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/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
*
* Copyright (C) 1997 University of Chicago.
* See COPYRIGHT notice in top-level directory.
*/
#include "adio.h"
#include "adio_extern.h"
/* Returns the absolute byte position in the file corresponding to
"offset" etypes relative to the current view. */
void ADIOI_Get_byte_offset(ADIO_File fd, ADIO_Offset offset, ADIO_Offset *disp)
{
ADIOI_Flatlist_node *flat_file;
int i;
ADIO_Offset n_filetypes, etype_in_filetype, sum, abs_off_in_filetype=0, size_in_filetype;
MPI_Count n_etypes_in_filetype, filetype_size, etype_size;
int filetype_is_contig;
MPI_Aint filetype_extent;
ADIOI_Datatype_iscontig(fd->filetype, &filetype_is_contig);
etype_size = fd->etype_size;
if (filetype_is_contig) *disp = fd->disp + etype_size * offset;
else {
/* filetype already flattened in ADIO_Open */
flat_file = ADIOI_Flatlist;
while (flat_file->type != fd->filetype) flat_file = flat_file->next;
MPI_Type_size_x(fd->filetype, &filetype_size);
n_etypes_in_filetype = filetype_size/etype_size;
n_filetypes = offset / n_etypes_in_filetype;
etype_in_filetype = offset % n_etypes_in_filetype;
size_in_filetype = etype_in_filetype * etype_size;
sum = 0;
for (i=0; i<flat_file->count; i++) {
sum += flat_file->blocklens[i];
if (sum > size_in_filetype) {
abs_off_in_filetype = flat_file->indices[i] +
size_in_filetype - (sum - flat_file->blocklens[i]);
break;
}
}
/* abs. offset in bytes in the file */
MPI_Type_extent(fd->filetype, &filetype_extent);
*disp = fd->disp + n_filetypes * ADIOI_AINT_CAST_TO_OFFSET filetype_extent + abs_off_in_filetype;
}
}
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