constraint_interpreter.cpp

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// Constraint_Interpreter.cpp,v 1.23 2003/10/28 18:34:24 bala Exp

#include "Constraint_Interpreter.h"
#include "Trader_Constraint_Visitors.h"

ACE_RCSID (Trader, 
           Constraint_Interpreter, 
           "Constraint_Interpreter.cpp,v 1.23 2003/10/28 18:34:24 bala Exp")

TAO_Constraint_Interpreter::TAO_Constraint_Interpreter (
    const CosTradingRepos::ServiceTypeRepository::TypeStruct& ts,
    const char* constraints
    ACE_ENV_ARG_DECL
  )
  ACE_THROW_SPEC ((CosTrading::IllegalConstraint,
                   CORBA::NO_MEMORY))
  : TAO_Interpreter ()
{
  // @@ Throwing Exception from constructor is very nasty situation to
  // deal with.

  TAO_Trader_Constraint_Validator type_checker (ts);

  if (TAO_Interpreter::is_empty_string (constraints))
    {
      ACE_NEW_THROW_EX (this->root_,
                        TAO_Literal_Constraint ((CORBA::Boolean) 1),
                        CORBA::NO_MEMORY ());
      ACE_CHECK;
    }
  else
    {
      if (this->build_tree (constraints) != 0)
        ACE_THROW (CosTrading::IllegalConstraint (constraints));

      if (type_checker.validate (this->root_) == -1)
        ACE_THROW (CosTrading::IllegalConstraint (constraints));
    }
}

TAO_Constraint_Interpreter::
TAO_Constraint_Interpreter (TAO_Constraint_Validator& validator,
                           const char* constraints
                           ACE_ENV_ARG_DECL)
  ACE_THROW_SPEC ((CosTrading::IllegalConstraint,
                   CORBA::NO_MEMORY))
{
  if (TAO_Interpreter::is_empty_string (constraints))
    {
      ACE_NEW_THROW_EX (this->root_,
                        TAO_Literal_Constraint ((CORBA::Boolean) 1),
                        CORBA::NO_MEMORY ());
      ACE_CHECK;
    }
  else
    {
      if (this->build_tree (constraints) != 0)
        ACE_THROW (CosTrading::IllegalConstraint (constraints));

      if (validator.validate (this->root_) == -1)
        ACE_THROW (CosTrading::IllegalConstraint (constraints));
    }
}

TAO_Constraint_Interpreter::~TAO_Constraint_Interpreter (void)
{
}

CORBA::Boolean
TAO_Constraint_Interpreter::evaluate (CosTrading::Offer* offer)
{
  TAO_Trader_Constraint_Evaluator evaluator (offer);
  return evaluator.evaluate_constraint (this->root_);
}

CORBA::Boolean
TAO_Constraint_Interpreter::evaluate (TAO_Constraint_Evaluator& evaluator)
{
  return evaluator.evaluate_constraint (this->root_);
}

TAO_Preference_Interpreter::TAO_Preference_Interpreter (
    const CosTradingRepos::ServiceTypeRepository::TypeStruct& ts,
    const char* preference
    ACE_ENV_ARG_DECL
  )
  ACE_THROW_SPEC ((CosTrading::Lookup::IllegalPreference,
                   CORBA::NO_MEMORY))
    : TAO_Interpreter ()
{
  TAO_Trader_Constraint_Validator type_checker (ts);

  if (TAO_Interpreter::is_empty_string (preference))
    {
      ACE_NEW_THROW_EX (this->root_,
                        TAO_Noop_Constraint (TAO_FIRST),
                        CORBA::NO_MEMORY ());
      ACE_CHECK;
    }
  else
    {
      if (this->build_tree (preference) != 0)
        ACE_THROW (CosTrading::Lookup::IllegalPreference (preference));

      if (type_checker.validate (this->root_) == -1)
        ACE_THROW (CosTrading::Lookup::IllegalPreference (preference));
    }
}

TAO_Preference_Interpreter::
TAO_Preference_Interpreter (TAO_Constraint_Validator& validator,
                           const char* preference
                           ACE_ENV_ARG_DECL)
  ACE_THROW_SPEC ((CosTrading::Lookup::IllegalPreference,
                   CORBA::NO_MEMORY))
    : TAO_Interpreter ()
{
  if (TAO_Interpreter::is_empty_string (preference))
    {
      ACE_NEW_THROW_EX (this->root_,
                        TAO_Noop_Constraint (TAO_FIRST),
                        CORBA::NO_MEMORY ());
      ACE_CHECK;
    }
  else
    {
      if (this->build_tree (preference) != 0)
        ACE_THROW (CosTrading::Lookup::IllegalPreference (preference));

      if (validator.validate (this->root_) == -1)
        ACE_THROW (CosTrading::Lookup::IllegalPreference (preference));
    }
}

TAO_Preference_Interpreter::~TAO_Preference_Interpreter ()
{
}

void
TAO_Preference_Interpreter::
order_offer (CosTrading::Offer* offer,
             CosTrading::OfferId offer_id)
{
  TAO_Trader_Constraint_Evaluator evaluator (offer);
  this->order_offer (evaluator, offer, offer_id);
}

void
TAO_Preference_Interpreter::
order_offer (TAO_Constraint_Evaluator& evaluator,
             CosTrading::Offer* offer,
             CosTrading::OfferId offer_id)
{
  if (this->root_ != 0)
    {
      Preference_Info pref_info;

      pref_info.offer_ = offer;
      pref_info.offer_id_ = offer_id;
      pref_info.evaluated_ = 1;

      if (evaluator.evaluate_preference (this->root_, pref_info.value_) == 0)
        {
          // If the evaluation succeeds, insert the node into the
          // correct place in the queue.
          TAO_Expression_Type expr_type = this->root_->expr_type ();

          if (expr_type == TAO_FIRST
              || (expr_type == TAO_WITH
                  && ! ACE_static_cast (CORBA::Boolean, pref_info.value_)))
            this->offers_.enqueue_tail (pref_info);
          else
            this->offers_.enqueue_head (pref_info);

          if (expr_type == TAO_MIN || expr_type == TAO_MAX)
            {
              Ordered_Offers::ITERATOR offer_iter (this->offers_);

              // Push the new item down the list until the min/max
              // criterion is satisfied. Observe the evaluation failed
              // / evaluation suceeded partion in the list.
              offer_iter.advance ();

              for (int i = 1;
                   offer_iter.done () == 0;
                   offer_iter.advance (), i++)
                {
                  Preference_Info* current_offer;
                  offer_iter.next (current_offer);

                  // Maintain the sorted order in the first partition.
                  if (current_offer->evaluated_ == 1
                      && ((expr_type == TAO_MIN
                        && pref_info.value_ > current_offer->value_)
                       || (expr_type == TAO_MAX
                           && pref_info.value_ < current_offer->value_)))
                    {
                      // Swap the out of order pair
                      this->offers_.set (*current_offer,
                                         i - 1);
                      this->offers_.set (pref_info, i);
                    }
                  else
                    break;
                }
            }
        }
      else
        {
          // If the evaluation fails, just tack the sucker onto the
          // end of the queue.
          pref_info.evaluated_ = 0;
          this->offers_.enqueue_tail (pref_info);
        }
    }
}

int
TAO_Preference_Interpreter::
remove_offer (CosTrading::Offer*& offer,
              CosTrading::OfferId& offer_id)
{
  int return_value = -1;
  Preference_Info pref_info;

  return_value = this->offers_.dequeue_head (pref_info);

  if (return_value == 0)
    {
      offer = pref_info.offer_;
      offer_id = pref_info.offer_id_;
    }

  return return_value;
}

int
TAO_Preference_Interpreter::
remove_offer (CosTrading::Offer*& offer)
{
  CosTrading::OfferId offer_id = 0;
  return this->remove_offer (offer, offer_id);
}


size_t
TAO_Preference_Interpreter::num_offers (void)
{
  return this->offers_.size ();
}

#if defined (ACE_HAS_EXPLICIT_TEMPLATE_INSTANTIATION)
template class ACE_Node<TAO_Preference_Interpreter::Preference_Info>;
template class ACE_Unbounded_Queue<TAO_Preference_Interpreter::Preference_Info>;
template class ACE_Unbounded_Queue_Iterator<TAO_Preference_Interpreter::Preference_Info>;
#elif defined (ACE_HAS_TEMPLATE_INSTANTIATION_PRAGMA)
#pragma instantiate ACE_Node<TAO_Preference_Interpreter::Preference_Info>
#pragma instantiate ACE_Unbounded_Queue<TAO_Preference_Interpreter::Preference_Info>
#pragma instantiate ACE_Unbounded_Queue_Iterator<TAO_Preference_Interpreter::Preference_Info>
#endif /* ACE_HAS_EXPLICIT_TEMPLATE_INSTANTIATION */