linpart.h

// Copyright 2009-2025 NTESS. Under the terms
// of Contract DE-NA0003525 with NTESS, the U.S.
// Government retains certain rights in this software.
//
// Copyright (c) 2009-2025, NTESS
// All rights reserved.
//
// This file is part of the SST software package. For license
// information, see the LICENSE file in the top level directory of the
// distribution.

#ifndef SST_CORE_IMPL_PARTITONERS_LINPART_H
#define SST_CORE_IMPL_PARTITONERS_LINPART_H

#include "sst/core/eli/elementinfo.h"
#include "sst/core/sstpart.h"

namespace SST {
class Output;
}

namespace SST::IMPL::Partition {

/**
Performs a linear partition scheme of an SST simulation configuration. In this
scheme a list of components (supplied as a graph) are grouped by slicing the list
into approximately equal parts. A "part" is generated for each MPI rank performing
the simulation. This means Components with sequential ids will be placed close together.
In general this scheme provides a very effective partition for most parallel
simulations which generate man similar components of interest close together in the input
Python configuration. It is also very fast to compute a linear partition scheme. For
more aggressive partition schemes users should try the simple partitioner.
*/
class SSTLinearPartition : public SST::Partition::SSTPartitioner
{

public:
    SST_ELI_REGISTER_PARTITIONER(
        SSTLinearPartition,
        "sst",
        "linear",
        SST_ELI_ELEMENT_VERSION(1,0,0),
        "Partitions components by dividing Component ID space into roughly equal portions.  "
        "Components with sequential IDs will be placed close together.")

protected:
    /** Number of ranks in the simulation */
    RankInfo rankcount;
    /** Output object to print partitioning information */
    Output*  partOutput;

public:
    /**
       Creates a new linear partition scheme.
       \param mpiRankCount Number of MPI ranks in the simulation
       \param verbosity The level of information to output
    */
    SSTLinearPartition(RankInfo rankCount, RankInfo my_rank, int verbosity);

    /**
       Performs a partition of an SST simulation configuration
       \param graph The simulation configuration to partition
    */
    void performPartition(PartitionGraph* graph) override;

    bool requiresConfigGraph() override { return false; }
    bool spawnOnAllRanks() override { return false; }
};

} // namespace SST::IMPL::Partition

#endif