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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 ; -*- */
/* 
 *
 *   Copyright (C) 1997 University of Chicago. 
 *   See COPYRIGHT notice in top-level directory.
 */

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

/* this used to be implemented in every file system as an fcntl.  It makes
 * deferred open easier if we know ADIO_Fcntl will always need a file to really
 * be open. set_view doesn't modify anything related to the open files.
 */
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 = CtvAccess(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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