Split internal H5R functionality into H5Rint.c.

1 files changed, 767 insertions, 0 deletions

diff --git a/src/H5Rint.c b/src/H5Rint.c
new file mode 100644
index 0000000..716a573
--- /dev/null
+++ b/src/H5Rint.c
@@ -0,0 +1,767 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#include "H5Rmodule.h"          /* This source code file is part of the H5R module */
+
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5ACprivate.h"        /* Metadata cache                           */
+#include "H5Dprivate.h"         /* Datasets                                 */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5HGprivate.h"        /* Global Heaps                             */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5MMprivate.h"        /* Memory management                        */
+#include "H5Oprivate.h"         /* Object headers                           */
+#include "H5Rpkg.h"             /* References                               */
+#include "H5Sprivate.h"         /* Dataspaces                               */
+#include "H5Tprivate.h"         /* Datatypes                                */
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+/* Package initialization variable */
+hbool_t H5_PKG_INIT_VAR = FALSE;
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+/* Reference ID class
+ *
+ * NOTE: H5I_REFERENCE is not used by the library and has been deprecated
+ *       with a tentative removal version of 1.12.0. (DER, July 2017)
+ */
+static const H5I_class_t H5I_REFERENCE_CLS[1] = {{
+    H5I_REFERENCE,          /* ID class value                                       */
+    0,                      /* Class flags                                          */
+    0,                      /* # of reserved IDs for class                          */
+    NULL                    /* Callback routine for closing objects of this class   */
+}};
+
+/* Flag indicating "top" of interface has been initialized */
+static hbool_t H5R_top_package_initialize_s = FALSE;
+
+
+/*--------------------------------------------------------------------------
+NAME
+   H5R__init_package -- Initialize interface-specific information
+USAGE
+    herr_t H5R__init_package()
+
+RETURNS
+    Non-negative on success/Negative on failure
+DESCRIPTION
+    Initializes any interface-specific data or routines.
+
+--------------------------------------------------------------------------*/
+herr_t
+H5R__init_package(void)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Initialize the atom group for the file IDs */
+    if (H5I_register_type(H5I_REFERENCE_CLS) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to initialize interface")
+
+    /* Mark "top" of interface as initialized, too */
+    H5R_top_package_initialize_s = TRUE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5R__init_package() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_top_term_package
+ PURPOSE
+    Terminate various H5R objects
+ USAGE
+    void H5R_top_term_package()
+ RETURNS
+    void
+ DESCRIPTION
+    Release IDs for the atom group, deferring full interface shutdown
+    until later (in H5R_term_package).
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+     Can't report errors...
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+int
+H5R_top_term_package(void)
+{
+    int	n = 0;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    if (H5R_top_package_initialize_s) {
+        if (H5I_nmembers(H5I_REFERENCE) > 0) {
+            (void)H5I_clear_type(H5I_REFERENCE, FALSE, FALSE);
+            n++;
+	    }
+
+        /* Mark closed */
+        if (0 == n)
+            H5R_top_package_initialize_s = FALSE;
+    }
+
+    FUNC_LEAVE_NOAPI(n)
+} /* end H5R_top_term_package() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_term_package
+ PURPOSE
+    Terminate various H5R objects
+ USAGE
+    void H5R_term_package()
+ RETURNS
+    void
+ DESCRIPTION
+    Release the atom group and any other resources allocated.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+     Can't report errors...
+
+     Finishes shutting down the interface, after H5R_top_term_package()
+     is called
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+int
+H5R_term_package(void)
+{
+    int	n = 0;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    if (H5_PKG_INIT_VAR) {
+        /* Sanity checks */
+        HDassert(0 == H5I_nmembers(H5I_REFERENCE));
+        HDassert(FALSE == H5R_top_package_initialize_s);
+
+        /* Destroy the reference id group */
+        n += (H5I_dec_type_ref(H5I_REFERENCE) > 0);
+
+        /* Mark closed */
+        if (0 == n)
+            H5_PKG_INIT_VAR = FALSE;
+    }
+
+    FUNC_LEAVE_NOAPI(n)
+} /* end H5R_term_package() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_create
+ PURPOSE
+    Creates a particular kind of reference for the user
+ USAGE
+    herr_t H5R_create(ref, loc, name, ref_type, space)
+        void *ref;          OUT: Reference created
+        H5G_loc_t *loc;     IN: File location used to locate object pointed to
+        const char *name;   IN: Name of object at location LOC_ID of object
+                                    pointed to
+        H5R_type_t ref_type;    IN: Type of reference to create
+        H5S_t *space;       IN: Dataspace ID with selection, used for Dataset
+                                    Region references.
+
+ RETURNS
+    Non-negative on success/Negative on failure
+ DESCRIPTION
+    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).
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5R_create(void *_ref, H5G_loc_t *loc, const char *name, H5R_type_t ref_type, H5S_t *space, hid_t dxpl_id)
+{
+    H5G_loc_t	obj_loc;		/* Group hier. location of object */
+    H5G_name_t  path;            	/* Object group hier. path */
+    H5O_loc_t   oloc;            	/* Object object location */
+    hbool_t     obj_found = FALSE;      /* Object location found */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(_ref);
+    HDassert(loc);
+    HDassert(name);
+    HDassert(ref_type > H5R_BADTYPE && ref_type < H5R_MAXTYPE);
+
+    /* Set up object location to fill in */
+    obj_loc.oloc = &oloc;
+    obj_loc.path = &path;
+    H5G_loc_reset(&obj_loc);
+
+    /* Find the object */
+    if (H5G_loc_find(loc, name, &obj_loc, H5P_DEFAULT, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_NOTFOUND, FAIL, "object not found")
+    obj_found = TRUE;
+
+    switch (ref_type) {
+        case H5R_OBJECT:
+        {
+            hobj_ref_t *ref = (hobj_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+
+            *ref = obj_loc.oloc->addr;
+            break;
+        }
+
+        case H5R_DATASET_REGION:
+        {
+            H5HG_t hobjid;      /* Heap object ID */
+            hdset_reg_ref_t *ref = (hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+            hssize_t buf_size;  /* Size of buffer needed to serialize selection */
+            uint8_t *p;       /* Pointer to OID to store */
+            uint8_t *buf;     /* Buffer to store serialized selection in */
+            unsigned heapid_found;  /* Flag for non-zero heap ID found */
+            unsigned u;        /* local index */
+
+            /* Set up information for dataset region */
+
+            /* Return any previous heap block to the free list if we are
+             * garbage collecting
+             */
+            if (H5F_GC_REF(loc->oloc->file)) {
+                /* Check for an existing heap ID in the reference */
+                for (u = 0, heapid_found = 0, p = (uint8_t *)ref; u < H5R_DSET_REG_REF_BUF_SIZE; u++)
+                    if (p[u] != 0) {
+                        heapid_found = 1;
+                        break;
+                    }
+
+                if (heapid_found != 0) {
+                    /* Return heap block to free list */
+                }
+            }
+
+            /* Zero the heap ID out, may leak heap space if user is re-using
+             * reference and doesn't have garbage collection turned on
+             */
+            HDmemset(ref, 0, H5R_DSET_REG_REF_BUF_SIZE);
+
+            /* Get the amount of space required to serialize the selection */
+            if ((buf_size = H5S_SELECT_SERIAL_SIZE(space)) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "Invalid amount of space for serializing selection")
+
+            /* Increase buffer size to allow for the dataset OID */
+            buf_size += (hssize_t)sizeof(haddr_t);
+
+            /* Allocate the space to store the serialized information */
+            H5_CHECK_OVERFLOW(buf_size, hssize_t, size_t);
+            if (NULL == (buf = (uint8_t *)H5MM_malloc((size_t)buf_size)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+            /* Serialize information for dataset OID into heap buffer */
+            p = (uint8_t *)buf;
+            H5F_addr_encode(loc->oloc->file, &p, obj_loc.oloc->addr);
+
+            /* Serialize the selection into heap buffer */
+            if (H5S_SELECT_SERIALIZE(space, &p) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "Unable to serialize selection")
+
+            /* Save the serialized buffer for later */
+            H5_CHECK_OVERFLOW(buf_size, hssize_t, size_t);
+            if (H5HG_insert(loc->oloc->file, dxpl_id, (size_t)buf_size, buf, &hobjid) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_WRITEERROR, FAIL, "Unable to serialize selection")
+
+            /* Serialize the heap ID and index for storage in the file */
+            p = (uint8_t *)ref;
+            H5F_addr_encode(loc->oloc->file, &p, hobjid.addr);
+            UINT32ENCODE(p, hobjid.idx);
+
+            /* Free the buffer we serialized data in */
+            H5MM_xfree(buf);
+            break;
+        } /* end case H5R_DATASET_REGION */
+
+        case H5R_BADTYPE:
+        case H5R_MAXTYPE:
+        default:
+            HDassert("unknown reference type" && 0);
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
+    } /* end switch */
+
+done:
+    if (obj_found)
+        H5G_loc_free(&obj_loc);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5R_create() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_dereference
+ PURPOSE
+    Opens the HDF5 object referenced.
+ USAGE
+    hid_t H5R_dereference(ref)
+        H5F_t *file;        IN: File the object being dereferenced is within
+        H5R_type_t ref_type;    IN: Type of reference
+        void *ref;          IN: Reference to open.
+
+ RETURNS
+    Valid ID on success, Negative on failure
+ DESCRIPTION
+    Given a reference to some object, open that object and return an ID for
+    that object.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    Currently only set up to work with references to datasets
+ EXAMPLES
+ REVISION LOG
+    Raymond Lu
+    13 July 2011
+    I added the OAPL_ID parameter for the object being referenced.  It only
+    supports dataset access property list currently.
+
+    M. Scot Breitenfeld
+    3 March 2015
+    Added a check for undefined reference pointer.
+--------------------------------------------------------------------------*/
+hid_t
+H5R_dereference(H5F_t *file, hid_t oapl_id, hid_t dxpl_id, H5R_type_t ref_type, const void *_ref, hbool_t app_ref)
+{
+    H5O_loc_t oloc;             /* Object location */
+    H5G_name_t path;            /* Path of object */
+    H5G_loc_t loc;              /* Group location */
+    unsigned rc;		/* Reference count of object */
+    H5O_type_t obj_type;        /* Type of object */
+    hid_t ret_value = H5I_INVALID_HID;  /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(_ref);
+    HDassert(ref_type > H5R_BADTYPE && ref_type < H5R_MAXTYPE);
+    HDassert(file);
+
+    /* Initialize the object location */
+    H5O_loc_reset(&oloc);
+    oloc.file = file;
+
+    switch (ref_type) {
+        case H5R_OBJECT:
+        {
+            oloc.addr = *(const hobj_ref_t *)_ref; /* Only object references currently supported */
+            if (!H5F_addr_defined(oloc.addr) || oloc.addr == 0)
+                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Undefined reference pointer")
+            break;
+        }
+
+        case H5R_DATASET_REGION:
+        {
+            H5HG_t hobjid;  /* Heap object ID */
+            uint8_t *buf;   /* Buffer to store serialized selection in */
+            const uint8_t *p;           /* Pointer to OID to store */
+
+            /* Get the heap ID for the dataset region */
+            p = (const uint8_t *)_ref;
+            H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
+            UINT32DECODE(p, hobjid.idx);
+
+            if (!H5F_addr_defined(hobjid.addr) || hobjid.addr == 0)
+                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Undefined reference pointer")
+
+            /* Get the dataset region from the heap (allocate inside routine) */
+            if (NULL == (buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)))
+                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")
+
+            /* Get the object oid for the dataset */
+            p = buf;
+            H5F_addr_decode(oloc.file, &p, &(oloc.addr));
+
+            /* Free the buffer allocated in H5HG_read() */
+            H5MM_xfree(buf);
+            break;
+        } /* end case H5R_DATASET_REGION */
+
+        case H5R_BADTYPE:
+        case H5R_MAXTYPE:
+        default:
+            HDassert("unknown reference type" && 0);
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
+    } /* end switch */
+
+    /* Get the # of links for object, and its type
+     * (To check to make certain that this object hasn't been deleted
+     *  since the reference was created)
+     */
+    if (H5O_get_rc_and_type(&oloc, dxpl_id, &rc, &obj_type) < 0 || 0 == rc)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object")
+
+    /* Construct a group location for opening the object */
+    H5G_name_reset(&path);
+    loc.oloc = &oloc;
+    loc.path = &path;
+
+    /* Open the object */
+    switch (obj_type) {
+        case H5O_TYPE_GROUP:
+        {
+            H5G_t *group;               /* Pointer to group to open */
+
+            if (NULL == (group = H5G_open(&loc, dxpl_id)))
+                HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "not found")
+
+            /* Create an atom for the group */
+            if ((ret_value = H5I_register(H5I_GROUP, group, app_ref)) < 0) {
+                H5G_close(group);
+                HGOTO_ERROR(H5E_SYM, H5E_CANTREGISTER, FAIL, "can't register group")
+            }
+
+            break;
+        }
+
+        case H5O_TYPE_NAMED_DATATYPE:
+        {
+            H5T_t *type;                /* Pointer to datatype to open */
+
+            if (NULL == (type = H5T_open(&loc, dxpl_id)))
+                HGOTO_ERROR(H5E_DATATYPE, H5E_NOTFOUND, FAIL, "not found")
+
+            /* Create an atom for the datatype */
+            if ((ret_value = H5I_register(H5I_DATATYPE, type, app_ref)) < 0) {
+                H5T_close(type);
+                HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREGISTER, FAIL, "can't register datatype")
+            }
+
+            break;
+        }
+
+        case H5O_TYPE_DATASET:
+        {
+            H5D_t *dset;                /* Pointer to dataset to open */
+
+            /* Open the dataset */
+            if (NULL == (dset = H5D_open(&loc, oapl_id, dxpl_id)))
+                HGOTO_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found")
+
+            /* Create an atom for the dataset */
+            if ((ret_value = H5I_register(H5I_DATASET, dset, app_ref)) < 0) {
+                H5D_close(dset);
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL, "can't register dataset")
+            }
+
+            break;
+        }
+
+        case H5O_TYPE_UNKNOWN:
+        case H5O_TYPE_NTYPES:
+        default:
+            HGOTO_ERROR(H5E_REFERENCE, H5E_BADTYPE, FAIL, "can't identify type of object referenced")
+     } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5R_dereference() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_get_region
+ PURPOSE
+    Retrieves a dataspace with the region pointed to selected.
+ USAGE
+    H5S_t *H5R_get_region(file, ref_type, ref)
+        H5F_t *file;        IN: File the object being dereferenced is within
+        void *ref;          IN: Reference to open.
+
+ RETURNS
+    Pointer to the dataspace on success, NULL on failure
+ DESCRIPTION
+    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.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+H5S_t *
+H5R_get_region(H5F_t *file, hid_t dxpl_id, const void *_ref)
+{
+    H5O_loc_t oloc;             /* Object location */
+    const uint8_t *p;           /* Pointer to OID to store */
+    H5HG_t hobjid;              /* Heap object ID */
+    uint8_t *buf = NULL;        /* Buffer to store serialized selection in */
+    H5S_t *ret_value;
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(_ref);
+    HDassert(file);
+
+    /* Initialize the object location */
+    H5O_loc_reset(&oloc);
+    oloc.file = file;
+
+    /* Get the heap ID for the dataset region */
+    p = (const uint8_t *)_ref;
+    H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
+    UINT32DECODE(p, hobjid.idx);
+
+    /* Get the dataset region from the heap (allocate inside routine) */
+    if ((buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)) == NULL)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, NULL, "Unable to read dataset region information")
+
+    /* Get the object oid for the dataset */
+    p = buf;
+    H5F_addr_decode(oloc.file, &p, &(oloc.addr));
+
+    /* Open and copy the dataset's dataspace */
+    if ((ret_value = H5S_read(&oloc, dxpl_id)) == NULL)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_NOTFOUND, NULL, "not found")
+
+    /* Unserialize the selection */
+    if (H5S_SELECT_DESERIALIZE(&ret_value, &p) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, NULL, "can't deserialize selection")
+
+done:
+    /* Free the buffer allocated in H5HG_read() */
+    if (buf)
+        H5MM_xfree(buf);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5R_get_region() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_get_obj_type
+ PURPOSE
+    Retrieves the type of object that an object reference points to
+ USAGE
+    H5O_type_t H5R_get_obj_type(file, ref_type, ref)
+        H5F_t *file;        IN: File the object being dereferenced is within
+        H5R_type_t ref_type;    IN: Type of reference to query
+        void *ref;          IN: Reference to query.
+
+ RETURNS
+    Success:	An object type defined in H5Gpublic.h
+    Failure:	H5G_UNKNOWN
+ DESCRIPTION
+    Given a reference to some object, this function returns the type of object
+    pointed to.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5R_get_obj_type(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type,
+    const void *_ref, H5O_type_t *obj_type)
+{
+    H5O_loc_t oloc;             /* Object location */
+    unsigned rc;		/* Reference count of object    */
+    herr_t ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(file);
+    HDassert(_ref);
+
+    /* Initialize the symbol table entry */
+    H5O_loc_reset(&oloc);
+    oloc.file = file;
+
+    switch (ref_type) {
+        case H5R_OBJECT:
+        {
+            /* Get the object oid */
+            oloc.addr = *(const hobj_ref_t *)_ref; /* Only object references currently supported */
+            break;
+        }
+
+        case H5R_DATASET_REGION:
+        {
+            H5HG_t hobjid;      /* Heap object ID */
+            const uint8_t *p;   /* Pointer to reference to decode */
+            uint8_t *buf;       /* Buffer to store serialized selection in */
+
+            /* Get the heap ID for the dataset region */
+            p = (const uint8_t *)_ref;
+            H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
+            UINT32DECODE(p, hobjid.idx);
+
+            /* Get the dataset region from the heap (allocate inside routine) */
+            if ((buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)) == NULL)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")
+
+            /* Get the object oid for the dataset */
+            p = buf;
+            H5F_addr_decode(oloc.file, &p, &(oloc.addr));
+
+            /* Free the buffer allocated in H5HG_read() */
+            H5MM_xfree(buf);
+
+            break;
+        }
+
+        case H5R_BADTYPE:
+        case H5R_MAXTYPE:
+        default:
+            HDassert("unknown reference type" && 0);
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
+    } /* end switch */
+
+    /* Get the # of links for object, and its type */
+    /* (To check to make certain that this object hasn't been deleted since the reference was created) */
+    if (H5O_get_rc_and_type(&oloc, dxpl_id, &rc, obj_type) < 0 || 0 == rc)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5R_get_obj_type() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5R_get_name
+ PURPOSE
+    Internal routine to determine a name for the object referenced
+ USAGE
+    ssize_t H5R_get_name(f, dxpl_id, ref_type, ref, name, size)
+        H5F_t *f;       IN: Pointer to the file that the reference is pointing
+                            into
+        hid_t lapl_id;  IN: LAPL to use for operation
+        hid_t dxpl_id;  IN: DXPL to use for operation
+        hid_t id;       IN: Location ID given for reference
+        H5R_type_t ref_type;    IN: Type of reference
+        void *ref;      IN: Reference to query.
+        char *name;     OUT: Buffer to place name of object referenced
+        size_t size;    IN: Size of name buffer
+
+ RETURNS
+    Non-negative length of the path on success, Negative on failure
+ DESCRIPTION
+    Given a reference to some object, determine a path to the object
+    referenced in the file.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    This may not be the only path to that object.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+ssize_t
+H5R_get_name(H5F_t *f, hid_t lapl_id, hid_t dxpl_id, hid_t id, H5R_type_t ref_type,
+    const void *_ref, char *name, size_t size)
+{
+    hid_t file_id = H5I_INVALID_HID;    /* ID for file that the reference is in */
+    H5O_loc_t oloc;             /* Object location describing object for reference */
+    ssize_t ret_value = -1;     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check args */
+    HDassert(f);
+    HDassert(_ref);
+
+    /* Initialize the object location */
+    H5O_loc_reset(&oloc);
+    oloc.file = f;
+
+    /* Get address for reference */
+    switch (ref_type) {
+        case H5R_OBJECT:
+        {
+            oloc.addr = *(const hobj_ref_t *)_ref;
+            break;
+        }
+
+        case H5R_DATASET_REGION:
+        {
+            H5HG_t hobjid;  /* Heap object ID */
+            uint8_t *buf;   /* Buffer to store serialized selection in */
+            const uint8_t *p;           /* Pointer to OID to store */
+
+            /* Get the heap ID for the dataset region */
+            p = (const uint8_t *)_ref;
+            H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
+            UINT32DECODE(p, hobjid.idx);
+
+            /* Get the dataset region from the heap (allocate inside routine) */
+            if ((buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)) == NULL)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")
+
+            /* Get the object oid for the dataset */
+            p = buf;
+            H5F_addr_decode(oloc.file, &p, &(oloc.addr));
+
+            /* Free the buffer allocated in H5HG_read() */
+            H5MM_xfree(buf);
+
+            break;
+        }
+
+        case H5R_BADTYPE:
+        case H5R_MAXTYPE:
+        default:
+            HDassert("unknown reference type" && 0);
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
+    } /* end switch */
+
+    /* Retrieve file ID for name search */
+    if ((file_id = H5I_get_file_id(id, FALSE)) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't retrieve file ID")
+
+    /* Get name, length, etc. */
+    if ((ret_value = H5G_get_name_by_addr(file_id, lapl_id, dxpl_id, &oloc, name, size)) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't determine name")
+
+done:
+    /* Close file ID used for search */
+    if (file_id > 0 && H5I_dec_ref(file_id) < 0)
+        HDONE_ERROR(H5E_REFERENCE, H5E_CANTDEC, FAIL, "can't decrement ref count of temp ID")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5R_get_name() */
+