[svn-r14286] Description:

	Add H5Ovisit() and H5Ovisit_by_name() API routines.


Tested on:
        FreeBSD/32 6.2 (duty) in debug mode
        FreeBSD/64 6.2 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (kagiso) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/default API=1.6.x, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Mac OS X/32 10.4.10 (amazon) in debug mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in production mode

5 files changed, 405 insertions, 6 deletions

diff --git a/src/H5G.c b/src/H5G.c
index 675b166..0fa2c1c 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -135,7 +135,7 @@ H5FL_DEFINE(H5G_t);
 H5FL_DEFINE(H5G_shared_t);
 
 /* Declare the free list to manage H5_obj_t's */
-H5FL_DEFINE_STATIC(H5_obj_t);
+H5FL_DEFINE(H5_obj_t);
 
 
 /* Private prototypes */
@@ -1933,7 +1933,7 @@ H5G_visit(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     udata.path_buf_size = 1;
     udata.curr_path_len = 0;
 
-    /* Create skip list to store reference path information */
+    /* Create skip list to store visited object information */
     if((udata.visited = H5SL_create(H5SL_TYPE_OBJ, 0.5, (size_t)16)) == NULL)
         HGOTO_ERROR(H5E_SYM, H5E_CANTCREATE, FAIL, "can't create skip list for visited objects")
 
diff --git a/src/H5Gpkg.h b/src/H5Gpkg.h
index 2d936a9..b2cef28 100644
--- a/src/H5Gpkg.h
+++ b/src/H5Gpkg.h
@@ -342,9 +342,6 @@ H5_DLL H5G_t *H5G_open_name(const H5G_loc_t *loc, const char *name,
 H5_DLL herr_t H5G_iterate(hid_t loc_id, const char *group_name,
     H5_index_t idx_type, H5_iter_order_t order, hsize_t skip, hsize_t *last_lnk,
     const H5G_link_iterate_t *lnk_op, void *op_data, hid_t lapl_id, hid_t dxpl_id);
-H5_DLL herr_t H5G_visit(hid_t loc_id, const char *group_name,
-    H5_index_t idx_type, H5_iter_order_t order, H5L_iterate_t op, void *op_data,
-    hid_t lapl_id, hid_t dxpl_id);
 
 /*
  * Group hierarchy traversal routines
diff --git a/src/H5Gprivate.h b/src/H5Gprivate.h
index 0ddb3e9..c54f11d 100644
--- a/src/H5Gprivate.h
+++ b/src/H5Gprivate.h
@@ -162,6 +162,9 @@ H5_DLL herr_t H5G_unmount(H5G_t *grp);
 #ifndef H5_NO_DEPRECATED_SYMBOLS
 H5_DLL H5G_obj_t H5G_map_obj_type(H5O_type_t obj_type);
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
+H5_DLL herr_t H5G_visit(hid_t loc_id, const char *group_name,
+    H5_index_t idx_type, H5_iter_order_t order, H5L_iterate_t op, void *op_data,
+    hid_t lapl_id, hid_t dxpl_id);
 
 /*
  * These functions operate on symbol table nodes.
diff --git a/src/H5O.c b/src/H5O.c
index 67aa960..70b6efe 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -57,6 +57,17 @@
 /* Local Typedefs */
 /******************/
 
+/* User data for recursive traversal over objects from a group */
+typedef struct {
+    hid_t       obj_id;         /* The ID for the starting group */
+    H5G_loc_t	*start_loc;     /* Location of starting group */
+    hid_t       lapl_id;        /* LAPL for walking across links */
+    hid_t       dxpl_id; 	/* DXPL for operations */
+    H5SL_t     *visited;        /* Skip list for tracking visited nodes */
+    H5O_iterate_t op;           /* Application callback */
+    void       *op_data;        /* Application's op data */
+} H5O_iter_visit_ud_t;
+
 
 /********************/
 /* Package Typedefs */
@@ -70,6 +81,9 @@
 static herr_t H5O_delete_oh(H5F_t *f, hid_t dxpl_id, H5O_t *oh);
 static const H5O_obj_class_t *H5O_obj_class(const H5O_loc_t *loc, hid_t dxpl_id);
 static herr_t H5O_obj_type_real(H5O_t *oh, H5O_type_t *obj_type);
+static herr_t H5O_visit(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, hid_t lapl_id,
+    hid_t dxpl_id);
 
 
 /*********************/
@@ -140,6 +154,9 @@ H5FL_BLK_DEFINE(chunk_image);
 /* Declare external the free list for time_t's */
 H5FL_EXTERN(time_t);
 
+/* Declare external the free list for H5_obj_t's */
+H5FL_EXTERN(H5_obj_t);
+
 
 /*******************/
 /* Local Variables */
@@ -827,6 +844,127 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Ovisit
+ *
+ * Purpose:	Recursively visit an object and all the objects reachable
+ *              from it.  If the starting object is a group, all the objects
+ *              linked to from that group will be visited.  Links within
+ *              each group are visited according to the order within the
+ *              specified index (unless the specified index does not exist for
+ *              a particular group, then the "name" index is used).
+ *
+ *              NOTE: Soft links and user-defined links are ignored during
+ *              this operation.
+ *
+ *              NOTE: Each _object_ reachable from the initial group will only
+ *              be visited once.  If multiple hard links point to the same
+ *              object, the first link to the object's path (according to the
+ *              iteration index and iteration order given) will be used to in
+ *              the callback about the object.
+ *
+ * Return:	Success:	The return value of the first operator that
+ *				returns non-zero, or zero if all members were
+ *				processed with no operator returning non-zero.
+ *
+ *		Failure:	Negative if something goes wrong within the
+ *				library, or the negative value returned by one
+ *				of the operators.
+ *
+ * Programmer:	Quincey Koziol
+ *		November 25 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Ovisit(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
+    H5O_iterate_t op, void *op_data)
+{
+    herr_t      ret_value;              /* Return value */
+
+    FUNC_ENTER_API(H5Ovisit, FAIL)
+
+    /* Check args */
+    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)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+    if(!op)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no callback operator specified")
+
+    /* Call internal object visitation routine */
+    if((ret_value = H5O_visit(obj_id, ".", idx_type, order, op, op_data, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_dxpl_id)) < 0)
+	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "object visitation failed")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Ovisit() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Ovisit_by_name
+ *
+ * Purpose:	Recursively visit an object and all the objects reachable
+ *              from it.  If the starting object is a group, all the objects
+ *              linked to from that group will be visited.  Links within
+ *              each group are visited according to the order within the
+ *              specified index (unless the specified index does not exist for
+ *              a particular group, then the "name" index is used).
+ *
+ *              NOTE: Soft links and user-defined links are ignored during
+ *              this operation.
+ *
+ *              NOTE: Each _object_ reachable from the initial group will only
+ *              be visited once.  If multiple hard links point to the same
+ *              object, the first link to the object's path (according to the
+ *              iteration index and iteration order given) will be used to in
+ *              the callback about the object.
+ *
+ * Return:	Success:	The return value of the first operator that
+ *				returns non-zero, or zero if all members were
+ *				processed with no operator returning non-zero.
+ *
+ *		Failure:	Negative if something goes wrong within the
+ *				library, or the negative value returned by one
+ *				of the operators.
+ *
+ * Programmer:	Quincey Koziol
+ *		November 24 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Ovisit_by_name(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, hid_t lapl_id)
+{
+    herr_t      ret_value;              /* Return value */
+
+    FUNC_ENTER_API(H5Ovisit_by_name, FAIL)
+
+    /* Check args */
+    if(!obj_name || !*obj_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    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)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+    if(!op)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no callback operator specified")
+    if(H5P_DEFAULT == lapl_id)
+        lapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
+
+    /* Call internal object visitation routine */
+    if((ret_value = H5O_visit(loc_id, obj_name, idx_type, order, op, op_data, lapl_id, H5AC_ind_dxpl_id)) < 0)
+	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "object visitation failed")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Ovisit_by_name() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Oclose
  *
  * Purpose:	Close an open file object.
@@ -1124,7 +1262,7 @@ H5O_open_name(H5G_loc_t *loc, const char *name, hid_t lapl_id)
     loc_found = TRUE;
 
     /* Open the object */
-    if((ret_value = H5O_open_by_loc(&obj_loc, H5AC_dxpl_id)) < 0)
+    if((ret_value = H5O_open_by_loc(&obj_loc, H5AC_ind_dxpl_id)) < 0)
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open object")
 
 done:
@@ -2456,3 +2594,255 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_get_rc_and_type() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_free_visit_visited
+ *
+ * Purpose:     Free the key for an object visited during a group traversal
+ *
+ * Return:      Non-negative on success, negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *	        Nov 25, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_free_visit_visited(void *item, void UNUSED *key, void UNUSED *operator_data/*in,out*/)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_free_visit_visited)
+
+    H5FL_FREE(H5_obj_t, item);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5O_free_visit_visited() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_visit_cb
+ *
+ * Purpose:     Callback function for recursively visiting objects from a group
+ *
+ * Return:	Success:        Non-negative
+ *		Failure:	Negative
+ *
+ * Programmer:	Quincey Koziol
+ *	        Nov 25, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_visit_cb(hid_t UNUSED group, const char *name, const H5L_info_t *linfo,
+    void *_udata)
+{
+    H5O_iter_visit_ud_t *udata = (H5O_iter_visit_ud_t *)_udata;     /* User data for callback */
+    H5G_loc_t   obj_loc;                /* Location of object */
+    H5G_name_t  obj_path;            	/* Object's group hier. path */
+    H5O_loc_t   obj_oloc;            	/* Object's object location */
+    hbool_t     obj_found = FALSE;      /* Object at 'name' found */
+    herr_t ret_value = H5_ITER_CONT;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_visit_cb)
+
+    /* Sanity check */
+    HDassert(name);
+    HDassert(linfo);
+    HDassert(udata);
+
+    /* Check if this is a hard link */
+    if(linfo->type == H5L_TYPE_HARD) {
+        H5_obj_t obj_pos;       /* Object "position" for this object */
+
+        /* Set up opened group location to fill in */
+        obj_loc.oloc = &obj_oloc;
+        obj_loc.path = &obj_path;
+        H5G_loc_reset(&obj_loc);
+
+        /* Find the object using the LAPL passed in */
+        /* (Correctly handles mounted files) */
+        if(H5G_loc_find(udata->start_loc, name, &obj_loc/*out*/, udata->lapl_id, udata->dxpl_id) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, H5_ITER_ERROR, "object not found")
+        obj_found = TRUE;
+
+        /* Construct unique "position" for this object */
+        H5F_GET_FILENO(obj_oloc.file, obj_pos.fileno);
+        obj_pos.addr = obj_oloc.addr;
+
+        /* Check if we've seen the object the link references before */
+        if(NULL == H5SL_search(udata->visited, &obj_pos)) {
+            H5O_info_t oinfo;           /* Object info */
+
+            /* Get the object's info */
+            if(H5O_get_info(&obj_oloc, udata->dxpl_id, TRUE, &oinfo) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, H5_ITER_ERROR, "unable to get object info")
+
+            /* Make the application callback */
+            ret_value = (udata->op)(udata->obj_id, name, &oinfo, udata->op_data);
+
+            /* Check for continuing to visit objects */
+            if(ret_value == H5_ITER_CONT) {
+                /* If its ref count is > 1, we add it to the list of visited objects */
+                /* (because it could come up again during traversal) */
+                if(oinfo.rc > 1) {
+                    H5_obj_t *new_node;                  /* New object node for visited list */
+
+                    /* Allocate new object "position" node */
+                    if((new_node = H5FL_MALLOC(H5_obj_t)) == NULL)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, H5_ITER_ERROR, "can't allocate object node")
+
+                    /* Set node information */
+                    *new_node = obj_pos;
+
+                    /* Add to list of visited objects */
+                    if(H5SL_insert(udata->visited, new_node, new_node) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTINSERT, H5_ITER_ERROR, "can't insert object node into visited list")
+                } /* end if */
+            } /* end if */
+        } /* end if */
+    } /* end if */
+
+done:
+    /* Release resources */
+    if(obj_found && H5G_loc_free(&obj_loc) < 0)
+        HDONE_ERROR(H5E_OHDR, H5E_CANTRELEASE, H5_ITER_ERROR, "can't free location")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_visit_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_visit
+ *
+ * Purpose:	Recursively visit an object and all the objects reachable
+ *              from it.  If the starting object is a group, all the objects
+ *              linked to from that group will be visited.  Links within
+ *              each group are visited according to the order within the
+ *              specified index (unless the specified index does not exist for
+ *              a particular group, then the "name" index is used).
+ *
+ *              NOTE: Soft links and user-defined links are ignored during
+ *              this operation.
+ *
+ *              NOTE: Each _object_ reachable from the initial group will only
+ *              be visited once.  If multiple hard links point to the same
+ *              object, the first link to the object's path (according to the
+ *              iteration index and iteration order given) will be used to in
+ *              the callback about the object.
+ *
+ * Return:	Success:	The return value of the first operator that
+ *				returns non-zero, or zero if all members were
+ *				processed with no operator returning non-zero.
+ *
+ *		Failure:	Negative if something goes wrong within the
+ *				library, or the negative value returned by one
+ *				of the operators.
+ *
+ * Programmer:	Quincey Koziol
+ *		November 24 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_visit(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, hid_t lapl_id,
+    hid_t dxpl_id)
+{
+    H5O_iter_visit_ud_t udata;  /* User data for callback */
+    H5G_loc_t	loc;            /* Location of reference object */
+    H5G_loc_t   obj_loc;        /* Location used to open object */
+    H5G_name_t  obj_path;       /* Opened object group hier. path */
+    H5O_loc_t   obj_oloc;       /* Opened object object location */
+    hbool_t     loc_found = FALSE;      /* Entry at 'name' found */
+    H5O_info_t  oinfo;          /* Object info struct */
+    hid_t       obj_id = (-1);  /* ID of object */
+    herr_t      ret_value;      /* Return value */
+
+    FUNC_ENTER_NOAPI(H5O_visit, FAIL)
+
+    /* Portably initialize user data struct to zeros */
+    HDmemset(&udata, 0, sizeof(udata));
+
+    /* Check args */
+    if(H5G_loc(loc_id, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+
+    /* Set up opened group location to fill in */
+    obj_loc.oloc = &obj_oloc;
+    obj_loc.path = &obj_path;
+    H5G_loc_reset(&obj_loc);
+
+    /* Find the object's location */
+    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    loc_found = TRUE;
+
+    /* Get the object's info */
+    if(H5O_get_info(&obj_oloc, dxpl_id, TRUE, &oinfo) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get object info")
+
+    /* Open the object */
+    /* (Takes ownership of the obj_loc information) */
+    if((obj_id = H5O_open_by_loc(&obj_loc, dxpl_id)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
+
+    /* Make callback for starting object */
+    if((ret_value = op(obj_id, ".", &oinfo, op_data)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "can't visit objects")
+
+    /* Check for object being a group */
+    if(oinfo.type == H5O_TYPE_GROUP) {
+        H5G_loc_t	start_loc;          /* Location of starting group */
+
+        /* Get the location of the starting group */
+        if(H5G_loc(obj_id, &start_loc) < 0)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+
+        /* Set up user data for visiting links */
+        udata.obj_id = obj_id;
+        udata.start_loc = &start_loc;
+        udata.lapl_id = lapl_id;
+        udata.dxpl_id = dxpl_id;
+        udata.op = op;
+        udata.op_data = op_data;
+        
+        /* Create skip list to store visited object information */
+        if((udata.visited = H5SL_create(H5SL_TYPE_OBJ, 0.5, (size_t)16)) == NULL)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTCREATE, FAIL, "can't create skip list for visited objects")
+
+        /* If its ref count is > 1, we add it to the list of visited objects */
+        /* (because it could come up again during traversal) */
+        if(oinfo.rc > 1) {
+            H5_obj_t *obj_pos;                  /* New object node for visited list */
+
+            /* Allocate new object "position" node */
+            if((obj_pos = H5FL_MALLOC(H5_obj_t)) == NULL)
+                HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, FAIL, "can't allocate object node")
+
+            /* Construct unique "position" for this object */
+            obj_pos->fileno = oinfo.fileno;
+            obj_pos->addr = oinfo.addr;
+
+            /* Add to list of visited objects */
+            if(H5SL_insert(udata.visited, obj_pos, obj_pos) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTINSERT, FAIL, "can't insert object node into visited list")
+        } /* end if */
+
+        /* Call internal group visitation routine */
+        if((ret_value = H5G_visit(obj_id, ".", idx_type, order, H5O_visit_cb, &udata, lapl_id, dxpl_id)) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
+    } /* end if */
+
+done:
+    if(obj_id > 0) {
+        if(H5I_dec_ref(obj_id) < 0)
+            HDONE_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "unable to close object")
+    } /* end if */
+    else if(loc_found && H5G_loc_free(&obj_loc) < 0)
+        HDONE_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
+    if(udata.visited)
+        H5SL_destroy(udata.visited, H5O_free_visit_visited, NULL);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_visit() */
+
+
diff --git a/src/H5Opublic.h b/src/H5Opublic.h
index 6ddd565..64fdd07 100644
--- a/src/H5Opublic.h
+++ b/src/H5Opublic.h
@@ -124,6 +124,10 @@ typedef struct H5O_info_t {
 /* Typedef for message creation indexes */
 typedef uint32_t H5O_msg_crt_idx_t;
 
+/* Prototype for H5Ovisit/H5Ovisit_by_name() operator */
+typedef herr_t (*H5O_iterate_t)(hid_t obj, const char *name, const H5O_info_t *info,
+    void *op_data);
+
 
 /********************/
 /* Public Variables */
@@ -159,6 +163,11 @@ H5_DLL herr_t H5Oset_comment_by_name(hid_t loc_id, const char *name,
 H5_DLL ssize_t H5Oget_comment(hid_t obj_id, char *comment, size_t bufsize);
 H5_DLL ssize_t H5Oget_comment_by_name(hid_t loc_id, const char *name,
     char *comment, size_t bufsize, hid_t lapl_id);
+H5_DLL herr_t H5Ovisit(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
+    H5O_iterate_t op, void *op_data);
+H5_DLL herr_t H5Ovisit_by_name(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, hid_t lapl_id);
 H5_DLL herr_t H5Oclose(hid_t object_id);
 
 /* Symbols defined for compatibility with previous versions of the HDF5 API.