[svn-r6136]

Purpose:
    new functions
Description:
    H5Gget_num_objs, H5Gget_objname_by_idx and H5Gget_objtype_by_idx.
Platforms tested:
    modi4, arabica, eirene
Misc. update:
    RELEASE.txt updated.

9 files changed, 481 insertions, 37 deletions

diff --git a/src/H5B.c b/src/H5B.c
index 4d1c328..700cf3f 100644
--- a/src/H5B.c
+++ b/src/H5B.c
@@ -1473,9 +1473,10 @@ H5B_iterate (H5F_t *f, const H5B_class_t *type, H5B_operator_t op, haddr_t addr,
     haddr_t		cur_addr = HADDR_UNDEF;
     haddr_t		*child = NULL;
     uint8_t		*key = NULL;
-    int		i, nchildren;
+    int		        i, nchildren;
     herr_t		ret_value = SUCCEED;
-
+    H5B_iterate_t       ret_flag = H5B_ITER_CONT;
+    
     FUNC_ENTER_NOAPI(H5B_iterate, FAIL);
 
     /*
@@ -1526,11 +1527,16 @@ H5B_iterate (H5F_t *f, const H5B_class_t *type, H5B_operator_t op, haddr_t addr,
 	     * Perform the iteration operator, which might invoke an
 	     * application callback.
 	     */
-	    for (i=0; i<nchildren && !ret_value; i++) {
-		ret_value = (*op)(f, key+i*type->sizeof_nkey,
+	    for (i=0; i<nchildren && ret_flag==H5B_ITER_CONT; i++) {
+		ret_flag = (*op)(f, key+i*type->sizeof_nkey,
                          child[i], key+(i+1)*type->sizeof_nkey, udata);
-		if (ret_value<0)
+		if (ret_flag==H5B_ITER_ERROR) {
 		    HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "iterator function failed");
+                } else if(ret_flag==H5B_ITER_STOP) {
+                    HGOTO_DONE(SUCCEED);
+                } else {
+                    ;
+                }
 	    } /* end for */
 	} /* end for */
     } /* end else */
diff --git a/src/H5Bprivate.h b/src/H5Bprivate.h
index 9f2937c..3a59d93 100644
--- a/src/H5Bprivate.h
+++ b/src/H5Bprivate.h
@@ -50,9 +50,16 @@ typedef enum H5B_ins_t {
     H5B_INS_REMOVE	 = 5	/*remove current node			     */
 } H5B_ins_t;
 
+/* Define return values from operator callback function for H5B_iterate */
+typedef enum H5B_iterate_t {
+    H5B_ITER_ERROR       = -1,  /*error return value                         */
+    H5B_ITER_CONT        = 0,   /*continue the loop                          */
+    H5B_ITER_STOP        = 1    /*stop and break the loop                    */
+} H5B_iterate_t;
+
 /* Define the operator callback function pointer for H5B_iterate() */
-typedef herr_t (*H5B_operator_t)(H5F_t *f, void *_lt_key, haddr_t addr,
-    void *_rt_key, void *_udata);
+typedef H5B_iterate_t (*H5B_operator_t)(H5F_t *f, void *_lt_key, haddr_t addr,
+                                        void *_rt_key, void *_udata);
 
 /*
  * Each class of object that can be pointed to by a B-link tree has a
diff --git a/src/H5Distore.c b/src/H5Distore.c
index 147e143..ea74165 100644
--- a/src/H5Distore.c
+++ b/src/H5Distore.c
@@ -122,9 +122,9 @@ static H5B_ins_t H5F_istore_insert(H5F_t *f, haddr_t addr, void *_lt_key,
 				   void *_udata, void *_rt_key,
 				   hbool_t *rt_key_changed,
 				   haddr_t *new_node/*out*/);
-static herr_t H5F_istore_iter_allocated(H5F_t *f, void *left_key, haddr_t addr,
+static H5B_iterate_t H5F_istore_iter_allocated(H5F_t *f, void *left_key, haddr_t addr,
 				 void *right_key, void *_udata);
-static herr_t H5F_istore_iter_dump(H5F_t *f, void *left_key, haddr_t addr,
+static H5B_iterate_t H5F_istore_iter_dump(H5F_t *f, void *left_key, haddr_t addr,
 				 void *right_key, void *_udata);
 static herr_t H5F_istore_decode_key(H5F_t *f, H5B_t *bt, uint8_t *raw,
 				    void *_key);
@@ -134,7 +134,7 @@ static herr_t H5F_istore_debug_key(FILE *stream, int indent, int fwidth,
 				   const void *key, const void *udata);
 static haddr_t H5F_istore_get_addr(H5F_t *f, const H5O_layout_t *layout,
 				  const hssize_t offset[]);
-static herr_t H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t addr,
+static H5B_iterate_t H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t addr,
         void *_rt_key, void *_udata);
 static H5B_ins_t H5F_istore_remove( H5F_t *f, haddr_t addr, void *_lt_key,
                   hbool_t *lt_key_changed, void *_udata, void *_rt_key,
@@ -768,7 +768,7 @@ done:
  *		Changed to callback from H5B_iterate
  *-------------------------------------------------------------------------
  */
-static herr_t
+static H5B_iterate_t 
 H5F_istore_iter_allocated (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
 		    void UNUSED *_rt_key, void *_udata)
 {
@@ -779,7 +779,7 @@ H5F_istore_iter_allocated (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
 
     bt_udata->total_storage += lt_key->nbytes;
 
-    FUNC_LEAVE(SUCCEED);
+    FUNC_LEAVE(H5B_ITER_CONT);
 } /* H5F_istore_iter_allocated() */
 
 
@@ -804,7 +804,7 @@ H5F_istore_iter_allocated (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
  *		Changed to callback from H5B_iterate
  *-------------------------------------------------------------------------
  */
-static herr_t
+static H5B_iterate_t
 H5F_istore_iter_dump (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
 		    void UNUSED *_rt_key, void *_udata)
 {
@@ -832,7 +832,7 @@ H5F_istore_iter_dump (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
         bt_udata->total_storage++;
     }
 
-    FUNC_LEAVE(SUCCEED);
+    FUNC_LEAVE(H5B_ITER_CONT);
 } /* H5F_istore_iter_dump() */
 
 
@@ -2737,7 +2737,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
+static H5B_iterate_t
 H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t UNUSED addr,
         void UNUSED *_rt_key, void *_udata)
 {
@@ -2745,7 +2745,7 @@ H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t UNUSED addr,
     H5F_istore_key_t       *lt_key = (H5F_istore_key_t *)_lt_key;
     unsigned                u;
     H5F_istore_ud1_t        udata;
-    herr_t      ret_value=SUCCEED;       /* Return value */
+    H5B_iterate_t           ret_value=H5B_ITER_CONT;       /* Return value */
 
     /* The LT_KEY is the left key (the one that describes the chunk). It points to a chunk of 
      * storage that contains the beginning of the logical address space represented by UDATA.
@@ -2771,7 +2771,7 @@ H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t UNUSED addr,
 
             /* Remove */
             if(H5B_remove(f, H5B_ISTORE, bt_udata->mesg.addr, &udata) < 0)
-                HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to remove entry");
+                HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, H5B_ITER_ERROR, "unable to remove entry");
 	    break;
 	} /* end if */
 
diff --git a/src/H5Fistore.c b/src/H5Fistore.c
index 147e143..ea74165 100644
--- a/src/H5Fistore.c
+++ b/src/H5Fistore.c
@@ -122,9 +122,9 @@ static H5B_ins_t H5F_istore_insert(H5F_t *f, haddr_t addr, void *_lt_key,
 				   void *_udata, void *_rt_key,
 				   hbool_t *rt_key_changed,
 				   haddr_t *new_node/*out*/);
-static herr_t H5F_istore_iter_allocated(H5F_t *f, void *left_key, haddr_t addr,
+static H5B_iterate_t H5F_istore_iter_allocated(H5F_t *f, void *left_key, haddr_t addr,
 				 void *right_key, void *_udata);
-static herr_t H5F_istore_iter_dump(H5F_t *f, void *left_key, haddr_t addr,
+static H5B_iterate_t H5F_istore_iter_dump(H5F_t *f, void *left_key, haddr_t addr,
 				 void *right_key, void *_udata);
 static herr_t H5F_istore_decode_key(H5F_t *f, H5B_t *bt, uint8_t *raw,
 				    void *_key);
@@ -134,7 +134,7 @@ static herr_t H5F_istore_debug_key(FILE *stream, int indent, int fwidth,
 				   const void *key, const void *udata);
 static haddr_t H5F_istore_get_addr(H5F_t *f, const H5O_layout_t *layout,
 				  const hssize_t offset[]);
-static herr_t H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t addr,
+static H5B_iterate_t H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t addr,
         void *_rt_key, void *_udata);
 static H5B_ins_t H5F_istore_remove( H5F_t *f, haddr_t addr, void *_lt_key,
                   hbool_t *lt_key_changed, void *_udata, void *_rt_key,
@@ -768,7 +768,7 @@ done:
  *		Changed to callback from H5B_iterate
  *-------------------------------------------------------------------------
  */
-static herr_t
+static H5B_iterate_t 
 H5F_istore_iter_allocated (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
 		    void UNUSED *_rt_key, void *_udata)
 {
@@ -779,7 +779,7 @@ H5F_istore_iter_allocated (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
 
     bt_udata->total_storage += lt_key->nbytes;
 
-    FUNC_LEAVE(SUCCEED);
+    FUNC_LEAVE(H5B_ITER_CONT);
 } /* H5F_istore_iter_allocated() */
 
 
@@ -804,7 +804,7 @@ H5F_istore_iter_allocated (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
  *		Changed to callback from H5B_iterate
  *-------------------------------------------------------------------------
  */
-static herr_t
+static H5B_iterate_t
 H5F_istore_iter_dump (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
 		    void UNUSED *_rt_key, void *_udata)
 {
@@ -832,7 +832,7 @@ H5F_istore_iter_dump (H5F_t UNUSED *f, void *_lt_key, haddr_t UNUSED addr,
         bt_udata->total_storage++;
     }
 
-    FUNC_LEAVE(SUCCEED);
+    FUNC_LEAVE(H5B_ITER_CONT);
 } /* H5F_istore_iter_dump() */
 
 
@@ -2737,7 +2737,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
+static H5B_iterate_t
 H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t UNUSED addr,
         void UNUSED *_rt_key, void *_udata)
 {
@@ -2745,7 +2745,7 @@ H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t UNUSED addr,
     H5F_istore_key_t       *lt_key = (H5F_istore_key_t *)_lt_key;
     unsigned                u;
     H5F_istore_ud1_t        udata;
-    herr_t      ret_value=SUCCEED;       /* Return value */
+    H5B_iterate_t           ret_value=H5B_ITER_CONT;       /* Return value */
 
     /* The LT_KEY is the left key (the one that describes the chunk). It points to a chunk of 
      * storage that contains the beginning of the logical address space represented by UDATA.
@@ -2771,7 +2771,7 @@ H5F_istore_prune_extent(H5F_t *f, void *_lt_key, haddr_t UNUSED addr,
 
             /* Remove */
             if(H5B_remove(f, H5B_ISTORE, bt_udata->mesg.addr, &udata) < 0)
-                HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to remove entry");
+                HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, H5B_ITER_ERROR, "unable to remove entry");
 	    break;
 	} /* end if */
 
diff --git a/src/H5G.c b/src/H5G.c
index d08ac5b..8980ee2 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -363,6 +363,143 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Gget_num_objs
+ *
+ * Purpose:     Returns the number of objects in the group.  It iterates 
+ *              all B-tree leaves and sum up total number of group members.
+ *
+ * Return:	Success:        Non-negative	
+ *
+ *		Failure:	Negative 
+ *
+ * Programmer:	Raymond Lu
+ *	        Nov 20, 2002	
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Gget_num_objs(hid_t group_id, hsize_t *num_objs)
+{
+    H5G_t		*group = NULL;
+    herr_t		ret_value;
+    
+    FUNC_ENTER_API(H5Gget_num_objs, FAIL);
+    H5TRACE2("e","i*h",group_id,num_objs);
+
+    /* Check args */
+    if (NULL==(group = H5I_object_verify(group_id,H5I_GROUP)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group");
+    if (!num_objs)
+	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "nil pointer");
+
+    /* Call private function. */
+    ret_value = H5G_get_num_objs(group, num_objs);
+
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Gget_objname_by_idx
+ *
+ * Purpose:     Returns the name of objects in the group by giving index.
+ *              If `name' is non-NULL then write up to `size' bytes into that
+ *              buffer and always return the length of the entry name.
+ *              Otherwise `size' is ignored and the function does not store the name,
+ *              just returning the number of characters required to store the name.
+ *              If an error occurs then the buffer pointed to by `name' (NULL or non-NULL)
+ *              is unchanged and the function returns a negative value.
+ *              If a zero is returned for the name's length, then there is no name
+ *              associated with the ID.
+ *
+ * Return:	Success:        Non-negative	
+ *
+ *		Failure:	Negative 
+ *
+ * Programmer:	Raymond Lu
+ *	        Nov 20, 2002	
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+ssize_t
+H5Gget_objname_by_idx(hid_t group_id, hsize_t idx, char* name/*out*/, size_t size)
+{
+    H5G_t		*group = NULL;
+    hsize_t             num_objs;
+    ssize_t		ret_value = FAIL;
+    
+    FUNC_ENTER_API(H5Gget_objname_by_idx, FAIL);
+
+    /* Check args */
+    if (NULL==(group = H5I_object_verify(group_id,H5I_GROUP)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group");
+    if (!name)   
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "nil pointer for name");
+        
+    if (H5G_get_num_objs(group, &num_objs)<0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unable to retrieve number of members");
+    if(idx >= num_objs)    
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "index out of bound");
+        
+    /*call private function*/
+    ret_value = H5G_get_objname_by_idx(group, idx, name, size);
+
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Gget_objtype_by_idx
+ *
+ * Purpose:     Returns the type of objects in the group by giving index.
+ *              
+ *
+ * Return:	Success:        H5G_GROUP(1), H5G_DATASET(2), H5G_TYPE(3)	
+ *
+ *		Failure:	H5G_UNKNOWN 
+ *
+ * Programmer:	Raymond Lu
+ *	        Nov 20, 2002	
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+H5Gget_objtype_by_idx(hid_t group_id, hsize_t idx)
+{
+    H5G_t		*group = NULL;
+    hsize_t             num_objs;
+    int		        ret_value = FAIL;
+    
+    FUNC_ENTER_API(H5Gget_objtype_by_idx, FAIL);
+    H5TRACE2("Is","ih",group_id,idx);
+
+    /* Check args */
+    if (NULL==(group = H5I_object_verify(group_id,H5I_GROUP)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group");
+        
+    if (H5G_get_num_objs(group, &num_objs)<0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unable to retrieve number of members");
+    if(idx >= num_objs)    
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "index out of bound");
+        
+    /*call private function*/
+    ret_value = H5G_get_objtype_by_idx(group, idx);
+
+done:
+    FUNC_LEAVE(ret_value);
+
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Gmove2
  *
  * Purpose:	Renames an object within an HDF5 file.  The original name SRC
@@ -2258,6 +2395,130 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5G_get_num_objs
+ *
+ * Purpose:     Private function for H5Gget_num_objs.  Returns the number 
+ *              of objects in the group.  It iterates all B-tree leaves 
+ *              and sum up total number of group members.
+ *
+ * Return:	Success:        Non-negative	
+ *
+ *		Failure:	Negative 
+ *
+ * Programmer:	Raymond Lu
+ *	        Nov 20, 2002	
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t 
+H5G_get_num_objs(H5G_t *grp, hsize_t *num_objs)
+{
+    herr_t		ret_value;
+    
+    FUNC_ENTER_NOAPI(H5G_get_num_objs, FAIL);
+
+    *num_objs = 0;
+    /* Iterate over the group members */
+    if ((ret_value = H5B_iterate (H5G_fileof(grp), H5B_SNODE,
+              H5G_node_sumup, grp->ent.cache.stab.btree_addr, num_objs))<0)
+        HERROR (H5E_SYM, H5E_CANTINIT, "iteration operator failed");
+        
+done:
+    FUNC_LEAVE(ret_value);   
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_get_objname_by_idx
+ *
+ * Purpose:     Private function for H5Gget_objname_by_idx.
+ *              Returns the name of objects in the group by giving index.
+ *
+ * Return:	Success:        Non-negative	
+ *
+ *		Failure:	Negative 
+ *
+ * Programmer:	Raymond Lu
+ *	        Nov 20, 2002	
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+ssize_t 
+H5G_get_objname_by_idx(H5G_t *grp, hsize_t idx, char* name, size_t size)
+{
+    ssize_t		ret_value = FAIL;
+    H5G_bt_ud3_t	udata;
+    
+    FUNC_ENTER_NOAPI(H5G_get_objname_by_idx, FAIL);
+
+    udata.idx = idx;
+    udata.num_objs = 0;
+    udata.group = grp;
+    udata.name = NULL;
+
+    /* Iterate over the group members */
+    if ((ret_value = H5B_iterate (H5G_fileof(grp), H5B_SNODE,
+              H5G_node_name, grp->ent.cache.stab.btree_addr, &udata))<0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "iteration operator failed");
+    
+    ret_value = HDstrlen(udata.name);
+    if(name && size>0) {
+        HDstrncpy(name, udata.name, MIN(ret_value+1,size-1));
+        if(ret_value >= size)
+            name[size-1]='\0';
+    }
+    
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_get_objtype_by_idx
+ *
+ * Purpose:     Private function for H5Gget_objtype_by_idx.
+ *              Returns the type of objects in the group by giving index.
+ *
+ * Return:	Success:        H5G_GROUP(1), H5G_DATASET(2), H5G_TYPE(3)	
+ *
+ *		Failure:	UNKNOWN 
+ *
+ * Programmer:	Raymond Lu
+ *	        Nov 20, 2002	
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+int 
+H5G_get_objtype_by_idx(H5G_t *grp, hsize_t idx)
+{
+    int		        ret_value = FAIL;
+    H5G_bt_ud3_t	udata;
+    
+    FUNC_ENTER_NOAPI(H5G_get_objname_by_idx, FAIL);
+    
+    udata.idx = idx;
+    udata.num_objs = 0;
+    udata.group = grp;
+    
+    /* Iterate over the group members */
+    if ((ret_value = H5B_iterate (H5G_fileof(grp), H5B_SNODE,
+              H5G_node_type, grp->ent.cache.stab.btree_addr, &udata))<0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "iteration operator failed");
+    
+    ret_value = udata.type;
+
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5G_linkval
  *
  * Purpose:	Returns the value of a symbolic link.
diff --git a/src/H5Gnode.c b/src/H5Gnode.c
index ca3b973..8671a43 100644
--- a/src/H5Gnode.c
+++ b/src/H5Gnode.c
@@ -1045,7 +1045,7 @@ done:
  *		Changed to callback from H5B_iterate
  *-------------------------------------------------------------------------
  */
-herr_t
+H5B_iterate_t
 H5G_node_iterate (H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
 		  void UNUSED *_rt_key, void *_udata)
 {
@@ -1055,9 +1055,9 @@ H5G_node_iterate (H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
     size_t		n, *name_off=NULL;
     const char		*name;
     char		buf[1024], *s;
-    herr_t		ret_value = FAIL;
+    H5B_iterate_t	ret_value = H5B_ITER_ERROR;
 
-    FUNC_ENTER_NOAPI(H5G_node_iterate, FAIL);
+    FUNC_ENTER_NOAPI(H5G_node_iterate, H5B_ITER_ERROR);
 
     /*
      * Check arguments.
@@ -1071,10 +1071,10 @@ H5G_node_iterate (H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
      * because we're about to call an application function.
      */
     if (NULL == (sn = H5AC_find(f, H5AC_SNODE, addr, NULL, NULL)))
-	HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, FAIL, "unable to load symbol table node");
+	HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, H5B_ITER_ERROR, "unable to load symbol table node");
     nsyms = sn->nsyms;
     if (NULL==(name_off = H5MM_malloc (nsyms*sizeof(name_off[0]))))
-	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
+	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, H5B_ITER_ERROR, "memory allocation failed");
     for (i=0; i<nsyms; i++)
         name_off[i] = sn->entry[i].name_off;
     sn = NULL;
@@ -1092,7 +1092,7 @@ H5G_node_iterate (H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
             n = HDstrlen (name);
             if (n+1>sizeof(buf)) {
                 if (NULL==(s = H5MM_malloc (n+1)))
-                    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
+                    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, H5B_ITER_ERROR, "memory allocation failed");
             } else {
                 s = buf;
             }
@@ -1117,12 +1117,159 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5G_node_sumup
+ *
+ * Purpose:	This function gets called during a group iterate operation
+ *              to return total number of members in the group. 
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              Nov 20, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+H5B_iterate_t
+H5G_node_sumup(H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		  void UNUSED *_rt_key, void *_udata)
+{
+    hsize_t	        *num_objs = (hsize_t *)_udata;
+    H5G_node_t		*sn = NULL;
+    H5B_iterate_t	ret_value = H5B_ITER_CONT;
+
+    FUNC_ENTER_NOAPI(H5G_node_sumup, H5B_ITER_ERROR);
+
+    /*
+     * Check arguments.
+     */
+    assert(f);
+    assert(H5F_addr_defined(addr));
+    assert(num_objs);
+
+    /* Find the object node and add the number of symbol entries. */
+    if (NULL == (sn = H5AC_find(f, H5AC_SNODE, addr, NULL, NULL)))
+	HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, H5B_ITER_ERROR, "unable to load symbol table node");
+    *num_objs += sn->nsyms;
+    
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_node_name
+ *
+ * Purpose:	This function gets called during a group iterate operation
+ *              to return object name by giving idx.
+ *
+ * Return:	0 if object isn't found in this node; 1 if object is found; 
+ *              Negative on failure
+ *
+ * Programmer:  Raymond Lu	
+ *              Nov 20, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+H5B_iterate_t
+H5G_node_name(H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		  void UNUSED *_rt_key, void *_udata)
+{
+    H5G_bt_ud3_t	*bt_udata = (H5G_bt_ud3_t *)_udata;
+    size_t		name_off;
+    hsize_t             loc_idx;
+    char		*name;   
+    H5G_node_t		*sn = NULL;
+    H5B_iterate_t	ret_value = H5B_ITER_CONT;
+
+    FUNC_ENTER_NOAPI(H5G_node_name, H5B_ITER_ERROR);
+
+    /*
+     * Check arguments.
+     */
+    assert(f);
+    assert(H5F_addr_defined(addr));
+    assert(bt_udata);
+
+
+    if (NULL == (sn = H5AC_find(f, H5AC_SNODE, addr, NULL, NULL)))
+	HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, H5B_ITER_ERROR, "unable to load symbol table node");
+    
+    /* Find the node, locate the object symbol table entry and retrieve the name */ 
+    if(bt_udata->idx >= bt_udata->num_objs && bt_udata->idx < (bt_udata->num_objs+sn->nsyms)) {
+            loc_idx = bt_udata->idx - bt_udata->num_objs; 
+            name_off = sn->entry[loc_idx].name_off;  
+            name = (char*)H5HL_peek (f, bt_udata->group->ent.cache.stab.heap_addr, name_off);
+            assert (name);
+            bt_udata->name = HDstrdup (name);
+            HGOTO_DONE(H5B_ITER_STOP);
+    }
+
+    bt_udata->num_objs += sn->nsyms;
+    
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_node_type
+ *
+ * Purpose:	This function gets called during a group iterate operation
+ *              to return object type by given idx.
+ *
+ * Return:	0 if object isn't found in this node; 1 if found;
+ *              Negative on failure
+ *
+ * Programmer:  Raymond Lu	
+ *              Nov 20, 2002
+ *
+ *
+ *-------------------------------------------------------------------------
+ */
+H5B_iterate_t
+H5G_node_type(H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		  void UNUSED *_rt_key, void *_udata)
+{
+    H5G_bt_ud3_t	*bt_udata = (H5G_bt_ud3_t*)_udata;
+    hsize_t             loc_idx;
+    H5G_node_t		*sn = NULL;
+    H5B_iterate_t	ret_value = H5B_ITER_CONT;
+
+    FUNC_ENTER_NOAPI(H5G_node_name, H5B_ITER_ERROR);
+
+    /* Check arguments. */
+    assert(f);
+    assert(H5F_addr_defined(addr));
+    assert(bt_udata);
+
+    /* Find the node, locate the object symbol table entry and retrieve the type */ 
+    if (NULL == (sn = H5AC_find(f, H5AC_SNODE, addr, NULL, NULL)))
+	HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, H5B_ITER_ERROR, "unable to load symbol table node");
+
+    if(bt_udata->idx >= bt_udata->num_objs && bt_udata->idx < (bt_udata->num_objs+sn->nsyms)) {
+            loc_idx = bt_udata->idx - bt_udata->num_objs; 
+            bt_udata->type = H5G_get_type(&(sn->entry[loc_idx]));  
+            HGOTO_DONE(H5B_ITER_STOP);
+    }
+
+    bt_udata->num_objs += sn->nsyms;
+    
+done:
+    FUNC_LEAVE(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5G_node_debug
  *
  * Purpose:	Prints debugging information about a symbol table node
  *		or a B-tree node for a symbol table B-tree.
  *
- * Return:	Non-negative on success/Negative on failure
+ * Return:	0(zero) on success/Negative on failure
  *
  * Programmer:	Robb Matzke
  *		matzke@llnl.gov
diff --git a/src/H5Gpkg.h b/src/H5Gpkg.h
index 9d2b98c..3fc8bd3 100644
--- a/src/H5Gpkg.h
+++ b/src/H5Gpkg.h
@@ -110,6 +110,18 @@ typedef struct H5G_bt_ud2_t {
 } H5G_bt_ud2_t;
 
 /*
+ * Data exchange structure to pass through the B-tree layer for the
+ * H5B_iterate function.
+ */
+typedef struct H5G_bt_ud3_t {
+    struct H5G_t *group;	/*the group to which group_id points	     */
+    hsize_t      idx;           /*index of group member to be querried       */
+    char         *name;         /*member name to be returned                 */
+    hsize_t      num_objs;      /*the number of objects having been traversed*/
+    int          type;          /*member type to be returned                 */
+} H5G_bt_ud3_t;
+
+/*
  * This is the class identifier to give to the B-tree functions.
  */
 H5_DLLVAR H5B_class_t H5B_SNODE[1];
@@ -140,7 +152,12 @@ H5_DLL herr_t H5G_ent_encode_vec(H5F_t *f, uint8_t **pp,
 
 /* Functions that understand symbol table nodes */
 H5_DLL unsigned H5G_node_k(const H5F_t *f);
-H5_DLL herr_t H5G_node_iterate (H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
-		  void UNUSED *_rt_key, void *_udata);
-
+H5_DLL H5B_iterate_t H5G_node_iterate (H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		     void UNUSED *_rt_key, void *_udata);
+H5_DLL H5B_iterate_t H5G_node_sumup(H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		     void UNUSED *_rt_key, void *_udata);
+H5_DLL H5B_iterate_t H5G_node_name(H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		     void UNUSED *_rt_key, void *_udata);
+H5_DLL H5B_iterate_t H5G_node_type(H5F_t *f, void UNUSED *_lt_key, haddr_t addr,
+		     void UNUSED *_rt_key, void *_udata);
 #endif
diff --git a/src/H5Gprivate.h b/src/H5Gprivate.h
index 1028764..8515b2d 100644
--- a/src/H5Gprivate.h
+++ b/src/H5Gprivate.h
@@ -145,6 +145,9 @@ H5_DLL H5G_t *H5G_open_oid(H5G_entry_t *ent);
 H5_DLL H5G_t *H5G_reopen(H5G_t *grp);
 H5_DLL herr_t H5G_close(H5G_t *grp);
 H5_DLL H5G_t *H5G_rootof(H5F_t *f);
+H5_DLL herr_t H5G_get_num_objs(H5G_t *grp, hsize_t *num_objs);
+H5_DLL ssize_t H5G_get_objname_by_idx(H5G_t *grp, hsize_t idx, char* name, size_t size);
+H5_DLL int H5G_get_objtype_by_idx(H5G_t *grp, hsize_t idx);
 H5_DLL htri_t H5G_isa(H5G_entry_t *ent);
 H5_DLL herr_t H5G_link(H5G_entry_t *cur_loc, const char *cur_name, 
 			H5G_entry_t *new_loc, const char *new_name, 
diff --git a/src/H5Gpublic.h b/src/H5Gpublic.h
index 96ed37f..5e40033 100644
--- a/src/H5Gpublic.h
+++ b/src/H5Gpublic.h
@@ -81,6 +81,9 @@ H5_DLL hid_t H5Gopen(hid_t loc_id, const char *name);
 H5_DLL herr_t H5Gclose(hid_t group_id);
 H5_DLL herr_t H5Giterate(hid_t loc_id, const char *name, int *idx,
 			  H5G_iterate_t op, void *op_data);
+H5_DLL herr_t H5Gget_num_objs(hid_t loc_id, hsize_t *num_objs);
+H5_DLL ssize_t H5Gget_objname_by_idx(hid_t group_id, hsize_t idx, char* name, size_t size);
+H5_DLL int H5Gget_objtype_by_idx(hid_t group_id, hsize_t idx);
 H5_DLL herr_t H5Gmove2(hid_t src_loc, const char *src, hid_t dst_loc, 
 			const char *dst);
 H5_DLL herr_t H5Glink2(hid_t src_loc, const char *cur_name, H5G_link_t type,