path: root/src/H5Gint.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:	H5Gint.c
 *		April 5 2007
 *		Quincey Koziol
 *
 * Purpose:	General use, "internal" routines for groups.
 *
 *-------------------------------------------------------------------------
 */

/****************/
/* Module Setup */
/****************/

#define H5G_PACKAGE /*suppress error about including H5Gpkg   */

/* Interface initialization */
#define H5_INTERFACE_INIT_FUNC H5G_init_int_interface

/***********/
/* Headers */
/***********/
#include "H5private.h"   /* Generic Functions                        */
#include "H5Eprivate.h"  /* Error handling                           */
#include "H5FOprivate.h" /* File objects                             */
#include "H5Gpkg.h"      /* Groups                                   */
#include "H5Iprivate.h"  /* IDs                                      */
#include "H5Lprivate.h"  /* Links                                    */
#include "H5MMprivate.h" /* Memory management                        */

/****************/
/* Local Macros */
/****************/

/******************/
/* Local Typedefs */
/******************/

/* User data for path traversal routine for "insertion file" routine */
typedef struct {
    H5G_loc_t *loc; /* Pointer to the location for insertion */
} H5G_trav_ins_t;

/* User data for application-style iteration over links in a group */
typedef struct {
    hid_t              gid;     /* The group ID for the application callback */
    H5G_link_iterate_t lnk_op;  /* Application callback */
    void *             op_data; /* Application's op data */
} H5G_iter_appcall_ud_t;

/* User data for recursive traversal over links from a group */
typedef struct {
    hid_t           gid;           /* The group ID for the starting group */
    H5G_loc_t *     curr_loc;      /* Location of starting group */
    hid_t           lapl_id;       /* LAPL for walking across links */
    hid_t           dxpl_id;       /* DXPL for operations */
    H5_index_t      idx_type;      /* Index to use */
    H5_iter_order_t order;         /* Iteration order within index */
    H5SL_t *        visited;       /* Skip list for tracking visited nodes */
    char *          path;          /* Path name of the link */
    size_t          curr_path_len; /* Current length of the path in the buffer */
    size_t          path_buf_size; /* Size of path buffer */
    H5L_iterate_t   op;            /* Application callback */
    void *          op_data;       /* Application's op data */
} H5G_iter_visit_ud_t;

/********************/
/* Package Typedefs */
/********************/

/********************/
/* Local Prototypes */
/********************/

static herr_t H5G_open_oid(H5G_t *grp, hid_t dxpl_id);

/*********************/
/* Package Variables */
/*********************/

/* Declare a free list to manage the H5G_t struct */
H5FL_DEFINE(H5G_t);
H5FL_DEFINE(H5G_shared_t);

/* Declare the free list to manage H5_obj_t's */
H5FL_DEFINE(H5_obj_t);

/*****************************/
/* Library Private Variables */
/*****************************/

/*******************/
/* Local Variables */
/*******************/

/*--------------------------------------------------------------------------
NAME
   H5G_init_int_interface -- Initialize interface-specific information
USAGE
    herr_t H5G_init_int_interface()
RETURNS
    Non-negative on success/Negative on failure
DESCRIPTION
    Initializes any interface-specific data or routines.  (Just calls
    H5G__init() currently).

--------------------------------------------------------------------------*/
static herr_t
H5G_init_int_interface(void)
{
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    /* Funnel all work to H5G__init() */
    if (H5G__init() < 0)
        HGOTO_ERROR(H5E_FUNC, H5E_CANTINIT, FAIL, "interface initialization failed")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5G_init_int_interface() */

/*-------------------------------------------------------------------------
 * Function:	H5G__create_named
 *
 * Purpose:	Internal routine to create a new "named" group.
 *
 * Return:	Success:	Non-NULL, pointer to new group object.
 *
 *		Failure:	NULL
 *
 * Programmer:  Quincey Koziol
 *	        April 5, 2007
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G__create_named(const H5G_loc_t *loc, const char *name, hid_t lcpl_id, hid_t gcpl_id, hid_t gapl_id,
                  hid_t dxpl_id)
{
    H5O_obj_create_t ocrt_info;        /* Information for object creation */
    H5G_obj_create_t gcrt_info;        /* Information for group creation */
    H5G_t *          ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments */
    HDassert(loc);
    HDassert(name && *name);
    HDassert(lcpl_id != H5P_DEFAULT);
    HDassert(gcpl_id != H5P_DEFAULT);
    HDassert(gapl_id != H5P_DEFAULT);
    HDassert(dxpl_id != H5P_DEFAULT);

    /* Set up group creation info */
    gcrt_info.gcpl_id    = gcpl_id;
    gcrt_info.cache_type = H5G_NOTHING_CACHED;
    HDmemset(&gcrt_info.cache, 0, sizeof(gcrt_info.cache));

    /* Set up object creation information */
    ocrt_info.obj_type = H5O_TYPE_GROUP;
    ocrt_info.crt_info = &gcrt_info;
    ocrt_info.new_obj  = NULL;

    /* Create the new group and link it to its parent group */
    if (H5L_link_object(loc, name, &ocrt_info, lcpl_id, gapl_id, dxpl_id) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to create and link to group")
    HDassert(ocrt_info.new_obj);

    /* Set the return value */
    ret_value = (H5G_t *)ocrt_info.new_obj;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G__create_named() */

/*-------------------------------------------------------------------------
 * 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.
 *
 * 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
 *		Aug 11 1997
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G__create(H5F_t *file, H5G_obj_create_t *gcrt_info, hid_t dxpl_id)
{
    H5G_t *  grp       = NULL; /*new group			*/
    unsigned oloc_init = 0;    /* Flag to indicate that the group object location was created successfully */
    H5G_t *  ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */
    HDassert(file);
    HDassert(gcrt_info->gcpl_id != H5P_DEFAULT);
    HDassert(dxpl_id != H5P_DEFAULT);

    /* create an open group */
    if (NULL == (grp = H5FL_CALLOC(H5G_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
    if (NULL == (grp->shared = H5FL_CALLOC(H5G_shared_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    /* Create the group object header */
    if (H5G__obj_create(file, dxpl_id, gcrt_info, &(grp->oloc) /*out*/) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to create group object header")
    oloc_init = 1; /* Indicate that the object location information is valid */

    /* Add group to list of open objects in file */
    if (H5FO_top_incr(grp->oloc.file, grp->oloc.addr) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTINC, NULL, "can't incr object ref. count")
    if (H5FO_insert(grp->oloc.file, grp->oloc.addr, grp->shared, TRUE) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, NULL, "can't insert group into list of open objects")

    /* Set the count of times the object is opened */
    grp->shared->fo_count = 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 (oloc_init) {
            if (H5O_dec_rc_by_loc(&(grp->oloc), dxpl_id) < 0)
                HDONE_ERROR(H5E_SYM, H5E_CANTDEC, NULL,
                            "unable to decrement refcount on newly created object")
            if (H5O_close(&(grp->oloc)) < 0)
                HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, NULL, "unable to release object header")
            if (H5O_delete(file, dxpl_id, grp->oloc.addr) < 0)
                HDONE_ERROR(H5E_SYM, H5E_CANTDELETE, NULL, "unable to delete object header")
        } /* end if */
        if (grp != NULL) {
            if (grp->shared != NULL)
                grp->shared = H5FL_FREE(H5G_shared_t, grp->shared);
            grp = H5FL_FREE(H5G_t, grp);
        } /* end if */
    }     /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G__create() */

/*-------------------------------------------------------------------------
 * Function:	H5G__open_name
 *
 * Purpose:	Opens an existing group by name.
 *
 * Return:	Success:	Ptr to a new group.
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		Monday, August	27, 2007
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G__open_name(const H5G_loc_t *loc, const char *name, hid_t gapl_id, hid_t dxpl_id)
{
    H5G_t *    grp = NULL;        /* Group to open */
    H5G_loc_t  grp_loc;           /* Location used to open group */
    H5G_name_t grp_path;          /* Opened object group hier. path */
    H5O_loc_t  grp_oloc;          /* Opened object object location */
    hbool_t    loc_found = FALSE; /* Location at 'name' found */
    H5O_type_t obj_type;          /* Type of object at location */
    H5G_t *    ret_value = NULL;  /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check args */
    HDassert(loc);
    HDassert(name);

    /* Set up opened group location to fill in */
    grp_loc.oloc = &grp_oloc;
    grp_loc.path = &grp_path;
    H5G_loc_reset(&grp_loc);

    /* Find the group object using the gapl passed in */
    if (H5G_loc_find(loc, name, &grp_loc /*out*/, gapl_id, dxpl_id) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, NULL, "group not found")
    loc_found = TRUE;

    /* Check that the object found is the correct type */
    if (H5O_obj_type(&grp_oloc, &obj_type, dxpl_id) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, NULL, "can't get object type")
    if (obj_type != H5O_TYPE_GROUP)
        HGOTO_ERROR(H5E_SYM, H5E_BADTYPE, NULL, "not a group")

    /* Open the group */
    if ((grp = H5G_open(&grp_loc, dxpl_id)) == NULL)
        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open group")

    /* Set return value */
    ret_value = grp;

done:
    if (!ret_value)
        if (loc_found && H5G_loc_free(&grp_loc) < 0)
            HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, NULL, "can't free location")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G__open_name() */

/*-------------------------------------------------------------------------
 * 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
 *
 *-------------------------------------------------------------------------
 */
H5G_t *
H5G_open(const H5G_loc_t *loc, hid_t dxpl_id)
{
    H5G_t *       grp = NULL;       /* Group opened */
    H5G_shared_t *shared_fo;        /* Shared group object */
    H5G_t *       ret_value = NULL; /* Return value */

    FUNC_ENTER_NOAPI(NULL)

    /* Check args */
    HDassert(loc);

    /* Allocate the group structure */
    if (NULL == (grp = H5FL_CALLOC(H5G_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "can't allocate space for group")

    /* Shallow copy (take ownership) of the group location object */
    if (H5O_loc_copy(&(grp->oloc), loc->oloc, H5_COPY_SHALLOW) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, NULL, "can't copy object location")
    if (H5G_name_copy(&(grp->path), loc->path, H5_COPY_SHALLOW) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, NULL, "can't copy path")

    /* Check if group was already open */
    if ((shared_fo = (H5G_shared_t *)H5FO_opened(grp->oloc.file, grp->oloc.addr)) == NULL) {

        /* Clear any errors from H5FO_opened() */
        H5E_clear_stack(NULL);

        /* Open the group object */
        if (H5G_open_oid(grp, dxpl_id) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, NULL, "not found")

        /* Add group to list of open objects in file */
        if (H5FO_insert(grp->oloc.file, grp->oloc.addr, grp->shared, FALSE) < 0) {
            grp->shared = H5FL_FREE(H5G_shared_t, grp->shared);
            HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, NULL, "can't insert group into list of open objects")
        } /* end if */

        /* Increment object count for the object in the top file */
        if (H5FO_top_incr(grp->oloc.file, grp->oloc.addr) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTINC, NULL, "can't increment object count")

        /* Set open object count */
        grp->shared->fo_count = 1;
    } /* end if */
    else {
        /* Point to shared group info */
        grp->shared = shared_fo;

        /* Increment shared reference count */
        shared_fo->fo_count++;

        /* Check if the object has been opened through the top file yet */
        if (H5FO_top_count(grp->oloc.file, grp->oloc.addr) == 0) {
            /* Open the object through this top file */
            if (H5O_open(&(grp->oloc)) < 0)
                HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open object header")
        } /* end if */

        /* Increment object count for the object in the top file */
        if (H5FO_top_incr(grp->oloc.file, grp->oloc.addr) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTINC, NULL, "can't increment object count")
    } /* end else */

    /* Set return value */
    ret_value = grp;

done:
    if (!ret_value && grp) {
        H5O_loc_free(&(grp->oloc));
        H5G_name_free(&(grp->path));
        grp = H5FL_FREE(H5G_t, grp);
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_open() */

/*-------------------------------------------------------------------------
 * 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
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_open_oid(H5G_t *grp, hid_t dxpl_id)
{
    hbool_t obj_opened = FALSE;
    herr_t  ret_value  = SUCCEED;

    FUNC_ENTER_NOAPI_NOINIT

    /* Check args */
    HDassert(grp);

    /* Allocate the shared information for the group */
    if (NULL == (grp->shared = H5FL_CALLOC(H5G_shared_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")

    /* Grab the object header */
    if (H5O_open(&(grp->oloc)) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group")
    obj_opened = TRUE;

    /* Check if this object has the right message(s) to be treated as a group */
    if ((H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, dxpl_id) <= 0) &&
        (H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, dxpl_id) <= 0))
        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "not a group")

done:
    if (ret_value < 0) {
        if (obj_opened)
            H5O_close(&(grp->oloc));
        if (grp->shared)
            grp->shared = H5FL_FREE(H5G_shared_t, grp->shared);
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_open_oid() */

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

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    HDassert(grp && grp->shared);
    HDassert(grp->shared->fo_count > 0);

    --grp->shared->fo_count;

    if (0 == grp->shared->fo_count) {
        HDassert(grp != H5G_rootof(H5G_fileof(grp)));

        /* Remove the group from the list of opened objects in the file */
        if (H5FO_top_decr(grp->oloc.file, grp->oloc.addr) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "can't decrement count for object")
        if (H5FO_delete(grp->oloc.file, H5AC_dxpl_id, grp->oloc.addr) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "can't remove group from list of open objects")
        if (H5O_close(&(grp->oloc)) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to close")
        grp->shared = H5FL_FREE(H5G_shared_t, grp->shared);
    }
    else {
        /* Decrement the ref. count for this object in the top file */
        if (H5FO_top_decr(grp->oloc.file, grp->oloc.addr) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "can't decrement count for object")

        /* Check reference count for this object in the top file */
        if (H5FO_top_count(grp->oloc.file, grp->oloc.addr) == 0) {
            if (H5O_close(&(grp->oloc)) < 0)
                HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to close")
        } /* end if */
        else
            /* Free object location (i.e. "unhold" the file if appropriate) */
            if (H5O_loc_free(&(grp->oloc)) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "problem attempting to free location")

        /* If this group is a mount point and the mount point is the last open
         * reference to the group, then attempt to close down the file hierarchy
         */
        if (grp->shared->mounted && grp->shared->fo_count == 1) {
            /* Attempt to close down the file hierarchy */
            if (H5F_try_close(grp->oloc.file) < 0)
                HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "problem attempting file close")
        } /* end if */
    }     /* end else */

    if (H5G_name_free(&(grp->path)) < 0) {
        grp = H5FL_FREE(H5G_t, grp);
        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "can't free group entry name")
    } /* end if */

    grp = H5FL_FREE(H5G_t, grp);

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_close() */

/*-------------------------------------------------------------------------
 * Function:	H5G_oloc
 *
 * Purpose:	Returns a pointer to the object location for a group.
 *
 * Return:	Success:	Ptr to group entry
 *		Failure:	NULL
 *
 * Programmer:	Robb Matzke
 *              Tuesday, March 24, 1998
 *
 *-------------------------------------------------------------------------
 */
H5O_loc_t *
H5G_oloc(H5G_t *grp)
{
    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    FUNC_LEAVE_NOAPI(grp ? &(grp->oloc) : NULL)
} /* end H5G_oloc() */

/*-------------------------------------------------------------------------
 * Function:	H5G_nameof
 *
 * Purpose:	Returns a pointer to the hier. name for a group.
 *
 * Return:	Success:	Ptr to hier. name
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *              Monday, September 12, 2005
 *
 *-------------------------------------------------------------------------
 */
H5G_name_t *
H5G_nameof(H5G_t *grp)
{
    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    FUNC_LEAVE_NOAPI(grp ? &(grp->path) : NULL)
} /* end H5G_nameof() */

/*-------------------------------------------------------------------------
 * 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
 *
 *-------------------------------------------------------------------------
 */
H5F_t *
H5G_fileof(H5G_t *grp)
{
    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    HDassert(grp);

    FUNC_LEAVE_NOAPI(grp->oloc.file)
} /* end H5G_fileof() */

/*-------------------------------------------------------------------------
 * Function:	H5G_get_shared_count
 *
 * Purpose:	Queries the group object's "shared count"
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Tuesday, July	 5, 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_get_shared_count(H5G_t *grp)
{
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    /* Check args */
    HDassert(grp && grp->shared);

    FUNC_LEAVE_NOAPI(grp->shared->fo_count)
} /* end H5G_get_shared_count() */

/*-------------------------------------------------------------------------
 * Function:	H5G_mount
 *
 * Purpose:	Sets the 'mounted' flag for a group
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Tuesday, July 19, 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_mount(H5G_t *grp)
{
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    /* Check args */
    HDassert(grp && grp->shared);
    HDassert(grp->shared->mounted == FALSE);

    /* Set the 'mounted' flag */
    grp->shared->mounted = TRUE;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5G_mount() */

/*-------------------------------------------------------------------------
 * Function:	H5G_mounted
 *
 * Purpose:	Retrieves the 'mounted' flag for a group
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Tuesday, July 15, 2008
 *
 *-------------------------------------------------------------------------
 */
hbool_t
H5G_mounted(H5G_t *grp)
{
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    /* Check args */
    HDassert(grp && grp->shared);

    FUNC_LEAVE_NOAPI(grp->shared->mounted)
} /* end H5G_mounted() */

/*-------------------------------------------------------------------------
 * Function:	H5G_unmount
 *
 * Purpose:	Resets the 'mounted' flag for a group
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Tuesday, July 19, 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_unmount(H5G_t *grp)
{
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    /* Check args */
    HDassert(grp && grp->shared);
    HDassert(grp->shared->mounted == TRUE);

    /* Reset the 'mounted' flag */
    grp->shared->mounted = FALSE;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5G_unmount() */

/*-------------------------------------------------------------------------
 * Function:	H5G_iterate_cb
 *
 * Purpose:     Callback function for iterating over links in a group
 *
 * Return:	Success:        Non-negative
 *		Failure:	Negative
 *
 * Programmer:	Quincey Koziol
 *	        Oct  3, 2005
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_iterate_cb(const H5O_link_t *lnk, void *_udata)
{
    H5G_iter_appcall_ud_t *udata     = (H5G_iter_appcall_ud_t *)_udata; /* User data for callback */
    herr_t                 ret_value = H5_ITER_ERROR;                   /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    /* Sanity check */
    HDassert(lnk);
    HDassert(udata);

    switch (udata->lnk_op.op_type) {
#ifndef H5_NO_DEPRECATED_SYMBOLS
        case H5G_LINK_OP_OLD:
            /* Make the old-type application callback */
            ret_value = (udata->lnk_op.op_func.op_old)(udata->gid, lnk->name, udata->op_data);
            break;
#endif /* H5_NO_DEPRECATED_SYMBOLS */

        case H5G_LINK_OP_NEW: {
            H5L_info_t info; /* Link info */

            /* Retrieve the info for the link */
            if (H5G_link_to_info(lnk, &info) < 0)
                HGOTO_ERROR(H5E_SYM, H5E_CANTGET, H5_ITER_ERROR, "unable to get info for link")

            /* Make the application callback */
            ret_value = (udata->lnk_op.op_func.op_new)(udata->gid, lnk->name, &info, udata->op_data);
        } break;

        default:
            HDassert(0 && "Unknown link op type?!?");
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_iterate_cb() */

/*-------------------------------------------------------------------------
 * Function:    H5G_iterate
 *
 * Purpose:     Private function for iterating over links in a group
 *
 * Return:      SUCCEED/FAIL
 *
 * Programmer:	Quincey Koziol
 *	        Oct  3, 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_iterate(hid_t loc_id, const char *group_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t skip,
            hsize_t *last_lnk, const H5G_link_iterate_t *lnk_op, void *op_data, hid_t lapl_id, hid_t dxpl_id)
{
    H5G_loc_t             loc;                   /* Location of parent for group */
    hid_t                 gid = H5I_INVALID_HID; /* ID of group to iterate over */
    H5G_t *               grp = NULL;            /* Pointer to group data structure to iterate over */
    H5G_iter_appcall_ud_t udata;                 /* User data for callback */
    herr_t                ret_value = FAIL;      /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Sanity check */
    HDassert(group_name);
    HDassert(last_lnk);
    HDassert(lnk_op && lnk_op->op_func.op_new);

    /* Open the group on which to operate.  We also create a group ID which
     * we can pass to the application-defined operator.
     */
    if (H5G_loc(loc_id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
    if (NULL == (grp = H5G__open_name(&loc, group_name, lapl_id, dxpl_id)))
        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group")
    if ((gid = H5I_register(H5I_GROUP, grp, TRUE)) < 0)
        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group")

    /* Set up user data for callback */
    udata.gid     = gid;
    udata.lnk_op  = *lnk_op;
    udata.op_data = op_data;

    /* Call the real group iteration routine */
    if ((ret_value = H5G__obj_iterate(&(grp->oloc), idx_type, order, skip, last_lnk, H5G_iterate_cb, &udata,
                                      dxpl_id)) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "error iterating over links")

done:
    /* Release the group opened */
    if (gid > 0) {
        if (H5I_dec_app_ref(gid) < 0)
            HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close group")
    }
    else if (grp && H5G_close(grp) < 0)
        HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_iterate() */

/*-------------------------------------------------------------------------
 * Function:    H5G_free_visit_visited
 *
 * Purpose:     Free the key for an object visited during a group traversal
 *
 * Return:      Non-negative on success, negative on failure
 *
 * Programmer:  Quincey Koziol
 *	        Nov  4, 2007
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_free_visit_visited(void *item, void H5_ATTR_UNUSED *key, void H5_ATTR_UNUSED *operator_data /*in,out*/)
{
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    item = H5FL_FREE(H5_obj_t, item);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5G_free_visit_visited() */

/*-------------------------------------------------------------------------
 * Function:	H5G_visit_cb
 *
 * Purpose:     Callback function for recursively visiting links from a group
 *
 * Return:	Success:        Non-negative
 *		Failure:	Negative
 *
 * Programmer:	Quincey Koziol
 *	        Nov  4, 2007
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5G_visit_cb(const H5O_link_t *lnk, void *_udata)
{
    H5G_iter_visit_ud_t *udata = (H5G_iter_visit_ud_t *)_udata; /* User data for callback */
    H5L_info_t           info;                                  /* Link info */
    H5G_loc_t            obj_loc;                               /* Location of object */
    H5G_name_t           obj_path;                              /* Object's group hier. path */
    H5O_loc_t            obj_oloc;                              /* Object's object location */
    hbool_t              obj_found = FALSE;                     /* Object at 'name' found */
    size_t old_path_len = udata->curr_path_len; /* Length of path before appending this link's name */
    size_t link_name_len;                       /* Length of link's name */
    size_t len_needed;                          /* Length of path string needed */
    herr_t ret_value = H5_ITER_CONT;            /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    /* Sanity check */
    HDassert(lnk);
    HDassert(udata);

    /* Check if we will need more space to store this link's relative path */
    /* ("+2" is for string terminator and possible '/' for group separator later) */
    link_name_len = HDstrlen(lnk->name);
    len_needed    = udata->curr_path_len + link_name_len + 2;
    if (len_needed > udata->path_buf_size) {
        void *new_path; /* Pointer to new path buffer */

        /* Attempt to allocate larger buffer for path */
        if (NULL == (new_path = H5MM_realloc(udata->path, len_needed)))
            HGOTO_ERROR(H5E_SYM, H5E_NOSPACE, H5_ITER_ERROR, "can't allocate path string")
        udata->path          = (char *)new_path;
        udata->path_buf_size = len_needed;
    } /* end if */

    /* Build the link's relative path name */
    HDassert(udata->path[old_path_len] == '\0');
    HDstrncpy(&(udata->path[old_path_len]), lnk->name, link_name_len + 1);
    udata->curr_path_len += link_name_len;

    /* Construct the link info from the link message */
    if (H5G_link_to_info(lnk, &info) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, H5_ITER_ERROR, "unable to get info for link")

    /* Make the application callback */
    ret_value = (udata->op)(udata->gid, udata->path, &info, udata->op_data);

    /* Check for doing more work */
    if (ret_value == H5_ITER_CONT && lnk->type == H5L_TYPE_HARD) {
        H5_obj_t obj_pos; /* Object "position" for this object */

        /* Set up opened group location to fill in */
        obj_loc.oloc = &obj_oloc;
        obj_loc.path = &obj_path;
        H5G_loc_reset(&obj_loc);

        /* Find the object using the LAPL passed in */
        /* (Correctly handles mounted files) */
        if (H5G_loc_find(udata->curr_loc, lnk->name, &obj_loc /*out*/, udata->lapl_id, udata->dxpl_id) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, H5_ITER_ERROR, "object not found")
        obj_found = TRUE;

        /* Construct unique "position" for this object */
        H5F_GET_FILENO(obj_oloc.file, obj_pos.fileno);
        obj_pos.addr = obj_oloc.addr;

        /* Check if we've seen the object the link references before */
        if (NULL == H5SL_search(udata->visited, &obj_pos)) {
            H5O_type_t otype; /* Basic object type (group, dataset, etc.) */
            unsigned   rc;    /* Reference count of object    */

            /* Get the object's reference count and type */
            if (H5O_get_rc_and_type(&obj_oloc, udata->dxpl_id, &rc, &otype) < 0)
                HGOTO_ERROR(H5E_SYM, H5E_CANTGET, H5_ITER_ERROR, "unable to get object info")

            /* If its ref count is > 1, we add it to the list of visited objects */
            /* (because it could come up again during traversal) */
            if (rc > 1) {
                H5_obj_t *new_node; /* New object node for visited list */

                /* Allocate new object "position" node */
                if ((new_node = H5FL_MALLOC(H5_obj_t)) == NULL)
                    HGOTO_ERROR(H5E_SYM, H5E_NOSPACE, H5_ITER_ERROR, "can't allocate object node")

                /* Set node information */
                *new_node = obj_pos;

                /* Add to list of visited objects */
                if (H5SL_insert(udata->visited, new_node, new_node) < 0)
                    HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, H5_ITER_ERROR,
                                "can't insert object node into visited list")
            } /* end if */

            /* If it's a group, we recurse into it */
            if (otype == H5O_TYPE_GROUP) {
                H5G_loc_t * old_loc  = udata->curr_loc; /* Pointer to previous group location info */
                H5_index_t  idx_type = udata->idx_type; /* Type of index to use */
                H5O_linfo_t linfo;                      /* Link info message */
                htri_t      linfo_exists;               /* Whether the link info message exists */

                /* Add the path separator to the current path */
                HDassert(udata->path[udata->curr_path_len] == '\0');
                HDstrncpy(&(udata->path[udata->curr_path_len]), "/", (size_t)2);
                udata->curr_path_len++;

                /* Attempt to get the link info for this group */
                if ((linfo_exists = H5G__obj_get_linfo(&obj_oloc, &linfo, udata->dxpl_id)) < 0)
                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, H5_ITER_ERROR, "can't check for link info message")
                if (linfo_exists) {
                    /* Check for creation order tracking, if creation order index lookup requested */
                    if (idx_type == H5_INDEX_CRT_ORDER) {
                        /* Check if creation order is tracked */
                        if (!linfo.track_corder)
                            /* Switch to name order for this group */
                            idx_type = H5_INDEX_NAME;
                    } /* end if */
                    else
                        HDassert(idx_type == H5_INDEX_NAME);
                } /* end if */
                else {
                    /* Can only perform name lookups on groups with symbol tables */
                    if (idx_type != H5_INDEX_NAME)
                        /* Switch to name order for this group */
                        idx_type = H5_INDEX_NAME;
                } /* end if */

                /* Point to this group's location info */
                udata->curr_loc = &obj_loc;

                /* Iterate over links in group */
                ret_value = H5G__obj_iterate(&obj_oloc, idx_type, udata->order, (hsize_t)0, NULL,
                                             H5G_visit_cb, udata, udata->dxpl_id);

                /* Restore location */
                udata->curr_loc = old_loc;
            } /* end if */
        }     /* end if */
    }         /* end if */

done:
    /* Reset path back to incoming path */
    udata->path[old_path_len] = '\0';
    udata->curr_path_len      = old_path_len;

    /* Release resources */
    if (obj_found && H5G_loc_free(&obj_loc) < 0)
        HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, H5_ITER_ERROR, "can't free location")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_visit_cb() */

/*-------------------------------------------------------------------------
 * Function:    H5G_visit
 *
 * Purpose:     Recursively visit all the links in a group and all
 *              the groups that are linked to from that group.  Links within
 *              each group are visited according to the order within the
 *              specified index (unless the specified index does not exist for
 *              a particular group, then the "name" index is used).
 *
 *              NOTE: Each _link_ reachable from the initial group will only be
 *              visited once.  However, because an object may be reached from
 *              more than one link, the visitation may call the application's
 *              callback with more than one link that points to a particular
 *              _object_.
 *
 * Return:      Success:    The return value of the first operator that
 *                          returns non-zero, or zero if all members were
 *                          processed with no operator returning non-zero.
 *
 *              Failure:    Negative if something goes wrong within the
 *                          library, or the negative value returned by one
 *                          of the operators.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5G_visit(hid_t loc_id, const char *group_name, H5_index_t idx_type, H5_iter_order_t order, H5L_iterate_t op,
          void *op_data, hid_t lapl_id, hid_t dxpl_id)
{
    H5G_iter_visit_ud_t udata;                 /* User data for callback */
    H5O_linfo_t         linfo;                 /* Link info message */
    htri_t              linfo_exists;          /* Whether the link info message exists */
    hid_t               gid = H5I_INVALID_HID; /* Group ID */
    H5G_t *             grp = NULL;            /* Group opened */
    H5G_loc_t           loc;                   /* Location of group passed in */
    H5G_loc_t           start_loc;             /* Location of starting group */
    unsigned            rc;                    /* Reference count of object    */
    herr_t              ret_value = FAIL;      /* Return value */

    /* Portably clear udata struct (before FUNC_ENTER) */
    HDmemset(&udata, 0, sizeof(udata));

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    if (H5G_loc(loc_id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")

    /* Open the group to begin visiting within */
    if ((grp = H5G__open_name(&loc, group_name, lapl_id, dxpl_id)) == NULL)
        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group")

    /* Register an ID for the starting group */
    if ((gid = H5I_register(H5I_GROUP, grp, TRUE)) < 0)
        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group")

    /* Get the location of the starting group */
    if (H5G_loc(gid, &start_loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")

    /* Set up user data */
    udata.gid      = gid;
    udata.curr_loc = &start_loc;
    udata.lapl_id  = lapl_id;
    udata.dxpl_id  = dxpl_id;
    udata.idx_type = idx_type;
    udata.order    = order;
    udata.op       = op;
    udata.op_data  = op_data;

    /* Allocate space for the path name */
    if (NULL == (udata.path = H5MM_strdup("")))
        HGOTO_ERROR(H5E_SYM, H5E_NOSPACE, FAIL, "can't allocate path name buffer")
    udata.path_buf_size = 1;
    udata.curr_path_len = 0;

    /* Create skip list to store visited object information */
    if ((udata.visited = H5SL_create(H5SL_TYPE_OBJ, NULL)) == NULL)
        HGOTO_ERROR(H5E_SYM, H5E_CANTCREATE, FAIL, "can't create skip list for visited objects")

    /* Get the group's reference count */
    if (H5O_get_rc_and_type(&grp->oloc, dxpl_id, &rc, NULL) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "unable to get object info")

    /* If its ref count is > 1, we add it to the list of visited objects */
    /* (because it could come up again during traversal) */
    if (rc > 1) {
        H5_obj_t *obj_pos; /* New object node for visited list */

        /* Allocate new object "position" node */
        if ((obj_pos = H5FL_MALLOC(H5_obj_t)) == NULL)
            HGOTO_ERROR(H5E_SYM, H5E_NOSPACE, FAIL, "can't allocate object node")

        /* Construct unique "position" for this object */
        H5F_GET_FILENO(grp->oloc.file, obj_pos->fileno);
        obj_pos->addr = grp->oloc.addr;

        /* Add to list of visited objects */
        if (H5SL_insert(udata.visited, obj_pos, obj_pos) < 0)
            HGOTO_ERROR(H5E_SYM, H5E_CANTINSERT, FAIL, "can't insert object node into visited list")
    } /* end if */

    /* Attempt to get the link info for this group */
    if ((linfo_exists = H5G__obj_get_linfo(&(grp->oloc), &linfo, dxpl_id)) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't check for link info message")
    if (linfo_exists) {
        /* Check for creation order tracking, if creation order index lookup requested */
        if (idx_type == H5_INDEX_CRT_ORDER) {
            /* Check if creation order is tracked */
            if (!linfo.track_corder)
                /* Switch to name order for this group */
                idx_type = H5_INDEX_NAME;
        } /* end if */
        else
            HDassert(idx_type == H5_INDEX_NAME);
    } /* end if */
    else {
        /* Can only perform name lookups on groups with symbol tables */
        if (idx_type != H5_INDEX_NAME)
            /* Switch to name order for this group */
            idx_type = H5_INDEX_NAME;
    } /* end if */

    /* Call the link iteration routine */
    if ((ret_value = H5G__obj_iterate(&(grp->oloc), idx_type, order, (hsize_t)0, NULL, H5G_visit_cb, &udata,
                                      dxpl_id)) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "can't visit links")

done:
    /* Release user data resources */
    H5MM_xfree(udata.path);
    if (udata.visited)
        H5SL_destroy(udata.visited, H5G_free_visit_visited, NULL);

    /* Release the group opened */
    if (gid > 0) {
        if (H5I_dec_app_ref(gid) < 0)
            HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close group")
    } /* end if */
    else if (grp && H5G_close(grp) < 0)
        HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5G_visit() */