Add new H5R API that abstracts object, region and attribute reference types

Also support references to external files

Add new H5T_REF type and type conversion routines

Support conversion from H5T_REF_OBJ/DSET_REG to H5T_REF

Add H5Treclaim() API to reclaim memory of vlen/reference types

Deprecate H5Dvlen_reclaim()

Fix H5T_vlen_reclaim() and H5T_reclaim() to use private callback

Add H5T_ref_reclaim()

Move previous H5R APIs to H5Rdeprec.c

Clean up H5Ocopy

Separate H5O_copy_expand_ref() to H5Ocopy_ref()

Add support for copying new reference types

Clean up deprecated routines to go through VOL and same code path

Fix return codes in existing trefer.c test

Rename trefer.c to trefer_deprec.c

trefer.c is for new references

Add performance test for trefer

Add additional obj_copy_ref test

Make use of tokens and blobs to store references

Skip blob encoding for object references

Start adding new reference examples

1 files changed, 437 insertions, 61 deletions

diff --git a/src/H5Rdeprec.c b/src/H5Rdeprec.c
index ab8d3b4..4743c77 100644
--- a/src/H5Rdeprec.c
+++ b/src/H5Rdeprec.c
@@ -37,14 +37,15 @@
 #include "H5Ppublic.h"          /* Property lists                           */
 
 /* Private headers needed by this file */
-#include "H5private.h"		/* Generic Functions                        */
-#include "H5ACprivate.h"	/* Metadata cache                           */
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5ACprivate.h"        /* Metadata cache                           */
 #include "H5CXprivate.h"        /* API Contexts                             */
-#include "H5Eprivate.h"		/* Error handling                           */
-#include "H5Gprivate.h"		/* Groups                                   */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Gprivate.h"         /* Groups                                   */
 #include "H5Iprivate.h"         /* IDs                                      */
-#include "H5Oprivate.h"		/* Object headers                           */
+#include "H5Oprivate.h"         /* Object headers                           */
 #include "H5Rpkg.h"             /* References                               */
+#include "H5Sprivate.h"         /* Dataspaces                               */
 
 
 /****************/
@@ -81,53 +82,61 @@
 /* Local Variables */
 /*******************/
 
-
 #ifndef H5_NO_DEPRECATED_SYMBOLS
-
+
 /*-------------------------------------------------------------------------
  * Function:    H5Rget_obj_type1
  *
- * Purpose:     Retrieves the type of the object that an object points to.
+ * Purpose: Retrieves the type of the object that a reference points to.
  *
- * Parameters:
- *      id          IN: Dataset reference object is in or location ID of
- *                      object that the dataset is located within
- *      ref_type    IN: Type of reference to query
- *      ref         IN: Reference to query
- *
- * Return:      Success:	An object type (as defined in H5Gpublic.h)
- *              Failure:    H5G_UNKNOWN
+ * Return: Object type (as defined in H5Gpublic.h) on success
+ *         H5G_UNKNOWN on failure
  *
  *-------------------------------------------------------------------------
  */
 H5G_obj_t
 H5Rget_obj_type1(hid_t id, H5R_type_t ref_type, const void *ref)
 {
-    H5VL_object_t    *vol_obj = NULL;        /* object token of loc_id */
-    H5VL_loc_params_t loc_params;
-    H5O_type_t obj_type;        /* Object type */
-    H5G_obj_t ret_value;        /* Return value */
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    haddr_t obj_addr;                   /* Object address */
+    H5O_type_t obj_type;                /* Object type */
+    const unsigned char *buf = (const unsigned char *)ref; /* Reference buffer */
+    H5G_obj_t ret_value;                /* Return value */
 
     FUNC_ENTER_API(H5G_UNKNOWN)
     H5TRACE3("Go", "iRt*x", id, ref_type, ref);
 
     /* Check args */
-    if (ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference type")
-    if (ref == NULL)
+    if(buf == NULL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference pointer")
+    if(ref_type != H5R_OBJECT1 && ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference type")
 
-    /* Set location parameters */
-    loc_params.type = H5VL_OBJECT_BY_SELF;
-    loc_params.obj_type = H5I_get_type(id);
+    /* Get the VOL object */
+    if(NULL == (vol_obj = H5VL_vol_object(id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "invalid location identifier")
 
-    /* Get the vol object */
-    if (NULL == (vol_obj = H5VL_vol_object(id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "invalid file identifier")
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
 
-    /* Get the object information */
-    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_type, (int)ref_type, ref) < 0)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, H5G_UNKNOWN, "unable to determine object type")
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "invalid location identifier")
+
+    /* Get object address */
+    if(H5R__decode_addr_compat(id, vol_obj_type, ref_type, buf, &obj_addr) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, H5G_UNKNOWN, "unable to get object address")
+
+    /* Set location parameters */
+    loc_params.type = H5VL_OBJECT_BY_TOKEN;
+    loc_params.loc_data.loc_by_token.token = &obj_addr;
+    loc_params.obj_type = vol_obj_type;
+
+    /* Retrieve object's type */
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_OBJECT_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_type) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5G_UNKNOWN, "can't retrieve object type")
 
     /* Set return value */
     ret_value = H5G_map_obj_type(obj_type);
@@ -140,54 +149,61 @@ done:
 /*-------------------------------------------------------------------------
  * Function:    H5Rdereference1
  *
- * Purpose:     Opens the HDF5 object referenced.
- *
- * Parameters:
- *      id          IN: Dataset reference object is in or location ID of
- *                      object that the dataset is located within
- *      ref_type    IN: Type of reference to create
- *      ref         IN: Reference to open
+ * Purpose: Given a reference to some object, open that object and return an
+ * ID for that object.
  *
- * Return:      Success:	Valid HDF5 ID
- *              Failure:    H5I_INVALID_HID
+ * Return:  Valid ID on success/Negative on failure
  *
  *-------------------------------------------------------------------------
  */
 hid_t
-H5Rdereference1(hid_t obj_id, H5R_type_t ref_type, const void *_ref)
+H5Rdereference1(hid_t obj_id, H5R_type_t ref_type, const void *ref)
 {
-    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 */
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    haddr_t obj_addr;                   /* Object address */
+    H5I_type_t opened_type;             /* Opened object type */
+    void *opened_obj = NULL;            /* Opened object */
+    const unsigned char *buf = (const unsigned char *)ref; /* Reference buffer */
+    hid_t ret_value = H5I_INVALID_HID;  /* Return value */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
-    H5TRACE3("i", "iRt*x", obj_id, ref_type, _ref);
+    H5TRACE3("i", "iRt*x", obj_id, ref_type, ref);
 
     /* Check args */
-    if (ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference type")
-    if (_ref == NULL)
+    if(buf == NULL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference pointer")
+    if(ref_type != H5R_OBJECT1 && ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference type")
 
     /* Get the VOL object */
-    if (NULL == (vol_obj = H5VL_vol_object(obj_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid file identifier")
+    if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
 
-    loc_params.type = H5VL_OBJECT_BY_REF;
-    loc_params.loc_data.loc_by_ref.ref_type = ref_type;
-    loc_params.loc_data.loc_by_ref._ref = _ref;
-    loc_params.loc_data.loc_by_ref.lapl_id = H5P_DATASET_ACCESS_DEFAULT;
-    loc_params.obj_type = H5I_get_type(obj_id);
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(obj_id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Get object address */
+    if(H5R__decode_addr_compat(obj_id, vol_obj_type, ref_type, buf, &obj_addr) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, H5I_INVALID_HID, "unable to get object address")
+
+    /* Set location parameters */
+    loc_params.type = H5VL_OBJECT_BY_TOKEN;
+    loc_params.loc_data.loc_by_token.token = &obj_addr;
+    loc_params.obj_type = vol_obj_type;
 
     /* Dereference */
     if(NULL == (opened_obj = H5VL_object_open(vol_obj, &loc_params, &opened_type, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
-        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to dereference object")
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object by address")
 
-    /* Get an atom for the object */
+    /* Register object */
     if((ret_value = H5VL_register(opened_type, opened_obj, vol_obj->connector, TRUE)) < 0)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to register object handle")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -195,3 +211,363 @@ done:
 
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Rcreate
+ *
+ * Purpose: Creates a particular type of reference specified with REF_TYPE,
+ * in the space pointed to by REF. The LOC_ID and NAME are used to locate the
+ * object pointed to and the SPACE_ID is used to choose the region pointed to
+ * (for Dataset Region references).
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type,
+    hid_t space_id)
+{
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    haddr_t obj_addr;                   /* Object address */
+    hid_t file_id = H5I_INVALID_HID;    /* File ID for region reference */
+    unsigned char *buf = (unsigned char *)ref; /* Return reference pointer */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE5("e", "*xi*sRti", ref, loc_id, name, ref_type, space_id);
+
+    /* Check args */
+    if(buf == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
+    if(!name || !*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
+    if(ref_type != H5R_OBJECT1 && ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
+
+    /* Set up collective metadata if appropriate */
+    if(H5CX_set_loc(loc_id) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTSET, FAIL, "can't set access property list info")
+
+    /* Get the VOL object */
+    if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
+
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(loc_id)) < 0)
+        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 = name;
+    loc_params.obj_type = vol_obj_type;
+
+    /* Get the object address */
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_addr) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve object address")
+
+    /* Create reference */
+    if(ref_type == H5R_OBJECT1) {
+        size_t buf_size = H5R_OBJ_REF_BUF_SIZE;
+
+        if((ret_value = H5R__encode_addr_obj_compat(obj_addr, buf, &buf_size)) < 0)
+            HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, FAIL, "unable to encode object reference")
+    } else {
+        void *vol_obj_file = NULL;
+        H5F_t *f = NULL;
+        H5S_t *space = NULL; /* Pointer to dataspace containing region */
+        size_t buf_size = H5R_DSET_REG_REF_BUF_SIZE;
+
+        /* Get the file for the object */
+        if((file_id = H5F_get_file_id(loc_id, vol_obj_type, FALSE)) < 0)
+                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+        /* Retrieve VOL object */
+        if(NULL == (vol_obj_file = H5VL_vol_object(file_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+        /* Retrieve file from VOL object */
+        if(NULL == (f = (H5F_t *)H5VL_object_data(vol_obj_file)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
+        /* Retrieve space */
+        if(space_id == H5I_BADID)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "reference region dataspace id must be valid")
+        if(NULL == (space = (struct H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+
+        /* Encode dataset region */
+        if((ret_value = H5R__encode_addr_region_compat(f, obj_addr, space, buf, &buf_size)) < 0)
+            HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, FAIL, "unable to encode region reference")
+    }
+
+done:
+    if(file_id != H5I_INVALID_HID && H5I_dec_ref(file_id) < 0)
+        HDONE_ERROR(H5E_REFERENCE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file")
+    FUNC_LEAVE_API(ret_value)
+}   /* end H5Rcreate() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Rget_obj_type2
+ *
+ * Purpose: Given a reference to some object, this function returns the type
+ * of object pointed to.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Rget_obj_type2(hid_t id, H5R_type_t ref_type, const void *ref,
+    H5O_type_t *obj_type)
+{
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    haddr_t obj_addr;                   /* Object address */
+    const unsigned char *buf = (const unsigned char *)ref; /* Reference pointer */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE4("e", "iRt*x*Ot", id, ref_type, ref, obj_type);
+
+    /* Check args */
+    if(buf == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
+    if(ref_type != H5R_OBJECT1 && ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
+
+    /* Get the VOL object */
+    if(NULL == (vol_obj = H5VL_vol_object(id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
+
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Get object address */
+    if(H5R__decode_addr_compat(id, vol_obj_type, ref_type, buf, &obj_addr) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "unable to get object address")
+
+    /* Set location parameters */
+    loc_params.type = H5VL_OBJECT_BY_TOKEN;
+    loc_params.loc_data.loc_by_token.token = &obj_addr;
+    loc_params.obj_type = vol_obj_type;
+
+    /* Retrieve object's type */
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_OBJECT_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_type) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object type")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+}   /* end H5Rget_obj_type2() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Rdereference2
+ *
+ * Purpose: Given a reference to some object, open that object and return an
+ * ID for that object.
+ *
+ * Return:  Valid ID on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5Rdereference2(hid_t obj_id, hid_t oapl_id, H5R_type_t ref_type,
+    const void *ref)
+{
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    haddr_t obj_addr;                   /* Object address */
+    H5I_type_t opened_type;             /* Opened object type */
+    void *opened_obj = NULL;            /* Opened object */
+    const unsigned char *buf = (const unsigned char *)ref; /* Reference pointer */
+    hid_t ret_value = H5I_INVALID_HID;  /* Return value */
+
+    FUNC_ENTER_API(H5I_INVALID_HID)
+    H5TRACE4("i", "iiRt*x", obj_id, oapl_id, ref_type, ref);
+
+    /* Check args */
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a property list")
+    if(buf == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference pointer")
+    if(ref_type != H5R_OBJECT1 && ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference type")
+
+    /* Verify access property list and set up collective metadata if appropriate */
+    if(H5CX_set_apl(&oapl_id, H5P_CLS_DACC, obj_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
+
+    /* Get the VOL object */
+    if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid file identifier")
+
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
+
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(obj_id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Get object address */
+    if(H5R__decode_addr_compat(obj_id, vol_obj_type, ref_type, buf, &obj_addr) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, H5I_INVALID_HID, "unable to get object address")
+
+    /* Set location parameters */
+    loc_params.type = H5VL_OBJECT_BY_TOKEN;
+    loc_params.loc_data.loc_by_token.token = &obj_addr;
+    loc_params.obj_type = vol_obj_type;
+
+    /* Open object by address */
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj, &loc_params, &opened_type, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object by address")
+
+    /* Register object */
+    if((ret_value = H5VL_register(opened_type, opened_obj, vol_obj->connector, TRUE)) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to register object handle")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+}   /* end H5Rdereference2() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Rget_region
+ *
+ * Purpose: Given a reference to some object, creates a copy of the dataset
+ * pointed to's dataspace and defines a selection in the copy which is the
+ * region pointed to.
+ *
+ * Return:  Valid ID on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5Rget_region(hid_t id, H5R_type_t ref_type, const void *ref)
+{
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    void *vol_obj_file = NULL;          /* VOL file */
+    H5F_t *f = NULL;                    /* Native file */
+    size_t buf_size = H5R_DSET_REG_REF_BUF_SIZE;    /* Reference buffer size */
+    H5S_t *space = NULL;                /* Dataspace object */
+    hid_t file_id = H5I_INVALID_HID;    /* File ID for region reference */
+    const unsigned char *buf = (const unsigned char *)ref; /* Reference pointer */
+    hid_t ret_value;                    /* Return value */
+
+    FUNC_ENTER_API(H5I_INVALID_HID)
+    H5TRACE3("i", "iRt*x", id, ref_type, ref);
+
+    /* Check args */
+    if(buf == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference pointer")
+    if(ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid reference type")
+
+    /* Get the VOL object */
+    if(NULL == (vol_obj = H5VL_vol_object(id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid file identifier")
+
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
+
+    /* Get the file for the object */
+    if((file_id = H5F_get_file_id(id, vol_obj_type, FALSE)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a file or file object")
+
+    /* Retrieve VOL object */
+    if(NULL == (vol_obj_file = H5VL_vol_object(file_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Retrieve file from VOL object */
+    if(NULL == (f = (H5F_t *)H5VL_object_data(vol_obj_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid VOL object")
+
+    /* Get the dataspace with the correct region selected */
+    if(H5R__decode_addr_region_compat(f, buf, &buf_size, NULL, &space) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, H5I_INVALID_HID, "unable to get dataspace")
+
+    /* Atomize */
+    if((ret_value = H5I_register(H5I_DATASPACE, space, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to register dataspace atom")
+
+done:
+    if(file_id != H5I_INVALID_HID && H5I_dec_ref(file_id) < 0)
+        HDONE_ERROR(H5E_REFERENCE, H5E_CANTDEC, H5I_INVALID_HID, "unable to decrement refcount on file")
+    FUNC_LEAVE_API(ret_value)
+}   /* end H5Rget_region1() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Rget_name
+ *
+ * Purpose: Given a reference to some object, determine a path to the object
+ * referenced in the file.
+ *
+ * Return:  Non-negative length of the path on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+ssize_t
+H5Rget_name(hid_t id, H5R_type_t ref_type, const void *ref, char *name,
+    size_t size)
+{
+    H5VL_object_t *vol_obj = NULL;      /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    haddr_t obj_addr;                   /* Object address */
+    const unsigned char *buf = (const unsigned char *)ref; /* Reference pointer */
+    ssize_t ret_value = -1;  /* Return value */
+
+    FUNC_ENTER_API((-1))
+    H5TRACE5("Zs", "iRt*x*sz", id, ref_type, ref, name, size);
+
+    /* Check args */
+    if(buf == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "invalid reference pointer")
+    if(ref_type != H5R_OBJECT1 && ref_type != H5R_DATASET_REGION1)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "invalid reference type")
+
+    /* Get the VOL object */
+    if(NULL == (vol_obj = H5VL_vol_object(id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid file identifier")
+
+    /* Currently restrict API usage to native VOL
+     * TODO check for terminal connector or use capability flag */
+
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
+
+    /* Get object address */
+    if(H5R__decode_addr_compat(id, vol_obj_type, ref_type, buf, &obj_addr) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, (-1), "unable to get object address")
+
+    /* Set location parameters */
+    loc_params.type = H5VL_OBJECT_BY_TOKEN;
+    loc_params.loc_data.loc_by_token.token = &obj_addr;
+    loc_params.obj_type = vol_obj_type;
+
+    /* Retrieve object's name */
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_OBJECT_GET_NAME, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value, name, size) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, (-1), "can't retrieve object name")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+}   /* end H5Rget_name() */