VOL FEATURE

1 files changed, 142 insertions, 134 deletions

diff --git a/src/H5D.c b/src/H5D.c
index af99a1f..9f56197 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -27,6 +27,7 @@
 #include "H5Eprivate.h"         /* Error handling                           */
 #include "H5FLprivate.h"        /* Free lists                               */
 #include "H5Iprivate.h"         /* IDs                                      */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
 
 
 /****************/
@@ -102,9 +103,10 @@ hid_t
 H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
     hid_t lcpl_id, hid_t dcpl_id, hid_t dapl_id)
 {
-    H5D_t              *dset = NULL;                        /* New dataset's info */
-    H5G_loc_t           loc;                                /* Object location to insert dataset into */
-    const H5S_t        *space;                              /* Dataspace for dataset */
+    void               *dset = NULL;                        /* New dataset's info */
+    H5VL_object_t      *vol_obj = NULL;                         /* object token of loc_id */
+    H5VL_loc_params_t   loc_params;
+    H5P_genplist_t     *plist = NULL;                       /* Property list pointer */
     hid_t               ret_value = H5I_INVALID_HID;        /* Return value */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
@@ -112,16 +114,10 @@ H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
              dapl_id);
 
     /* Check arguments */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location ID")
     if(!name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
     if(!*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be an empty string")
-    if(H5I_DATATYPE != H5I_get_type(type_id))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a datatype ID")
-    if(NULL == (space = (const H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a dataspace ID")
 
     /* Get link creation property list */
     if(H5P_DEFAULT == lcpl_id)
@@ -141,17 +137,38 @@ H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
     if(H5CX_set_apl(&dapl_id, H5P_CLS_DACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    /* Get the property list structure for the dcpl */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(dcpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, H5I_INVALID_HID, "can't find object for 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")
+
+    /* Set creation properties */
+    if(H5P_set(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for datatype id")
+    if(H5P_set(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for space id")
+    if(H5P_set(plist, H5VL_PROP_DSET_LCPL_ID, &lcpl_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for lcpl id")
+
+    /* Set location parameters */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
+
     /* Create the dataset */
-    if(NULL == (dset = H5D__create_named(&loc, name, type_id, space, lcpl_id, dcpl_id, dapl_id)))
+    if(NULL == (dset = H5VL_dataset_create(vol_obj->data, loc_params, vol_obj->driver->cls, 
+                                           name, dcpl_id, dapl_id, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, H5I_INVALID_HID, "unable to create dataset")
 
     /* Get an atom for the dataset */
-    if((ret_value = H5I_register(H5I_DATASET, dset, TRUE)) < 0)
+    if((ret_value = H5VL_register_id(H5I_DATASET, dset, vol_obj->driver, TRUE)) < 0)
         HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize dataset handle")
 
 done:
     if(H5I_INVALID_HID == ret_value)
-        if(dset && H5D_close(dset) < 0)
+        if(dset && H5VL_dataset_close(dset, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, H5I_INVALID_HID, "unable to release dataset")
 
     FUNC_LEAVE_API(ret_value)
@@ -194,21 +211,16 @@ hid_t
 H5Dcreate_anon(hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id,
     hid_t dapl_id)
 {
-    H5G_loc_t	   loc;                 /* Object location to insert dataset into */
-    H5D_t	   *dset = NULL;        /* New dataset's info */
-    const H5S_t    *space;              /* Dataspace for dataset */
+    void                *dset       = NULL;             /* dset token from VOL plugin */
+    H5VL_object_t       *vol_obj        = NULL;             /* object token of loc_id */
+    H5VL_loc_params_t   loc_params;
+    H5P_genplist_t      *plist;                         /* Property list pointer */
     hid_t               ret_value   = H5I_INVALID_HID;  /* Return value */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE5("i", "iiiii", loc_id, type_id, space_id, dcpl_id, dapl_id);
 
     /* Check arguments */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location ID")
-    if(H5I_DATATYPE != H5I_get_type(type_id))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a datatype ID")
-    if(NULL == (space = (const H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a dataspace ID")
     if(H5P_DEFAULT == dcpl_id)
         dcpl_id = H5P_DATASET_CREATE_DEFAULT;
     else
@@ -219,31 +231,38 @@ H5Dcreate_anon(hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id,
     if(H5CX_set_apl(&dapl_id, H5P_CLS_DACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_DATASET, 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")
+
+    /* Get the plist structure */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(dcpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, H5I_INVALID_HID, "can't find object for ID")
+
+    /* set creation properties */
+    if(H5P_set(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for datatype id")
+    if(H5P_set(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for space id")
+
+    /* Set location parameters */
+    loc_params.type     = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
     /* Create the dataset */
-    if(NULL == (dset = H5D__create(loc.oloc->file, type_id, space, dcpl_id, dapl_id)))
+    if(NULL == (dset = H5VL_dataset_create(vol_obj->data, loc_params, vol_obj->driver->cls, 
+                                           NULL, dcpl_id, dapl_id, 
+                                           H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, H5I_INVALID_HID, "unable to create dataset")
 
     /* Get an atom for the dataset */
-    if((ret_value = H5I_register(H5I_DATASET, dset, TRUE)) < 0)
+    if((ret_value = H5VL_register_id(H5I_DATASET, dset, vol_obj->driver, TRUE)) < 0)
         HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to register dataset")
 
 done:
-    /* Release the dataset's object header, if it was created */
-    if(dset) {
-        H5O_loc_t *oloc;         /* Object location for dataset */
-
-        /* Get the new dataset's object location */
-        if(NULL == (oloc = H5D_oloc(dset)))
-            HDONE_ERROR(H5E_DATASET, H5E_CANTGET, H5I_INVALID_HID, "unable to get object location of dataset")
-
-        /* Decrement refcount on dataset's object header in memory */
-        if(H5O_dec_rc_by_loc(oloc) < 0)
-           HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, H5I_INVALID_HID, "unable to decrement refcount on newly created object")
-    } /* end if */
-
     /* Cleanup on failure */
     if(H5I_INVALID_HID == ret_value)
-        if(dset && H5D_close(dset) < 0)
+        if(dset && H5VL_dataset_close (dset, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, H5I_INVALID_HID, "unable to release dataset")
 
     FUNC_LEAVE_API(ret_value)
@@ -268,16 +287,15 @@ done:
 hid_t
 H5Dopen2(hid_t loc_id, const char *name, hid_t dapl_id)
 {
-    H5D_t       *dset = NULL;
-    H5G_loc_t   loc;                    /* Object location of group */
+    void               *dset = NULL;        /* dset token from VOL plugin */
+    H5VL_object_t      *vol_obj = NULL;         /* object token of loc_id */
+    H5VL_loc_params_t   loc_params;
     hid_t               ret_value   = H5I_INVALID_HID;  /* Return value */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "i*si", loc_id, name, dapl_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, H5I_INVALID_HID, "name parameter cannot be NULL")
     if(!*name)
@@ -287,17 +305,26 @@ H5Dopen2(hid_t loc_id, const char *name, hid_t dapl_id)
     if(H5CX_set_apl(&dapl_id, H5P_CLS_DACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_DATASET, 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 the location parameters */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
+
     /* Open the dataset */
-    if(NULL == (dset = H5D__open_name(&loc, name, dapl_id)))
+    if(NULL == (dset = H5VL_dataset_open(vol_obj->data, loc_params, vol_obj->driver->cls, name, 
+                                         dapl_id, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open dataset")
 
     /* Register an atom for the dataset */
-    if((ret_value = H5I_register(H5I_DATASET, dset, TRUE)) < 0)
+    if((ret_value = H5VL_register_id(H5I_DATASET, dset, vol_obj->driver, TRUE)) < 0)
         HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "can't register dataset atom")
 
 done:
     if(H5I_INVALID_HID == ret_value)
-        if(dset && H5D_close(dset) < 0)
+        if(dset && H5VL_dataset_close(dset, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, H5I_INVALID_HID, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dopen2() */
@@ -323,7 +350,7 @@ H5Dclose(hid_t dset_id)
     H5TRACE1("e", "i", dset_id);
 
     /* Check args */
-    if(NULL == H5I_object_verify(dset_id, H5I_DATASET))
+    if(H5I_DATASET != H5I_get_type(dset_id))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset ID")
 
     /* Decrement the counter on the dataset.  It will be freed if the count
@@ -353,18 +380,19 @@ done:
 hid_t
 H5Dget_space(hid_t dset_id)
 {
-    H5D_t	       *dset = NULL;                    /* Dataset structure    */
+    H5VL_object_t  *vol_obj = NULL;                    /* Dataset structure    */
     hid_t           ret_value = H5I_INVALID_HID;    /* Return value         */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid dataset identifier")
 
     /* Get the dataspace */
-    if((ret_value = H5D__get_space(dset)) < 0)
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_SPACE, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, H5I_INVALID_HID, "unable to get dataspace")
 
 done:
@@ -384,18 +412,19 @@ done:
 herr_t
 H5Dget_space_status(hid_t dset_id, H5D_space_status_t *allocation)
 {
-    H5D_t 	       *dset = NULL;                    /* Dataset structure    */
+    H5VL_object_t  *vol_obj = NULL;                    /* Dataset structure    */
     herr_t          ret_value = SUCCEED;            /* Return value         */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*Ds", dset_id, allocation);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset identifier")
 
     /* Get dataspace status */
-    if(H5D__get_space_status(dset, allocation) < 0)
+    if((ret_value = H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_SPACE_STATUS, 
+                                     H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, allocation)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "unable to get space status")
 
 done:
@@ -419,18 +448,19 @@ done:
 hid_t
 H5Dget_type(hid_t dset_id)
 {
-    H5D_t	       *dset;                           /* Dataset structure    */
+    H5VL_object_t  *vol_obj;                           /* Dataset structure    */
     hid_t           ret_value = H5I_INVALID_HID;    /* Return value         */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid dataset identifier")
 
     /* get the datatype */
-    if((ret_value = H5D__get_type(dset)) < 0)
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_TYPE, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, H5I_INVALID_HID, "unable to get datatype")
 
 done:
@@ -457,18 +487,19 @@ done:
 hid_t
 H5Dget_create_plist(hid_t dset_id)
 {
-    H5D_t	*dataset;               /* Dataset structure */
+    H5VL_object_t  *vol_obj;                           /* Dataset structure    */
     hid_t           ret_value = H5I_INVALID_HID;    /* Return value         */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dataset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid dataset identifier")
 
     /* Get the dataset creation property list */
-    if((ret_value = H5D_get_create_plist(dataset)) < 0)
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_DCPL, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, H5I_INVALID_HID, "unable to get dataset creation properties")
 
 done:
@@ -512,18 +543,19 @@ done:
 hid_t
 H5Dget_access_plist(hid_t dset_id)
 {
-    H5D_t           *dset;          /* Dataset structure */
+    H5VL_object_t  *vol_obj;                           /* Dataset structure    */
     hid_t           ret_value = H5I_INVALID_HID;    /* Return value         */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid dataset identifier")
 
     /* Get the dataset access property list */
-    if((ret_value = H5D_get_access_plist(dset)) < 0)
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_DAPL, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, H5I_INVALID_HID, "unable to get dataset access properties")
 
 done:
@@ -549,18 +581,19 @@ done:
 hsize_t
 H5Dget_storage_size(hid_t dset_id)
 {
-    H5D_t	       *dset;                           /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                           /* Dataset for this operation   */
     hsize_t         ret_value = 0;                  /* Return value                 */
 
     FUNC_ENTER_API(0)
     H5TRACE1("h", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid dataset identifier")
 
     /* Get the storage size */
-    if(H5D__get_storage_size(dset, &ret_value) < 0)
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_STORAGE_SIZE, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "unable to get storage size")
 
 done:
@@ -582,18 +615,20 @@ done:
 haddr_t
 H5Dget_offset(hid_t dset_id)
 {
-    H5D_t	       *dset;                           /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                           /* Dataset for this operation   */
     haddr_t         ret_value = HADDR_UNDEF;        /* Return value                 */
 
     FUNC_ENTER_API(HADDR_UNDEF)
     H5TRACE1("a", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, HADDR_UNDEF, "invalid dataset identifier")
 
     /* Get the offset */
-    ret_value = H5D__get_offset(dset);
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_OFFSET, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, HADDR_UNDEF, "unable to get offset")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -775,8 +810,7 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
         hsize_t *size)
 {
     H5D_vlen_bufsize_t vlen_bufsize = {0, 0, 0, 0, 0, 0};
-    H5D_t *dset;                /* Dataset for this operation */
-    H5S_t *fspace = NULL;       /* Dataset's dataspace */
+    H5VL_object_t  *vol_obj;       /* Dataset for this operation */
     H5S_t *mspace = NULL;       /* Memory dataspace */
     char bogus;                 /* bogus value to pass to H5Diterate() */
     H5S_t *space;               /* Dataspace for iteration */
@@ -791,7 +825,7 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
     if(H5I_DATASET != H5I_get_type(dataset_id) ||
             H5I_DATATYPE != H5I_get_type(type_id) || size == NULL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid argument")
-    if(NULL == (dset = (H5D_t *)H5I_object(dataset_id)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object(dataset_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset identifier")
     if(NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an valid base datatype")
@@ -801,21 +835,20 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "dataspace does not have extent set")
 
     /* Save the dataset */
-    vlen_bufsize.dset = dset;
+    vlen_bufsize.dset_vol_obj = vol_obj;
     vlen_bufsize.fspace_id = H5I_INVALID_HID;
     vlen_bufsize.mspace_id = H5I_INVALID_HID;
 
     /* Get a copy of the dataset's dataspace */
-    if(NULL == (fspace = H5S_copy(dset->shared->space, FALSE, TRUE)))
+    if(H5VL_dataset_get(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_GET_SPACE, 
+                        H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &vlen_bufsize.fspace_id) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't copy dataspace")
-    if((vlen_bufsize.fspace_id = H5I_register(H5I_DATASPACE, fspace, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register file dataspace")
 
     /* Create a scalar for the memory dataspace */
     if(NULL == (mspace = H5S_create(H5S_SCALAR)))
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCREATE, FAIL, "can't create dataspace")
     if((vlen_bufsize.mspace_id = H5I_register(H5I_DATASPACE, mspace, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register memory dataspace")
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace atom")
 
     /* Grab the temporary buffers required */
     if(NULL == (vlen_bufsize.fl_tbuf = H5FL_BLK_MALLOC(vlen_fl_buf, (size_t)1)))
@@ -842,17 +875,14 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
         *size = vlen_bufsize.size;
 
 done:
-    if(ret_value < 0) {
-        if(fspace && H5S_close(fspace) < 0)
-            HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release file dataspace")
+    if(ret_value < 0)
         if(mspace && H5S_close(mspace) < 0)
-            HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release memory dataspace")
-    }
+            HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release dataspace")
 
     if(vlen_bufsize.fspace_id && H5I_dec_app_ref(vlen_bufsize.fspace_id) < 0)
-        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing file dataspace id")
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing id")
     if(vlen_bufsize.mspace_id && H5I_dec_app_ref(vlen_bufsize.mspace_id) < 0)
-        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing memory dataspace id")
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing id")
     if(vlen_bufsize.fl_tbuf != NULL)
         vlen_bufsize.fl_tbuf = H5FL_BLK_FREE(vlen_fl_buf, vlen_bufsize.fl_tbuf);
     if(vlen_bufsize.vl_tbuf != NULL)
@@ -875,14 +905,14 @@ done:
 herr_t
 H5Dset_extent(hid_t dset_id, const hsize_t size[])
 {
-    H5D_t          *dset;                   /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                   /* Dataset for this operation   */
     herr_t          ret_value = SUCCEED;    /* Return value                 */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*h", dset_id, size);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dset_id parameter is not a valid dataset identifier")
     if(!size)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "size array cannot be NULL")
@@ -892,7 +922,8 @@ H5Dset_extent(hid_t dset_id, const hsize_t size[])
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set collective metadata read info")
 
     /* Set the extent */
-    if(H5D__set_extent(dset, size) < 0)
+    if ((ret_value = H5VL_dataset_specific(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_SET_EXTENT, 
+                                          H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, size)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "unable to set dataset extent")
 
 done:
@@ -912,22 +943,26 @@ done:
 herr_t
 H5Dflush(hid_t dset_id)
 {
-    H5D_t          *dset;                   /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                   /* Dataset for this operation   */
     herr_t          ret_value = SUCCEED;    /* Return value                 */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", dset_id);
     
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dset_id parameter is not a valid dataset identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(dset_id) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set collective metadata read info")
 
-    /* Flush dataset information cached in memory */
-    if(H5D__flush(dset, dset_id) < 0)
+    /* Flush dataset information cached in memory
+     * XXX: Note that we need to pass the ID to the VOL since the H5F_flush_cb_t
+     *      callback needs it and that's in the public API.
+     */
+    if((ret_value = H5VL_dataset_specific(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_FLUSH, 
+                                          H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, dset_id)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTFLUSH, FAIL, "unable to flush dataset")
 
 done:
@@ -947,14 +982,14 @@ done:
 herr_t
 H5Drefresh(hid_t dset_id)
 {
-    H5D_t          *dset;                   /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                   /* Dataset for this operation   */
     herr_t          ret_value = SUCCEED;    /* Return value                 */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dset_id parameter is not a valid dataset identifier")
 
     /* Set up collective metadata if appropriate */
@@ -962,7 +997,8 @@ H5Drefresh(hid_t dset_id)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set collective metadata read info")
 
     /* Refresh the dataset object */
-    if((H5D__refresh(dset_id, dset)) < 0)
+    if((ret_value = H5VL_dataset_specific(vol_obj->data, vol_obj->driver->cls, H5VL_DATASET_REFRESH, 
+                                          H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, dset_id)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to refresh dataset")
 
 done:
@@ -990,47 +1026,24 @@ done:
 herr_t
 H5Dformat_convert(hid_t dset_id)
 {
-    H5D_t          *dset;                   /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                   /* Dataset for this operation   */
     herr_t          ret_value = SUCCEED;    /* Return value                 */
     
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dset_id parameter is not a valid dataset identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(dset_id) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set collective metadata read info")
 
-    switch(dset->shared->layout.type) {
-	case H5D_CHUNKED:
-	    /* Convert the chunk indexing type to version 1 B-tree if not */
-	    if(dset->shared->layout.u.chunk.idx_type != H5D_CHUNK_IDX_BTREE)
-                if((H5D__format_convert(dset)) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to downgrade chunk indexing type for dataset")
-	    break;
-
-	case H5D_CONTIGUOUS:
-	case H5D_COMPACT:
-	    /* Downgrade the layout version to 3 if greater than 3 */
-	    if(dset->shared->layout.version > H5O_LAYOUT_VERSION_DEFAULT)
-                if((H5D__format_convert(dset)) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to downgrade layout version for dataset")
-	    break;
-
-	case H5D_VIRTUAL:
-	    /* Nothing to do even though layout is version 4 */
-	    break;
-
-        case H5D_LAYOUT_ERROR:
-        case H5D_NLAYOUTS:
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset layout type")
-
-	default: 
-	    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown dataset layout type")
-    } /* end switch */
+    /* Convert the dataset */
+    if(H5VL_dataset_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT,
+            H5_REQUEST_NULL, H5VL_DATASET_FORMAT_CONVERT) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_INTERNAL, FAIL, "can't convert dataset format")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1052,25 +1065,22 @@ done:
 herr_t
 H5Dget_chunk_index_type(hid_t dset_id, H5D_chunk_index_t *idx_type)
 {
-    H5D_t          *dset;                   /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                   /* Dataset for this operation   */
     herr_t          ret_value = SUCCEED;    /* Return value                 */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*Dk", dset_id, idx_type);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dset_id parameter is not a valid dataset identifier")
     if(NULL == idx_type)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "idx_type parameter cannot be NULL")
 
-    /* Should be a chunked dataset */
-    if(dset->shared->layout.type != H5D_CHUNKED)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not chunked")
-
     /* Get the chunk indexing type */
-    if(idx_type)
-        *idx_type = dset->shared->layout.u.chunk.idx_type;
+    if(H5VL_dataset_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT,
+            H5_REQUEST_NULL, H5VL_DATASET_GET_CHUNK_INDEX_TYPE, idx_type) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get chunk index type")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1095,25 +1105,23 @@ done:
 herr_t
 H5Dget_chunk_storage_size(hid_t dset_id, const hsize_t *offset, hsize_t *chunk_nbytes)
 {
-    H5D_t          *dset;                   /* Dataset for this operation   */
+    H5VL_object_t  *vol_obj;                   /* Dataset for this operation   */
     herr_t          ret_value = SUCCEED;    /* Return value                 */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "i*h*h", dset_id, offset, chunk_nbytes);
 
     /* Check arguments */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object_verify(dset_id, H5I_DATASET)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dset_id parameter is not a valid dataset identifier")
     if(NULL == offset)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "offset parameter cannot be NULL")
     if(NULL == chunk_nbytes)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "chunk_nbytes parameter cannot be NULL")
 
-    if(H5D_CHUNKED != dset->shared->layout.type)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
-
     /* Get the dataset creation property list */
-    if(H5D__get_chunk_storage_size(dset, offset, chunk_nbytes) < 0)
+    if(H5VL_dataset_optional(vol_obj->data, vol_obj->driver->cls, H5P_DATASET_XFER_DEFAULT,
+            H5_REQUEST_NULL, H5VL_DATASET_GET_CHUNK_STORAGE_SIZE, offset, chunk_nbytes) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get storage size of chunk")
 
 done: