path: root/src/H5VLnative_object.c

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

/*
 * Purpose:     Object callbacks for the native VOL connector
 *
 */

#define H5O_FRIEND              /* Suppress error about including H5Opkg    */
#define H5F_FRIEND              /* Suppress error about including H5Fpkg    */

#include "H5private.h"          /* Generic Functions                        */
#include "H5Eprivate.h"         /* Error handling                           */
#include "H5Fpkg.h"             /* Files (pkg needed for id_exists)         */
#include "H5Gprivate.h"         /* Groups                                   */
#include "H5Iprivate.h"         /* IDs                                      */
#include "H5Opkg.h"             /* Object headers                           */
#include "H5Pprivate.h"         /* Property lists                           */
#include "H5VLprivate.h"        /* Virtual Object Layer                     */

#include "H5VLnative_private.h" /* Native VOL connector                     */


/*-------------------------------------------------------------------------
 * Function:    H5VL__native_object_open
 *
 * Purpose:     Handles the object open callback
 *
 * Return:      Success:    object pointer
 *              Failure:    NULL
 *
 *-------------------------------------------------------------------------
 */
void *
H5VL__native_object_open(void *obj, const H5VL_loc_params_t *loc_params, H5I_type_t *opened_type, 
    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
{
    H5G_loc_t   loc;
    void       *ret_value = NULL;

    FUNC_ENTER_PACKAGE

    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")

    switch(loc_params->type) {
        case H5VL_OBJECT_BY_NAME:
            {
                /* Open the object */
                if(NULL == (ret_value = H5O_open_name(&loc, loc_params->loc_data.loc_by_name.name, opened_type)))
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by name")
                break;
            }

        case H5VL_OBJECT_BY_IDX:
            {
                /* Open the object */
                if(NULL == (ret_value = H5O_open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
                        loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, opened_type)))
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by index")
                break;
            }

        case H5VL_OBJECT_BY_TOKEN:
            {
                H5O_token_t token = *loc_params->loc_data.loc_by_token.token;
                haddr_t addr;

                /* Decode token */
                if(H5VL_native_token_to_addr(loc.oloc->file, H5I_FILE, token, &addr) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTUNSERIALIZE, NULL, "can't deserialize object token into address")

                /* Open the object */
                if(NULL == (ret_value = H5O_open_by_addr(&loc, addr, opened_type)))
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by address")
                break;
            }

        case H5VL_OBJECT_BY_SELF:
        default:
            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown open parameters")
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5VL__native_object_open() */


/*-------------------------------------------------------------------------
 * Function:    H5VL__native_object_copy
 *
 * Purpose:     Handles the object copy callback
 *
 * Return:      SUCCEED/FAIL
 *
 *-------------------------------------------------------------------------
 */
herr_t 
H5VL__native_object_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, const char *src_name, 
    void *dst_obj, const H5VL_loc_params_t *loc_params2, const char *dst_name, 
    hid_t ocpypl_id, hid_t lcpl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
{
    H5G_loc_t   src_loc;                /* Source object group location */
    H5G_loc_t   dst_loc;                /* Destination group location */
    herr_t      ret_value = FAIL;
    
    FUNC_ENTER_PACKAGE

    /* get location for objects */
    if(H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
    if(H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")

    /* Copy the object */
    if((ret_value = H5O_copy(&src_loc, src_name, &dst_loc, dst_name, ocpypl_id, lcpl_id)) < 0)
        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, FAIL, "unable to copy object")    

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5VL__native_object_copy() */


/*-------------------------------------------------------------------------
 * Function:    H5VL__native_object_get
 *
 * Purpose:     Handles the object get callback
 *
 * Return:      SUCCEED/FAIL
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5VL__native_object_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_get_t get_type, 
    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
{
    herr_t      ret_value = SUCCEED;    /* Return value */
    H5G_loc_t   loc;                    /* Location of group */

    FUNC_ENTER_PACKAGE

    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")

    switch(get_type) {

        /* Object file */
        case H5VL_OBJECT_GET_FILE:
            {
                void **ret = HDva_arg(arguments, void **);

                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
                    *ret = (void *)loc.oloc->file;

                    /* TODO we currently need to set id_exists to TRUE because
                     * the upper layer will create an ID from the returned
                     * object. In theory this should not be needed and id_exists
                     * should be removed once the H5Fmount code gets fixed. */
                    loc.oloc->file->id_exists = TRUE;
                } else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown get_file parameters")
                break;
            }

        /* Object name */
        case H5VL_OBJECT_GET_NAME:
            {
                ssize_t *ret = HDva_arg(arguments, ssize_t *);
                char *name = HDva_arg(arguments, char *);
                size_t size = HDva_arg(arguments, size_t);

                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
                    /* Retrieve object's name */
                    if((*ret = H5G_get_name(&loc, name, size, NULL)) < 0)
                        HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't retrieve object name")
                } /* end if */
                else if(loc_params->type == H5VL_OBJECT_BY_TOKEN) {
                    H5O_loc_t obj_oloc; /* Object location */
                    H5O_token_t token = *loc_params->loc_data.loc_by_token.token;

                    /* Initialize the object location */
                    H5O_loc_reset(&obj_oloc);
                    obj_oloc.file = loc.oloc->file;

                    /* Decode token */
                    if(H5VL_native_token_to_addr(obj_oloc.file, H5I_FILE, token, &obj_oloc.addr) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTUNSERIALIZE, FAIL, "can't deserialize object token into address")

                    /* Retrieve object's name */
                    if((*ret = H5G_get_name_by_addr(loc.oloc->file, &obj_oloc, name, size)) < 0)
                        HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't determine object name")
                } /* end else-if */
                else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown get_name parameters")
                break;
            }

        /* Object type */
        case H5VL_OBJECT_GET_TYPE:
            {
                H5O_type_t *obj_type = HDva_arg(arguments, H5O_type_t *);

                if(loc_params->type == H5VL_OBJECT_BY_TOKEN) {
                    H5O_loc_t obj_oloc; /* Object location */
                    unsigned rc;        /* Reference count of object */
                    H5O_token_t token = *loc_params->loc_data.loc_by_token.token;

                    /* Initialize the object location */
                    H5O_loc_reset(&obj_oloc);
                    obj_oloc.file = loc.oloc->file;

                    /* Decode token */
                    if(H5VL_native_token_to_addr(obj_oloc.file, H5I_FILE, token, &obj_oloc.addr) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTUNSERIALIZE, FAIL, "can't deserialize object token into address")

                    /* Get the # of links for object, and its type */
                    /* (To check to make certain that this object hasn't been deleted) */
                    if(H5O_get_rc_and_type(&obj_oloc, &rc, obj_type) < 0 || 0 == rc)
                        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object")
                } else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown get_type parameters")
                break;
            }

        /* H5Oget_info(_name|_by_idx)3 */
        case H5VL_OBJECT_GET_INFO:
            {
                H5O_info2_t  *oinfo = HDva_arg(arguments, H5O_info2_t *);
                unsigned fields         = HDva_arg(arguments, unsigned);

                /* Use the original H5Oget_info code to get the data */

                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_info */
                    /* Retrieve the object's information */
                    if(H5G_loc_info(&loc, ".", oinfo, fields) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end if */
                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_info_by_name */
                    /* Retrieve the object's information */
                    if(H5G_loc_info(&loc, loc_params->loc_data.loc_by_name.name, oinfo, fields) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end else-if */
                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Oget_info_by_idx */
                    H5G_loc_t   obj_loc;                /* Location used to open group */
                    H5G_name_t  obj_path;               /* Opened object group hier. path */
                    H5O_loc_t   obj_oloc;               /* Opened object object location */

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

                    /* Find the object's location, according to the order in the index */
                    if(H5G_loc_find_by_idx(&loc, loc_params->loc_data.loc_by_idx.name,
                                           loc_params->loc_data.loc_by_idx.idx_type,
                                           loc_params->loc_data.loc_by_idx.order,
                                           loc_params->loc_data.loc_by_idx.n, &obj_loc/*out*/) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "group not found")

                    /* Retrieve the object's information */
                    if(H5O_get_info(obj_loc.oloc, oinfo, fields) < 0) {
                        H5G_loc_free(&obj_loc);
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't retrieve object info")
                    } /* end if */

                    /* Release the object location */
                    if(H5G_loc_free(&obj_loc) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
                } /* end else-if */
                else
                    HGOTO_ERROR(H5E_OHDR, H5E_UNSUPPORTED, FAIL, "unknown get info parameters")
                break;
            }

        default:
            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from object")
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5VL__native_object_get() */


/*-------------------------------------------------------------------------
 * Function:    H5VL__native_object_specific
 *
 * Purpose:     Handles the object specific callback
 *
 * Return:      SUCCEED/FAIL
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5VL__native_object_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_specific_t specific_type, 
    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
{
    H5G_loc_t    loc;
    herr_t       ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_PACKAGE

    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")

    switch(specific_type) {
        /* H5Oincr_refcount / H5Odecr_refcount */
        case H5VL_OBJECT_CHANGE_REF_COUNT:
            {
                int update_ref  = HDva_arg(arguments, int);
                H5O_loc_t  *oloc = loc.oloc;

                if(H5O_link(oloc, update_ref) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")

                break;
            }

        /* H5Oexists_by_name */
        case H5VL_OBJECT_EXISTS:
            {
                htri_t *ret = HDva_arg(arguments, htri_t *);

                if(loc_params->type == H5VL_OBJECT_BY_NAME) {
                    /* Check if the object exists */
                    if((*ret = H5G_loc_exists(&loc, loc_params->loc_data.loc_by_name.name)) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", loc_params->loc_data.loc_by_name.name)
                } /* end if */
                else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object exists parameters")
                break;
            }

        /* Lookup object */
        case H5VL_OBJECT_LOOKUP:
            {
                H5O_token_t *token = va_arg(arguments, H5O_token_t *);

                HDassert(token);

                if(loc_params->type == H5VL_OBJECT_BY_NAME) {
                    H5G_loc_t obj_loc;      /* Group hier. location of object */
                    H5G_name_t obj_path;    /* Object group hier. path */
                    H5O_loc_t obj_oloc;     /* Object object location */

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

                    /* Find the object */
                    if(H5G_loc_find(&loc, loc_params->loc_data.loc_by_name.name, &obj_loc) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")

                    /* Encode token */
                    if(H5VL_native_addr_to_token(loc.oloc->file, H5I_FILE, obj_loc.oloc->addr, token) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTSERIALIZE, FAIL, "can't serialize address into object token")

                    /* Release the object location */
                    if(H5G_loc_free(&obj_loc) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
                } /* end if */
                else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object exists parameters")
                break;
            }

        case H5VL_OBJECT_VISIT:
            {
                H5_index_t idx_type     = (H5_index_t)HDva_arg(arguments, int); /* enum work-around */
                H5_iter_order_t order   = (H5_iter_order_t)HDva_arg(arguments, int); /* enum work-around */
                H5O_iterate2_t op       = HDva_arg(arguments, H5O_iterate2_t);
                void *op_data           = HDva_arg(arguments, void *);
                unsigned fields         = HDva_arg(arguments, unsigned);

                /* Call internal object visitation routine */
                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
                    /* H5Ovisit */
                    if((ret_value = H5O__visit(&loc, ".", idx_type, order, op, op_data, fields)) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
                } /* end if */
                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
                    /* H5Ovisit_by_name */
                    if((ret_value = H5O__visit(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, op, op_data, fields)) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
                } /* end else-if */
                else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object visit params");
                break;
            }

        case H5VL_OBJECT_FLUSH:
            {
                hid_t   oid     = HDva_arg(arguments, hid_t);

                /* Flush the object's metadata */
                if(H5O_flush(loc.oloc, oid) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to flush object")

                break;
            }

        case H5VL_OBJECT_REFRESH:
            {
                hid_t                   oid         = HDva_arg(arguments, hid_t);
                H5O_loc_t              *oloc        = loc.oloc;

                /* Refresh the metadata */
                if(H5O_refresh_metadata(oid, *oloc) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, FAIL, "unable to refresh object")

                break;
            }

        default:
            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't recognize this operation type")
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5VL__native_object_specific() */


/*-------------------------------------------------------------------------
 * Function:    H5VL__native_object_optional
 *
 * Purpose:     Handles the object optional callback
 *
 * Return:      SUCCEED/FAIL
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5VL__native_object_optional(void *obj, H5VL_object_optional_t optional_type,
    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
{
    H5VL_loc_params_t *loc_params = HDva_arg(arguments, H5VL_loc_params_t *);
    H5G_loc_t   loc;                    /* Location of group */
    herr_t       ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_PACKAGE

    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")

    switch(optional_type) {
        /* H5Oget_comment / H5Oget_comment_by_name */
        case H5VL_NATIVE_OBJECT_GET_COMMENT:
            {
                char     *comment =  HDva_arg(arguments, char *);
                size_t   bufsize  =  HDva_arg(arguments, size_t);
                ssize_t  *ret     =  HDva_arg(arguments, ssize_t *);

                /* Retrieve the object's comment */
                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_comment */
                    if((*ret = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize)) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end if */
                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_comment_by_name */
                    if((*ret = H5G_loc_get_comment(&loc, loc_params->loc_data.loc_by_name.name, comment/*out*/, bufsize)) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end else-if */
                else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown set_coment parameters")
                break;
            }

        /* H5Oset_comment */
        case H5VL_NATIVE_OBJECT_SET_COMMENT:
            {
                const char    *comment  = HDva_arg(arguments, char *);

                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oset_comment */
                    /* (Re)set the object's comment */
                    if(H5G_loc_set_comment(&loc, ".", comment) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end if */
                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oset_comment_by_name */
                    /* (Re)set the object's comment */
                    if(H5G_loc_set_comment(&loc, loc_params->loc_data.loc_by_name.name, comment) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end else-if */
                else
                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown set_coment parameters")
                break;
            }

        /* H5Odisable_mdc_flushes */
        case H5VL_NATIVE_OBJECT_DISABLE_MDC_FLUSHES:
            {
                H5O_loc_t  *oloc = loc.oloc;

                if (H5O_disable_mdc_flushes(oloc) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCORK, FAIL, "unable to cork the metadata cache");

                break;
            }

        /* H5Oenable_mdc_flushes */
        case H5VL_NATIVE_OBJECT_ENABLE_MDC_FLUSHES:
            {
                H5O_loc_t  *oloc = loc.oloc;

                if (H5O_enable_mdc_flushes(oloc) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTUNCORK, FAIL, "unable to uncork the metadata cache");

                break;
            }

        /* H5Oare_mdc_flushes_disabled */
        case H5VL_NATIVE_OBJECT_ARE_MDC_FLUSHES_DISABLED:
            {
                H5O_loc_t  *oloc = loc.oloc;
                hbool_t *are_disabled = (hbool_t *)HDva_arg(arguments, hbool_t *);

                if (H5O_are_mdc_flushes_disabled(oloc, are_disabled) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine metadata cache cork status");

                break;
            }

        /* H5Oget_native_info(_name|_by_idx) */
        case H5VL_NATIVE_OBJECT_GET_NATIVE_INFO:
            {
                H5O_native_info_t  *native_info = HDva_arg(arguments, H5O_native_info_t *);
                unsigned fields         = HDva_arg(arguments, unsigned);

                /* Use the original H5Oget_info code to get the data */

                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_info */
                    /* Retrieve the object's information */
                    if(H5G_loc_native_info(&loc, ".", native_info, fields) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end if */
                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_info_by_name */
                    /* Retrieve the object's information */
                    if(H5G_loc_native_info(&loc, loc_params->loc_data.loc_by_name.name, native_info, fields) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
                } /* end else-if */
                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Oget_info_by_idx */
                    H5G_loc_t   obj_loc;                /* Location used to open group */
                    H5G_name_t  obj_path;               /* Opened object group hier. path */
                    H5O_loc_t   obj_oloc;               /* Opened object object location */

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

                    /* Find the object's location, according to the order in the index */
                    if(H5G_loc_find_by_idx(&loc, loc_params->loc_data.loc_by_idx.name,
                                           loc_params->loc_data.loc_by_idx.idx_type,
                                           loc_params->loc_data.loc_by_idx.order,
                                           loc_params->loc_data.loc_by_idx.n, &obj_loc/*out*/) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "group not found")

                    /* Retrieve the object's information */
                    if(H5O_get_native_info(obj_loc.oloc, native_info, fields) < 0) {
                        H5G_loc_free(&obj_loc);
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't retrieve object info")
                    } /* end if */

                    /* Release the object location */
                    if(H5G_loc_free(&obj_loc) < 0)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
                } /* end else-if */
                else
                    HGOTO_ERROR(H5E_OHDR, H5E_UNSUPPORTED, FAIL, "unknown get info parameters")

                break;
            }

        default:
            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't perform this operation on object");       
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5VL__native_object_optional() */