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 = MakeFilename(s.outputfile, ".bp");

    ad = new adios2::ADIOS(s.configfile, comm, adios2::DebugON);

    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
        // ISO-POSIX file is the default transport
    }

    // 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});

    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();
    // using PutDeferred() you promise the pointer to the data will be intact
    // until the end of the output step.
    // We need to have the vector object here not to destruct here until the end
    // of function.
    std::vector<double> v = ht.data_noghost();
    bpWriter->PutDeferred<double>(*varT, v.data());
    bpWriter->EndStep();
}