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libs/ck-libs/ampi/romio/adio/common/ad_set_view.c

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/* -*- Mode: C; c-basic-offset:4 ; -*- */
/* 
 *   $Id$
 *
 *   Copyright (C) 1997 University of Chicago. 
 *   See COPYRIGHT notice in top-level directory.
 */

#include "adio.h"
#include "adio_extern.h"

void ADIO_Set_view(ADIO_File fd, ADIO_Offset disp, MPI_Datatype etype, 
                MPI_Datatype filetype, MPI_Info info,  int *error_code) 
{
        int combiner, i, j, k, err, filetype_is_contig;
        MPI_Datatype copy_etype, copy_filetype;
        ADIOI_Flatlist_node *flat_file;
        /* free copies of old etypes and filetypes and delete flattened 
       version of filetype if necessary */

        MPI_Type_get_envelope(fd->etype, &i, &j, &k, &combiner);
        if (combiner != MPI_COMBINER_NAMED) MPI_Type_free(&(fd->etype));

        ADIOI_Datatype_iscontig(fd->filetype, &filetype_is_contig);
        if (!filetype_is_contig) ADIOI_Delete_flattened(fd->filetype);

        MPI_Type_get_envelope(fd->filetype, &i, &j, &k, &combiner);
        if (combiner != MPI_COMBINER_NAMED) MPI_Type_free(&(fd->filetype));

        /* set new info */
        ADIO_SetInfo(fd, info, &err);

        /* set new etypes and filetypes */

        MPI_Type_get_envelope(etype, &i, &j, &k, &combiner);
        if (combiner == MPI_COMBINER_NAMED) fd->etype = etype;
        else {
            MPI_Type_contiguous(1, etype, &copy_etype);
            MPI_Type_commit(&copy_etype);
            fd->etype = copy_etype;
        }
        MPI_Type_get_envelope(filetype, &i, &j, &k, &combiner);
        if (combiner == MPI_COMBINER_NAMED) 
            fd->filetype = filetype;
        else {
            MPI_Type_contiguous(1, filetype, &copy_filetype);
            MPI_Type_commit(&copy_filetype);
            fd->filetype = copy_filetype;
            ADIOI_Flatten_datatype(fd->filetype);
            /* this function will not flatten the filetype if it turns out
               to be all contiguous. */
        }

        MPI_Type_size(fd->etype, &(fd->etype_size));
        fd->disp = disp;

        /* reset MPI-IO file pointer to point to the first byte that can
           be accessed in this view. */

        ADIOI_Datatype_iscontig(fd->filetype, &filetype_is_contig);
        if (filetype_is_contig) fd->fp_ind = disp;
        else {
            flat_file = ADIOI_Flatlist;
            while (flat_file->type != fd->filetype) 
                flat_file = flat_file->next;
            for (i=0; i<flat_file->count; i++) {
                if (flat_file->blocklens[i]) {
                    fd->fp_ind = disp + flat_file->indices[i];
                    break;
                }
            }
        }
        *error_code = MPI_SUCCESS;
}

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