Teko_EpetraBlockPreconditioner.cpp

// @HEADER
// *****************************************************************************
//      Teko: A package for block and physics based preconditioning
//
// Copyright 2010 NTESS and the Teko contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#include "Teko_EpetraBlockPreconditioner.hpp"
#include "Teko_Preconditioner.hpp"

// Thyra includes
#include "Thyra_DefaultLinearOpSource.hpp"
#include "Thyra_EpetraLinearOp.hpp"

// Teuchos includes
#include "Teuchos_Time.hpp"

// Teko includes
#include "Teko_BasicMappingStrategy.hpp"

namespace Teko {
namespace Epetra {

using Teuchos::RCP;
using Teuchos::rcp;
using Teuchos::rcp_dynamic_cast;
using Teuchos::rcpFromRef;

EpetraBlockPreconditioner::EpetraBlockPreconditioner(
    const Teuchos::RCP<const PreconditionerFactory>& bfp)
    : preconFactory_(bfp), firstBuildComplete_(false) {}

void EpetraBlockPreconditioner::initPreconditioner(bool clearOld) {
  if ((not clearOld) && preconObj_ != Teuchos::null) return;
  preconObj_ = preconFactory_->createPrec();
}

void EpetraBlockPreconditioner::buildPreconditioner(const Teuchos::RCP<const Epetra_Operator>& A,
                                                    bool clear) {
  Teko_DEBUG_SCOPE("EBP::buildPreconditioner", 10);

  // extract EpetraOperatorWrapper (throw on failure) and corresponding thyra operator
  RCP<const Thyra::LinearOpBase<double> > thyraA = extractLinearOp(A);

  // set the mapping strategy
  // SetMapStrategy(rcp(new InverseMappingStrategy(eow->getMapStrategy())));
  SetMapStrategy(rcp(new InverseMappingStrategy(extractMappingStrategy(A))));

  // build preconObj_
  initPreconditioner(clear);

  // actually build the preconditioner
  RCP<const Thyra::LinearOpSourceBase<double> > lOpSrc = Thyra::defaultLinearOpSource(thyraA);
  preconFactory_->initializePrec(lOpSrc, &*preconObj_, Thyra::SUPPORT_SOLVE_UNSPECIFIED);

  // extract preconditioner operator
  RCP<const Thyra::LinearOpBase<double> > preconditioner = preconObj_->getUnspecifiedPrecOp();

  SetOperator(preconditioner, false);

  firstBuildComplete_ = true;

  TEUCHOS_ASSERT(preconObj_ != Teuchos::null);
  TEUCHOS_ASSERT(getThyraOp() != Teuchos::null);
  TEUCHOS_ASSERT(getMapStrategy() != Teuchos::null);
  TEUCHOS_ASSERT(firstBuildComplete_ == true);
}

void EpetraBlockPreconditioner::buildPreconditioner(const Teuchos::RCP<const Epetra_Operator>& A,
                                                    const Epetra_MultiVector& epetra_mv,
                                                    bool clear) {
  Teko_DEBUG_SCOPE("EBP::buildPreconditioner - with solution", 10);

  // extract EpetraOperatorWrapper (throw on failure) and corresponding thyra operator
  RCP<const Thyra::LinearOpBase<double> > thyraA = extractLinearOp(A);

  // set the mapping strategy
  SetMapStrategy(rcp(new InverseMappingStrategy(extractMappingStrategy(A))));

  TEUCHOS_ASSERT(getMapStrategy() != Teuchos::null);

  // build the thyra version of the source multivector
  RCP<Thyra::MultiVectorBase<double> > thyra_mv =
      Thyra::createMembers(thyraA->range(), epetra_mv.NumVectors());
  getMapStrategy()->copyEpetraIntoThyra(epetra_mv, thyra_mv.ptr());

  // build preconObj_
  initPreconditioner(clear);

  // actually build the preconditioner
  preconFactory_->initializePrec(Thyra::defaultLinearOpSource(thyraA), thyra_mv, &*preconObj_,
                                 Thyra::SUPPORT_SOLVE_UNSPECIFIED);
  RCP<const Thyra::LinearOpBase<double> > preconditioner = preconObj_->getUnspecifiedPrecOp();

  SetOperator(preconditioner, false);

  firstBuildComplete_ = true;

  TEUCHOS_ASSERT(preconObj_ != Teuchos::null);
  TEUCHOS_ASSERT(getThyraOp() != Teuchos::null);
  TEUCHOS_ASSERT(getMapStrategy() != Teuchos::null);
  TEUCHOS_ASSERT(firstBuildComplete_ == true);
}

void EpetraBlockPreconditioner::rebuildPreconditioner(
    const Teuchos::RCP<const Epetra_Operator>& A) {
  Teko_DEBUG_SCOPE("EBP::rebuildPreconditioner", 10);

  // if the preconditioner hasn't been built yet, rebuild from scratch
  if (not firstBuildComplete_) {
    buildPreconditioner(A, false);
    return;
  }
  Teko_DEBUG_EXPR(Teuchos::Time timer(""));

  // extract EpetraOperatorWrapper (throw on failure) and corresponding thyra operator
  Teko_DEBUG_EXPR(timer.start(true));
  RCP<const Thyra::LinearOpBase<double> > thyraA = extractLinearOp(A);
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild get thyraop time =  " << timer.totalElapsedTime(), 2);

  // reinitialize the preconditioner
  Teko_DEBUG_EXPR(timer.start(true));
  preconFactory_->initializePrec(Thyra::defaultLinearOpSource(thyraA), &*preconObj_,
                                 Thyra::SUPPORT_SOLVE_UNSPECIFIED);
  RCP<const Thyra::LinearOpBase<double> > preconditioner = preconObj_->getUnspecifiedPrecOp();
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild initialize prec time =  " << timer.totalElapsedTime(), 2);

  Teko_DEBUG_EXPR(timer.start(true));
  SetOperator(preconditioner, false);
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild set operator time =  " << timer.totalElapsedTime(), 2);

  TEUCHOS_ASSERT(preconObj_ != Teuchos::null);
  TEUCHOS_ASSERT(getThyraOp() != Teuchos::null);
  TEUCHOS_ASSERT(firstBuildComplete_ == true);
}

void EpetraBlockPreconditioner::rebuildPreconditioner(const Teuchos::RCP<const Epetra_Operator>& A,
                                                      const Epetra_MultiVector& epetra_mv) {
  Teko_DEBUG_SCOPE("EBP::rebuildPreconditioner - with solution", 10);

  // if the preconditioner hasn't been built yet, rebuild from scratch
  if (not firstBuildComplete_) {
    buildPreconditioner(A, epetra_mv, false);
    return;
  }
  Teko_DEBUG_EXPR(Teuchos::Time timer(""));

  // extract EpetraOperatorWrapper (throw on failure) and corresponding thyra operator
  Teko_DEBUG_EXPR(timer.start(true));
  RCP<const Thyra::LinearOpBase<double> > thyraA = extractLinearOp(A);
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild get thyraop time =  " << timer.totalElapsedTime(), 2);

  // build the thyra version of the source multivector
  Teko_DEBUG_EXPR(timer.start(true));
  RCP<Thyra::MultiVectorBase<double> > thyra_mv =
      Thyra::createMembers(thyraA->range(), epetra_mv.NumVectors());
  getMapStrategy()->copyEpetraIntoThyra(epetra_mv, thyra_mv.ptr());
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild vector copy time =  " << timer.totalElapsedTime(), 2);

  // reinitialize the preconditioner
  Teko_DEBUG_EXPR(timer.start(true));
  preconFactory_->initializePrec(Thyra::defaultLinearOpSource(thyraA), thyra_mv, &*preconObj_,
                                 Thyra::SUPPORT_SOLVE_UNSPECIFIED);
  RCP<const Thyra::LinearOpBase<double> > preconditioner = preconObj_->getUnspecifiedPrecOp();
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild initialize prec time =  " << timer.totalElapsedTime(), 2);

  Teko_DEBUG_EXPR(timer.start(true));
  SetOperator(preconditioner, false);
  Teko_DEBUG_EXPR(timer.stop());
  Teko_DEBUG_MSG("EBP::rebuild set operator time =  " << timer.totalElapsedTime(), 2);

  TEUCHOS_ASSERT(preconObj_ != Teuchos::null);
  TEUCHOS_ASSERT(getThyraOp() != Teuchos::null);
  TEUCHOS_ASSERT(firstBuildComplete_ == true);
}

Teuchos::RCP<PreconditionerState> EpetraBlockPreconditioner::getPreconditionerState() {
  Teuchos::RCP<Preconditioner> bp = rcp_dynamic_cast<Preconditioner>(preconObj_);

  if (bp != Teuchos::null) return bp->getStateObject();

  return Teuchos::null;
}

Teuchos::RCP<const PreconditionerState> EpetraBlockPreconditioner::getPreconditionerState() const {
  Teuchos::RCP<const Preconditioner> bp = rcp_dynamic_cast<const Preconditioner>(preconObj_);

  if (bp != Teuchos::null) return bp->getStateObject();

  return Teuchos::null;
}

Teuchos::RCP<const Thyra::LinearOpBase<double> > EpetraBlockPreconditioner::extractLinearOp(
    const Teuchos::RCP<const Epetra_Operator>& A) const {
  // extract EpetraOperatorWrapper (throw on failure) and corresponding thyra operator
  const RCP<const EpetraOperatorWrapper>& eow = rcp_dynamic_cast<const EpetraOperatorWrapper>(A);

  // if it is an EpetraOperatorWrapper, then get the Thyra operator
  if (eow != Teuchos::null) return eow->getThyraOp();

  // otherwise wrap it up as a thyra operator
  return Thyra::epetraLinearOp(A);
}

Teuchos::RCP<const MappingStrategy> EpetraBlockPreconditioner::extractMappingStrategy(
    const Teuchos::RCP<const Epetra_Operator>& A) const {
  // extract EpetraOperatorWrapper (throw on failure) and corresponding thyra operator
  const RCP<const EpetraOperatorWrapper>& eow = rcp_dynamic_cast<const EpetraOperatorWrapper>(A);

  // if it is an EpetraOperatorWrapper, then get the Thyra operator
  if (eow != Teuchos::null) return eow->getMapStrategy();

  // otherwise wrap it up as a thyra operator
  RCP<const Epetra_Map> range  = rcpFromRef(A->OperatorRangeMap());
  RCP<const Epetra_Map> domain = rcpFromRef(A->OperatorDomainMap());
  return rcp(new BasicMappingStrategy(range, domain, A->Comm()));
}

}  // end namespace Epetra
}  // end namespace Teko