tagTapeReverse.hpp

/*
 * CoDiPack, a Code Differentiation Package
 *
 * Copyright (C) 2015-2026 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 "../interfaces/fullTapeInterface.hpp"
#include "../misc/adjointVectorAccess.hpp"
#include "tagTapeBase.hpp"

namespace codi {

  template<typename T_Real, typename T_Tag>
  struct TagTapeReverse : public FullTapeInterface<T_Real, T_Real, TagData<T_Tag>, EmptyPosition, TagData<T_Tag>>,
                          public TagTapeBase<T_Real, T_Tag, T_Real, TagTapeReverse<T_Real, T_Tag>> {
      using Real = CODI_DD(T_Real, double);  
      using Tag = CODI_DD(T_Tag, int);       

      struct TapeTypes {
          struct IndexManager {
              using Index = int;
          };
      };
 
      using Gradient = Real;                    
      using Identifier = int;                   
      using ActiveTypeTapeData = TagData<Tag>;  
      using Position = EmptyPosition;           
 
      using PassiveReal = RealTraits::PassiveReal<Real>;  
 
      using Base = TagTapeBase<T_Real, T_Tag, T_Real, TagTapeReverse>;  
 
    private:
      bool active;  
 
      Real tempPrimal;        
      Gradient tempGradient;  
 
      std::set<TapeParameters> parameters;  
 
    public:

      TagTapeReverse() : Base(), active(), tempPrimal(), tempGradient(), parameters() {}
 
      using Base::AllowJacobianOptimization;
      using Base::destroyTapeData;
      using Base::getIdentifier;
      using Base::initTapeData;
      using Base::store;
 
      /*******************************************************************************/

      template<typename Adjoint>
      void evaluate(Position const& start, Position const& end, Adjoint* data) {
        CODI_UNUSED(start, end, data);
      }

      template<typename Adjoint>
      void evaluateForward(Position const& start, Position const& end, Adjoint* data) {
        CODI_UNUSED(start, end, data);
      }

      /*******************************************************************************/

      void writeToFile(std::string const& filename) const {
        CODI_UNUSED(filename);
      }

      void readFromFile(std::string const& filename) {
        CODI_UNUSED(filename);
      }

      void deleteData() {}

      std::set<TapeParameters> const& getAvailableParameters() const {
        return parameters;
      }

      size_t getParameter(TapeParameters parameter) const {
        CODI_UNUSED(parameter);
 
        return 0;
      }

      bool hasParameter(TapeParameters parameter) const {
        CODI_UNUSED(parameter);
 
        return false;
      }

      void setParameter(TapeParameters parameter, size_t value) {
        CODI_UNUSED(parameter, value);
      }

      VectorAccessInterface<Real, Identifier>* createVectorAccess() {
        return nullptr;
      }

      template<typename Adjoint>
      VectorAccessInterface<Real, Identifier>* createVectorAccessCustomAdjoints(Adjoint* data) {
        CODI_UNUSED(data);
        return nullptr;
      }

      void deleteVectorAccess(VectorAccessInterface<Real, Identifier>* access) {
        delete access;
      }

      void swap(TagTapeReverse& other) {
        std::swap(active, other.active);
        std::swap(parameters, other.parameters);
        Base::swap(other);
      }
      void resetHard() {}  
 
      void deleteAdjointVector() {}    
      void resizeAdjointVector() {}    
      void beginUseAdjointVector() {}  
      void endUseAdjointVector() {}    

      /*******************************************************************************/

      template<typename Lhs>
      Real registerExternalFunctionOutput(LhsExpressionInterface<Real, Gradient, TagTapeReverse, Lhs>& value) {
        registerInput(value);
 
        return Real();
      }

      void pushExternalFunction(ExternalFunction<TagTapeReverse> const& extFunc) {
        CODI_UNUSED(extFunc);
      }

      /*******************************************************************************/

      void evaluateForward(Position const& start, Position const& end) {
        CODI_UNUSED(start, end);
      }

      void evaluateForward() {}

      /*******************************************************************************/

      void setGradient(Identifier const& identifier, Gradient const& gradient,
                       AdjointsManagement adjointsManagement = AdjointsManagement::Automatic) {
        CODI_UNUSED(identifier, gradient, adjointsManagement);
      }

      Gradient const& getGradient(Identifier const& identifier,
                                  AdjointsManagement adjointsManagement = AdjointsManagement::Automatic) const {
        CODI_UNUSED(identifier, adjointsManagement);
 
        return tempGradient;
      }

      Gradient& gradient(Identifier const& identifier,
                         AdjointsManagement adjointsManagement = AdjointsManagement::Automatic) {
        CODI_UNUSED(identifier, adjointsManagement);
 
        return tempGradient;
      }

      Gradient const& gradient(Identifier const& identifier,
                               AdjointsManagement adjointsManagement = AdjointsManagement::Automatic) const {
        CODI_UNUSED(identifier, adjointsManagement);
 
        return tempGradient;
      }

      /*******************************************************************************/

      static bool constexpr LinearIndexHandling = true;

      Identifier getPassiveIndex() const {
        return Identifier(IndexManagerInterface<int>::InactiveIndex);
      }

      Identifier getInvalidIndex() const {
        return Identifier(IndexManagerInterface<int>::InvalidIndex);
      }

      bool isIdentifierActive(Identifier const& index) const {
        return index != Base::PassiveTag;
      }

      template<typename Lhs>
      void deactivateValue(LhsExpressionInterface<Real, Gradient, TagTapeReverse, Lhs>& value) {
        value.getTapeData() = ActiveTypeTapeData();
      }

      /*******************************************************************************/

      void pushJacobiManual(Real const& jacobian, Real const& value, ActiveTypeTapeData const& index) {
        CODI_UNUSED(jacobian, value, index);
      }

      void storeManual(Real const& lhsValue, ActiveTypeTapeData& lhsIndex, Config::ArgumentSize const& size) {
        CODI_UNUSED(lhsValue, size);
 
        Base::checkLhsError(lhsValue, lhsIndex, lhsValue);
        setTag(lhsIndex.tag);
      }

      /*******************************************************************************/

      void evaluate(Position const& start, Position const& end) {
        CODI_UNUSED(start, end);
      }

      void clearAdjoints(Position const& start, Position const& end) {
        CODI_UNUSED(start, end);
      }

      Position getPosition() const {
        return Position();
      }

      Position getZeroPosition() const {
        return Position();
      }

      void resetTo(Position const& pos, bool resetAdjoints = true) {
        CODI_UNUSED(pos, resetAdjoints);
      }

      /*******************************************************************************/

      void evaluateKeepState(Position const& start, Position const& end) {
        CODI_UNUSED(start, end);
      }

      void evaluateForwardKeepState(Position const& start, Position const& end) {
        CODI_UNUSED(start, end);
      }

      /*******************************************************************************/
 
      static bool constexpr HasPrimalValues = false;        
      static bool constexpr RequiresPrimalRestore = false;  

      void evaluatePrimal(Position const& start, Position const& end) {
        CODI_UNUSED(start, end);
      }

      void evaluatePrimal() {}

      void setPrimal(Identifier const& identifier, Real const& gradient) {
        CODI_UNUSED(identifier, gradient);
      }

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

      Real& primal(Identifier const& identifier) {
        CODI_UNUSED(identifier);
        return tempPrimal;
      }

      Real const& primal(Identifier const& identifier) const {
        CODI_UNUSED(identifier);
        return tempPrimal;
      }

      void revertPrimals(Position const& pos) {
        CODI_UNUSED(pos);
      }

      /*******************************************************************************/

      template<typename Lhs>
      void registerInput(LhsExpressionInterface<Real, Gradient, TagTapeReverse, Lhs>& value) {
        Base::setTag(value.cast().getTapeData().tag);
        Base::verifyRegisterValue(value, value.cast().getTapeData());  // verification is mainly for the properties
      }

      template<typename Lhs>
      void registerOutput(LhsExpressionInterface<Real, Gradient, TagTapeReverse, Lhs>& value) {
        Base::verifyRegisterValue(value, value.cast().getTapeData());
      }

      void setActive() {
        active = true;
      }

      void setPassive() {
        active = false;
      }

      bool isActive() const {
        return active;
      }

      bool isActive(Identifier const& identifier) const {
        return identifier != getPassiveIndex();
      }
 
      void evaluate() {}  

      void clearAdjoints() {}

      void reset(bool resetAdjoints = true) {
        CODI_UNUSED(resetAdjoints);
      }

      template<typename Stream = std::ostream>
      void printStatistics(Stream& out = std::cout) const {
        CODI_UNUSED(out);
      }

      template<typename Stream = std::ostream>
      void printTableHeader(Stream& out = std::cout) const {
        CODI_UNUSED(out);
      }

      template<typename Stream = std::ostream>
      void printTableRow(Stream& out = std::cout) const {
        CODI_UNUSED(out);
      }

      TapeValues getTapeValues() const {
        return TapeValues("TagTapeReverse");
      }

  };
}