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/*
* ADIOS is freely available under the terms of the BSD license described
* in the COPYING file in the top level directory of this source distribution.
*
* Copyright (c) 2008 - 2009. UT-BATTELLE, LLC. All rights reserved.
*/
/* ADIOS C Example: read global arrays from a BP file
*
* This code is using the generic read API, which can read in
* arbitrary slices of an array and thus we can read in an array
* on arbitrary number of processes (provided our code is smart
* enough to do the domain decomposition).
*
* Run this example after adios_global, which generates
* adios_global.bp. Run this example on equal or less
* number of processes since we decompose only on one
* dimension of the global array here.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mpi.h"
#include "adios_read.h"
int main (int argc, char ** argv)
{
int rank, size, i, j, datasize=0;
MPI_Comm comm = MPI_COMM_WORLD;
enum ADIOS_READ_METHOD method = ADIOS_READ_METHOD_BP;
ADIOS_SELECTION * sel;
void * data = NULL;
MPI_Init (&argc, &argv);
MPI_Comm_rank (comm, &rank);
MPI_Comm_size (comm, &size);
adios_read_init_method (method, comm, "verbose=4");
ADIOS_FILE * f = adios_read_open_file ("adios_global.bp", method, comm);
if (f != NULL)
{
printf ("rank %d: Passed adios_read_open_file\n", rank);
ADIOS_VARINFO * varinfo = adios_inq_var (f, "temperature");
if (varinfo)
{
printf ("nsteps = %d\n", varinfo->nsteps);
for (i = 0; i < varinfo->nsteps; i++)
{
printf ("step: %d has %d", i, varinfo->nblocks[i]);
}
printf ("\n");
adios_inq_var_blockinfo (f, varinfo);
for (i = 0; i < varinfo->sum_nblocks; i++)
{
printf ("block[%d]: ", i);
printf ("start=");
for (j = 0; j < varinfo->ndim; j++)
{
printf ("%" PRIu64, varinfo->blockinfo[i].start[j]);
}
printf ("count=");
for (j = 0; j < varinfo->ndim; j++)
{
printf ("%" PRIu64, varinfo->blockinfo[i].count[j]);
}
printf ("\n");
}
datasize = 8;
for (i = 0; i < varinfo->ndim; i++)
{
datasize *= varinfo->blockinfo[rank].count[i];
}
data = malloc (datasize);
sel = adios_selection_writeblock (rank);
adios_schedule_read (f, sel, "temperature", 0, 1, data);
adios_perform_reads (f, 1);
adios_selection_delete (sel);
}
adios_free_varinfo (varinfo);
adios_read_close (f);
printf ("data:\n");
for (i = 0; i < datasize/8; i ++)
{
printf ("%7.4f ", * ((double *)data + i));
}
printf ("\n");
free (data);
}
adios_read_finalize_method (ADIOS_READ_METHOD_BP);
MPI_Finalize ();
return 0;
}
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