path: root/src/H5G.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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 files COPYING and Copyright.html.  COPYING can be found at the root   *
 * of the source code distribution tree; Copyright.html can be found at the  *
 * root level of an installed copy of the electronic HDF5 document set and   *
 * is linked from the top-level documents page.  It can also be found at     *
 * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
 * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:	H5G.c
 *		Jul 18 1997
 *		Robb Matzke <matzke@llnl.gov>
 *
 * Purpose:	Symbol table functions.	 The functions that begin with
 *		`H5G_stab_' don't understand the naming system; they operate
 * 		on a single symbol table at a time.
 *
 *		The functions that begin with `H5G_node_' operate on the leaf
 *		nodes of a symbol table B-tree.  They should be defined in
 *		the H5Gnode.c file. 
 *
 *		The remaining functions know how to traverse the group
 *		directed graph.
 *
 * Names:	Object names are a slash-separated list of components.  If
 *		the name begins with a slash then it's absolute, otherwise
 *		it's relative ("/foo/bar" is absolute while "foo/bar" is
 *		relative).  Multiple consecutive slashes are treated as
 *		single slashes and trailing slashes are ignored.  The special
 *		case `/' is the root group.  Every file has a root group.
 *
 *		API functions that look up names take a location ID and a
 *		name.  The location ID can be a file ID or a group ID and the
 *		name can be relative or absolute.
 *
 *              +--------------+----------- +--------------------------------+
 * 		| Location ID  | Name       | Meaning                        |
 *              +--------------+------------+--------------------------------+
 * 		| File ID      | "/foo/bar" | Find `foo' within `bar' within |
 *		|              |            | the root group of the specified|
 *		|              |            | file.                          |
 *              +--------------+------------+--------------------------------+
 * 		| File ID      | "foo/bar"  | Find `foo' within `bar' within |
 *		|              |            | the current working group of   |
 *		|              |            | the specified file.            |
 *              +--------------+------------+--------------------------------+
 * 		| File ID      | "/"        | The root group of the specified|
 *		|              |            | file.                          |
 *              +--------------+------------+--------------------------------+
 * 		| File ID      | "."        | The current working group of   |
 *		|              |            | the specified file.            |
 *              +--------------+------------+--------------------------------+
 * 		| Group ID     | "/foo/bar" | Find `foo' within `bar' within |
 *		|              |            | the root group of the file     |
 *		|              |            | containing the specified group.|
 *              +--------------+------------+--------------------------------+
 * 		| Group ID     | "foo/bar"  | File `foo' within `bar' within |
 *		|              |            | the specified group.           |
 *              +--------------+------------+--------------------------------+
 * 		| Group ID     | "/"        | The root group of the file     |
 *		|              |            | containing the specified group.|
 *              +--------------+------------+--------------------------------+
 * 		| Group ID     | "."        | The specified group.           |
 *              +--------------+------------+--------------------------------+
 *
 *
 * Modifications:
 *
 *	Robb Matzke, 5 Aug 1997
 *	Added calls to H5E.
 *
 *	Robb Matzke, 30 Aug 1997
 *	Added `Errors:' field to function prologues.
 *
 *      Pedro Vicente, 22 Aug 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */

#define H5G_PACKAGE     /*suppress error message about including H5Gpkg.h */
#define H5F_PACKAGE     /*suppress error about including H5Fpkg	  */

/* Packages needed by this file... */
#include "H5private.h"		/* Generic Functions			*/
#include "H5Aprivate.h"		/* Attributes				*/
#include "H5Bprivate.h"		/* B-link trees				*/
#include "H5Dprivate.h"		/* Datasets				*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5Fpkg.h"		/* File access				*/
#include "H5FLprivate.h"	/* Free Lists                           */
#include "H5Gpkg.h"		/* Groups		  		*/
#include "H5HLprivate.h"	/* Local Heaps				*/
#include "H5Iprivate.h"		/* IDs			  		*/
#include "H5MMprivate.h"	/* Memory management			*/
#include "H5Oprivate.h"		/* Object headers		  	*/

/* Local macros */
#define H5G_INIT_HEAP		8192
#define H5G_RESERVED_ATOMS	0
#define H5G_SIZE_HINT   256             /*default root grp size hint         */
#define H5G_NLINKS	16		/*max symlinks to follow per lookup  */

/*
 * During name lookups (see H5G_namei()) we sometimes want information about
 * a symbolic link or a mount point.  The normal operation is to follow the
 * symbolic link or mount point and return information about its target.
 */
#define H5G_TARGET_NORMAL	0x0000
#define H5G_TARGET_SLINK	0x0001
#define H5G_TARGET_MOUNT	0x0002

#define PABLO_MASK		H5G_mask

/* Interface initialization */
static int interface_initialize_g = 0;
#define INTERFACE_INIT	H5G_init_interface
static herr_t H5G_init_interface(void);

/* Local typedefs */

/* Struct only used by change name callback function */
typedef struct H5G_names_t {
    H5G_entry_t	*loc;
    H5RS_str_t *src_name;
    H5G_entry_t	*src_loc;
    H5RS_str_t *dst_name;
    H5G_entry_t	*dst_loc;
    H5G_names_op_t op;
} H5G_names_t;  

/* Enum for H5G_namei actions */
typedef enum {
    H5G_NAMEI_TRAVERSE,         /* Just traverse groups */
    H5G_NAMEI_INSERT            /* Insert entry in group */
} H5G_namei_act_t ;

/*
 * This table contains a list of object types, descriptions, and the
 * functions that determine if some object is a particular type.  The table
 * is allocated dynamically.
 */
typedef struct H5G_typeinfo_t {
    H5G_obj_t 	type;			        /*one of the public H5G_* types	     */
    htri_t	(*isa)(H5G_entry_t*, hid_t);	/*function to determine type	     */
    char	*desc;			        /*description of object type	     */
} H5G_typeinfo_t;

/* Local variables */
static H5G_typeinfo_t *H5G_type_g = NULL;	/*object typing info	*/
static size_t H5G_ntypes_g = 0;			/*entries in type table	*/
static size_t H5G_atypes_g = 0;			/*entries allocated	*/
static char *H5G_comp_g = NULL;                 /*component buffer      */
static size_t H5G_comp_alloc_g = 0;             /*sizeof component buffer */

/* Declare a free list to manage the H5G_t struct */
H5FL_DEFINE(H5G_t);

/* Declare extern the PQ free list for the wrapped strings */
H5FL_BLK_EXTERN(str_buf);

/* Private prototypes */
static H5G_t *H5G_create(H5G_entry_t *loc, const char *name, size_t size_hint, hid_t dxpl_id);
#ifdef NOT_YET
static H5G_t *H5G_reopen(H5G_t *grp);
#endif /* NOT_YET */
static htri_t H5G_isa(H5G_entry_t *ent, hid_t dxpl_id);
static herr_t H5G_link(H5G_entry_t *cur_loc, const char *cur_name, 
			H5G_entry_t *new_loc, const char *new_name, 
			H5G_link_t type, unsigned namei_flags, hid_t dxpl_id);
static herr_t H5G_linkval(H5G_entry_t *loc, const char *name, size_t size,
			   char *buf/*out*/, hid_t dxpl_id);
static herr_t H5G_move(H5G_entry_t *src_loc, const char *src_name,
			H5G_entry_t *dst_loc, const char *dst_name, hid_t dxpl_it);
static herr_t H5G_unlink(H5G_entry_t *loc, const char *name, hid_t dxpl_id);
static herr_t H5G_get_num_objs(H5G_entry_t *grp, hsize_t *num_objs, hid_t dxpl_id);
static ssize_t H5G_get_objname_by_idx(H5G_entry_t *loc, hsize_t idx, char* name, size_t size, hid_t dxpl_id);
static H5G_obj_t H5G_get_objtype_by_idx(H5G_entry_t *loc, hsize_t idx, hid_t dxpl_id);
static int H5G_replace_ent(void *obj_ptr, hid_t obj_id, void *key);
static herr_t H5G_traverse_slink(H5G_entry_t *grp_ent/*in,out*/,
                  H5G_entry_t *obj_ent/*in,out*/, int *nlinks/*in,out*/, hid_t dxpl_id);
static herr_t H5G_set_comment(H5G_entry_t *loc, const char *name,
			       const char *buf, hid_t dxpl_id);
static int H5G_get_comment(H5G_entry_t *loc, const char *name,
			     size_t bufsize, char *buf, hid_t dxpl_id);
static herr_t H5G_register_type(H5G_obj_t type, htri_t(*isa)(H5G_entry_t*, hid_t),
				 const char *desc);
static H5G_t *H5G_rootof(H5F_t *f);


/*-------------------------------------------------------------------------
 * Function:	H5Gcreate
 *
 * Purpose:	Creates a new group relative to LOC_ID and gives it the
 *		specified NAME.  The group is opened for write access
 *		and it's object ID is returned.
 *
 *		The optional SIZE_HINT specifies how much file space to
 *		reserve to store the names that will appear in this
 *		group. If a non-positive value is supplied for the SIZE_HINT
 *		then a default size is chosen.
 *
 * See also:	H5Gset(), H5Gpush(), H5Gpop()
 *
 * Errors:
 *
 * Return:	Success:	The object ID of a new, empty group open for
 *				writing.  Call H5Gclose() when finished with
 *				the group.
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *		Wednesday, September 24, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5Gcreate(hid_t loc_id, const char *name, size_t size_hint)
{
    H5G_entry_t		   *loc = NULL;
    H5G_t		   *grp = NULL;
    hid_t		    ret_value;

    FUNC_ENTER_API(H5Gcreate, FAIL);
    H5TRACE3("i","isz",loc_id,name,size_hint);

    /* Check arguments */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given");
    
    /* Create the group */
    if (NULL == (grp = H5G_create(loc, name, size_hint, H5AC_dxpl_id)))
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group");
    if ((ret_value = H5I_register(H5I_GROUP, grp)) < 0)
	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group");

done:
    if(ret_value<0) {
        if(grp!=NULL)
            H5G_close(grp);
    } /* end if */

    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gopen
 *
 * Purpose:	Opens an existing group for modification.  When finished,
 *		call H5Gclose() to close it and release resources.
 *
 * Errors:
 *
 * Return:	Success:	Object ID of the group.
 *
 *		Failure:	FAIL
 *
 * Programmer:	Robb Matzke
 *		Wednesday, December 31, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5Gopen(hid_t loc_id, const char *name)
{
    hid_t	ret_value = FAIL;
    H5G_t	*grp = NULL;
    H5G_entry_t	*loc = NULL;

    FUNC_ENTER_API(H5Gopen, FAIL);
    H5TRACE2("i","is",loc_id,name);

    /* Check args */
    if (NULL==(loc=H5G_loc(loc_id)))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name");
    
    /* Open the group */
    if (NULL == (grp = H5G_open(loc, name, H5AC_dxpl_id)))
	HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group");
    /* Register an atom for the group */
    if ((ret_value = H5I_register(H5I_GROUP, grp)) < 0)
	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group");

done:
    if(ret_value<0) {
        if(grp!=NULL)
            H5G_close(grp);
    } /* end if */

    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gclose
 *
 * Purpose:	Closes the specified group.  The group ID will no longer be
 *		valid for accessing the group.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		Wednesday, December 31, 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Gclose(hid_t group_id)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_API(H5Gclose, FAIL);
    H5TRACE1("e","i",group_id);

    /* Check args */
    if (NULL == H5I_object_verify(group_id,H5I_GROUP))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group");

    /*
     * Decrement the counter on the group atom.	 It will be freed if the count
     * reaches zero.
     */
    if (H5I_dec_ref(group_id) < 0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to close group");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Giterate
 *
 * Purpose:	Iterates over the entries of a group.  The LOC_ID and NAME
 *		identify the group over which to iterate and IDX indicates
 *		where to start iterating (zero means at the beginning).	 The
 *		OPERATOR is called for each member and the iteration
 *		continues until the operator returns non-zero or all members
 *		are processed. The operator is passed a group ID for the
 *		group being iterated, a member name, and OP_DATA for each
 *		member.
 *
 * 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:	Robb Matzke
 *		Monday, March 23, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Giterate(hid_t loc_id, const char *name, int *idx_p,
	    H5G_iterate_t op, void *op_data)
{
    int			idx;
    H5G_bt_ud2_t	udata;
    H5G_entry_t		*loc = NULL;
    H5G_t		*grp = NULL;
    herr_t		ret_value;
    
    FUNC_ENTER_API(H5Giterate, FAIL);
    H5TRACE5("e","is*Isxx",loc_id,name,idx_p,op,op_data);

    /* Check args */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified");
    idx = (idx_p == NULL ? 0 : *idx_p);
    if (!idx_p)
        idx_p = &idx;
    if (idx<0)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index specified");
    if (!op)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "no operator specified");

    /*
     * Open the group on which to operate.  We also create a group ID which
     * we can pass to the application-defined operator.
     */
    if (NULL==(grp = H5G_open (loc, name, H5AC_dxpl_id)))
	HGOTO_ERROR (H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group");
    if ((udata.group_id=H5I_register (H5I_GROUP, grp))<0) {
	H5G_close(grp);
	HGOTO_ERROR (H5E_SYM, H5E_CANTREGISTER, FAIL, "unable to register group");
    }
    
    /* Build udata to pass through H5B_iterate() to H5G_node_iterate() */
    udata.skip = idx;
    udata.ent = &(grp->ent);
    udata.op = op;
    udata.op_data = op_data;

    /* Set the number of entries looked at to zero */
    udata.final_ent = 0;

    /* Iterate over the group members */
    if ((ret_value = H5B_iterate (H5G_fileof(grp), H5AC_dxpl_id, H5B_SNODE,
              H5G_node_iterate, udata.ent->cache.stab.btree_addr, &udata))<0)
        HERROR (H5E_SYM, H5E_CANTNEXT, "iteration operator failed");

    H5I_dec_ref (udata.group_id); /*also closes 'grp'*/

    /* Check for too high of a starting index (ex post facto :-) */
    /* (Skipping exactly as many entries as are in the group is currently an error) */
    if (idx>0 && idx>=udata.final_ent)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index specified");

    /* Set the index we stopped at */
    *idx_p=udata.final_ent;

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * 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 loc_id, hsize_t *num_objs)
{
    H5G_entry_t		*loc = NULL;    /* Pointer to symbol table entry */
    herr_t		ret_value;
    
    FUNC_ENTER_API(H5Gget_num_objs, FAIL);
    H5TRACE2("e","i*h",loc_id,num_objs);

    /* Check args */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location ID");
    if(H5G_get_type(loc,H5AC_ind_dxpl_id)!=H5G_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(loc, num_objs, H5AC_ind_dxpl_id);

done:
    FUNC_LEAVE_API(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 loc_id, hsize_t idx, char *name, size_t size)
{
    H5G_entry_t		*loc = NULL;    /* Pointer to symbol table entry */
    hsize_t             num_objs;
    ssize_t		ret_value = FAIL;
    
    FUNC_ENTER_API(H5Gget_objname_by_idx, FAIL);
    H5TRACE4("Zs","ihsz",loc_id,idx,name,size);

    /* Check args */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location ID");
    if(H5G_get_type(loc,H5AC_ind_dxpl_id)!=H5G_GROUP)
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a group");
        
    if (H5G_get_num_objs(loc, &num_objs, H5AC_ind_dxpl_id)<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(loc, idx, name, size, H5AC_ind_dxpl_id);

done:
    FUNC_LEAVE_API(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:
 *
 *-------------------------------------------------------------------------
 */
H5G_obj_t
H5Gget_objtype_by_idx(hid_t loc_id, hsize_t idx)
{
    H5G_entry_t		*loc = NULL;    /* Pointer to symbol table entry */
    hsize_t             num_objs;
    H5G_obj_t		ret_value;
    
    FUNC_ENTER_API(H5Gget_objtype_by_idx, H5G_UNKNOWN);
    H5TRACE2("Go","ih",loc_id,idx);

    /* Check args */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "not a location ID");
    if(H5G_get_type(loc,H5AC_ind_dxpl_id)!=H5G_GROUP)
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "not a group");
        
    if (H5G_get_num_objs(loc, &num_objs, H5AC_ind_dxpl_id)<0)
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "unable to retrieve number of members");
    if(idx >= num_objs)    
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "index out of bound");
        
    /*call private function*/
    ret_value = H5G_get_objtype_by_idx(loc, idx, H5AC_ind_dxpl_id);

done:
    FUNC_LEAVE_API(ret_value);

}


/*-------------------------------------------------------------------------
 * Function:	H5Gmove2
 *
 * Purpose:	Renames an object within an HDF5 file.  The original name SRC
 *		is unlinked from the group graph and the new name DST is
 *		inserted as an atomic operation.  Both names are interpreted
 *		relative to SRC_LOC_ID and DST_LOC_ID, which are either a file 
 *		ID or a group ID.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Monday, April  6, 1998
 *
 * Modifications:
 *
 *		Raymond Lu
 *		Thursday, April 18, 2002
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Gmove2(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id, 
	 const char *dst_name)
{
    H5G_entry_t		*src_loc=NULL;
    H5G_entry_t		*dst_loc=NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_API(H5Gmove2, FAIL);
    H5TRACE4("e","isis",src_loc_id,src_name,dst_loc_id,dst_name);

    if (src_loc_id != H5G_SAME_LOC && NULL==(src_loc=H5G_loc(src_loc_id)))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (dst_loc_id != H5G_SAME_LOC && NULL==(dst_loc=H5G_loc(dst_loc_id)))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!src_name || !*src_name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no current name specified");
    if (!dst_name || !*dst_name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no new name specified");

    if(src_loc_id == H5G_SAME_LOC && dst_loc_id == H5G_SAME_LOC) {
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should not be both H5G_SAME_LOC");
    } else if(src_loc_id == H5G_SAME_LOC) {
	src_loc = dst_loc;
    }
    else if(dst_loc_id == H5G_SAME_LOC) {
	dst_loc = src_loc;
    }
    else if(src_loc->file != dst_loc->file)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should be in the same file.");
	
    if (H5G_move(src_loc, src_name, dst_loc, dst_name, H5AC_dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to change object name");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Glink2
 *
 * Purpose:	Creates a link of the specified type from NEW_NAME to
 *		CUR_NAME.
 *
 *		If TYPE is H5G_LINK_HARD then CUR_NAME must name an existing
 *		object.  CUR_NAME and NEW_NAME are interpreted relative to 
 *		CUR_LOC_ID and NEW_LOC_ID, which is either a file ID or a 
 *		group ID.
 *
 * 		If TYPE is H5G_LINK_SOFT then CUR_NAME can be anything and is
 *		interpreted at lookup time relative to the group which
 *		contains the final component of NEW_NAME.  For instance, if
 *		CUR_NAME is `./foo' and NEW_NAME is `./x/y/bar' and a request
 *		is made for `./x/y/bar' then the actual object looked up is
 *		`./x/y/./foo'.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Monday, April  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Glink2(hid_t cur_loc_id, const char *cur_name, H5G_link_t type, 
	 hid_t new_loc_id, const char *new_name)
{
    H5G_entry_t	*cur_loc = NULL;
    H5G_entry_t *new_loc = NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_API(H5Glink2, FAIL);
    H5TRACE5("e","isGlis",cur_loc_id,cur_name,type,new_loc_id,new_name);

    /* Check arguments */
    if (cur_loc_id != H5G_SAME_LOC && NULL==(cur_loc=H5G_loc(cur_loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (new_loc_id != H5G_SAME_LOC && NULL==(new_loc=H5G_loc(new_loc_id)))
        HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (type!=H5G_LINK_HARD && type!=H5G_LINK_SOFT)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "unrecognized link type");
    if (!cur_name || !*cur_name)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "no current name specified");
    if (!new_name || !*new_name)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "no new name specified");

    if(cur_loc_id == H5G_SAME_LOC && new_loc_id == H5G_SAME_LOC) {
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should not be both H5G_SAME_LOC");
    }
    else if(cur_loc_id == H5G_SAME_LOC) {
        cur_loc = new_loc;
    }
    else if(new_loc_id == H5G_SAME_LOC) {
   	new_loc = cur_loc;
    }
    else if(cur_loc->file != new_loc->file)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should be in the same file.");

    if (H5G_link(cur_loc, cur_name, new_loc, new_name, type, H5G_TARGET_NORMAL, H5AC_dxpl_id) <0)
	HGOTO_ERROR (H5E_SYM, H5E_LINK, FAIL, "unable to create link");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gunlink
 *
 * Purpose:	Removes the specified NAME from the group graph and
 *		decrements the link count for the object to which NAME
 *		points.  If the link count reaches zero then all file-space
 *		associated with the object will be reclaimed (but if the
 *		object is open, then the reclamation of the file space is
 *		delayed until all handles to the object are closed).
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Monday, April  6, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Gunlink(hid_t loc_id, const char *name)
{
    H5G_entry_t	*loc = NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_API(H5Gunlink, FAIL);
    H5TRACE2("e","is",loc_id,name);

    /* Check arguments */
    if (NULL==(loc=H5G_loc(loc_id)))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name");

    /* Unlink */
    if (H5G_unlink(loc, name, H5AC_dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to unlink object");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gget_objinfo
 *
 * Purpose:	Returns information about an object.  If FOLLOW_LINK is
 *		non-zero then all symbolic links are followed; otherwise all
 *		links except the last component of the name are followed.
 *
 * Return:	Non-negative on success, with the fields of STATBUF (if
 *              non-null) initialized. Negative on failure.
 *
 * Programmer:	Robb Matzke
 *              Monday, April 13, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Gget_objinfo(hid_t loc_id, const char *name, hbool_t follow_link,
	       H5G_stat_t *statbuf/*out*/)
{
    H5G_entry_t	*loc = NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_API(H5Gget_objinfo, FAIL);
    H5TRACE4("e","isbx",loc_id,name,follow_link,statbuf);

    /* Check arguments */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified");

    /* Get info */
    if (H5G_get_objinfo (loc, name, follow_link, statbuf, H5AC_ind_dxpl_id)<0)
	HGOTO_ERROR (H5E_ARGS, H5E_CANTINIT, FAIL, "cannot stat object");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gget_linkval
 *
 * Purpose:	Returns the value of a symbolic link whose name is NAME.  At
 *		most SIZE characters (counting the null terminator) are
 *		copied to the BUF result buffer.
 *
 * Return:	Success:	Non-negative with the link value in BUF.
 *
 * 		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Monday, April 13, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Gget_linkval(hid_t loc_id, const char *name, size_t size, char *buf/*out*/)
{
    H5G_entry_t	*loc = NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_API(H5Gget_linkval, FAIL);
    H5TRACE4("e","iszx",loc_id,name,size,buf);

    /* Check arguments */
    if (NULL==(loc=H5G_loc (loc_id)))
	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified");

    /* Get the link value */
    if (H5G_linkval (loc, name, size, buf, H5AC_ind_dxpl_id)<0)
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to get link value");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gset_comment
 *
 * Purpose:     Gives the specified object a comment.  The COMMENT string
 *		should be a null terminated string.  An object can have only
 *		one comment at a time.  Passing NULL for the COMMENT argument
 *		will remove the comment property from the object.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Monday, July 20, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Gset_comment(hid_t loc_id, const char *name, const char *comment)
{
    H5G_entry_t	*loc = NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_API(H5Gset_comment, FAIL);
    H5TRACE3("e","iss",loc_id,name,comment);

    if (NULL==(loc=H5G_loc(loc_id)))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified");

    if (H5G_set_comment(loc, name, comment, H5AC_dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to set comment value");

done:
    FUNC_LEAVE_API(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5Gget_comment
 *
 * Purpose:	Return at most BUFSIZE characters of the comment for the
 *		specified object.  If BUFSIZE is large enough to hold the
 *		entire comment then the comment string will be null
 *		terminated, otherwise it will not.  If the object does not
 *		have a comment value then no bytes are copied to the BUF
 *		buffer.
 *
 * Return:	Success:	Number of characters in the comment counting
 *				the null terminator.  The value returned may
 *				be larger than the BUFSIZE argument.
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Monday, July 20, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
int
H5Gget_comment(hid_t loc_id, const char *name, size_t bufsize, char *buf)
{
    H5G_entry_t	*loc = NULL;
    int	ret_value;
    
    FUNC_ENTER_API(H5Gget_comment, FAIL);
    H5TRACE4("Is","iszs",loc_id,name,bufsize,buf);

    if (NULL==(loc=H5G_loc(loc_id)))
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
    if (!name || !*name)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified");
    if (bufsize>0 && !buf)
	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no buffer specified");

    if ((ret_value=H5G_get_comment(loc, name, bufsize, buf, H5AC_ind_dxpl_id))<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to get comment value");

done:
    FUNC_LEAVE_API(ret_value);
}

/*
 *-------------------------------------------------------------------------
 *-------------------------------------------------------------------------
 *   N O   A P I   F U N C T I O N S   B E Y O N D   T H I S   P O I N T
 *-------------------------------------------------------------------------
 *------------------------------------------------------------------------- 
 */

/*-------------------------------------------------------------------------
 * Function:	H5G_init_interface
 *
 * Purpose:	Initializes the H5G interface.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		Monday, January	 5, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_init_interface(void)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOINIT(H5G_init_interface);

    /* Initialize the atom group for the group IDs */
    if (H5I_init_group(H5I_GROUP, H5I_GROUPID_HASHSIZE, H5G_RESERVED_ATOMS,
		       (H5I_free_t)H5G_close) < 0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to initialize interface");

    /*
     * Initialize the type info table.  Begin with the most general types and
     * end with the most specific. For instance, any object that has a data
     * type message is a datatype but only some of them are datasets.
     */
    H5G_register_type(H5G_TYPE,    H5T_isa,  "datatype");
    H5G_register_type(H5G_GROUP,   H5G_isa,  "group");
    H5G_register_type(H5G_DATASET, H5D_isa,  "dataset");

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_term_interface
 *
 * Purpose:	Terminates the H5G interface
 *
 * Return:	Success:	Positive if anything is done that might
 *				affect other interfaces; zero otherwise.
 *
 * 		Failure:	Negative.
 *
 * Programmer:	Robb Matzke
 *		Monday, January	 5, 1998
 *
 * Modifications:
 *              Robb Matzke, 2002-03-28
 *              Free the global component buffer.
 *-------------------------------------------------------------------------
 */
int
H5G_term_interface(void)
{
    size_t	i;
    int	n=0;

    FUNC_ENTER_NOINIT(H5G_term_interface);
    
    if (interface_initialize_g) {
	if ((n=H5I_nmembers(H5I_GROUP))) {
	    H5I_clear_group(H5I_GROUP, FALSE);
	} else {
	    /* Empty the object type table */
	    for (i=0; i<H5G_ntypes_g; i++)
		H5MM_xfree(H5G_type_g[i].desc);
	    H5G_ntypes_g = H5G_atypes_g = 0;
	    H5G_type_g = H5MM_xfree(H5G_type_g);
    
	    /* Destroy the group object id group */
	    H5I_destroy_group(H5I_GROUP);

            /* Free the global component buffer */
            H5G_comp_g = H5MM_xfree(H5G_comp_g);
            H5G_comp_alloc_g = 0;

	    /* Mark closed */
	    interface_initialize_g = 0;
	    n = 1; /*H5I*/
	}
    }
    
    FUNC_LEAVE_NOAPI(n);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_register_type
 *
 * Purpose:	Register a new object type so H5G_get_type() can detect it.
 *		One should always register a general type before a more
 *		specific type.  For instance, any object that has a datatype
 *		message is a datatype, but only some of those objects are
 *		datasets.
 *
 * Return:	Success:	Non-negative
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Wednesday, November  4, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_register_type(H5G_obj_t type, htri_t(*isa)(H5G_entry_t*, hid_t), const char *_desc)
{
    char	*desc = NULL;
    size_t	i;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_register_type, FAIL);

    assert(type>=0);
    assert(isa);
    assert(_desc);

    /* Copy the description */
    if (NULL==(desc=H5MM_strdup(_desc)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for object type description");

    /*
     * If the type is already registered then just update its entry without
     * moving it to the end
     */
    for (i=0; i<H5G_ntypes_g; i++) {
	if (H5G_type_g[i].type==type) {
	    H5G_type_g[i].isa = isa;
	    H5MM_xfree(H5G_type_g[i].desc);
	    H5G_type_g[i].desc = desc;
            HGOTO_DONE(SUCCEED);
	}
    }

    /* Increase table size */
    if (H5G_ntypes_g>=H5G_atypes_g) {
	size_t n = MAX(32, 2*H5G_atypes_g);
	H5G_typeinfo_t *x = H5MM_realloc(H5G_type_g,
					 n*sizeof(H5G_typeinfo_t));
	if (!x)
	    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for objec type table");
	H5G_atypes_g = n;
	H5G_type_g = x;
    }
    
    /* Add a new entry */
    H5G_type_g[H5G_ntypes_g].type = type;
    H5G_type_g[H5G_ntypes_g].isa = isa;
    H5G_type_g[H5G_ntypes_g].desc = desc; /*already copied*/
    H5G_ntypes_g++;

done:
    if (ret_value<0)
        H5MM_xfree(desc);
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_component
 *
 * Purpose:	Returns the pointer to the first component of the
 *		specified name by skipping leading slashes.  Returns
 *		the size in characters of the component through SIZE_P not
 *		counting leading slashes or the null terminator.
 *
 * Errors:
 *
 * Return:	Success:	Ptr into NAME.
 *
 *		Failure:	Ptr to the null terminator of NAME.
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Aug 11 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static const char *
H5G_component(const char *name, size_t *size_p)
{
    /* Use FUNC_ENTER_NOINIT here to avoid performance issues */
    FUNC_ENTER_NOINIT(H5G_component);

    assert(name);

    while ('/' == *name)
        name++;
    if (size_p)
        *size_p = HDstrcspn(name, "/");

    FUNC_LEAVE_NOAPI(name);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_basename
 *
 * Purpose:	Returns a pointer to the last component of the specified
 *		name. The length of the component is returned through SIZE_P.
 *		The base name is followed by zero or more slashes and a null
 *		terminator, but SIZE_P does not count the slashes or the null
 *		terminator.
 *
 * Note:	The base name of the root directory is a single slash.
 *
 * Return:	Success:	Ptr to base name.
 *
 *		Failure:	Ptr to the null terminator.
 *
 * Programmer:	Robb Matzke
 *              Thursday, September 17, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static const char *
H5G_basename(const char *name, size_t *size_p)
{
    size_t	i;
    
    FUNC_ENTER_NOINIT(H5G_basename);

    /* Find the end of the base name */
    i = HDstrlen(name);
    while (i>0 && '/'==name[i-1])
        --i;

    /* Skip backward over base name */
    while (i>0 && '/'!=name[i-1])
        --i;

    /* Watch out for root special case */
    if ('/'==name[i] && size_p)
        *size_p = 1;

    FUNC_LEAVE_NOAPI(name+i);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_normalize
 *
 * Purpose:	Returns a pointer to a new string which has duplicate and
 *              trailing slashes removed from it.
 *
 * Return:	Success:	Ptr to normalized name.
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *              Saturday, August 16, 2003
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static char *
H5G_normalize(const char *name)
{
    char *norm;         /* Pointer to the normalized string */
    size_t	s,d;    /* Positions within the strings */
    unsigned    last_slash;     /* Flag to indicate last character was a slash */
    char *ret_value;    /* Return value */
    
    FUNC_ENTER_NOINIT(H5G_normalize);

    /* Sanity check */
    assert(name);

    /* Duplicate the name, to return */
    if (NULL==(norm=H5MM_strdup(name)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for normalized string");

    /* Walk through the characters, omitting duplicated '/'s */
    s=d=0;
    last_slash=0;
    while(name[s]!='\0') {
        if(name[s]=='/')
            if(last_slash)
                ;
            else {
                norm[d++]=name[s];
                last_slash=1;
            } /* end else */
        else {
            norm[d++]=name[s];
            last_slash=0;
        } /* end else */
        s++;
    } /* end while */

    /* Terminate normalized string */
    norm[d]='\0';

    /* Check for final '/' on normalized name & eliminate it */
    if(d>1 && last_slash)
        norm[d-1]='\0';

    /* Set return value */
    ret_value=norm;

done:
    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5G_normalize() */


/*-------------------------------------------------------------------------
 * Function:	H5G_namei
 *
 * Purpose:	Translates a name to a symbol table entry.
 *
 *		If the specified name can be fully resolved, then this
 *		function returns the symbol table entry for the named object
 *		through the OBJ_ENT argument. The symbol table entry for the
 *		group containing the named object is returned through the
 *		GRP_ENT argument if it is non-null.  However, if the name
 *		refers to the root object then the GRP_ENT will be
 *		initialized with an undefined object header address.  The
 *		REST argument, if present, will point to the null terminator
 *		of NAME.
 *
 *		If the specified name cannot be fully resolved, then OBJ_ENT
 *		is initialized with the undefined object header address. The
 *		REST argument will point into the NAME argument to the start
 *		of the component that could not be located.  The GRP_ENT will
 *		contain the entry for the symbol table that was being
 *		searched at the time of the failure and will have an
 *		undefined object header address if the search failed at the
 *		root object. For instance, if NAME is `/foo/bar/baz' and the
 *		root directory exists and contains an entry for `foo', and
 *		foo is a group that contains an entry for bar, but bar is not
 *		a group, then the results will be that REST points to `baz',
 *		OBJ_ENT has an undefined object header address, and GRP_ENT
 *		is the symbol table entry for `bar' in `/foo'.
 *
 *		Every file has a root group whose name is `/'.  Components of
 *		a name are separated from one another by one or more slashes
 *		(/).  Slashes at the end of a name are ignored.  If the name
 *		begins with a slash then the search begins at the root group
 *		of the file containing LOC_ENT. Otherwise it begins at
 *		LOC_ENT.  The component `.' is a no-op, but `..' is not
 *		understood by this function (unless it appears as an entry in
 *		the symbol table).
 *
 *		Symbolic links are followed automatically, but if TARGET
 *		includes the H5G_TARGET_SLINK bit and the last component of
 *		the name is a symbolic link then that link is not followed.
 *		The *NLINKS value is decremented each time a link is followed
 *		and link traversal fails if the value would become negative.
 *		If NLINKS is the null pointer then a default value is used.
 *
 *		Mounted files are handled by calling H5F_mountpoint() after
 *		each step of the translation.  If the input argument to that
 *		function is a mount point then the argument shall be replaced
 *		with information about the root group of the mounted file.
 *		But if TARGET includes the H5G_TARGET_MOUNT bit and the last
 *		component of the name is a mount point then H5F_mountpoint()
 *		is not called and information about the mount point itself is
 *		returned.
 *		
 * Errors:
 *
 * Return:	Success:	Non-negative if name can be fully resolved.
 *				See above for values of REST, GRP_ENT, and
 *				OBJ_ENT.  NLINKS has been decremented for
 *				each symbolic link that was followed.
 *
 *		Failure:	Negative if the name could not be fully
 *				resolved. See above for values of REST,
 *				GRP_ENT, and OBJ_ENT.
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Aug 11 1997
 *
 * Modifications:
 *      Robb Matzke, 2002-03-28
 *      The component name buffer on the stack has been replaced by
 *      a dynamically allocated buffer on the heap in order to
 *      remove limitations on the length of a name component.
 *      There are two reasons that the buffer pointer is global:
 *        (1) We want to be able to reuse the buffer without
 *            allocating and freeing it each time this function is
 *            called.
 *        (2) We need to be able to free it from H5G_term_interface()
 *            when the library terminates.
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
 *      Modified to deep copies of symbol table entries
 *      Added `id to name' support.
 *
 *      Quincey Koziol, 2003-01-06
 *      Added "action" and "ent" parameters to allow different actions when
 *      working on the last component of a name.  (Specifically, this allows
 *      inserting an entry into a group, instead of trying to look it up)
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_namei(H5G_entry_t *loc_ent, const char *name, const char **rest/*out*/,
	  H5G_entry_t *grp_ent/*out*/, H5G_entry_t *obj_ent/*out*/,
	  unsigned target, int *nlinks/*out*/, H5G_namei_act_t action,
          H5G_entry_t *ent, hid_t dxpl_id)
{
    H5G_entry_t		  _grp_ent;     /*entry for current group	*/
    H5G_entry_t		  _obj_ent;     /*entry found			*/
    size_t		  nchars;	/*component name length		*/
    int			  _nlinks = H5G_NLINKS;
    const char		   *s = NULL;
    unsigned null_obj;          /* Flag to indicate this function was called with obj_ent set to NULL */
    unsigned null_grp;          /* Flag to indicate this function was called with grp_ent set to NULL */
    unsigned group_copy = 0;    /* Flag to indicate that the group entry is copied */
    unsigned last_comp = 0;     /* Flag to indicate that a component is the last component in the name */
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOINIT(H5G_namei);

    /* Set up "out" parameters */
    if (rest)
        *rest = name;
    if (!grp_ent) {
        grp_ent = &_grp_ent;
        null_grp = 1;
    } /* end if */
    else
        null_grp = 0;
    if (!obj_ent) {
        obj_ent = &_obj_ent;
        null_obj = 1;
    } /* end if */
    else
        null_obj = 0;
    if (!nlinks)
        nlinks = &_nlinks;
    
    /* Check args */
    if (!name || !*name)
        HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "no name given");
    if (!loc_ent)
        HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "no current working group");

    /*
     * Where does the searching start?  For absolute names it starts at the
     * root of the file; for relative names it starts at CWG.
     */
    /* Check if we need to get the root group's entry */
    if ('/' == *name) {
        H5G_t *tmp_grp;         /* Temporary pointer to root group of file */
     
        tmp_grp=H5G_rootof(loc_ent->file);
        assert(tmp_grp);

        /* Set the location entry to the root group's entry*/
        loc_ent=&(tmp_grp->ent);
    } /* end if */

    /* Deep copy of the symbol table entry */
    if (H5G_ent_copy(obj_ent, loc_ent,H5G_COPY_DEEP)<0)
        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTOPENOBJ, FAIL, "unable to copy entry");
    
    HDmemset(grp_ent, 0, sizeof(H5G_entry_t));
    grp_ent->header = HADDR_UNDEF;

    /* traverse the name */
    while ((name = H5G_component(name, &nchars)) && *name) {
        /* Update the "rest of name" pointer */
	if (rest)
            *rest = name;

	/*
	 * Copy the component name into a null-terminated buffer so
	 * we can pass it down to the other symbol table functions.
	 */
        if (nchars+1 > H5G_comp_alloc_g) {
            H5G_comp_alloc_g = MAX3(1024, 2*H5G_comp_alloc_g, nchars+1);
            H5G_comp_g = H5MM_realloc(H5G_comp_g, H5G_comp_alloc_g);
            if (!H5G_comp_g) {
                H5G_comp_alloc_g = 0;
                HGOTO_ERROR(H5E_SYM, H5E_NOSPACE, FAIL, "unable to allocate component buffer");
            }
        }
	HDmemcpy(H5G_comp_g, name, nchars);
	H5G_comp_g[nchars] = '\0';

	/*
	 * The special name `.' is a no-op.
	 */
	if ('.' == H5G_comp_g[0] && !H5G_comp_g[1]) {
	    name += nchars;
	    continue;
	}

	/*
	 * Advance to the next component of the name.
	 */
        /* If we've already copied a new entry into the group entry,
         * it needs to be freed before overwriting it with another entry
         */
	if(group_copy)
            H5G_free_ent_name(grp_ent);

        /* Transfer "ownership" of the entry's information to the group entry */
        H5G_ent_copy(grp_ent,obj_ent,H5G_COPY_SHALLOW);
	HDmemset(obj_ent, 0, sizeof(H5G_entry_t));
	obj_ent->header = HADDR_UNDEF;

	/* Set flag that we've copied a new entry into the group entry */
	group_copy =1;

        /* Check if this is the last component of the name */
        if(!((s=H5G_component(name+nchars, NULL)) && *s))
            last_comp=1;

        switch(action) {
            case H5G_NAMEI_TRAVERSE:
                if (H5G_stab_find(grp_ent, H5G_comp_g, obj_ent/*out*/, dxpl_id )<0) {
                    /*
                     * Component was not found in the current symbol table, possibly
                     * because GRP_ENT isn't a symbol table.
                     */
                    HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "component not found");
                }
                break;

            case H5G_NAMEI_INSERT:
                if(!last_comp) {
                    if (H5G_stab_find(grp_ent, H5G_comp_g, obj_ent/*out*/, dxpl_id )<0) {
                        /*
                         * Component was not found in the current symbol table, possibly
                         * because GRP_ENT isn't a symbol table.
                         */
                        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "component not found");
                    }
                } /* end if */
                else {
                    if (H5G_stab_insert(grp_ent, H5G_comp_g, ent, dxpl_id) < 0)
                        HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, FAIL, "unable to insert name");
                    HGOTO_DONE(SUCCEED);
                } /* end else */
                break;
        } /* end switch */

	/*
	 * If we found a symbolic link then we should follow it.  But if this
	 * is the last component of the name and the H5G_TARGET_SLINK bit of
	 * TARGET is set then we don't follow it.
	 */
	if(H5G_CACHED_SLINK==obj_ent->type &&
                (0==(target & H5G_TARGET_SLINK) || !last_comp)) {
	    if ((*nlinks)-- <= 0)
		HGOTO_ERROR (H5E_SYM, H5E_SLINK, FAIL, "too many symbolic links");
	    if (H5G_traverse_slink (grp_ent, obj_ent, nlinks, dxpl_id)<0)
		HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "symbolic link traversal failed");
	}

	/*
	 * Resolve mount points to the mounted group.  Do not do this step if
	 * the H5G_TARGET_MOUNT bit of TARGET is set and this is the last
	 * component of the name.
	 */
	if (0==(target & H5G_TARGET_MOUNT) || !last_comp)
	    H5F_mountpoint(obj_ent/*in,out*/);
	
	/* next component */
	name += nchars;
    } /* end while */
    
    /* Update the "rest of name" pointer */
    if (rest)
        *rest = name; /*final null */

done:
    /* If we started with a NULL obj_ent, free the entry information */
    if(null_obj)
        H5G_free_ent_name(obj_ent);
    /* If we started with a NULL grp_ent and we copied something into it, free the entry information */
    if(null_grp && group_copy)
        H5G_free_ent_name(grp_ent);
   FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_traverse_slink
 *
 * Purpose:	Traverses symbolic link.  The link head appears in the group
 *		whose entry is GRP_ENT and the link head entry is OBJ_ENT.
 *
 * Return:	Success:	Non-negative, OBJ_ENT will contain information
 *				about the object to which the link points and
 *				GRP_ENT will contain the information about
 *				the group in which the link tail appears.
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Friday, April 10, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_traverse_slink (H5G_entry_t *grp_ent/*in,out*/,
		    H5G_entry_t *obj_ent/*in,out*/,
		    int *nlinks/*in,out*/, hid_t dxpl_id)
{
    H5O_stab_t		stab_mesg;		/*info about local heap	*/
    const char		*clv = NULL;		/*cached link value	*/
    char		*linkval = NULL;	/*the copied link value	*/
    H5G_entry_t         tmp_grp_ent;            /* Temporary copy of group entry */
    H5RS_str_t          *tmp_user_path_r=NULL, *tmp_canon_path_r=NULL; /* Temporary pointer to object's user path & canonical path */
    const H5HL_t        *heap;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_traverse_slink, FAIL);

    /* Portably initialize the temporary group entry */
    HDmemset(&tmp_grp_ent,0,sizeof(H5G_entry_t));

    /* Get the link value */
    if (NULL==H5O_read (grp_ent, H5O_STAB_ID, 0, &stab_mesg, dxpl_id))
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to determine local heap address");

    if (NULL == (heap = H5HL_protect(grp_ent->file, dxpl_id, stab_mesg.heap_addr)))
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read protect link value")

    clv = H5HL_offset_into(grp_ent->file, heap, obj_ent->cache.slink.lval_offset);

    linkval = H5MM_xstrdup (clv);
    assert(linkval);

    if (H5HL_unprotect(grp_ent->file, dxpl_id, heap, stab_mesg.heap_addr) < 0)
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read unprotect link value")
		
    /* Hold the entry's name (& old_name) to restore later */
    tmp_user_path_r=obj_ent->user_path_r;
    obj_ent->user_path_r=NULL;
    tmp_canon_path_r=obj_ent->canon_path_r;
    obj_ent->canon_path_r=NULL;

    /* Free the names for the group entry */
    H5G_free_ent_name(grp_ent);

    /* Clone the group entry, so we can track the names properly */
    H5G_ent_copy(&tmp_grp_ent,grp_ent,H5G_COPY_DEEP);

    /* Traverse the link */
    if (H5G_namei (&tmp_grp_ent, linkval, NULL, grp_ent, obj_ent, H5G_TARGET_NORMAL, nlinks, H5G_NAMEI_TRAVERSE, NULL, dxpl_id))
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to follow symbolic link");

    /* Free the entry's names, we will use the original name for the object */
    H5G_free_ent_name(obj_ent);

    /* Restore previous name for object */
    obj_ent->user_path_r = tmp_user_path_r;
    tmp_user_path_r=NULL;
    obj_ent->canon_path_r = tmp_canon_path_r;
    tmp_canon_path_r=NULL;
	
done:
    /* Error cleanup */
    if(tmp_user_path_r)
        H5RS_decr(tmp_user_path_r);
    if(tmp_canon_path_r)
        H5RS_decr(tmp_canon_path_r);

    /* Release cloned copy of group entry */
    H5G_free_ent_name(&tmp_grp_ent);

    H5MM_xfree (linkval);
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_mkroot
 *
 * Purpose:	Creates a root group in an empty file and opens it.  If a
 *		root group is already open then this function immediately
 *		returns.   If ENT is non-null then it's the symbol table
 *		entry for an existing group which will be opened as the root
 *		group.  Otherwise a new root group is created and then
 *		opened.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Aug 11 1997
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_mkroot (H5F_t *f, hid_t dxpl_id, H5G_entry_t *ent)
{
    H5G_entry_t	new_root;		/*new root object		*/
    H5O_stab_t	stab;			/*symbol table message		*/
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5G_mkroot, FAIL);

    /* check args */
    assert(f);
    if (f->shared->root_grp)
        HGOTO_DONE(SUCCEED);

    /*
     * If there is no root object then create one. The root group always has
     * a hard link count of one since it's pointed to by the boot block.
     */
    if (!ent) {
	ent = &new_root;
        HDmemset(ent, 0, sizeof(H5G_entry_t));
	if (H5G_stab_create (f, dxpl_id, H5G_SIZE_HINT, ent/*out*/)<0)
	    HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "unable to create root group");
	if (1 != H5O_link (ent, 1, dxpl_id))
	    HGOTO_ERROR (H5E_SYM, H5E_LINK, FAIL, "internal error (wrong link count)");
    } else {
	/*
	 * Open the root object as a group.
	 */
	if (H5O_open (ent)<0)
	    HGOTO_ERROR (H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open root group");
	if (NULL==H5O_read (ent, H5O_STAB_ID, 0, &stab, dxpl_id)) {
	    H5O_close(ent);
	    HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "root object is not a group");
	}
	H5O_reset (H5O_STAB_ID, &stab);
    }

    /* Create the path names for the root group's entry */
    ent->user_path_r=H5RS_create("/");
    assert(ent->user_path_r);
    ent->canon_path_r=H5RS_create("/");
    assert(ent->canon_path_r);
    ent->user_path_hidden=0;

    /*
     * Create the group pointer.  Also decrement the open object count so we
     * don't count the root group as an open object.  The root group will
     * never be closed.
     */
    if (NULL==(f->shared->root_grp = H5FL_CALLOC (H5G_t)))
	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
    f->shared->root_grp->ent = *ent;
    f->shared->root_grp->nref = 1;
    assert (1==f->nopen_objs);
    f->nopen_objs = 0;

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_create
 *
 * Purpose:	Creates a new empty group with the specified name. The name
 *		is either an absolute name or is relative to LOC.
 *
 * Errors:
 *
 * Return:	Success:	A handle for the group.	 The group is opened
 *				and should eventually be close by calling
 *				H5G_close().
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Aug 11 1997
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static H5G_t *
H5G_create(H5G_entry_t *loc, const char *name, size_t size_hint, hid_t dxpl_id)
{
    H5G_t	*grp = NULL;	/*new group			*/
    H5F_t       *file = NULL;   /* File new group will be in    */
    unsigned    stab_init=0;    /* Flag to indicate that the symbol stable was created successfully */
    H5G_t	*ret_value;	/* Return value */

    FUNC_ENTER_NOAPI(H5G_create, NULL);

    /* check args */
    assert(loc);
    assert(name && *name);

    /* create an open group */
    if (NULL==(grp = H5FL_CALLOC(H5G_t)))
	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    /* What file is the group being added to? */
    if (NULL==(file=H5G_insertion_file(loc, name, dxpl_id)))
        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to locate insertion point");

    /* Create the group entry */
    if (H5G_stab_create(file, dxpl_id, size_hint, &(grp->ent)/*out*/) < 0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "can't create grp");
    stab_init=1;    /* Indicate that the symbol table information is valid */
    
    /* insert child name into parent */
    if(H5G_insert(loc,name,&(grp->ent), dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, NULL, "can't insert group");

    grp->nref = 1;

    /* Set return value */
    ret_value=grp;

done:
    if(ret_value==NULL) {
        /* Check if we need to release the file-oriented symbol table info */
        if(stab_init) {
            if(H5O_close(&(grp->ent))<0)
                HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, NULL, "unable to release object header");
            if(H5O_delete(file, dxpl_id,grp->ent.header)<0)
                HDONE_ERROR(H5E_SYM, H5E_CANTDELETE, NULL, "unable to delete object header");
        } /* end if */
        if(grp!=NULL)
            H5FL_FREE(H5G_t,grp);
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_isa
 *
 * Purpose:	Determines if an object has the requisite messages for being
 *		a group.
 *
 * Return:	Success:	TRUE if the required group messages are
 *				present; FALSE otherwise.
 *
 *		Failure:	FAIL if the existence of certain messages
 *				cannot be determined.
 *
 * Programmer:	Robb Matzke
 *              Monday, November  2, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static htri_t
H5G_isa(H5G_entry_t *ent, hid_t dxpl_id)
{
    htri_t	ret_value;
    
    FUNC_ENTER_NOAPI(H5G_isa, FAIL);

    assert(ent);

    if ((ret_value=H5O_exists(ent, H5O_STAB_ID, 0, dxpl_id))<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header");

done:
    FUNC_LEAVE_NOAPI(ret_value);
}
    

/*-------------------------------------------------------------------------
 * Function:	H5G_open
 *
 * Purpose:	Opens an existing group.  The group should eventually be
 *		closed by calling H5G_close().
 *
 * Return:	Success:	Ptr to a new group.
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *		Monday, January	 5, 1998
 *
 * Modifications:
 *      Modified to call H5G_open_oid - QAK - 3/17/99
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G_open(H5G_entry_t *loc, const char *name, hid_t dxpl_id)
{
    H5G_t		*grp = NULL;
    H5G_t		*ret_value = NULL;
    H5G_entry_t         ent;    /* group symbol table entry	*/

    FUNC_ENTER_NOAPI(H5G_open, NULL);

    /* Check args */
    assert(loc);
    assert(name && *name);

    /* Open the object, making sure it's a group */
    if (H5G_find(loc, name, NULL, &ent/*out*/, dxpl_id) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, NULL, "group not found");

    /* Open the group object */
    if ((grp=H5G_open_oid(&ent, dxpl_id)) ==NULL)
        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, NULL, "not found");

    /* Set return value */
    ret_value = grp;

done:
    if (!ret_value && grp)
        H5FL_FREE(H5G_t,grp);

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_open_oid
 *
 * Purpose:	Opens an existing group.  The group should eventually be
 *		closed by calling H5G_close().
 *
 * Return:	Success:	Ptr to a new group.
 *
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *	    Wednesday, March	17, 1999
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
 *      Added a deep copy of the symbol table entry
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G_open_oid(H5G_entry_t *ent, hid_t dxpl_id)
{
    H5G_t		*grp = NULL;
    H5G_t		*ret_value = NULL;
    H5O_stab_t		mesg;

    FUNC_ENTER_NOAPI(H5G_open_oid, NULL);

    /* Check args */
    assert(ent);

    /* Open the object, making sure it's a group */
    if (NULL==(grp = H5FL_CALLOC(H5G_t)))
        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    /* Copy over (take ownership) of the group entry object */
    H5G_ent_copy(&(grp->ent),ent,H5G_COPY_SHALLOW);

    /* Grab the object header */
    if (H5O_open(&(grp->ent)) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open group");
    if (NULL==H5O_read (&(grp->ent), H5O_STAB_ID, 0, &mesg, dxpl_id)) {
        H5O_close(&(grp->ent));
        HGOTO_ERROR (H5E_SYM, H5E_CANTOPENOBJ, NULL, "not a group");
    }
    grp->nref = 1;

    /* Set return value */
    ret_value = grp;

done:
    if (!ret_value && grp)
        H5FL_FREE(H5G_t,grp);

    FUNC_LEAVE_NOAPI(ret_value);
}

#ifdef NOT_YET

/*-------------------------------------------------------------------------
 * Function:	H5G_reopen
 *
 * Purpose:	Reopens a group by incrementing the open count.
 *
 * Return:	Success:	The GRP argument.
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *		Monday, January	 5, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G_reopen(H5G_t *grp)
{
    H5G_t *ret_value;   /* Return value */

    FUNC_ENTER_NOAPI(H5G_reopen, NULL);

    assert(grp);
    assert(grp->nref > 0);

    grp->nref++;

    /* Set return value */
    ret_value=grp;

done:
    FUNC_LEAVE_NOAPI(ret_value);
}
#endif /* NOT_YET */


/*-------------------------------------------------------------------------
 * Function:	H5G_close
 *
 * Purpose:	Closes the specified group.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		Monday, January	 5, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_close(H5G_t *grp)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5G_close, FAIL);

    /* Check args */
    assert(grp);
    assert(grp->nref > 0);

    if (1 == grp->nref) {
	assert (grp!=H5G_rootof(H5G_fileof(grp)));
	if (H5O_close(&(grp->ent)) < 0)
	    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to close");
	grp->nref = 0;
	H5FL_FREE (H5G_t,grp);
    } else {
	--grp->nref;
    }

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_rootof
 *
 * Purpose:	Return a pointer to the root group of the file.  If the file
 *		is part of a virtual file then the root group of the virtual
 *		file is returned.
 *
 * Return:	Success:	Ptr to the root group of the file.  Do not
 *				free the pointer -- it points directly into
 *				the file struct.
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Tuesday, October 13, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static H5G_t *
H5G_rootof(H5F_t *f)
{
    H5G_t *ret_value;   /* Return value */

    FUNC_ENTER_NOAPI(H5G_rootof, NULL);
    while (f->mtab.parent)
        f = f->mtab.parent;

    /* Set return value */
    ret_value=f->shared->root_grp;

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_insert
 *
 * Purpose:	Inserts a symbol table entry into the group graph.
 *
 * Errors:
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		Friday, September 19, 1997
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_insert(H5G_entry_t *loc, const char *name, H5G_entry_t *ent, hid_t dxpl_id)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5G_insert, FAIL);

    /* Check args. */
    assert (loc);
    assert (name && *name);
    assert (ent);

    /*
     * Lookup and insert the name -- it shouldn't exist yet.
     */
    if (H5G_namei(loc, name, NULL, NULL, NULL, H5G_TARGET_NORMAL, NULL, H5G_NAMEI_INSERT, ent, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_EXISTS, FAIL, "already exists");

    /*
     * Insert the object into a symbol table.
     */
    if (H5O_link(ent, 1, dxpl_id) < 0)
	HGOTO_ERROR(H5E_SYM, H5E_LINK, FAIL, "unable to increment hard link count");

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_find
 *
 * Purpose:	Finds an object with the specified NAME at location LOC.  On
 *		successful return, GRP_ENT (if non-null) will be initialized
 *		with the symbol table information for the group in which the
 *		object appears (it will have an undefined object header
 *		address if the object is the root object) and OBJ_ENT will be
 *		initialized with the symbol table entry for the object
 *		(OBJ_ENT is optional when the caller is interested only in
 * 		the existence of the object).
 *
 * Errors:
 *
 * Return:	Success:	Non-negative, see above for values of GRP_ENT
 *				and OBJ_ENT.
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Aug 12 1997
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_find(H5G_entry_t *loc, const char *name,
	 H5G_entry_t *grp_ent/*out*/, H5G_entry_t *obj_ent/*out*/, hid_t dxpl_id)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5G_find, FAIL);

    /* check args */
    assert (loc);
    assert (name && *name);

    if (H5G_namei(loc, name, NULL, grp_ent, obj_ent, H5G_TARGET_NORMAL, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found");

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_entof
 *
 * Purpose:	Returns a pointer to the entry for a group.
 *
 * Return:	Success:	Ptr to group entry
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Tuesday, March 24, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5G_entry_t *
H5G_entof (H5G_t *grp)
{
    /* Use FUNC_ENTER_NOINIT here to avoid performance issues */
    FUNC_ENTER_NOINIT(H5G_entof);

    FUNC_LEAVE_NOAPI(grp ? &(grp->ent) : NULL);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_fileof
 *
 * Purpose:	Returns the file to which the specified group belongs.
 *
 * Return:	Success:	File pointer.
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Tuesday, March 24, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5F_t *
H5G_fileof (H5G_t *grp)
{
    /* Use FUNC_ENTER_NOINIT here to avoid performance issues */
    FUNC_ENTER_NOINIT(H5G_fileof);

    assert (grp);

    FUNC_LEAVE_NOAPI(grp->ent.file);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_loc
 *
 * Purpose:	Given an object ID return a symbol table entry for the
 *		object.
 *
 * Return:	Success:	Group pointer.
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Tuesday, March 24, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5G_entry_t *
H5G_loc (hid_t loc_id)
{
    H5F_t	*f;
    H5G_entry_t	*ret_value=NULL;
    H5G_t	*group=NULL;
    H5T_t	*dt=NULL;
    H5D_t	*dset=NULL;
    H5A_t	*attr=NULL;

    FUNC_ENTER_NOAPI(H5G_loc, NULL);

    switch (H5I_get_type(loc_id)) {
        case H5I_FILE:
            if (NULL==(f=H5I_object (loc_id)))
                HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, NULL, "invalid file ID");
            if (NULL==(ret_value=H5G_entof(H5G_rootof(f))))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry for root group");
            break;

        case H5I_GENPROP_CLS:
        case H5I_GENPROP_LST:
            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of property list");
            
        case H5I_ERROR_CLASS:
        case H5I_ERROR_MSG:
        case H5I_ERROR_STACK:
            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of error class, message or stack");

        case H5I_GROUP:
            if (NULL==(group=H5I_object (loc_id)))
                HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, NULL, "invalid group ID");
            if (NULL==(ret_value=H5G_entof(group)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of group");
            break;

        case H5I_DATATYPE:
            if (NULL==(dt=H5I_object(loc_id)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid type ID");
            if (NULL==(ret_value=H5T_entof(dt)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of datatype");
            break;

        case H5I_DATASPACE:
            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of dataspace");

        case H5I_DATASET:
            if (NULL==(dset=H5I_object(loc_id)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid data ID");
            if (NULL==(ret_value=H5D_entof(dset)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of dataset");
            break;

        case H5I_ATTR:
            if (NULL==(attr=H5I_object(loc_id)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid attribute ID");
            if (NULL==(ret_value=H5A_entof(attr)))
                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of attribute");
            break;
                
        case H5I_REFERENCE:
            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "unable to get symbol table entry of reference");

        case H5I_NGROUPS:
        case H5I_BADID:
        case H5I_FILE_CLOSING:
        case H5I_VFL:
            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object ID");
    }

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_link
 *
 * Purpose:	Creates a link from NEW_NAME to CUR_NAME.  See H5Glink() for
 *		full documentation.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Monday, April  6, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_link (H5G_entry_t *cur_loc, const char *cur_name, H5G_entry_t *new_loc,
	  const char *new_name, H5G_link_t type, unsigned namei_flags, hid_t dxpl_id)
{
    H5G_entry_t		cur_obj;	/*entry for the link tail	*/
    unsigned            cur_obj_init=0; /* Flag to indicate that the current object is initialized */
    H5G_entry_t		grp_ent;	/*ent for grp containing link hd*/
    H5O_stab_t		stab_mesg;	/*symbol table message		*/
    const char		*rest = NULL;	/*last component of new name	*/
    char		*norm_cur_name = NULL;	/* Pointer to normalized current name */
    char		*norm_new_name = NULL;	/* Pointer to normalized current name */
    char		_comp[1024];	/*name component		*/
    size_t		nchars;		/*characters in component	*/
    size_t		offset;		/*offset to sym-link value	*/
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_link, FAIL);

    /* Check args */
    assert (cur_loc);
    assert (new_loc);
    assert (cur_name && *cur_name);
    assert (new_name && *new_name);

    /* Get normalized copies of the current and new names */
    if((norm_cur_name=H5G_normalize(cur_name))==NULL)
        HGOTO_ERROR (H5E_SYM, H5E_BADVALUE, FAIL, "can't normalize name");
    if((norm_new_name=H5G_normalize(new_name))==NULL)
        HGOTO_ERROR (H5E_SYM, H5E_BADVALUE, FAIL, "can't normalize name");

    switch (type) {
        case H5G_LINK_SOFT:
            /*
             * Lookup the the new_name so we can get the group which will contain
             * the new entry.  The entry shouldn't exist yet.
             */
            if (H5G_namei(new_loc, norm_new_name, &rest, &grp_ent, NULL, 
                            H5G_TARGET_NORMAL, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)>=0)
                HGOTO_ERROR (H5E_SYM, H5E_EXISTS, FAIL, "already exists");
            H5E_clear (NULL); /*it's okay that we didn't find it*/
            rest = H5G_component (rest, &nchars);

            /*
             * There should be one component left.  Make sure it's null
             * terminated and that `rest' points to it.
             */
            if (rest[nchars]) {
                if (nchars+1 > sizeof _comp) {
                    HGOTO_ERROR (H5E_SYM, H5E_COMPLEN, FAIL, "name component is too long");
                } else {
                    HDmemcpy (_comp, rest, nchars);
                    _comp[nchars] = '\0';
                    rest = _comp;
                }
            }

            /*
             * Add the link-value to the local heap for the symbol table which
             * will contain the link.
             */
            if (NULL==H5O_read (&grp_ent, H5O_STAB_ID, 0, &stab_mesg, dxpl_id))
                HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "unable to determine local heap address");
            if ((size_t)(-1)==(offset=H5HL_insert (grp_ent.file, dxpl_id,
                   stab_mesg.heap_addr, HDstrlen(norm_cur_name)+1, norm_cur_name)))
                HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "unable to write link value to local heap");
            H5O_reset (H5O_STAB_ID, &stab_mesg);

            /*
             * Create a symbol table entry for the link.  The object header is
             * undefined and the cache contains the link-value offset.
             */
            HDmemset (&cur_obj, 0, sizeof cur_obj);
            cur_obj.header = HADDR_UNDEF;
            cur_obj.file = grp_ent.file;
            cur_obj.type = H5G_CACHED_SLINK;
            cur_obj.cache.slink.lval_offset = offset;
            cur_obj_init=1;     /* Indicate that the cur_obj struct is initialized */

            /*
             * Insert the link head in the symbol table.  This shouldn't ever
             * fail because we've already checked that the link head doesn't
             * exist and the file is writable (because the local heap is
             * writable).  But if it does, the only side effect is that the local
             * heap has some extra garbage in it.
             */
            if (H5G_stab_insert (&grp_ent, rest, &cur_obj, dxpl_id)<0)
                HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "unable to create new name/link for object");
            break;

        case H5G_LINK_HARD:
            if (H5G_namei(cur_loc, norm_cur_name, NULL, NULL, &cur_obj, namei_flags, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
                HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "source object not found");
            cur_obj_init=1;     /* Indicate that the cur_obj struct is initialized */
            if (H5G_insert (new_loc, norm_new_name, &cur_obj, dxpl_id)<0)
                HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "unable to create new name/link for object");
            break;

        default:
            HGOTO_ERROR (H5E_SYM, H5E_BADVALUE, FAIL, "unrecognized link type");
    }

done:
    /* Free the group's ID to name buffer, if creating a soft link */
    if(type == H5G_LINK_SOFT)
        H5G_free_ent_name(&grp_ent);
			  
    /* Free the ID to name buffer */
    if(cur_obj_init)
        H5G_free_ent_name(&cur_obj);

    /* Free the normalized path names */
    if(norm_cur_name)
        H5MM_xfree(norm_cur_name);
    if(norm_new_name)
        H5MM_xfree(norm_new_name);

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_get_type
 *
 * Purpose:	Returns the type of object pointed to by `ent'.
 *
 * Return:	Success:	An object type defined in H5Gpublic.h
 *
 *		Failure:	H5G_UNKNOWN
 *
 * Programmer:	Robb Matzke
 *              Wednesday, November  4, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
H5G_obj_t
H5G_get_type(H5G_entry_t *ent, hid_t dxpl_id)
{
    htri_t	isa;
    size_t	i;
    H5G_obj_t   ret_value=H5G_UNKNOWN;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_get_type, H5G_UNKNOWN);

    for (i=H5G_ntypes_g; i>0; --i) {
	if ((isa=(H5G_type_g[i-1].isa)(ent, dxpl_id))<0) {
	    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, H5G_UNKNOWN, "unable to determine object type");
	} else if (isa) {
	    HGOTO_DONE(H5G_type_g[i-1].type);
	}
    }

    if (0==i)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, H5G_UNKNOWN, "unable to determine object type");

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_get_objinfo
 *
 * Purpose:	Returns information about an object.
 *
 * Return:	Success:	Non-negative with info about the object
 *				returned through STATBUF if it isn't the null
 *				pointer.
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Monday, April 13, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_get_objinfo (H5G_entry_t *loc, const char *name, hbool_t follow_link,
		 H5G_stat_t *statbuf/*out*/, hid_t dxpl_id)
{
    H5O_stab_t		stab_mesg;
    H5G_entry_t		grp_ent, obj_ent;
    const char		*s = NULL;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_get_objinfo, FAIL);

    assert (loc);
    assert (name && *name);
    if (statbuf) HDmemset (statbuf, 0, sizeof *statbuf);

    /* Find the object's symbol table entry */
    if (H5G_namei(loc, name, NULL, &grp_ent/*out*/, &obj_ent/*out*/,
		   (unsigned)(follow_link?H5G_TARGET_NORMAL:H5G_TARGET_SLINK), NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to stat object");

    /*
     * Initialize the stat buf.  Symbolic links aren't normal objects and
     * therefore don't have much of the normal info.  However, the link value
     * length is specific to symbolic links.
     */
    if (statbuf) {
	if (H5G_CACHED_SLINK==obj_ent.type) {
            const H5HL_t *heap;

	    /* Named object is a symbolic link */
	    if (NULL == H5O_read(&grp_ent, H5O_STAB_ID, 0, &stab_mesg, dxpl_id))
		HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read symbolic link value")

            if (NULL == (heap = H5HL_protect(grp_ent.file, dxpl_id, stab_mesg.heap_addr)))
                HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read protect link value")

            s = H5HL_offset_into(grp_ent.file, heap, obj_ent.cache.slink.lval_offset);

	    statbuf->linklen = HDstrlen(s) + 1; /*count the null terminator*/

            if (H5HL_unprotect(grp_ent.file, dxpl_id, heap, stab_mesg.heap_addr) < 0)
                HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read unprotect link value")

	    statbuf->objno = 0;
	    statbuf->nlink = 0;
	    statbuf->type = H5G_LINK;
	    statbuf->mtime = 0;
	} else {
	    /* Some other type of object */
	    statbuf->objno = obj_ent.header;
	    statbuf->nlink = H5O_link (&obj_ent, 0, dxpl_id);
	    if (NULL==H5O_read(&obj_ent, H5O_MTIME_ID, 0, &(statbuf->mtime), dxpl_id)) {
                H5E_clear(NULL);
                if (NULL==H5O_read(&obj_ent, H5O_MTIME_NEW_ID, 0, &(statbuf->mtime), dxpl_id)) {
                    H5E_clear(NULL);
                    statbuf->mtime = 0;
                }
	    }
	    statbuf->type = H5G_get_type(&obj_ent, dxpl_id);
	    H5E_clear(NULL); /*clear errors resulting from checking type*/

            /* Get object header information */
            if(H5O_get_info(&obj_ent, &(statbuf->ohdr), dxpl_id)<0)
                HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "unable to get object header information")
	}

        /* Common code to retrieve the file's fileno */
        if(H5F_get_fileno(obj_ent.file,&statbuf->fileno)<0)
            HGOTO_ERROR (H5E_FILE, H5E_BADVALUE, FAIL, "unable to read fileno");
    }

done:
    /* Free the ID to name buffers */
    H5G_free_ent_name(&grp_ent);
    H5G_free_ent_name(&obj_ent);

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * 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:
 *
 *-------------------------------------------------------------------------
 */
static herr_t 
H5G_get_num_objs(H5G_entry_t *loc, hsize_t *num_objs, hid_t dxpl_id)
{
    herr_t		ret_value;
    
    FUNC_ENTER_NOAPI(H5G_get_num_objs, FAIL);

    /* Sanity check */
    assert(loc);
    assert(loc->type==H5G_CACHED_STAB);
    assert(num_objs);

    /* Reset the number of objects in the group */
    *num_objs = 0;

    /* Iterate over the group members */
    if ((ret_value = H5B_iterate (loc->file, dxpl_id, H5B_SNODE,
              H5G_node_sumup, loc->cache.stab.btree_addr, num_objs))<0)
        HERROR (H5E_SYM, H5E_CANTINIT, "iteration operator failed");
        
done:
    FUNC_LEAVE_NOAPI(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:
 *
 *-------------------------------------------------------------------------
 */
static ssize_t 
H5G_get_objname_by_idx(H5G_entry_t *loc, hsize_t idx, char* name, size_t size, hid_t dxpl_id)
{
    H5G_bt_ud3_t	udata;          /* Iteration information */
    ssize_t		ret_value;      /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_get_objname_by_idx, FAIL);

    /* Sanity check */
    assert(loc);
    assert(loc->type==H5G_CACHED_STAB);

    /* Set iteration information */
    udata.idx = idx;
    udata.num_objs = 0;
    udata.ent = loc;
    udata.name = NULL;

    /* Iterate over the group members */
    if ((ret_value = H5B_iterate (loc->file, dxpl_id, H5B_SNODE,
              H5G_node_name, loc->cache.stab.btree_addr, &udata))<0)
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "iteration operator failed");
    
    /* Get the length of the name */
    ret_value = (ssize_t)HDstrlen(udata.name);

    /* Copy the name into the user's buffer, if given */
    if(name) {
        HDstrncpy(name, udata.name, MIN((size_t)(ret_value+1),size));
        if((size_t)ret_value >= size)
            name[size-1]='\0';
    } /* end if */

done:
    /* Free the duplicated name */
    if(udata.name!=NULL)
        H5MM_xfree(udata.name);
    FUNC_LEAVE_NOAPI(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:
 *
 *-------------------------------------------------------------------------
 */
static H5G_obj_t 
H5G_get_objtype_by_idx(H5G_entry_t *loc, hsize_t idx, hid_t dxpl_id)
{
    H5G_bt_ud3_t    udata;              /* User data for B-tree callback */
    H5G_obj_t	    ret_value;          /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_get_objtype_by_idx, H5G_UNKNOWN);
    
    /* Sanity check */
    assert(loc);
    assert(loc->type==H5G_CACHED_STAB);

    /* Set iteration information */
    udata.idx = idx;
    udata.num_objs = 0;
    udata.ent = loc;
    
    /* Iterate over the group members */
    if (H5B_iterate (loc->file, dxpl_id, H5B_SNODE,
              H5G_node_type, loc->cache.stab.btree_addr, &udata)<0)
	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "iteration operator failed");
    
    ret_value = udata.type;

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_linkval
 *
 * Purpose:	Returns the value of a symbolic link.
 *
 * Return:	Success:	Non-negative, with at most SIZE bytes of the
 *				link value copied into the BUF buffer.  If the
 *				link value is larger than SIZE characters
 *				counting the null terminator then the BUF
 *				result will not be null terminated.
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Monday, April 13, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_linkval (H5G_entry_t *loc, const char *name, size_t size, char *buf/*out*/, hid_t dxpl_id)
{
    const char		*s = NULL;
    H5G_entry_t		grp_ent, obj_ent;
    H5O_stab_t		stab_mesg;
    const H5HL_t        *heap;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_linkval, FAIL);

    /*
     * Get the symbol table entry for the link head and the symbol table
     * entry for the group in which the link head appears.
     */
    if (H5G_namei(loc, name, NULL, &grp_ent/*out*/, &obj_ent/*out*/,
		   H5G_TARGET_SLINK, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "symbolic link was not found");
    if (H5G_CACHED_SLINK!=obj_ent.type)
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "object is not a symbolic link");

    /*
     * Get the address of the local heap for the link value and a pointer
     * into that local heap.
     */
    if (NULL==H5O_read (&grp_ent, H5O_STAB_ID, 0, &stab_mesg, dxpl_id))
	HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "unable to determine local heap address");

    if (NULL == (heap = H5HL_protect(grp_ent.file, dxpl_id, stab_mesg.heap_addr)))
        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read protect link value")
    
    s = H5HL_offset_into(grp_ent.file, heap, obj_ent.cache.slink.lval_offset);

    /* Copy to output buffer */
    if (size>0 && buf)
	HDstrncpy (buf, s, size);

    if (H5HL_unprotect(grp_ent.file, dxpl_id, heap, stab_mesg.heap_addr) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read unprotect link value")

done:
    /* Free the ID to name buffers */
    H5G_free_ent_name(&grp_ent);
    H5G_free_ent_name(&obj_ent);

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_set_comment
 *
 * Purpose:	(Re)sets the comment for an object.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Monday, July 20, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_set_comment(H5G_entry_t *loc, const char *name, const char *buf, hid_t dxpl_id)
{
    H5G_entry_t	obj_ent;
    H5O_name_t	comment;
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_set_comment, FAIL);

    /* Get the symbol table entry for the object */
    if (H5G_namei(loc, name, NULL, NULL, &obj_ent/*out*/, H5G_TARGET_NORMAL,
		  NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found");

    /* Remove the previous comment message if any */
    if (H5O_remove(&obj_ent, H5O_NAME_ID, 0, dxpl_id)<0)
        H5E_clear(NULL);

    /* Add the new message */
    if (buf && *buf) {
	comment.s = H5MM_xstrdup(buf);
	if (H5O_modify(&obj_ent, H5O_NAME_ID, H5O_NEW_MESG, 0, 1, &comment, dxpl_id)<0)
	    HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to set comment object header message");
	H5O_reset(H5O_NAME_ID, &comment);
    }

done:
    /* Free the ID to name buffer */
    H5G_free_ent_name(&obj_ent);

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_get_comment
 *
 * Purpose:	Get the comment value for an object.
 *
 * Return:	Success:	Number of bytes in the comment including the
 *				null terminator.  Zero if the object has no
 *				comment.
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Monday, July 20, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static int
H5G_get_comment(H5G_entry_t *loc, const char *name, size_t bufsize, char *buf, hid_t dxpl_id)
{
    H5O_name_t	comment;
    H5G_entry_t	obj_ent;
    int	ret_value;
    
    FUNC_ENTER_NOAPI(H5G_get_comment, FAIL);

    /* Get the symbol table entry for the object */
    if (H5G_namei(loc, name, NULL, NULL, &obj_ent/*out*/, H5G_TARGET_NORMAL,
		  NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found");

    /* Get the message */
    comment.s = NULL;
    if (NULL==H5O_read(&obj_ent, H5O_NAME_ID, 0, &comment, dxpl_id)) {
	if (buf && bufsize>0)
            buf[0] = '\0';
	ret_value = 0;
    } else {
        if(buf && bufsize)
	   HDstrncpy(buf, comment.s, bufsize);
	ret_value = (int)HDstrlen(comment.s);
	H5O_reset(H5O_NAME_ID, &comment);
    }

done:
    /* Free the ID to name buffer */
    H5G_free_ent_name(&obj_ent);

    FUNC_LEAVE_NOAPI(ret_value);
}
    

/*-------------------------------------------------------------------------
 * Function:	H5G_unlink
 *
 * Purpose:	Unlink a name from a group.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Thursday, September 17, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_unlink(H5G_entry_t *loc, const char *name, hid_t dxpl_id)
{
    H5G_entry_t		grp_ent, obj_ent;
    size_t		len;
    const char		*base=NULL;
    char		*norm_name = NULL;	/* Pointer to normalized name */
    H5G_stat_t		statbuf;        /* Info about object to unlink */
    H5RS_str_t          *name_r;        /* Ref-counted version of name */
    herr_t      ret_value=SUCCEED;       /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_unlink, FAIL);
    assert(loc);
    assert(name && *name);

    /* Get normalized copy of the name */
    if((norm_name=H5G_normalize(name))==NULL)
        HGOTO_ERROR (H5E_SYM, H5E_BADVALUE, FAIL, "can't normalize name");

    /* Reset the group entries to known values in a portable way */
    HDmemset(&grp_ent,0,sizeof(H5G_entry_t));
    HDmemset(&obj_ent,0,sizeof(H5G_entry_t));

    /* Get object type before unlink */
    if (H5G_get_objinfo(loc, norm_name, FALSE, &statbuf, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found");

    /* Get the entry for the group that contains the object to be unlinked */
    if (H5G_namei(loc, norm_name, NULL, &grp_ent, &obj_ent,
		  H5G_TARGET_SLINK|H5G_TARGET_MOUNT, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found");
    if (!H5F_addr_defined(grp_ent.header))
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "no containing group specified");
    if (NULL==(base=H5G_basename(norm_name, &len)) || '/'==*base)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "problems obtaining object base name");
    
    /* Remove the name from the symbol table */
    if (H5G_stab_remove(&grp_ent, base, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to unlink name from symbol table");

    /* Search the open IDs and replace names for unlinked object */
    name_r=H5RS_wrap(norm_name);
    assert(name_r);
    if (H5G_replace_name(statbuf.type, &obj_ent, name_r, NULL, NULL, NULL, OP_UNLINK )<0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to replace name");
    H5RS_decr(name_r);

done:
    /* Free the ID to name buffers */
    H5G_free_ent_name(&grp_ent);
    H5G_free_ent_name(&obj_ent);

    /* Free the normalized path name */
    if(norm_name)
        H5MM_xfree(norm_name);

    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_move
 *
 * Purpose:	Atomically rename an object.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *              Friday, September 25, 1998
 *
 * Modifications:
 *
 *	Raymond Lu
 *	Thursday, April 18, 2002
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_move(H5G_entry_t *src_loc, const char *src_name, H5G_entry_t *dst_loc, 
		const char *dst_name, hid_t dxpl_id)
{
    H5G_stat_t		sb;
    char		*linkval=NULL;
    size_t		lv_size=32;
    H5G_entry_t         obj_ent;        /* Object entry for object being moved */
    H5RS_str_t         *src_name_r;     /* Ref-counted version of src name */
    H5RS_str_t         *dst_name_r;     /* Ref-counted version of dest name */
    herr_t      ret_value=SUCCEED;      /* Return value */
    
    FUNC_ENTER_NOAPI(H5G_move, FAIL);
    assert(src_loc);
    assert(dst_loc);
    assert(src_name && *src_name);
    assert(dst_name && *dst_name);

    if (H5G_get_objinfo(src_loc, src_name, FALSE, &sb, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "object not found");
    if (H5G_LINK==sb.type) {
	/*
	 * When renaming a symbolic link we rename the link but don't change
	 * the value of the link.
	 */
	do {
	    if (NULL==(linkval=H5MM_realloc(linkval, 2*lv_size)))
		HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate space for symbolic link value");
	    linkval[lv_size-1] = '\0';
	    if (H5G_linkval(src_loc, src_name, lv_size, linkval, dxpl_id)<0)
		HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read symbolic link value");
	} while (linkval[lv_size-1]);
	if (H5G_link(src_loc, linkval, dst_loc, dst_name, H5G_LINK_SOFT,
		     H5G_TARGET_NORMAL, dxpl_id)<0)
	    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to rename symbolic link");
	H5MM_xfree(linkval);
	
    } else {
	/*
	 * Rename the object.
	 */
	if (H5G_link(src_loc, src_name, dst_loc, dst_name, H5G_LINK_HARD,
		     H5G_TARGET_MOUNT, dxpl_id)<0)
	    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to register new name for object");
    }

    /* Search the open ID list and replace names for the move operation
     * This has to be done here because H5G_link and H5G_unlink have 
     * internal object entries, and do not modify the entries list
    */
    if (H5G_namei(src_loc, src_name, NULL, NULL, &obj_ent, H5G_TARGET_NORMAL|H5G_TARGET_SLINK, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id))
	HGOTO_ERROR (H5E_SYM, H5E_NOTFOUND, FAIL, "unable to follow symbolic link");
    src_name_r=H5RS_wrap(src_name);
    assert(src_name_r);
    dst_name_r=H5RS_wrap(dst_name);
    assert(dst_name_r);
    if (H5G_replace_name(sb.type, &obj_ent, src_name_r, src_loc, dst_name_r, dst_loc, OP_MOVE )<0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to replace name ");
    H5RS_decr(src_name_r);
    H5RS_decr(dst_name_r);
    H5G_free_ent_name(&obj_ent);

    /* Remove the old name */
    if (H5G_unlink(src_loc, src_name, dxpl_id)<0)
	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to deregister old object name");

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_insertion_file
 *
 * Purpose:	Given a location and name that specifies a not-yet-existing
 *		object return the file into which the object is about to be
 *		inserted.
 *
 * Return:	Success:	File pointer
 *
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Wednesday, October 14, 1998
 *
 * Modifications:
 *
 *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 18 Sep 2002
 *      Added `id to name' support.
 *
 *-------------------------------------------------------------------------
 */
H5F_t *
H5G_insertion_file(H5G_entry_t *loc, const char *name, hid_t dxpl_id)
{
    H5F_t      *ret_value;       /* Return value */

    FUNC_ENTER_NOAPI(H5G_insertion_file, NULL);

    assert(loc);
    assert(name && *name);

    /* Check if the location the object will be inserted into is part of a
     * file mounting chain (either a parent or a child) and perform a more
     * rigorous determination of the location's file (which traverses into
     * mounted files, etc.).
     */
    if(H5F_has_mount(loc->file) || H5F_is_mount(loc->file)) {
        const char	*rest;
        H5G_entry_t	grp_ent;
        size_t	size;

        /*
         * Look up the name to get the containing group and to make sure the name
         * doesn't already exist.
         */
        if (H5G_namei(loc, name, &rest, &grp_ent, NULL, H5G_TARGET_NORMAL, NULL, H5G_NAMEI_TRAVERSE, NULL, dxpl_id)>=0) {
            H5G_free_ent_name(&grp_ent);
            HGOTO_ERROR(H5E_SYM, H5E_EXISTS, NULL, "name already exists");
        } /* end if */
        H5E_clear(NULL);

        /* Make sure only the last component wasn't resolved */
        rest = H5G_component(rest, &size);
        assert(*rest && size>0);
        rest = H5G_component(rest+size, NULL);
        if (*rest) {
            H5G_free_ent_name(&grp_ent);
            HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, NULL, "insertion point not found");
        } /* end if */

        /* Set return value */
        ret_value=grp_ent.file;

        /* Free the ID to name buffer */
        H5G_free_ent_name(&grp_ent);
    } /* end if */
    else
        /* Use the location's file */
        ret_value=loc->file;

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_free_grp_name
 *
 * Purpose:	Free the 'ID to name' buffers.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: August 22, 2002
 *
 * Comments: Used now only on the root group close, in H5F_close()
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_free_grp_name(H5G_t *grp)
{
    H5G_entry_t *ent;           /* Group object's entry */
    herr_t ret_value=SUCCEED;   /* Return value */
 
    FUNC_ENTER_NOAPI(H5G_free_grp_name, FAIL);
 
    /* Check args */
    assert(grp);
    assert(grp->nref > 0);

    /* Get the entry for the group */
    if (NULL==( ent = H5G_entof(grp)))
        HGOTO_ERROR (H5E_SYM, H5E_CANTINIT, FAIL, "cannot get entry");

    /* Free the entry */
    H5G_free_ent_name(ent);

done:
     FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function:	H5G_free_ent_name
 *
 * Purpose:	Free the 'ID to name' buffers.
 *
 * Return:	Success
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: August 22, 2002
 *
 * Comments: 
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_free_ent_name(H5G_entry_t *ent)
{
    herr_t      ret_value=SUCCEED;       /* Return value */
 
    FUNC_ENTER_NOAPI(H5G_free_ent_name, FAIL);
 
    /* Check args */
    assert(ent);

    if(ent->user_path_r) {
        H5RS_decr(ent->user_path_r);
        ent->user_path_r=NULL;
    } /* end if */
    if(ent->canon_path_r) {
        H5RS_decr(ent->canon_path_r);
        ent->canon_path_r=NULL;
    } /* end if */
 
done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function: H5G_replace_name
 *
 * Purpose: Search the list of open IDs and replace names according to a
 *              particular operation.  The operation occured on the LOC
 *              entry, which had SRC_NAME previously.  The new name (if there
 *              is one) is DST_NAME.  Additional entry location information
 *              (currently only needed for the 'move' operation) is passed
 *              in SRC_LOC and DST_LOC.
 *
 * Return: Success: 0, Failure: -1
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: June 11, 2002
 *
 * Comments: 
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_replace_name(int type, H5G_entry_t *loc,
    H5RS_str_t *src_name, H5G_entry_t *src_loc,
    H5RS_str_t *dst_name, H5G_entry_t *dst_loc, H5G_names_op_t op )
{
    H5G_names_t names;          /* Structure to hold operation information for callback */
    unsigned search_group=0;    /* Flag to indicate that groups are to be searched */
    unsigned search_dataset=0;  /* Flag to indicate that datasets are to be searched */
    unsigned search_datatype=0; /* Flag to indicate that datatypes are to be searched */
    herr_t  ret_value = SUCCEED;       

    FUNC_ENTER_NOAPI(H5G_replace_name, FAIL);

    /* Set up common information for callback */
    names.src_name=src_name;
    names.dst_name=dst_name;
    names.loc=loc;
    names.src_loc=src_loc;
    names.dst_loc=dst_loc;
    names.op=op;

    /* Determine which types of IDs need to be operated on */
    switch(type) {
        /* Object is a group  */
        case H5G_GROUP:
            /* Search and replace names through group IDs */
            search_group=1;
            break;

        /* Object is a dataset */
        case H5G_DATASET:
            /* Search and replace names through dataset IDs */
            search_dataset=1;
            break;

        /* Object is a named datatype */
        case H5G_TYPE:
            /* Search and replace names through datatype IDs */
            search_datatype=1;
            break;

        case H5G_UNKNOWN:   /* We pass H5G_UNKNOWN as object type when we need to search all IDs */
        case H5G_LINK:      /* Symbolic links might resolve to any object, so we need to search all IDs */
            /* Check if we will need to search groups */
            if(H5I_nmembers(H5I_GROUP)>0)
                search_group=1;

            /* Check if we will need to search datasets */
            if(H5I_nmembers(H5I_DATASET)>0)
                search_dataset=1;

            /* Check if we will need to search datatypes */
            if(H5I_nmembers(H5I_DATATYPE)>0)
                search_datatype=1;
            break;

        default:
            HGOTO_ERROR (H5E_DATATYPE, H5E_BADTYPE, FAIL, "not valid object type");
    } /* end switch */

    /* Search through group IDs */
    if(search_group)
        H5I_search(H5I_GROUP, H5G_replace_ent, &names);

    /* Search through dataset IDs */
    if(search_dataset)
        H5I_search(H5I_DATASET, H5G_replace_ent, &names);

    /* Search through datatype IDs */
    if(search_datatype)
        H5I_search(H5I_DATATYPE, H5G_replace_ent, &names);

done: 
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function: H5G_common_path
 *
 * Purpose: Determine if one path is a valid prefix of another path
 *
 * Return: TRUE for valid prefix, FALSE for not a valid prefix, FAIL
 *              on error
 *
 * Programmer: Quincey Koziol, koziol@ncsa.uiuc.edu
 *
 * Date: September 24, 2002
 *
 * Comments: 
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static htri_t
H5G_common_path(const H5RS_str_t *fullpath_r, const H5RS_str_t *prefix_r)
{
    const char *fullpath;       /* Pointer to actual fullpath string */
    const char *prefix;         /* Pointer to actual prefix string */
    size_t  nchars1,nchars2;    /* Number of characters in components */
    htri_t ret_value=FALSE;     /* Return value */
  
    FUNC_ENTER_NOINIT(H5G_common_path);
  
    /* Get component of each name */
    fullpath=H5RS_get_str(fullpath_r);
    assert(fullpath);
    fullpath=H5G_component(fullpath,&nchars1);
    assert(fullpath);
    prefix=H5RS_get_str(prefix_r);
    assert(prefix);
    prefix=H5G_component(prefix,&nchars2);
    assert(prefix);

    /* Check if we have a real string for each component */
    while(*fullpath && *prefix) {
        /* Check that the components we found are the same length */
        if(nchars1==nchars2) {
            /* Check that the two components are equal */
            if(HDstrncmp(fullpath,prefix,nchars1)==0) {
                /* Advance the pointers in the names */
                fullpath+=nchars1;
                prefix+=nchars2;

                /* Get next component of each name */
                fullpath=H5G_component(fullpath,&nchars1);
                assert(fullpath);
                prefix=H5G_component(prefix,&nchars2);
                assert(prefix);
            } /* end if */
            else
                HGOTO_DONE(FALSE);
        } /* end if */
        else
            HGOTO_DONE(FALSE);
    } /* end while */

    /* If we reached the end of the prefix path to check, it must be a valid prefix */
    if(*prefix=='\0')
        ret_value=TRUE;

done:
    FUNC_LEAVE_NOAPI(ret_value);
}


/*-------------------------------------------------------------------------
 * Function: H5G_replace_ent
 *
 * Purpose: H5I_search callback function to replace group entry names
 *
 * Return: Success: 0, Failure: -1
 *
 * Programmer: Pedro Vicente, pvn@ncsa.uiuc.edu
 *
 * Date: June 5, 2002
 *
 * Comments: 
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static int
H5G_replace_ent(void *obj_ptr, hid_t obj_id, void *key)
{
    const H5G_names_t *names = (const H5G_names_t *)key;        /* Get operation's information */
    H5G_entry_t *ent = NULL;    /* Group entry for object that the ID refers to */
    H5F_t *top_ent_file;        /* Top file in entry's mounted file chain */
    H5F_t *top_loc_file;        /* Top file in location's mounted file chain */
    herr_t      ret_value = SUCCEED;       /* Return value */
  
    FUNC_ENTER_NOINIT(H5G_replace_ent);
  
    assert(obj_ptr);
 
    /* Get the symbol table entry */
    switch(H5I_get_type(obj_id)) {
        case H5I_GROUP:
            ent = H5G_entof((H5G_t*)obj_ptr);
            break;

        case H5I_DATASET:
            ent = H5D_entof((H5D_t*)obj_ptr);
            break;

        case H5I_DATATYPE:
            /* Avoid non-named datatypes */
            if(!H5T_is_named((H5T_t*)obj_ptr))
                HGOTO_DONE(SUCCEED); /* Do not exit search over IDs */
 
            ent = H5T_entof((H5T_t*)obj_ptr);
            break;

        default:
            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown data object");
    } /* end switch */
    assert(ent);
  
    switch(names->op) {
        /*-------------------------------------------------------------------------
        * OP_MOUNT
        *-------------------------------------------------------------------------
        */
        case OP_MOUNT:
            if(ent->file->mtab.parent && H5RS_cmp(ent->user_path_r,ent->canon_path_r)) {
                /* Find the "top" file in the chain of mounted files */
                top_ent_file=ent->file->mtab.parent;
                while(top_ent_file->mtab.parent!=NULL)
                    top_ent_file=top_ent_file->mtab.parent;
            } /* end if */
            else
                top_ent_file=ent->file;

            /* Check for entry being in correct file (or mounted file) */
            if(top_ent_file->shared == names->loc->file->shared) {
                /* Check if the source is along the entry's path */
                /* (But not actually the entry itself) */
                if(H5G_common_path(ent->user_path_r,names->src_name) &&
                        H5RS_cmp(ent->user_path_r,names->src_name)!=0) {
                    /* Hide the user path */
                    ent->user_path_hidden++;
                } /* end if */
            } /* end if */
            break;

        /*-------------------------------------------------------------------------
        * OP_UNMOUNT
        *-------------------------------------------------------------------------
        */
        case OP_UNMOUNT:
            if(ent->file->mtab.parent) {
                /* Find the "top" file in the chain of mounted files for the entry */
                top_ent_file=ent->file->mtab.parent;
                while(top_ent_file->mtab.parent!=NULL)
                    top_ent_file=top_ent_file->mtab.parent;
            } /* end if */
            else
                top_ent_file=ent->file;

            if(names->loc->file->mtab.parent) {
                /* Find the "top" file in the chain of mounted files for the location */
                top_loc_file=names->loc->file->mtab.parent;
                while(top_loc_file->mtab.parent!=NULL)
                    top_loc_file=top_loc_file->mtab.parent;
            } /* end if */
            else
                top_loc_file=names->loc->file;

            if(ent->user_path_hidden) {
                /* If the ID's entry is not in the file we operated on, skip it */
                if(top_ent_file->shared == top_loc_file->shared) {
                    if(H5G_common_path(ent->user_path_r,names->src_name)) {
                        /* Un-hide the user path */
                        ent->user_path_hidden--;
                    } /* end if */
                } /* end if */
            } /* end if */
            else {
                /* If the ID's entry is not in the file we operated on, skip it */
                if(top_ent_file->shared == top_loc_file->shared) {
                    if(ent->user_path_r && H5G_common_path(ent->user_path_r,names->src_name)) {
                        /* Free user path */
                        if(ent->user_path_r!=NULL) {
                            H5RS_decr(ent->user_path_r);
                            ent->user_path_r=NULL;
                        } /* end if */
                    } /* end if */
                } /* end if */
            } /* end else */
            break;

        /*-------------------------------------------------------------------------
        * OP_UNLINK
        *-------------------------------------------------------------------------
        */
        case OP_UNLINK:
            /* If the ID's entry is not in the file we operated on, skip it */
            if(ent->file->shared == names->loc->file->shared) {
                /* Check if we are referring to the same object */
                if(H5F_addr_eq(ent->header, names->loc->header)) {
                    /* Check if the object was opened with the same canonical path as the one being moved */
                    if(H5RS_cmp(ent->canon_path_r,names->loc->canon_path_r)==0) {
                        /* Free user path */
                        if(ent->user_path_r!=NULL) {
                            H5RS_decr(ent->user_path_r);
                            ent->user_path_r=NULL;
                        } /* end if */
                    } /* end if */
                } /* end if */
                else {
                    /* Check if the location being unlinked is in the canonical path for the current object */
                    if(H5G_common_path(ent->canon_path_r,names->loc->canon_path_r)) {
                        /* Free user path */
                        if(ent->user_path_r!=NULL) {
                            H5RS_decr(ent->user_path_r);
                            ent->user_path_r=NULL;
                        } /* end if */
                    } /* end if */
                } /* end else */
            } /* end if */
            break;

        /*-------------------------------------------------------------------------
        * OP_MOVE
        *-------------------------------------------------------------------------
        */
        case OP_MOVE: /* H5Gmove case, check for relative names case */
            /* If the ID's entry is not in the file we operated on, skip it */
            if(ent->file->shared == names->loc->file->shared) {
                H5RS_str_t *src_path_r; /* Full user path of source name */
                H5RS_str_t *dst_path_r; /* Full user path of destination name */
                H5RS_str_t *canon_src_path_r;   /* Copy of canonical part of source path */
                H5RS_str_t *canon_dst_path_r;   /* Copy of canonical part of destination path */

                /* Make certain that the source and destination names are full (not relative) paths */
                if(*(H5RS_get_str(names->src_name))!='/') {
                    const char *src_name;         /* Pointer to raw string of src_name */
                    char *src_path;         /* Full user path of source name */
                    const char *src_user_path;    /* Pointer to raw string of src path */
                    size_t src_path_len;    /* Length of the source path */
                    unsigned need_sep;      /* Flag to indicate if separator is needed */

                    /* Get the pointer to the raw src user path */
                    src_user_path=H5RS_get_str(names->src_loc->user_path_r);

                    /* Get the length of the name for the source group's user path */
                    src_path_len=HDstrlen(src_user_path);

                    /* Determine if there is a trailing separator in the name */
                    if(src_user_path[src_path_len-1]=='/')
                        need_sep=0;
                    else
                        need_sep=1;

                    /* Get the pointer to the raw src user path */
                    src_name=H5RS_get_str(names->src_name);

                    /* Add in the length needed for the '/' separator and the relative path */
                    src_path_len+=HDstrlen(src_name)+need_sep;

                    /* Allocate space for the path */
                    if(NULL==(src_path = H5FL_BLK_MALLOC(str_buf,src_path_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");

                    HDstrcpy(src_path,src_user_path);
                    if(need_sep)
                        HDstrcat(src_path,"/");
                    HDstrcat(src_path,src_name);

                    /* Create reference counted string for src path */
                    src_path_r=H5RS_own(src_path);
                } /* end if */
                else
                    src_path_r=H5RS_dup(names->src_name);
                if(*(H5RS_get_str(names->dst_name))!='/') {
                    const char *dst_name;         /* Pointer to raw string of dst_name */
                    char *dst_path;         /* Full user path of destination name */
                    const char *dst_user_path;    /* Pointer to raw string of dst path */
                    size_t dst_path_len;    /* Length of the destination path */
                    unsigned need_sep;      /* Flag to indicate if separator is needed */

                    /* Get the pointer to the raw dst user path */
                    dst_user_path=H5RS_get_str(names->dst_loc->user_path_r);

                    /* Get the length of the name for the destination group's user path */
                    dst_path_len=HDstrlen(dst_user_path);

                    /* Determine if there is a trailing separator in the name */
                    if(dst_user_path[dst_path_len-1]=='/')
                        need_sep=0;
                    else
                        need_sep=1;

                    /* Get the pointer to the raw dst user path */
                    dst_name=H5RS_get_str(names->dst_name);

                    /* Add in the length needed for the '/' separator and the relative path */
                    dst_path_len+=HDstrlen(dst_name)+need_sep;

                    /* Allocate space for the path */
                    if(NULL==(dst_path = H5FL_BLK_MALLOC(str_buf,dst_path_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");

                    HDstrcpy(dst_path,dst_user_path);
                    if(need_sep)
                        HDstrcat(dst_path,"/");
                    HDstrcat(dst_path,dst_name);

                    /* Create reference counted string for dst path */
                    dst_path_r=H5RS_own(dst_path);
                } /* end if */
                else
                    dst_path_r=H5RS_dup(names->dst_name);

                /* Get the canonical parts of the source and destination names */

                /* Check if the object being moved was accessed through a mounted file */
                if(H5RS_cmp(names->loc->user_path_r,names->loc->canon_path_r)!=0) {
                    size_t non_canon_name_len;   /* Length of non-canonical part of name */

                    /* Get current string lengths */
                    non_canon_name_len=H5RS_len(names->loc->user_path_r)-H5RS_len(names->loc->canon_path_r);

                    canon_src_path_r=H5RS_create(H5RS_get_str(src_path_r)+non_canon_name_len);
                    canon_dst_path_r=H5RS_create(H5RS_get_str(dst_path_r)+non_canon_name_len);
                } /* end if */
                else {
                    canon_src_path_r=H5RS_dup(src_path_r);
                    canon_dst_path_r=H5RS_dup(dst_path_r);
                } /* end else */

                /* Check if the link being changed in the file is along the canonical path for this object */
                if(H5G_common_path(ent->canon_path_r,canon_src_path_r)) {
                    size_t user_dst_len;    /* Length of destination user path */
                    size_t canon_dst_len;   /* Length of destination canonical path */
                    const char *old_user_path;    /* Pointer to previous user path */
                    char *new_user_path;    /* Pointer to new user path */
                    char *new_canon_path;   /* Pointer to new canonical path */
                    const char *tail_path;  /* Pointer to "tail" of path */
                    size_t tail_len;    /* Pointer to "tail" of path */
                    char *src_canon_prefix;     /* Pointer to source canonical path prefix of component which is moving */
                    size_t src_canon_prefix_len;/* Length of the source canonical path prefix */
                    char *dst_canon_prefix;     /* Pointer to destination canonical path prefix of component which is moving */
                    size_t dst_canon_prefix_len;/* Length of the destination canonical path prefix */
                    char *user_prefix;      /* Pointer to user path prefix of component which is moving */
                    size_t user_prefix_len; /* Length of the user path prefix */
                    char *src_comp;     /* The source name of the component which is actually changing */
                    char *dst_comp;     /* The destination name of the component which is actually changing */
                    const char *canon_src_path;   /* pointer to canonical part of source path */
                    const char *canon_dst_path;   /* pointer to canonical part of destination path */

                    /* Get the pointers to the raw strings */
                    canon_src_path=H5RS_get_str(canon_src_path_r);
                    canon_dst_path=H5RS_get_str(canon_dst_path_r);

                    /* Get the source & destination components */
                    src_comp=HDstrrchr(canon_src_path,'/');
                    assert(src_comp);
                    dst_comp=HDstrrchr(canon_dst_path,'/');
                    assert(dst_comp);

                    /* Find the canonical prefixes for the entry */
                    src_canon_prefix_len=HDstrlen(canon_src_path)-HDstrlen(src_comp);
                    if(NULL==(src_canon_prefix = H5MM_malloc(src_canon_prefix_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
                    HDstrncpy(src_canon_prefix,canon_src_path,src_canon_prefix_len);
                    src_canon_prefix[src_canon_prefix_len]='\0';

                    dst_canon_prefix_len=HDstrlen(canon_dst_path)-HDstrlen(dst_comp);
                    if(NULL==(dst_canon_prefix = H5MM_malloc(dst_canon_prefix_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
                    HDstrncpy(dst_canon_prefix,canon_dst_path,dst_canon_prefix_len);
                    dst_canon_prefix[dst_canon_prefix_len]='\0';

                    /* Hold this for later use */
                    old_user_path=H5RS_get_str(ent->user_path_r);

                    /* Find the user prefix for the entry */
                    user_prefix_len=HDstrlen(old_user_path)-H5RS_len(ent->canon_path_r);
                    if(NULL==(user_prefix = H5MM_malloc(user_prefix_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
                    HDstrncpy(user_prefix,old_user_path,user_prefix_len);
                    user_prefix[user_prefix_len]='\0';

                    /* Set the tail path info */
                    tail_path=old_user_path+user_prefix_len+src_canon_prefix_len+HDstrlen(src_comp);
                    tail_len=HDstrlen(tail_path);

                    /* Get the length of the destination paths */
                    user_dst_len=user_prefix_len+dst_canon_prefix_len+HDstrlen(dst_comp)+tail_len;
                    canon_dst_len=dst_canon_prefix_len+HDstrlen(dst_comp)+tail_len;

                    /* Allocate space for the new user path */
                    if(NULL==(new_user_path = H5FL_BLK_MALLOC(str_buf,user_dst_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
                    
                    /* Allocate space for the new canonical path */
                    if(NULL==(new_canon_path = H5FL_BLK_MALLOC(str_buf,canon_dst_len+1)))
                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
                    
                    /* Create the new names */
                    HDstrcpy(new_user_path,user_prefix);
                    HDstrcat(new_user_path,dst_canon_prefix);
                    HDstrcat(new_user_path,dst_comp);
                    HDstrcat(new_user_path,tail_path);
                    HDstrcpy(new_canon_path,dst_canon_prefix);
                    HDstrcat(new_canon_path,dst_comp);
                    HDstrcat(new_canon_path,tail_path);

                    /* Release the old user & canonical paths */
                    H5RS_decr(ent->user_path_r);
                    H5RS_decr(ent->canon_path_r);

                    /* Take ownership of the new user & canonical paths */
                    ent->user_path_r=H5RS_own(new_user_path);
                    ent->canon_path_r=H5RS_own(new_canon_path);

                    /* Free the extra paths allocated */
                    H5MM_xfree(src_canon_prefix);
                    H5MM_xfree(dst_canon_prefix);
                    H5MM_xfree(user_prefix);
                } /* end if */


                /* Free the extra paths allocated */
                H5RS_decr(src_path_r);
                H5RS_decr(dst_path_r);
                H5RS_decr(canon_src_path_r);
                H5RS_decr(canon_dst_path_r);
            } /* end if */
            break;

        default:
            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid call");
    } /* end switch */
 
done:
    FUNC_LEAVE_NOAPI(ret_value); 
}