;
     hid_t ret_value = H5I_INVALID_HID;
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE6("i", "i*sIiIohi", loc_id, group_name, idx_type, order, n, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(!group_name || !*group_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no name specified")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
@@ -174,10 +190,26 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = group_name;
+    loc_params.loc_data.loc_by_idx.idx_type = idx_type;
+    loc_params.loc_data.loc_by_idx.order = order;
+    loc_params.loc_data.loc_by_idx.n = n;
+    loc_params.loc_data.loc_by_idx.lapl_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the location object */
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
     /* Open the object */
-    if((ret_value = H5O_open_by_idx(&loc, group_name, idx_type, order, n)) < 0)
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj->data, loc_params, vol_obj->driver->cls, 
+                                              &opened_type, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object")
 
+    if((ret_value = H5VL_register_id(opened_type, opened_obj, vol_obj->driver, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_idx() */
@@ -221,22 +253,32 @@ done:
 hid_t
 H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
 {
-    H5G_loc_t	loc;                    /* Location within file */
+    H5VL_object_t *vol_obj = NULL;        /* object token of loc_id */
+    H5I_type_t opened_type;
+    void *opened_obj = NULL;
+    H5VL_loc_params_t loc_params;
     hid_t       ret_value = H5I_INVALID_HID;	/* Return value */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE2("i", "ia", loc_id, addr);
 
-    /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
-    if(!H5F_addr_defined(addr))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no address supplied")
+    loc_params.type = H5VL_OBJECT_BY_ADDR;
+    loc_params.loc_data.loc_by_addr.addr = addr;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
     /* Open the object */
-    if((ret_value = H5O_open_by_addr(&loc, addr)) < 0)
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj->data, loc_params, vol_obj->driver->cls, &opened_type, 
+                                              H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object")
 
+    /* Register the dataset ID */
+    if((ret_value = H5VL_register_id(opened_type, opened_obj, vol_obj->driver, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_addr() */
@@ -267,20 +309,19 @@ herr_t
 H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     hid_t lapl_id)
 {
-    H5G_loc_t	new_loc;		/* Location of group to link from */
-    H5G_loc_t	obj_loc;		/* Location of object to link to */
-    herr_t      ret_value = SUCCEED;       /* Return value */
+    H5VL_object_t    *vol_obj1 = NULL;        /* object token of obj_id */
+    H5VL_object_t    *vol_obj2 = NULL;        /* object token of new_loc_id */
+    H5VL_loc_params_t loc_params1;
+    H5VL_loc_params_t loc_params2;
+    H5P_genplist_t *plist;      /* Property list pointer */
+    herr_t         ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE5("e", "ii*sii", obj_id, new_loc_id, new_name, lcpl_id, lapl_id);
 
     /* Check arguments */
-    if(H5G_loc(obj_id, &obj_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(new_loc_id == H5L_SAME_LOC)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "cannot use H5L_SAME_LOC when only one location is specified")
-    if(H5G_loc(new_loc_id, &new_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!new_name || !*new_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
 /* Avoid compiler warning on 32-bit machines */
@@ -291,12 +332,52 @@ H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     if(lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a link creation property list")
 
+    /* Check the group access property list */
+    if(H5P_DEFAULT == lcpl_id)
+        lcpl_id = H5P_LINK_CREATE_DEFAULT;
+
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, obj_id, TRUE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    /* Link to the object */
-    if(H5L_link(&new_loc, new_name, &obj_loc, lcpl_id) < 0)
+    loc_params1.type = H5VL_OBJECT_BY_SELF;
+    loc_params1.obj_type = H5I_get_type(obj_id);
+
+    loc_params2.type = H5VL_OBJECT_BY_NAME;
+    loc_params2.obj_type = H5I_get_type(new_loc_id);
+    loc_params2.loc_data.loc_by_name.name = new_name;
+    loc_params2.loc_data.loc_by_name.lapl_id = lapl_id;
+
+    if(H5L_SAME_LOC != obj_id) {
+        /* get the location object */
+        if(NULL == (vol_obj1 = H5VL_get_object(obj_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    }
+    if(H5L_SAME_LOC != new_loc_id) {
+        /* get the location object */
+        if(NULL == (vol_obj2 = H5VL_get_object(new_loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    }
+    /* Make sure that the VOL plugins are the same */
+    if(vol_obj1 && vol_obj2) {
+        if (vol_obj1->driver->cls->value != vol_obj2->driver->cls->value)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "Objects are accessed through different VOL plugins and can't be linked")
+    }
+
+    /* Get the plist structure */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(lcpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* set creation properties */
+    if(H5P_set(plist, H5VL_PROP_LINK_TARGET, &vol_obj1->data) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for target id")
+    if(H5P_set(plist, H5VL_PROP_LINK_TARGET_LOC_PARAMS, &loc_params1) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for target id")
+
+    /* Create a link to the object */
+    if(H5VL_link_create(H5VL_LINK_CREATE_HARD, vol_obj2->data, loc_params2, 
+                        (vol_obj1 != NULL ? vol_obj1->driver->cls : vol_obj2->driver->cls),
+                        lcpl_id, lapl_id, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTCREATE, FAIL, "unable to create link")
 
 done:
@@ -327,22 +408,27 @@ done:
 herr_t
 H5Oincr_refcount(hid_t object_id)
 {
-    H5O_loc_t  *oloc;			/* Object location */
-    herr_t      ret_value = SUCCEED;	/* Return value */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
+    herr_t      ret_value = SUCCEED;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", object_id);
 
-    /* Get the object's oloc so we can adjust its link count */
-    if((oloc = H5O_get_loc(object_id)) == NULL)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(object_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Change the object's reference count */
-    if(H5O_link(oloc, 1) < 0)
+    if(H5VL_object_specific(vol_obj->data, loc_params, vol_obj->driver->cls, H5VL_OBJECT_CHANGE_REF_COUNT, 
+                            H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
@@ -373,22 +459,27 @@ done:
 herr_t
 H5Odecr_refcount(hid_t object_id)
 {
-    H5O_loc_t  *oloc;			/* Object location */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;	/* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", object_id);
 
-    /* Get the object's oloc so we can adjust its link count */
-    if((oloc = H5O_get_loc(object_id)) == NULL)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(object_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Change the object's reference count */
-    if(H5O_link(oloc, -1) < 0)
+    if(H5VL_object_specific(vol_obj->data, loc_params, vol_obj->driver->cls, H5VL_OBJECT_CHANGE_REF_COUNT, 
+                            H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, -1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
@@ -412,15 +503,14 @@ done:
 htri_t
 H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location info */
+    H5VL_object_t  *vol_obj         = NULL;         /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     htri_t      ret_value = FAIL;       /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("t", "i*si", loc_id, name, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
     if(!*name)
@@ -430,8 +520,19 @@ H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Set the location struct fields */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
     /* Check if the object exists */
-    if((ret_value = H5G_loc_exists(&loc, name)) < 0)
+    if(H5VL_object_specific(vol_obj->data, loc_params, vol_obj->driver->cls, H5VL_OBJECT_EXISTS, 
+                            H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", name)
 
 done:
@@ -456,22 +557,30 @@ done:
 herr_t
 H5Oget_info2(hid_t loc_id, H5O_info_t *oinfo, unsigned fields)
 {
-    H5G_loc_t   loc;                    /* Location of group */
+    H5VL_object_t      *vol_obj         = NULL;         /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "i*xIu", loc_id, oinfo, fields);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!oinfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "oinfo parameter cannot be NULL")
     if(fields & ~H5O_INFO_ALL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid fields")
 
+    /* Set location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, ".", oinfo, fields) < 0)
+    if(H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, 
+                            H5_REQUEST_NULL, H5VL_OBJECT_GET_INFO, loc_params, oinfo, fields) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object")
 
 done:
@@ -497,15 +606,14 @@ herr_t
 H5Oget_info_by_name2(hid_t loc_id, const char *name, H5O_info_t *oinfo,
     unsigned fields, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE5("e", "i*s*xIui", loc_id, name, oinfo, fields, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
     if(!*name)
@@ -519,8 +627,19 @@ H5Oget_info_by_name2(hid_t loc_id, const char *name, H5O_info_t *oinfo,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Fill out location struct */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, name, oinfo/*out*/, fields) < 0)
+    if(H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL,
+                            H5VL_OBJECT_GET_INFO, loc_params, oinfo, fields) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object: '%s'", name)
 
 done:
@@ -548,7 +667,8 @@ herr_t
 H5Oget_info_by_idx2(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, H5O_info_t *oinfo, unsigned fields, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -556,8 +676,6 @@ H5Oget_info_by_idx2(hid_t loc_id, const char *group_name, H5_index_t idx_type,
              fields, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!group_name || !*group_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
@@ -573,8 +691,21 @@ H5Oget_info_by_idx2(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = group_name;
+    loc_params.loc_data.loc_by_idx.idx_type = idx_type;
+    loc_params.loc_data.loc_by_idx.order = order;
+    loc_params.loc_data.loc_by_idx.n = n;
+    loc_params.loc_data.loc_by_idx.lapl_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* Retrieve the object's information */
-    if(H5O__get_info_by_idx(&loc, group_name, idx_type, order, n, oinfo, fields) < 0)
+    if(H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 
+                            H5VL_OBJECT_GET_INFO, loc_params, oinfo, fields) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object")
 
 done:
@@ -602,22 +733,28 @@ done:
 herr_t
 H5Oset_comment(hid_t obj_id, const char *comment)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*s", obj_id, comment);
 
-    /* Check args */
-    if(H5G_loc(obj_id, &loc) < 0)
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(obj_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(obj_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set collective metadata read info")
 
+    /* Fill in location struct fields */
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(obj_id);
+
     /* (Re)set the object's comment */
-    if(H5G_loc_set_comment(&loc, ".", comment) < 0)
+    if(H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, 
+                            H5_REQUEST_NULL, H5VL_OBJECT_SET_COMMENT, loc_params, comment) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set comment for object")
 
 done:
@@ -646,15 +783,14 @@ herr_t
 H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
     hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE4("e", "i*s*si", loc_id, name, comment, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
 
@@ -662,8 +798,19 @@ H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Fill in location struct fields */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* (Re)set the object's comment */
-    if(H5G_loc_set_comment(&loc, name, comment) < 0)
+    if(H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 
+                            H5VL_OBJECT_SET_COMMENT, loc_params, comment) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set comment for object: '%s'", name)
 
 done:
@@ -690,18 +837,24 @@ done:
 ssize_t
 H5Oget_comment(hid_t obj_id, char *comment, size_t bufsize)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     ssize_t     ret_value = -1;              /* Return value */
 
     FUNC_ENTER_API((-1))
     H5TRACE3("Zs", "i*sz", obj_id, comment, bufsize);
 
-    /* Check args */
-    if(H5G_loc(obj_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "not a location")
+    /* Get the object */
+    if (NULL == (vol_obj = H5VL_get_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
+
+    /* Set fields in the location struct */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(obj_id);
 
     /* Retrieve the object's comment */
-    if((ret_value = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize)) < 0)
+    if (H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 
+                            H5VL_OBJECT_GET_COMMENT, loc_params, comment, bufsize, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, (-1), "can't get comment for object")
 
 done:
@@ -729,15 +882,14 @@ ssize_t
 H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t bufsize,
     hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     ssize_t     ret_value = -1;              /* Return value */
 
     FUNC_ENTER_API((-1))
     H5TRACE5("Zs", "i*s*szi", loc_id, name, comment, bufsize, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "not a location")
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "no name")
 
@@ -745,8 +897,19 @@ H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t buf
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, (-1), "can't set access property list info")
 
+    /* Fill in location struct fields */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
+
     /* Retrieve the object's comment */
-    if((ret_value = H5G_loc_get_comment(&loc, name, comment/*out*/, bufsize)) < 0)
+    if(H5VL_object_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 
+                            H5VL_OBJECT_GET_COMMENT, loc_params, comment, bufsize, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, (-1), "can't get comment for object: '%s'", name)
 
 done:
@@ -793,15 +956,14 @@ herr_t
 H5Ovisit2(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     H5O_iterate_t op, void *op_data, unsigned fields)
 {
-    H5G_loc_t           loc;
+    H5VL_object_t      *vol_obj         = NULL;     /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;
     herr_t              ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "iIiIox*xIu", obj_id, idx_type, order, op, op_data, fields);
 
     /* Check args */
-    if(H5G_loc(obj_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
@@ -811,8 +973,18 @@ H5Ovisit2(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     if(fields & ~H5O_INFO_ALL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid fields")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Set location parameters */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(obj_id);
+
     /* Visit the objects */
-    if((ret_value = H5O__visit(&loc, ".", idx_type, order, op, op_data, fields)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj->data, loc_params, vol_obj->driver->cls,
+                                         H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 
+                                         idx_type, order, op, op_data, fields)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object iteration failed")
 
 done:
@@ -859,7 +1031,8 @@ herr_t
 H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, H5O_iterate_t op, void *op_data, unsigned fields, hid_t lapl_id)
 {
-    H5G_loc_t           loc;
+    H5VL_object_t       *vol_obj        = NULL;     /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params; 
     herr_t              ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -867,8 +1040,6 @@ H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
              fields, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "obj_name parameter cannot be NULL")
     if(!*obj_name)
@@ -886,8 +1057,20 @@ H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Set location parameters */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = obj_name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
     /* Visit the objects */
-    if((ret_value = H5O__visit(&loc, obj_name, idx_type, order, op, op_data, fields)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj->data, loc_params, vol_obj->driver->cls, 
+                                         H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 
+                                         idx_type, order, op, op_data, fields)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object iteration failed")
 
 done:
@@ -938,6 +1121,7 @@ H5Oclose(hid_t object_id)
         case H5I_ATTR:
         case H5I_REFERENCE:
         case H5I_VFL:
+        case H5I_VOL:
         case H5I_GENPROP_CLS:
         case H5I_GENPROP_LST:
         case H5I_ERROR_CLASS: