text: /* ************************************************************************
   * Copyright (c) 2018 Advanced Micro Devices, Inc.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   *
   * ************************************************************************ */
  
  #include "preconditioner_as.hpp"
  #include "../../base/local_matrix.hpp"
  #include "../../base/local_vector.hpp"
  #include "../../utils/def.hpp"
  #include "../solver.hpp"
  
  #include "../../utils/log.hpp"
  
  #include "preconditioner.hpp"
  
  #include <complex>
  
  namespace rocalution
  {
  
      template <class OperatorType, class VectorType, typename ValueType>
      AS<OperatorType, VectorType, ValueType>::AS()
      {
          log_debug(this, "AS::AS()", "default constructor");
  
          this->pos_        = NULL;
          this->sizes_      = NULL;
          this->num_blocks_ = 0;
          this->overlap_    = -1;
  
          this->local_precond_ = NULL;
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      AS<OperatorType, VectorType, ValueType>::~AS()
      {
          log_debug(this, "AS::~AS()", "destructor");
  
          this->Clear();
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::Print(void) const
      {
          if(this->build_ == true)
          {
              LOG_INFO("Additive Schwarz preconditioner"
                       << " number of blocks = " << this->num_blocks_
                       << "; overlap = " << this->overlap_ << "; block preconditioner:");
  
              this->local_precond_[0]->Print();
          }
          else
          {
              LOG_INFO("Additive Schwarz preconditioner");
          }
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::Set(
          int nb, int overlap, Solver<OperatorType, VectorType, ValueType>** preconds)
      {
          log_debug(this, "AS::Set()", nb, overlap, preconds);
  
          if((this->build_ == true) || (this->local_precond_ != NULL))
          {
              this->Clear();
          }
  
          assert(nb > 0);
          assert(overlap >= 0);
          assert(preconds != NULL);
  
          this->num_blocks_ = nb;
          this->overlap_    = overlap;
  
          this->local_precond_ = new Solver<OperatorType, VectorType, ValueType>*[nb];
          this->pos_           = new int[nb];
          this->sizes_         = new int[nb];
  
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->local_precond_[i] = preconds[i];
          }
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::Build(void)
      {
          log_debug(this, "AS::Build()", this->build_, " #*# begin");
  
          assert(this->op_ != NULL);
          assert(this->num_blocks_ > 0);
          assert(this->overlap_ >= 0);
          assert(this->local_precond_ != NULL);
  
          int size   = this->op_->GetLocalM() / this->num_blocks_;
          int offset = 0;
  
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->pos_[i] = offset - this->overlap_;
              offset += size;
              this->sizes_[i] = size + 2 * this->overlap_;
          }
  
          // Built for AS and RAS
          // correct fist and last
          this->pos_[0]                       = 0;
          this->sizes_[0]                     = size + this->overlap_;
          this->sizes_[this->num_blocks_ - 1] = size + this->overlap_;
  
          this->weight_.MoveToHost();
          this->weight_.Allocate("Overlapping weights", this->op_->GetM());
          this->weight_.Ones();
  
          ValueType* ptr_w = NULL;
          this->weight_.LeaveDataPtr(&ptr_w);
  
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              for(int j = 0; j < this->overlap_; ++j)
              {
                  if(i != 0)
                  {
                      ptr_w[this->pos_[i] + j] = 0.5;
                  }
  
                  if(i != this->num_blocks_ - 1)
                  {
                      ptr_w[this->pos_[i] + size + j] = 0.5;
                  }
              }
          }
  
          this->weight_.SetDataPtr(&ptr_w, "Overlapping weights", this->op_->GetLocalM());
          this->weight_.CloneBackend(*this->op_);
  
          this->local_mat_ = new OperatorType*[this->num_blocks_];
          this->r_         = new VectorType*[this->num_blocks_];
          this->z_         = new VectorType*[this->num_blocks_];
  
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->r_[i] = new VectorType;
              this->r_[i]->CloneBackend(*this->op_);
              this->r_[i]->Allocate("AS residual vector", this->sizes_[i]);
  
              this->z_[i] = new VectorType;
              this->z_[i]->CloneBackend(*this->op_);
              this->z_[i]->Allocate("AS residual vector", this->sizes_[i]);
  
              this->local_mat_[i] = new OperatorType;
              this->local_mat_[i]->CloneBackend(*this->op_);
  
              this->op_->ExtractSubMatrix(this->pos_[i],
                                          this->pos_[i],
                                          this->sizes_[i],
                                          this->sizes_[i],
                                          this->local_mat_[i]);
  
              this->local_precond_[i]->SetOperator(*this->local_mat_[i]);
              this->local_precond_[i]->Build();
          }
  
          this->build_ = true;
  
          log_debug(this, "AS::Build()", this->build_, " #*# end");
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::Clear(void)
      {
          log_debug(this, "AS::Clear()", this->build_);
  
          if(this->build_ == true)
          {
              this->weight_.Clear();
  
              for(int i = 0; i < this->num_blocks_; ++i)
              {
                  if(this->local_precond_[i] != NULL)
                  {
                      this->local_precond_[i]->Clear();
                      this->local_precond_[i] = NULL;
                  }
  
                  this->r_[i]->Clear();
                  delete this->r_[i];
  
                  this->z_[i]->Clear();
                  delete this->z_[i];
  
                  this->local_mat_[i]->Clear();
                  delete this->local_mat_[i];
              }
  
              delete[] this->local_precond_;
              delete[] this->r_;
              delete[] this->z_;
              delete[] this->local_mat_;
  
              delete[] this->pos_;
              delete[] this->sizes_;
  
              this->pos_   = NULL;
              this->sizes_ = NULL;
  
              this->num_blocks_    = 0;
              this->overlap_       = -1;
              this->local_precond_ = NULL;
  
              this->build_ = false;
          }
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::Solve(const VectorType& rhs, VectorType* x)
      {
          log_debug(this, "AS::Solve_()", " #*# begin", (const void*&)rhs, x);
  
          assert(this->build_ == true);
          assert(x != NULL);
          assert(x != &rhs);
  
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->r_[i]->CopyFrom(rhs, this->pos_[i], 0, this->sizes_[i]);
          }
  
          // Solve
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->local_precond_[i]->SolveZeroSol(*this->r_[i], // rhs
                                                    this->z_[i]); // x
          }
  
          x->Zeros();
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              x->ScaleAddScale(static_cast<ValueType>(1),
                               *this->z_[i],
                               static_cast<ValueType>(1),
                               0,
                               this->pos_[i],
                               this->sizes_[i]);
          }
  
          x->PointWiseMult(this->weight_);
  
          log_debug(this, "AS::Solve_()", " #*# end");
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::MoveToHostLocalData_(void)
      {
          log_debug(this, "AS::MoveToAcceleratorLocalData_()", this->build_);
  
          if(this->build_ == true)
          {
              this->weight_.MoveToHost();
  
              for(int i = 0; i < this->num_blocks_; ++i)
              {
                  this->local_precond_[i]->MoveToHost();
                  this->r_[i]->MoveToHost();
                  this->z_[i]->MoveToHost();
                  this->local_mat_[i]->MoveToHost();
              }
          }
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void AS<OperatorType, VectorType, ValueType>::MoveToAcceleratorLocalData_(void)
      {
          log_debug(this, "AS::MoveToHostLocalData_()", this->build_);
  
          if(this->build_ == true)
          {
              this->weight_.MoveToAccelerator();
  
              for(int i = 0; i < this->num_blocks_; ++i)
              {
                  this->local_precond_[i]->MoveToAccelerator();
                  this->r_[i]->MoveToAccelerator();
                  this->z_[i]->MoveToAccelerator();
                  this->local_mat_[i]->MoveToAccelerator();
              }
          }
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      RAS<OperatorType, VectorType, ValueType>::RAS()
      {
          log_debug(this, "RAS::RAS()", "default constructor");
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      RAS<OperatorType, VectorType, ValueType>::~RAS()
      {
          log_debug(this, "RAS::~RAS()", "destructor");
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void RAS<OperatorType, VectorType, ValueType>::Print(void) const
      {
          if(this->build_ == true)
          {
              LOG_INFO("Restricted Additive Schwarz preconditioner"
                       << " number of blocks = " << this->num_blocks_
                       << "; overlap = " << this->overlap_ << "; block preconditioner:");
  
              this->local_precond_[0]->Print();
          }
          else
          {
              LOG_INFO("Additive Schwarz preconditioner");
          }
      }
  
      template <class OperatorType, class VectorType, typename ValueType>
      void RAS<OperatorType, VectorType, ValueType>::Solve(const VectorType& rhs, VectorType* x)
      {
          log_debug(this, "RAS::Solve_()", " #*# begin", (const void*&)rhs, x);
  
          assert(this->build_ == true);
          assert(x != NULL);
          assert(x != &rhs);
  
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->r_[i]->CopyFrom(rhs, this->pos_[i], 0, this->sizes_[i]);
          }
  
          // Solve
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              this->local_precond_[i]->SolveZeroSol(*this->r_[i], // rhs
                                                    this->z_[i]); // x
          }
  
          int size     = this->op_->GetLocalM() / this->num_blocks_;
          int z_offset = 0;
          for(int i = 0; i < this->num_blocks_; ++i)
          {
              x->CopyFrom(*this->z_[i], z_offset, this->pos_[i] + z_offset, size);
  
              z_offset = this->overlap_;
          }
  
          log_debug(this, "RAS::Solve_()", " #*# end");
      }
  
      template class AS<LocalMatrix<double>, LocalVector<double>, double>;
      template class AS<LocalMatrix<float>, LocalVector<float>, float>;
  #ifdef SUPPORT_COMPLEX
      template class AS<LocalMatrix<std::complex<double>>,
                        LocalVector<std::complex<double>>,
                        std::complex<double>>;
      template class AS<LocalMatrix<std::complex<float>>,
                        LocalVector<std::complex<float>>,
                        std::complex<float>>;
  #endif
  
      template class RAS<LocalMatrix<double>, LocalVector<double>, double>;
      template class RAS<LocalMatrix<float>, LocalVector<float>, float>;
  #ifdef SUPPORT_COMPLEX
      template class RAS<LocalMatrix<std::complex<double>>,
                         LocalVector<std::complex<double>>,
                         std::complex<double>>;
      template class RAS<LocalMatrix<std::complex<float>>,
                         LocalVector<std::complex<float>>,
                         std::complex<float>>;
  #endif
  
  } // namespace rocalution
  