path: root/tools/h5repack/h5repack_refs.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://support.hdfgroup.org/ftp/HDF5/releases.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "h5repack.h"
#include "h5diff.h"
#include "h5tools.h"


/*-------------------------------------------------------------------------
 * local functions
 *-------------------------------------------------------------------------
 */

static const char* MapIdToName(hid_t refobj_id,trav_table_t *travt);
static int copy_refs_attr(hid_t loc_in, hid_t loc_out, pack_opt_t *options,
                          trav_table_t *travt, hid_t fidout);
static herr_t update_ref_value(hid_t obj_id, H5R_type_t ref_type, void *ref_in,
        hid_t fid_out, void *ref_out, trav_table_t *travt);

/*-------------------------------------------------------------------------
 * Function: do_copy_refobjs
 *
 * Purpose:  duplicate all referenced HDF5 objects in the file
 *           and create hard links
 *
 * Return:   0, ok, -1 no
 *-------------------------------------------------------------------------
 */

int do_copy_refobjs(hid_t fidin,
                    hid_t fidout,
                    trav_table_t *travt,
                    pack_opt_t *options) /* repack options */
{
    int       ret_value = 0;          /*no need to LEAVE() on ERROR: HERR_INIT(int, SUCCEED) */
    hid_t     grp_in = -1;            /* read group ID */
    hid_t     grp_out = -1;           /* write group ID */
    hid_t     dset_in = -1;           /* read dataset ID */
    hid_t     dset_out = -1;          /* write dataset ID */
    hid_t     type_in = -1;           /* named type ID */
    hid_t     dcpl_id = -1;           /* dataset creation property list ID */
    hid_t     space_id = -1;          /* space ID */
    hid_t     ftype_id = -1;          /* file data type ID */
    hid_t     mtype_id = -1;          /* memory data type ID */
    size_t    msize;                  /* memory size of memory type */
    hsize_t   nelmts;                 /* number of elements in dataset */
    int       rank;                   /* rank of dataset */
    hsize_t   dims[H5S_MAX_RANK];     /* dimensions of dataset */
    unsigned int i, j;
    int       k;
    named_dt_t *named_dt_head = NULL; /* Pointer to the stack of named datatypes copied */

    /*-------------------------------------------------------------------------
    * browse
    *-------------------------------------------------------------------------
    */
    for(i = 0; i < travt->nobjs; i++) {
        switch(travt->objs[i].type) {
            /*-------------------------------------------------------------------------
             * H5TRAV_TYPE_GROUP
             *-------------------------------------------------------------------------
             */
            case H5TRAV_TYPE_GROUP:
                /*-------------------------------------------------------------------------
                 * copy referenced objects in attributes
                 *-------------------------------------------------------------------------
                 */
                if((grp_out = H5Gopen2(fidout, travt->objs[i].name, H5P_DEFAULT)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Gopen2 failed");

                if((grp_in = H5Gopen2(fidin, travt->objs[i].name, H5P_DEFAULT)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Gopen2 failed");

                if(copy_refs_attr(grp_in, grp_out, options, travt, fidout) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "copy_refs_attr failed");

                if(H5Gclose(grp_out) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Gclose failed");
                if(H5Gclose(grp_in) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Gclose failed");

                /*-------------------------------------------------------------------------
                 * check for hard links
                 *-------------------------------------------------------------------------
                 */
                if(travt->objs[i].nlinks)
                    for(j = 0; j < travt->objs[i].nlinks; j++)
                        H5Lcreate_hard(fidout, travt->objs[i].name, H5L_SAME_LOC, travt->objs[i].links[j].new_name, H5P_DEFAULT, H5P_DEFAULT);
                break;

            /*-------------------------------------------------------------------------
             * H5TRAV_TYPE_DATASET
             *-------------------------------------------------------------------------
             */
            case H5TRAV_TYPE_DATASET:
                if((dset_in = H5Dopen2(fidin, travt->objs[i].name, H5P_DEFAULT)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dopen2 failed");
                if((space_id = H5Dget_space(dset_in)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dget_space failed");
                if((ftype_id = H5Dget_type(dset_in)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dget_type failed");
                if((dcpl_id = H5Dget_create_plist(dset_in)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dget_create_plist failed");
                if((rank = H5Sget_simple_extent_ndims(space_id)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sget_simple_extent_ndims failed");
                if(H5Sget_simple_extent_dims(space_id, dims, NULL) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sget_simple_extent_dims failed");
                nelmts = 1;
                for(k = 0; k < rank; k++)
                    nelmts *= dims[k];

                if((mtype_id = H5Tget_native_type(ftype_id, H5T_DIR_DEFAULT)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_native_type failed");

                if((msize = H5Tget_size(mtype_id)) == 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_size failed");

                /*-------------------------------------------------------------------------
                 * check if the dataset creation property list has filters that
                 * are not registered in the current configuration
                 * 1) the external filters GZIP and SZIP might not be available
                 * 2) the internal filters might be turned off
                 *-------------------------------------------------------------------------
                 */
                if(h5tools_canreadf(NULL, dcpl_id) == 1) {
                    /*-------------------------------------------------------------------------
                     * test for a valid output dataset
                     *-------------------------------------------------------------------------
                     */
                    dset_out = FAIL;

                    /*-------------------------------------------------------------------------
                     * object references are a special case
                     * we cannot just copy the buffers, but instead we recreate the reference
                     *-------------------------------------------------------------------------
                     */
                    if(H5Tequal(mtype_id, H5T_STD_REF_OBJ)) {
                        hid_t            refobj_id = -1;
                        hobj_ref_t       *refbuf = NULL; /* buffer for object references */
                        hobj_ref_t       *buf = NULL;
                        const char*      refname;
                        unsigned         u;

                        /*-------------------------------------------------------------------------
                         * read to memory
                         *-------------------------------------------------------------------------
                         */
                        if(nelmts) {
                            buf = (hobj_ref_t *)HDmalloc((unsigned)(nelmts * msize));
                            if(buf==NULL) {
                                printf("cannot read into memory\n" );
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDmalloc failed");
                            } /* end if */
                            if(H5Dread(dset_in, mtype_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dread failed");

                            refbuf = (hobj_ref_t*) HDcalloc((unsigned)nelmts, msize);
                            if(refbuf == NULL){
                                printf("cannot allocate memory\n" );
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDcalloc failed");
                            } /* end if */
                            for(u = 0; u < nelmts; u++) {
                                H5E_BEGIN_TRY {
                                    if((refobj_id = H5Rdereference(dset_in, H5R_OBJECT, &buf[u])) < 0)
                                        continue;
                                } H5E_END_TRY;

                                /* get the name. a valid name could only occur
                                 * in the second traversal of the file
                                 */
                                if((refname = MapIdToName(refobj_id, travt)) != NULL) {
                                    /* create the reference, -1 parameter for objects */
                                    if(H5Rcreate(&refbuf[u], fidout, refname, H5R_OBJECT, (hid_t)-1) < 0)
                                        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Rcreate failed");
                                    if(options->verbose) {
                                        printf(FORMAT_OBJ,"dset",travt->objs[i].name );
                                        printf("object <%s> object reference created to <%s>\n",
                                            travt->objs[i].name,
                                            refname);
                                    }
                                } /*refname*/
                                if (H5Oclose(refobj_id) < 0)
                                    H5TOOLS_INFO(H5E_tools_min_id_g, "H5Oclose refob failed");
                            } /* u */
                        } /*nelmts*/

                        /*-------------------------------------------------------------------------
                         * create/write dataset/close
                         *-------------------------------------------------------------------------
                         */
                        if((dset_out = H5Dcreate2(fidout, travt->objs[i].name, mtype_id, space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT)) < 0)
                            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dcreate2 failed");
                        if(nelmts)
                            if(H5Dwrite(dset_out, mtype_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, refbuf) < 0)
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dwrite failed");

                        if(buf)
                            HDfree(buf);
                        if(refbuf)
                            HDfree(refbuf);

                       /*------------------------------------------------------
                        * copy attrs
                        *----------------------------------------------------*/
                        if(copy_attr(dset_in, dset_out, &named_dt_head, travt, options) < 0)
                            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "copy_attr failed");
                    } /*H5T_STD_REF_OBJ*/

                    /*-------------------------------------------------------------------------
                     * dataset region references
                     *-------------------------------------------------------------------------
                     */
                    else if(H5Tequal(mtype_id, H5T_STD_REF_DSETREG)) {
                        hid_t            refobj_id = -1;
                        hdset_reg_ref_t  *refbuf = NULL; /* input buffer for region references */
                        hdset_reg_ref_t  *buf = NULL;    /* output buffer */
                        const char*      refname;
                        unsigned         u;

                        /*-------------------------------------------------------------------------
                         * read input to memory
                         *-------------------------------------------------------------------------
                         */
                        if(nelmts) {
                            buf = (hdset_reg_ref_t *)HDmalloc((unsigned)(nelmts * msize));
                            if(buf == NULL) {
                                printf("cannot read into memory\n");
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDmalloc failed");
                            } /* end if */
                            if(H5Dread(dset_in, mtype_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dread failed");

                            /*-------------------------------------------------------------------------
                             * create output
                             *-------------------------------------------------------------------------
                             */
                            refbuf = (hdset_reg_ref_t *)HDcalloc(sizeof(hdset_reg_ref_t), (size_t)nelmts); /*init to zero */
                            if(refbuf == NULL) {
                                printf("cannot allocate memory\n");
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDcalloc failed");
                            } /* end if */

                            for(u = 0; u < nelmts; u++) {
                                H5E_BEGIN_TRY {
                                    if((refobj_id = H5Rdereference(dset_in, H5R_DATASET_REGION, &buf[u])) < 0)
                                        continue;
                                } H5E_END_TRY;

                                /* get the name. a valid name could only occur
                                 * in the second traversal of the file
                                 */
                                if((refname = MapIdToName(refobj_id, travt)) != NULL) {
                                    hid_t region_id = -1;    /* region id of the referenced dataset */

                                    if((region_id = H5Rget_region(dset_in, H5R_DATASET_REGION, &buf[u])) < 0)
                                        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Rget_region failed");

                                    /* create the reference, we need the space_id */
                                    if(H5Rcreate(&refbuf[u], fidout, refname, H5R_DATASET_REGION, region_id) < 0)
                                        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Rcreate failed");
                                    if(H5Sclose(region_id) < 0)
                                        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sclose failed");
                                    if(options->verbose) {
                                        printf(FORMAT_OBJ,"dset",travt->objs[i].name );
                                        printf("object <%s> region reference created to <%s>\n",
                                            travt->objs[i].name,
                                            refname);
                                    }
                                } /*refname*/
                                if (H5Oclose(refobj_id) < 0)
                                    H5TOOLS_INFO(H5E_tools_min_id_g, "H5Oclose refobj_id failed");
                            } /* u */
                        } /*nelmts*/

                        /*-------------------------------------------------------------------------
                         * create/write dataset/close
                         *-------------------------------------------------------------------------
                         */
                        if((dset_out = H5Dcreate2(fidout, travt->objs[i].name, mtype_id, space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT)) < 0)
                            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dcreate2 failed");
                        if(nelmts)
                            if(H5Dwrite(dset_out, mtype_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, refbuf) < 0)
                                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dwrite failed");

                        if(buf)
                            HDfree(buf);
                        if(refbuf)
                            HDfree(refbuf);

                       /*-----------------------------------------------------
                        * copy attrs
                        *----------------------------------------------------*/
                        if(copy_attr(dset_in, dset_out, &named_dt_head, travt, options) < 0)
                            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "copy_attr failed");
                    } /* H5T_STD_REF_DSETREG */
                    /*-------------------------------------------------------------------------
                     * not references, open previously created object in 1st traversal
                     *-------------------------------------------------------------------------
                     */
                    else {
                        if((dset_out = H5Dopen2(fidout, travt->objs[i].name, H5P_DEFAULT)) < 0)
                            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dopen2 failed");
                    } /* end else */

                    /*-------------------------------------------------------------------------
                     * copy referenced objects in attributes
                     *-------------------------------------------------------------------------
                     */
                    if(copy_refs_attr(dset_in, dset_out, options, travt, fidout) < 0)
                        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "copy_refs_attr failed");

                    /*-------------------------------------------------------------------------
                     * check for hard links
                     *-------------------------------------------------------------------------
                     */
                    if(travt->objs[i].nlinks)
                        for(j = 0; j < travt->objs[i].nlinks; j++)
                            H5Lcreate_hard(fidout, travt->objs[i].name, H5L_SAME_LOC, travt->objs[i].links[j].new_name, H5P_DEFAULT, H5P_DEFAULT);

                    if(H5Dclose(dset_out) < 0)
                        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dclose failed");
                } /*can_read*/

                /*-------------------------------------------------------------------------
                 * close
                 *-------------------------------------------------------------------------
                 */
                if(H5Tclose(ftype_id) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tclose failed");
                if(H5Tclose(mtype_id) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tclose failed");
                if(H5Pclose(dcpl_id) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Pclose failed");
                if(H5Sclose(space_id) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sclose failed");
                if(H5Dclose(dset_in) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dclose failed");
                break;

            /*-------------------------------------------------------------------------
             * H5TRAV_TYPE_NAMED_DATATYPE
             *-------------------------------------------------------------------------
             */
            case H5TRAV_TYPE_NAMED_DATATYPE:
                if((type_in = H5Topen2(fidin, travt->objs[i].name, H5P_DEFAULT)) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Topen2 failed");
                if(H5Tclose(type_in) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tclose failed");
                break;

            /*-------------------------------------------------------------------------
             * H5TRAV_TYPE_LINK
             *-------------------------------------------------------------------------
             */
            case H5TRAV_TYPE_LINK:
                /*nothing to do */
                break;

            case H5TRAV_TYPE_UNKNOWN:
            case H5TRAV_TYPE_UDLINK:
                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5TRAV invalid type");

            default:
                break;
        } /* end switch */
    } /* end for */

    /* Finalize (link) the stack of named datatypes (if any)
     * This function is paired with copy_named_datatype() which is called
     * in copy_attr(), so need to free.
     */
    if (named_datatype_free(&named_dt_head, 0) < 0)
        H5TOOLS_INFO(H5E_tools_min_id_g, "named_datatype_free failed");

    return ret_value;

done:
    H5E_BEGIN_TRY {
        H5Gclose(grp_in);
        H5Gclose(grp_out);
        H5Pclose(dcpl_id);
        H5Sclose(space_id);
        H5Dclose(dset_in);
        H5Dclose(dset_out);
        H5Tclose(ftype_id);
        H5Tclose(mtype_id);
        H5Tclose(type_in);
        named_datatype_free(&named_dt_head, 1);
    } H5E_END_TRY;

    return ret_value;
}


/*-------------------------------------------------------------------------
 * Function: copy_refs_attr
 *
 * Purpose:  duplicate all referenced HDF5 located in attributes
 *           relative to LOC_IN, which is obtained either from
 *           loc_id = H5Gopen2(fid, name, H5P_DEFAULT);
 *           loc_id = H5Dopen2(fid, name, H5P_DEFAULT);
 *           loc_id = H5Topen2(fid, name, H5P_DEFAULT);
 *
 * Return:   0, ok, -1 no
 *
 * Modified:
 *           Update values of references(object and region) for the following types:
 *               1) References,
 *               2) ARRAY of reference,
 *               3) VLEN of references.
 *               4) COMPOUND of references.
 *           This function does not handle references in other complicated structures,
 *           such as references in nested compound datatypes.
 *-------------------------------------------------------------------------
 */

static int copy_refs_attr(hid_t loc_in,
                          hid_t loc_out,
                          pack_opt_t *options,
                          trav_table_t *travt,
                          hid_t fidout)         /* for saving references */
{
    int         ret_value = 0;     /*no need to LEAVE() on ERROR: HERR_INIT(int, SUCCEED) */
    hid_t       attr_id = -1;      /* attr ID */
    hid_t       attr_out = -1;     /* attr ID */
    hid_t       space_id = -1;     /* space ID */
    hid_t       ftype_id = -1;     /* file data type ID */
    hid_t       mtype_id = -1;     /* memory data type ID */
    size_t      msize;             /* memory size of type */
    hsize_t     nelmts;            /* number of elements in dataset */
    hsize_t     dims[H5S_MAX_RANK];/* dimensions of dataset */
    char        name[255];
    H5O_info_t  oinfo;             /* Object info */
    unsigned    u, i, j;
    int         rank;
    H5T_class_t type_class = -1;
    hbool_t     is_ref = 0,
                is_ref_vlen = 0,
                is_ref_array = 0,
                is_ref_comp = 0;
    void       *refbuf = NULL;
    void       *buf = NULL;
    const char *refname = NULL;
    unsigned   *ref_comp_index = NULL;
    size_t     *ref_comp_size = NULL;
    int         ref_comp_field_n = 0;


    if(H5Oget_info(loc_in, &oinfo) < 0)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Oget_info failed");

    for(u = 0; u < (unsigned)oinfo.num_attrs; u++) {
        is_ref = is_ref_vlen = is_ref_array = is_ref_comp = 0;

        /* open attribute */
        if((attr_id = H5Aopen_by_idx(loc_in, ".", H5_INDEX_CRT_ORDER, H5_ITER_INC, (hsize_t)u, H5P_DEFAULT, H5P_DEFAULT)) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aopen_by_idx failed");

        /* get the file datatype  */
        if((ftype_id = H5Aget_type(attr_id)) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aget_type failed");

        type_class = H5Tget_class(ftype_id);

        if((mtype_id = H5Tget_native_type(ftype_id, H5T_DIR_DEFAULT)) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_native_type failed");

        if((msize = H5Tget_size(mtype_id)) == 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_size failed");

        is_ref = (type_class == H5T_REFERENCE);

        if(type_class == H5T_VLEN ) {
            hid_t base_type = H5Tget_super(ftype_id);

            is_ref_vlen = (H5Tget_class(base_type) == H5T_REFERENCE);
            msize = H5Tget_size(base_type);
            if (H5Tclose(base_type) < 0)
                H5TOOLS_INFO(H5E_tools_min_id_g, "H5Tclose base_type failed");
        }
        else if(type_class == H5T_ARRAY ) {
            hid_t base_type = H5Tget_super(ftype_id);

            is_ref_array = (H5Tget_class(base_type) == H5T_REFERENCE);
            msize = H5Tget_size(base_type);
            if (H5Tclose(base_type) < 0)
                H5TOOLS_INFO(H5E_tools_min_id_g, "H5Tclose base_type failed");
        }
        else if(type_class == H5T_COMPOUND) {
            int nmembers = H5Tget_nmembers(ftype_id) ;

            if (nmembers < 1)
                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_nmembers failed");

            ref_comp_index = (unsigned *)HDmalloc((size_t)nmembers*sizeof(unsigned));
            ref_comp_size = (size_t *)HDmalloc((size_t)nmembers*sizeof(ref_comp_size));
            ref_comp_field_n = 0;

            for (i=0; i<(unsigned)nmembers; i++) {
                hid_t mtid = H5Tget_member_type(ftype_id, i);

                if ((H5Tget_class(mtid) == H5T_REFERENCE)) {
                    ref_comp_index[ref_comp_field_n] = i;
                    ref_comp_size[ref_comp_field_n] = H5Tget_size(mtid);
                    ref_comp_field_n++;
                }
                if (H5Tclose(mtid) < 0)
                    H5TOOLS_INFO(H5E_tools_min_id_g, "H5Tclose mtid failed");
            }

            /* if compound don't contain reference type member, free the above
             * mallocs. Otherwise there can be memory leaks by the 'continue'
             * statement below. */
            if (!ref_comp_field_n) {
                if (ref_comp_index) {
                    HDfree(ref_comp_index);
                    ref_comp_index = NULL;
                }

                if (ref_comp_size) {
                    HDfree(ref_comp_size);
                    ref_comp_size = NULL;
                }
            }
        }

        is_ref_comp = (ref_comp_field_n > 0);

        if (!(is_ref || is_ref_vlen || is_ref_array || is_ref_comp)) {
            if (H5Tclose(mtype_id) < 0)
                H5TOOLS_INFO(H5E_tools_min_id_g, "H5Tclose mtype_id failed");
            if (H5Tclose(ftype_id) < 0)
                H5TOOLS_INFO(H5E_tools_min_id_g, "H5Tclose ftype_id failed");
            if (H5Aclose(attr_id) < 0)
                H5TOOLS_INFO(H5E_tools_min_id_g, "H5Aclose attr_id failed");
            continue;
        }

        /* get name */
        if(H5Aget_name(attr_id, 255, name) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aget_name failed");

        /* get the dataspace handle  */
        if((space_id = H5Aget_space(attr_id)) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aget_space failed");

        /* get dimensions  */
        if((rank = H5Sget_simple_extent_dims(space_id, dims, NULL)) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sget_simple_extent_dims failed");


        /*-------------------------------------------------------------------------
        * elements
        *-------------------------------------------------------------------------
        */
        nelmts = 1;
        for(j = 0; j < (unsigned)rank; j++)
            nelmts *= dims[j];

        if (is_ref_array) {
            unsigned  array_rank = 0;
            hsize_t   array_size = 1;
            hsize_t array_dims[H5S_MAX_RANK];
            hid_t base_type = H5Tget_super(ftype_id);

            msize = H5Tget_size(base_type);
            if (H5Tclose(base_type) < 0)
                H5TOOLS_INFO(H5E_tools_min_id_g, "H5Tclose base_type failed");

            array_rank = (unsigned)H5Tget_array_ndims(mtype_id);
            H5Tget_array_dims2(mtype_id, array_dims);
            for(j = 0; j <array_rank; j++)
                array_size *= array_dims[j];
            nelmts *= array_size;
        }

        if((attr_out = H5Acreate2(loc_out, name, ftype_id, space_id, H5P_DEFAULT, H5P_DEFAULT)) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Acreate2 failed");

        if (nelmts>0) {
            /* handle object references */
            if((is_ref || is_ref_array) && (H5R_OBJ_REF_BUF_SIZE==msize)) {
                buf = (hobj_ref_t *)HDmalloc((unsigned)(nelmts * msize));
                if(buf == NULL) {
                    printf("cannot read into memory\n");
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDmalloc failed");
                } /* end if */
                if(H5Aread(attr_id, mtype_id, buf) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aread failed");

                refbuf = (hobj_ref_t *)HDcalloc((unsigned)nelmts, msize);
                if(refbuf == NULL) {
                    printf("cannot allocate memory\n");
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDcalloc failed");
                } /* end if */

                for(i = 0; i < (unsigned)nelmts; i++) {
                    if (update_ref_value(attr_id, H5R_OBJECT, &((hobj_ref_t *)buf)[i], fidout, &((hobj_ref_t *)refbuf)[i], travt)<0)
                        continue;
                    if(options->verbose)
                        printf("object <%s> reference created to <%s>\n", name, refname);
                } /* i */
            } /* H5T_STD_REF_OBJ */
            /* handle region references */
            else if((is_ref || is_ref_array) && (H5R_DSET_REG_REF_BUF_SIZE == msize)) {
                buf = (hdset_reg_ref_t *)HDmalloc((unsigned)(nelmts * msize));

                if(buf == NULL) {
                    printf( "cannot read into memory\n" );
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDmalloc failed");
                } /* end if */
                if(H5Aread(attr_id, mtype_id, buf) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aread failed");

                /*-------------------------------------------------------------------------
                 * create output
                 *-------------------------------------------------------------------------
                 */
                refbuf = (hdset_reg_ref_t *)HDcalloc(sizeof(hdset_reg_ref_t), (size_t)nelmts); /*init to zero */
                if(refbuf == NULL) {
                    printf( "cannot allocate memory\n" );
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDcalloc failed");
                } /* end if */

                for(i = 0; i < (unsigned)nelmts; i++) {
                    if (update_ref_value(attr_id, H5R_DATASET_REGION, &((hdset_reg_ref_t *)buf)[i], fidout, &((hdset_reg_ref_t *)refbuf)[i], travt)<0)
                        continue;
                    if(options->verbose)
                        printf("object <%s> region reference created to <%s>\n", name, refname);
                }
            } /* H5T_STD_REF_DSETREG */
            else if (is_ref_vlen) {
                /* handle VLEN of references */

                buf = (hvl_t *)HDmalloc((unsigned)(nelmts * sizeof(hvl_t)));
                refbuf = buf; /* reuse the read buffer for write */

                if(buf == NULL) {
                    printf( "cannot read into memory\n" );
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDmalloc failed");
                } /* end if */

                if(H5Aread(attr_id, mtype_id, buf) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aread failed");

                if (H5R_OBJ_REF_BUF_SIZE==msize) {
                    hobj_ref_t ref_out;

                    for (i=0; i<(unsigned)nelmts; i++) {
                        hobj_ref_t *ptr = (hobj_ref_t *)((hvl_t *)buf)[i].p;

                        for (j=0; j<((hvl_t *)buf)[i].len; j++ ) {
                            if (update_ref_value(attr_id, H5R_OBJECT, &(ptr[j]), fidout, &ref_out, travt)<0)
                                continue;
                            HDmemcpy(&(ptr[j]), &ref_out, msize);
                        }
                    }  /* for (i=0; i<nelems; i++) */
                }
                else if (H5R_DSET_REG_REF_BUF_SIZE == msize) {
                    hdset_reg_ref_t ref_out;

                    for (i=0; i<(unsigned)nelmts; i++) {
                        hdset_reg_ref_t *ptr = (hdset_reg_ref_t *)((hvl_t *)buf)[i].p;

                        for (j=0; j<((hvl_t *)buf)[i].len; j++ ) {
                            if (update_ref_value(attr_id, H5R_DATASET_REGION, &(ptr[j]), fidout, &ref_out, travt)<0)
                                continue;
                            HDmemcpy(&(ptr[j]), &ref_out, msize);
                        }
                    }  /* for (i=0; i<nelems; i++) */
                }
            } /* else if (is_ref_vlen) */
            else if (is_ref_comp) {
                /* handle ref fields in a compound */

                buf = HDmalloc((unsigned)(nelmts * msize));
                refbuf = buf; /* reuse the read buffer for write */

                if(buf == NULL) {
                    printf( "cannot read into memory\n" );
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "HDmalloc failed");
                } /* end if */

                if(H5Aread(attr_id, mtype_id, buf) < 0)
                    HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aread failed");

                for (i=0; i<(unsigned)nelmts; i++) {
                    for (j=0; j<(unsigned)ref_comp_field_n; j++) {
                        if (ref_comp_size[j] == H5R_OBJ_REF_BUF_SIZE) {
                            size_t idx = (i * msize) + H5Tget_member_offset(mtype_id, ref_comp_index[j]);
                            hobj_ref_t ref_out;

                            if (update_ref_value(attr_id, H5R_OBJECT, (hobj_ref_t *)(((char *)buf)+idx), fidout, &ref_out, travt)<0)
                                continue;
                            HDmemcpy(((char *)buf)+idx, &ref_out, ref_comp_size[j]);
                        } /* if */
                        else if (ref_comp_size[j] == H5R_DSET_REG_REF_BUF_SIZE) {
                            size_t idx = i * msize + H5Tget_member_offset(mtype_id, ref_comp_index[j]);
                            hdset_reg_ref_t ref_out;

                            if (update_ref_value(attr_id, H5R_DATASET_REGION, (hdset_reg_ref_t *)(((char *)buf)+idx), fidout, &ref_out, travt)<0)
                                continue;
                            HDmemcpy(((char *)buf)+idx, &ref_out, ref_comp_size[j]);
                        } /* else if */
                    } /* j */
                } /* i */
            } /* else if (is_ref_comp) */

            if(H5Awrite(attr_out, mtype_id, refbuf) < 0)
                HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Awrite failed");

            if (is_ref_vlen && buf)
                H5Dvlen_reclaim (mtype_id, space_id, H5P_DEFAULT, buf);
        } /* if (nelmts) */

        if (refbuf == buf)
            refbuf = NULL; /* set it to NULL to avoid double free since buf and refbuf are the same. */

        if(buf) {
            HDfree(buf);
            buf = NULL;
        }

        if(refbuf) {
            HDfree(refbuf);
            refbuf = NULL;
        }

        if (ref_comp_index) {
            HDfree(ref_comp_index);
            ref_comp_index = NULL;
        }

        if (ref_comp_size) {
            HDfree(ref_comp_size);
            ref_comp_size = NULL;
        }

        if(H5Aclose(attr_out) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aclose failed");

        /*-------------------------------------------------------------------------
        * close
        *-------------------------------------------------------------------------
        */
        if(H5Tclose(ftype_id) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tclose failed");
        if(H5Tclose(mtype_id) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tclose failed");
        if(H5Sclose(space_id) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sclose failed");
        if(H5Aclose(attr_id) < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Aclose failed");
    } /* for(u = 0; u < (unsigned)oinfo.num_attrs; u++) */

done:
    if(refbuf)
        HDfree(refbuf);
    if(buf)
        HDfree(buf);

    if (ref_comp_index)
        HDfree(ref_comp_index);

    if (ref_comp_size)
        HDfree(ref_comp_size);

    H5E_BEGIN_TRY {
        H5Tclose(ftype_id);
        H5Tclose(mtype_id);
        H5Sclose(space_id);
        H5Aclose(attr_id);
        H5Aclose(attr_out);
    } H5E_END_TRY;

    return ret_value;
}

/*-------------------------------------------------------------------------
 * Function:    MapIdToName
 *
 * Purpose:     map a ID from a reference to a dataset name
 *
 *-------------------------------------------------------------------------
 */
static const char*
MapIdToName(hid_t refobj_id, trav_table_t *travt)
{
    unsigned int u;
    const char   *ret = NULL;

    /* linear search */
    for(u = 0; u < travt->nobjs; u++) {
        if(travt->objs[u].type == (h5trav_type_t)H5O_TYPE_DATASET ||
                travt->objs[u].type == (h5trav_type_t)H5O_TYPE_GROUP ||
                travt->objs[u].type == (h5trav_type_t)H5O_TYPE_NAMED_DATATYPE) {
            H5O_info_t   ref_oinfo;     /* Stat for the refobj id */

            /* obtain information to identify the referenced object uniquely */
            if(H5Oget_info(refobj_id, &ref_oinfo) < 0)
                goto out;

            if(ref_oinfo.addr == travt->objs[u].objno) {
                ret = travt->objs[u].name;
                goto out;
            } /* end if */
        }  /* end if */
    } /* u */

out:
    return ret;
}

/*-------------------------------------------------------------------------
 * Function:    Update_Ref_value
 *
 * Purpose:     Update a reference value
 *-------------------------------------------------------------------------
 */
static herr_t update_ref_value(hid_t obj_id, H5R_type_t ref_type, void *ref_in,
        hid_t fid_out, void *ref_out, trav_table_t *travt)
{
    int         ret_value = 0;   /*no need to LEAVE() on ERROR: HERR_INIT(int, SUCCEED) */
    const char *ref_obj_name;
    hid_t       space_id = -1;
    hid_t       ref_obj_id = -1;

    ref_obj_id = H5Rdereference(obj_id, ref_type, ref_in);
    if (ref_obj_id < 0)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Rdereference2 failed");

    ref_obj_name = MapIdToName(ref_obj_id, travt);
    if (ref_obj_name == NULL)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "MapIdToName failed");

    if (ref_type == H5R_DATASET_REGION) {
        space_id = H5Rget_region(obj_id, H5R_DATASET_REGION, ref_in);
        if (space_id < 0)
            HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Rget_region failed");
    }

    if(H5Rcreate(ref_out, fid_out, ref_obj_name, ref_type, space_id) < 0)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Rcreate failed");

done:
    H5E_BEGIN_TRY {
      H5Sclose(space_id);
      H5Oclose(ref_obj_id);
    } H5E_END_TRY;

    return ret_value;
}