PreprocessSolution.py

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# This file is part of the ExaHyPE2 project. For conditions of distribution and 
# use, please see the copyright notice at www.peano-framework.org
 
from .AbstractFVActionSet import AbstractFVActionSet
 
import peano4
import jinja2
 
class EmptyPreprocessSolution(AbstractFVActionSet):
  """
  
  PreprocessSolution differs from other action sets, as I only create it once. See 
  FV.create_action_sets(). Once the instance does exist, you can tailor it. But you
  can also completely overwrite it.
  
  """
  def __init__(self,solver):
    AbstractFVActionSet.__init__(self,solver)
    # Is there for compatibility reasons
    self.guard               = "true"
    self.descend_invocation_orderdescend_invocation_order            = 2
    
 
  def get_body_of_operation(self,operation_name):
    result = ""
    return result
 
 
  def get_action_set_name(self):
    return __name__.replace(".py", "").replace(".", "_")
 
 
 
 
 
class VolumeWisePreprocessSolution(AbstractFVActionSet):
  """!
  
  Run over solution volume by volume
  
  PreprocessSolution differs from other action sets, as I only create it once. See 
  FV.create_action_sets(). Once the instance does exist, you can tailor it. But you
  can also completely overwrite it.
  
  See also FV.postprocess_updated_patch(self, kernel) for a discussion what options
  ExaHyPE offers for postprocessing. This volume-wise postprocessing might be too
  heavy-weight for some applications.
  
  The postprocessing plugs into touch cell last time. It is the last action set added
  by the default implementation. Therefore, it is the first action set of which 
  touchCellLastTime() is called. The reason why I plug into the leaving of the cell
  is that some solvers may add further action sets to the solve. Enclave tasking for
  example adds the merger as additional action set. These action sets plug into 
  touchCellFirstTime() - and consequently their first time is called after the
  postprocessing's first time. By making the postprocessing use touchCellLastTime(),
  I ensure that any additional action set added by a subclass can still precede the 
  postprocessing.
  
  
  """
  def __init__(self,solver):
    AbstractFVActionSet.__init__(self,solver)
    self.guard               = "true"
    self._compute_kernel     = ""
    self.descend_invocation_orderdescend_invocation_order            = 1 
 
 
  def add_postprocessing_kernel(self, operation_per_point):
    """
    
    Add a code snippet which is applied to each and every point. You have the following
    variables which are well-defined:
    
    - value: Is a pointer to the current finite volume's data
    - volumeX: A tarch::la::Vector over doubles
    - volumeH: A tarch::la::Vector over doubles
    
    
    operation_per_point: String
      C/C++ code snippet
    
    """
    self._compute_kernel += """
{
  {{COMPUTE_TIME_STEP_SIZE}}
  const double timeStamp = fineGridCell{{SOLVER_NAME}}CellLabel.getTimeStamp();
    
  if (
    not marker.hasBeenRefined() 
    and 
    {{PREDICATE}}
  ) { 
    logTraceIn( "touchCellFirstTime(...)" );
    
    int index = 0;
    dfor( volume, {{NUMBER_OF_VOLUMES_PER_AXIS}} ) {
      double* value   = fineGridCell{{UNKNOWN_IDENTIFIER}}.value + index;
      auto    volumeX = ::exahype2::fv::getVolumeCentre( marker.x(), marker.h(), {{NUMBER_OF_VOLUMES_PER_AXIS}}, volume);
      auto    volumeH = ::exahype2::fv::getVolumeSize( marker.h(), {{NUMBER_OF_VOLUMES_PER_AXIS}});
      
      """ + operation_per_point + """
      
      index += {{NUMBER_OF_UNKNOWNS}} + {{NUMBER_OF_AUXILIARY_VARIABLES}};
    }
    logTraceOut( "touchCellFirstTime(...)" );
  } 
}
"""
 
    
 
  def get_body_of_operation(self,operation_name):
    result = ""
    if operation_name==peano4.solversteps.ActionSet.OPERATION_TOUCH_CELL_LAST_TIME:
      d = {}
      self._solver._init_dictionary_with_default_parameters(d)
      self._solver.add_entries_to_text_replacement_dictionary(d)
      d[ "PREDICATE" ]           = jinja2.Template(self.guard, undefined=jinja2.DebugUndefined).render(**d)
      result = jinja2.Template(self._compute_kernel, undefined=jinja2.DebugUndefined).render(**d)
      pass 
    return result
 
 
  def get_action_set_name(self):
    return __name__.replace(".py", "").replace(".", "_")