adjointVectorAccess.hpp

/*
 * CoDiPack, a Code Differentiation Package
 *
 * Copyright (C) 2015-2025 Chair for Scientific Computing (SciComp), University of Kaiserslautern-Landau
 * Homepage: http://scicomp.rptu.de
 * Contact:  Prof. Nicolas R. Gauger (codi@scicomp.uni-kl.de)
 *
 * Lead developers: Max Sagebaum, Johannes Blühdorn (SciComp, University of Kaiserslautern-Landau)
 *
 * This file is part of CoDiPack (http://scicomp.rptu.de/software/codi).
 *
 * CoDiPack is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * CoDiPack is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU General Public License for more details.
 * You should have received a copy of the GNU
 * General Public License along with CoDiPack.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 * For other licensing options please contact us.
 *
 * Authors:
 *  - SciComp, University of Kaiserslautern-Landau:
 *    - Max Sagebaum
 *    - Johannes Blühdorn
 *    - Former members:
 *      - Tim Albring
 */
#pragma once
 
#include <array>
#include <cstddef>
 
#include "../../config.h"
#include "../../misc/macros.hpp"
#include "../../tools/data/direction.hpp"
#include "../../traits/adjointVectorTraits.hpp"
#include "../../traits/realTraits.hpp"
#include "vectorAccessInterface.hpp"

namespace codi {

  template<typename T_Real, typename T_Identifier, typename T_AdjointVector>
  struct AdjointVectorAccess : public VectorAccessInterface<T_Real, T_Identifier> {
    public:
      using Real = CODI_DD(T_Real, double);                                              
      using Identifier = CODI_DD(T_Identifier, int);                                     
      using Gradient = CODI_DD(AdjointVectorTraits::Gradient<T_AdjointVector>, double);  
      using AdjointVector = CODI_DD(T_AdjointVector, double*);                           
 
    protected:
 
      AdjointVector adjointVector;  
 
    private:
 
      std::array<Gradient, Config::MaxArgumentSize> lhs;  
      size_t lhsPos;  
 
      std::array<Real, GradientTraits::dim<Gradient>()> buffer;  
 
    public:

      AdjointVectorAccess(AdjointVector adjointVector) : adjointVector(adjointVector), lhs(), lhsPos(0) {}
 
      /*******************************************************************************/

      size_t getVectorSize() const {
        return GradientTraits::dim<Gradient>();
      }

      bool isLhsZero() {
        return RealTraits::isTotalZero(lhs[lhsPos]);
      }

      VectorAccessInterface<Real, Identifier>* clone() const {
        return new AdjointVectorAccess(this->adjointVector);
      }
 
      /*******************************************************************************/

      void setLhsAdjoint(Identifier const& index) {
        lhs[lhsPos] = adjointVector[index];
        adjointVector[index] = Gradient();
      }

      void updateAdjointWithLhs(Identifier const& index, Real const& jacobian) {
        adjointVector[index] += jacobian * lhs[lhsPos];
      }
 
      /*******************************************************************************/

      void setLhsTangent(Identifier const& index) {
        adjointVector[index] = lhs[lhsPos];
        lhs[lhsPos] = Gradient();
      }

      void updateTangentWithLhs(Identifier const& index, Real const& jacobian) {
        lhs[lhsPos] += jacobian * adjointVector[index];
      }
 
      /*******************************************************************************/

      void setActiveVariableForIndirectAccess(size_t pos) {
        codiAssert(pos < lhs.size());
        lhsPos = pos;
      }
 
      /*******************************************************************************/

      void resetAdjoint(Identifier const& index, size_t dim) {
        GradientTraits::at(adjointVector[index], dim) = typename GradientTraits::Real<Gradient>();
      }

      void resetAdjointVec(Identifier const& index) {
        adjointVector[index] = Gradient();
      }

      Real getAdjoint(Identifier const& index, size_t dim) {
        CODI_UNUSED(dim);
 
        return (Real)GradientTraits::at(adjointVector[index], dim);
      }

      void getAdjointVec(Identifier const& index, Real* const vec) {
        for (size_t i = 0; i < getVectorSize(); ++i) {
          vec[i] = (Real)GradientTraits::at(adjointVector[index], i);
        }
      }

      Real const* getAdjointVec(Identifier const& index) {
        getAdjointVec(index, buffer.data());
        return buffer.data();
      }

      void updateAdjoint(Identifier const& index, size_t dim, Real const& adjoint) {
        GradientTraits::at(adjointVector[index], dim) += adjoint;
      }

      void updateAdjointVec(Identifier const& index, Real const* const vec) {
        for (size_t i = 0; i < getVectorSize(); ++i) {
          GradientTraits::at(adjointVector[index], i) += vec[i];
        }
      }
 
      /*******************************************************************************/

      void setPrimal(Identifier const& index, Real const& primal) {
        CODI_UNUSED(index, primal);
      }

      Real getPrimal(Identifier const& index) {
        CODI_UNUSED(index);
 
        return Real();
      }

      bool hasPrimals() {
        return false;
      }
  };
}