IO_adios2.cpp

/*
 * Distributed under the OSI-approved Apache License, Version 2.0.  See
 * accompanying file Copyright.txt for details.
 *
 * IO_ADIOS2.cpp
 *
 *  Created on: Feb 2017
 *      Author: Norbert Podhorszki
 */

#include "IO.h"

#include <string>

#include <adios2.h>

adios2::ADIOS *ad = nullptr;
adios2::Engine *bpWriter = nullptr;
adios2::Variable<double> *varT = nullptr;
adios2::Variable<unsigned int> *varGndx = nullptr;

IO::IO(const Settings &s, MPI_Comm comm)
{
    m_outputfilename = s.outputfile + ".bp";
    ad = new adios2::ADIOS(s.configfile, comm, adios2::DebugON);

    // Define method for engine creation

    adios2::IO &bpio = ad->DeclareIO("writer");
    if (!bpio.InConfigFile())
    {
        // if not defined by user, we can change the default settings
        // BPFileWriter is the default engine

        // Allow an extra thread for data processing
        // ISO-POSIX file is the default transport
        // Passing parameters to the transport
    }

    varGndx = &bpio.DefineVariable<unsigned int>("gndx");
    bpio.DefineVariable<unsigned int>("gndy");

    // define T as 2D global array
    varT = &bpio.DefineVariable<double>(
        "T",
        // Global dimensions
        {s.gndx, s.gndy},
        // starting offset of the local array in the global space
        {s.offsx, s.offsy},
        // local size, could be defined later using SetSelection()
        {s.ndx, s.ndy});

    // add transform to variable
    // adios2::Transform tr = adios2::transform::BZIP2( );
    // varT.AddTransform( tr, "" );
    // varT.AddTransform( tr,"accuracy=0.001" );  // for ZFP

    bpWriter = &bpio.Open(m_outputfilename, adios2::Mode::Write, comm);
}

IO::~IO()
{
    bpWriter->Close();
    delete ad;
}

void IO::write(int step, const HeatTransfer &ht, const Settings &s,
               MPI_Comm comm)
{
    bpWriter->BeginStep();
    /* This selection is redundant and not required, since we defined
     * the selection already in DefineVariable(). It is here just as an example.
     */
    // Make a selection to describe the local dimensions of the variable we
    // write and its offsets in the global spaces. This could have been done in
    // adios.DefineVariable()
    varT->SetSelection(
        adios2::Box<adios2::Dims>({s.offsx, s.offsy}, {s.ndx, s.ndy}));

    if (!step)
    {
        int rank;
        MPI_Comm_rank(comm, &rank);
        if (!rank)
        {
            bpWriter->PutSync<unsigned int>(*varGndx, s.gndx);
            bpWriter->PutSync<unsigned int>("gndy", s.gndy);
        }
    }
    bpWriter->PutSync<double>(*varT, ht.data_noghost().data());
    // bpWriter->PerformPuts();
    bpWriter->EndStep();
}