Notify_Constraint_Visitors.cpp

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// $Id: Notify_Constraint_Visitors.cpp 81641 2008-05-07 19:18:59Z parsons $

#include "orbsvcs/Notify/Notify_Constraint_Visitors.h"

#include "ace/ETCL/ETCL_y.h"

#include "tao/ETCL/TAO_ETCL_Constraint.h"

#include "tao/DynamicAny/DynArray_i.h"
#include "tao/DynamicAny/DynSequence_i.h"
#include "tao/DynamicAny/DynStruct_i.h"
#include "tao/DynamicAny/DynUnion_i.h"
#include "tao/DynamicAny/DynEnum_i.h"
#include "tao/DynamicAny/DynAnyFactory.h"
#include "tao/DynamicAny/DynAnyUtils_T.h"

#include "tao/AnyTypeCode/Any_Unknown_IDL_Type.h"
#include "tao/CDR.h"

TAO_BEGIN_VERSIONED_NAMESPACE_DECL

TAO_Notify_Constraint_Visitor::TAO_Notify_Constraint_Visitor (void)
  : implicit_id_ (TAO_Notify_Constraint_Visitor::EMPTY),
    implicit_ids_(implicit_ids_size_),
    filterable_data_(filterable_data_size_),
    variable_header_(variable_header_size_)
{
  (void) this->implicit_ids_.bind (ACE_CString ("filterable_data",
    0,
    false),
    FILTERABLE_DATA);
  (void) this->implicit_ids_.bind (ACE_CString ("header",
    0,
    false),
    HEADER);
  (void) this->implicit_ids_.bind (ACE_CString ("remainder_of_body",
    0,
    false),
    REMAINDER_OF_BODY);
  (void) this->implicit_ids_.bind (ACE_CString ("fixed_header",
    0,
    false),
    FIXED_HEADER);
  (void) this->implicit_ids_.bind (ACE_CString ("variable_header",
    0,
    false),
    VARIABLE_HEADER);
  (void) this->implicit_ids_.bind (ACE_CString ("event_name",
    0,
    false),
    EVENT_NAME);
  (void) this->implicit_ids_.bind (ACE_CString ("event_type",
    0,
    false),
    EVENT_TYPE);
  (void) this->implicit_ids_.bind (ACE_CString ("domain_name",
    0,
    false),
    DOMAIN_NAME);
  (void) this->implicit_ids_.bind (ACE_CString ("type_name",
    0,
    false),
    TYPE_NAME);
}

int
TAO_Notify_Constraint_Visitor::bind_structured_event (const CosNotification::StructuredEvent &s_event)
{
  // The two sequences contained in a structured event are
  // copied into hash tables so iteration is done only once.

  CORBA::ULong length = s_event.filterable_data.length ();
  CORBA::ULong index = 0;

  for (index = 0; index < length; ++index)
  {
    ACE_CString name_str (s_event.filterable_data[index].name, 0, false);

    int status =
      this->filterable_data_.bind (
        name_str,
        s_event.filterable_data[index].value
        );

    if (status != 0)
      return -1;
  }

  length = s_event.header.variable_header.length ();

  for (index = 0; index < length; ++index)
  {
    ACE_CString name_str (s_event.header.variable_header[index].name, 0, false);

    int status =
      this->variable_header_.bind (
        name_str,
        s_event.header.variable_header[index].value
        );

    if (status != 0)
      return -1;
  }

  this->domain_name_ =
    CORBA::string_dup (s_event.header.fixed_header.event_type.domain_name);

  this->type_name_ =
    CORBA::string_dup (s_event.header.fixed_header.event_type.type_name);

  this->event_name_ =
    CORBA::string_dup (s_event.header.fixed_header.event_name);

  this->remainder_of_body_ = s_event.remainder_of_body;

  return 0;
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::evaluate_constraint (ETCL_Constraint* root)
{
  CORBA::Boolean result = 0;
  this->queue_.reset ();

  // Evaluate the constraint in root_;
  if (root != 0)
    {
      if ((root->accept (this) == 0) && (! this->queue_.is_empty ()))
        {
          TAO_ETCL_Literal_Constraint top;
          this->queue_.dequeue_head (top);
          result = (CORBA::Boolean) top;
        }
    }

  // If a property couldn't be evaluated we must return 0.
  return result;
}

int
TAO_Notify_Constraint_Visitor::visit_literal (
    ETCL_Literal_Constraint *literal
  )
{
  TAO_ETCL_Literal_Constraint lit (literal);
  this->queue_.enqueue_head (lit);
  return 0;
}

int
TAO_Notify_Constraint_Visitor::visit_identifier (ETCL_Identifier *ident)
{
  int return_value = -1;
  const char *name = ident->value ();
  ACE_CString key (name, 0, false);

  CORBA::Any any;

  if (this->filterable_data_.find (key, any) == 0)
    {
      if (any.impl () != 0)
        {
          this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (&any));
          return_value = 0;
        }
    }

  return return_value;
}

int
TAO_Notify_Constraint_Visitor::visit_union_value (
    ETCL_Union_Value *union_value
  )
{
  switch (union_value->sign ())
  {
    case 0:
      {
        TAO_ETCL_Literal_Constraint lit (union_value->string ());
        this->queue_.enqueue_head (lit);
      }
      break;
    case -1:
      {
        CORBA::Long value = -(*union_value->integer ());
        TAO_ETCL_Literal_Constraint lit (value);
        this->queue_.enqueue_head (lit);
      }
      break;
    case 1:
      {
        TAO_ETCL_Literal_Constraint lit (union_value->integer ());
        this->queue_.enqueue_head (lit);
      }
      break;
    default:
      return -1;
  }

  return 0;
}

int
TAO_Notify_Constraint_Visitor::visit_union_pos (
    ETCL_Union_Pos *union_pos
  )
{
  try
  {
    if (union_pos->union_value ()->accept (this) == 0)
      {
        TAO_ETCL_Literal_Constraint disc_val;
        this->queue_.dequeue_head (disc_val);

        TAO_DynUnion_i dyn_union;
        dyn_union.init (this->current_value_.in ());

        CORBA::TypeCode_var tc = this->current_value_->type ();

        switch (disc_val.expr_type ())
        {
        case ETCL_INTEGER:
        case ETCL_SIGNED:
        case ETCL_UNSIGNED:
          {
            CORBA::Any disc_any;
            CORBA::TypeCode_var disc_tc =
              tc->discriminator_type ();
            CORBA::TCKind disc_kind =
              TAO_DynAnyFactory::unalias (disc_tc.in ());

            switch (disc_kind)
            {
            case CORBA::tk_boolean:
              disc_any <<= CORBA::Any::from_boolean ((CORBA::Boolean) disc_val);
              break;
            case CORBA::tk_short:
              disc_any <<= (CORBA::Short) ((CORBA::Long) disc_val);
              break;
            case CORBA::tk_ushort:
              disc_any <<= (CORBA::UShort) ((CORBA::ULong) disc_val);
              break;
            case CORBA::tk_long:
              disc_any <<= (CORBA::Long) disc_val;
              break;
            case CORBA::tk_ulong:
              disc_any <<= (CORBA::ULong) disc_val;
              break;
            case CORBA::tk_enum:
              {
                TAO_OutputCDR cdr;
                cdr.write_ulong ((CORBA::ULong) disc_val);
                TAO_InputCDR in_cdr (cdr);
                TAO::Unknown_IDL_Type *unk = 0;
                ACE_NEW_RETURN (unk,
                                TAO::Unknown_IDL_Type (disc_tc.in (),
                                in_cdr),
                                -1);

                disc_any.replace (unk);
                break;
              }
              // @@@ (JP) I don't think ETCL handles 64-bit
              // integers at this point, and I also think that
              // chars and/or wchars will just come out in the
              // constraint as (w)strings of length 1.
            case CORBA::tk_longlong:
            case CORBA::tk_ulonglong:
            case CORBA::tk_char:
            case CORBA::tk_wchar:
            default:
              return -1;
            }

            DynamicAny::DynAny_var dyn_any =
              TAO::MakeDynAnyUtils::make_dyn_any_t<const CORBA::Any &> (
                disc_tc.in (),
                disc_any);
            dyn_union.set_discriminator (dyn_any.in ());
            DynamicAny::DynAny_var u_member =
              dyn_union.member ();
            this->current_value_ =
              u_member->to_any ();

            break;
          }
        case ETCL_STRING:
          {
            const char *name = (const char *) disc_val;
            CORBA::ULong count = tc->member_count ();

            const char *member_name = 0;
            CORBA::ULong i = 0;

            for (i = 0; i < count; ++i)
              {
                member_name = tc->member_name (i);

                if (ACE_OS::strcmp (name, member_name) == 0)
                  {
                    break;
                  }
              }

            // If there's no match, member_label will throw
            // CORBA::TypeCode::Bounds and the catch block will
            // return -1;
            this->current_value_ = tc->member_label (i);

            break;
          }
          // The ETCL_Union_Value that was put on the queue
          // shouldn't have any other type.
        default:
          return -1;
        }

        ETCL_Constraint *nested = union_pos->component ();

        // If there's no nested component, then we just want the
        // union member value on the queue. Otherwise, we want
        // the member value in current_value_ while we visit
        // the nested component.
        if (nested == 0)
          {
            TAO_ETCL_Literal_Constraint lit (this->current_value_.ptr ());
            this->queue_.enqueue_head (lit);
            return 0;
          }
        else
          {
            return nested->accept (this);
          }
      }
    else
      {
        return -1;
      }
  }
  catch (const CORBA::Exception&)
  {
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_component_pos (
    ETCL_Component_Pos *pos
  )
{
  try
  {
    // If we are here (from visit_component) the Any containing the
    // component as found in filterable_data_ will be in current_value_.
    CORBA::TypeCode_var tc = this->current_value_->type ();
    CORBA::TCKind kind = TAO_DynAnyFactory::unalias (tc.in ());

    DynamicAny::DynAny_var member;
    CORBA::Boolean success = 0;
    CORBA::ULong slot = (CORBA::ULong) *pos->integer ();

    switch (kind)
    {
    case CORBA::tk_enum:
      {
        TAO_DynEnum_i dyn_enum;
        dyn_enum.init (this->current_value_.in ());
        success = dyn_enum.seek (slot);

        if (!success)
          {
            return -1;
          }

        member = dyn_enum.current_component ();
        break;
      }
    case CORBA::tk_struct:
      {
        TAO_DynStruct_i dyn_struct;
        dyn_struct.init (this->current_value_.in ());
        success = dyn_struct.seek (slot);

        if (!success)
          {
            return -1;
          }

        member = dyn_struct.current_component ();
        break;
      }
      // @@@ (JP) I think enums and structs are the only two cases
      // handled by Component_Pos, since arrays and sequences are
      // handled by Component_Array, and unions are handled by
      // Union_Pos.
    default:
      return -1;
    }

    CORBA::Any_var value = member->to_any ();
    ETCL_Constraint *comp = pos->component ();

    if (comp == 0)
      {
        TAO_ETCL_Literal_Constraint result (value.ptr ());
        this->queue_.enqueue_head (result);
        return 0;
      }
    else
      {
        this->current_value_ = value._retn ();
        return comp->accept (this);
      }
  }
  catch (const CORBA::Exception&)
  {
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_component_assoc (
    ETCL_Component_Assoc *assoc
  )
{
  CORBA::Any any;
  ACE_CString name (assoc->identifier ()->value (),
                    0,
                    false);

  switch (this->implicit_id_)
  {
  case FILTERABLE_DATA:
    if (this->filterable_data_.find (name, any) != 0 || any.impl () == 0)
      {
        return -1;
      }
    break;
  case VARIABLE_HEADER:
    if (this->variable_header_.find (name, any) != 0|| any.impl () == 0)
      {
        return -1;
      }
    break;
    // Only the sequence members of CosNotification::StructuredEvent
    // can be treated as associative arrays.
  default:
    return -1;
  }

  ETCL_Constraint *comp = assoc->component ();
  CORBA::Any *any_ptr = 0;

  if (comp == 0)
    {
      TAO_ETCL_Literal_Constraint result (&any);
      this->queue_.enqueue_head (result);

      // If we're at the end of the line, put the name into
      // current_value_ so visit_exist can use it.
      ACE_NEW_RETURN (any_ptr,
                      CORBA::Any,
                      -1);
                      
      (*any_ptr) <<= name.c_str ();
      this->current_value_ = any_ptr;

      return 0;
    }
  else
    {
      ACE_NEW_RETURN (any_ptr,
                      CORBA::Any (any),
                      -1);
                      
      this->current_value_ = any_ptr;
      return comp->accept (this);
    }
}

int
TAO_Notify_Constraint_Visitor::visit_component_array (
    ETCL_Component_Array *array
  )
{
  try
  {
    // If we are here (from visit_component) the Any containing the
    // component as found in filterable_data_ will be in
    // current_value_.
    CORBA::TypeCode_var tc = this->current_value_->type ();
    CORBA::TCKind kind = TAO_DynAnyFactory::unalias (tc.in ());

    DynamicAny::DynAny_var member;
    CORBA::Boolean success = 0;
    CORBA::ULong slot = (CORBA::ULong) *array->integer ();

    switch (kind)
    {
    case CORBA::tk_array:
      {
        TAO_DynEnum_i dyn_array;
        dyn_array.init (this->current_value_.in ());
        success = dyn_array.seek (slot);

        if (!success)
          {
            return -1;
          }

        member = dyn_array.current_component ();
        break;
      }
    case CORBA::tk_sequence:
      {
        TAO_DynStruct_i dyn_sequence;
        dyn_sequence.init (this->current_value_.in ());
        success = dyn_sequence.seek (slot);

        if (!success)
          {
            return -1;
          }

        member =dyn_sequence.current_component ();
        break;
      }
      // Enums and sequences are the only two cases handled
      // by Component_Array.
    default:
      return -1;
    }

    CORBA::Any_var value = member->to_any ();
    ETCL_Constraint *comp = array->component ();

    if (comp == 0)
      {
        TAO_ETCL_Literal_Constraint result (value.ptr ());
        this->queue_.enqueue_head (result);
        return 0;
      }
    else
      {
        this->current_value_ = value._retn ();
        return comp->accept (this);
      }
  }
  catch (const CORBA::Exception&)
  {
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_special (ETCL_Special *special)
{
  try
  {
    CORBA::TypeCode_var tc = this->current_value_->type ();
    tc = TAO_DynAnyFactory::strip_alias (tc.in ());
    CORBA::TCKind kind = tc->kind ();

    switch (special->type ())
    {
    case ETCL_LENGTH:
      {
        CORBA::ULong length;

        switch (kind)
        {
        case CORBA::tk_sequence:
          {
            TAO_DynSequence_i dyn_seq;
            dyn_seq.init (current_value_.in());

            DynamicAny::AnySeq_var any_seq =
              dyn_seq.get_elements ();

            length = any_seq->length ();
          }
          break;
        case CORBA::tk_array:
          length = tc->length ();
          break;
        default:
          return -1;
        }

        TAO_ETCL_Literal_Constraint lit (length);
        this->queue_.enqueue_head (lit);
        return 0;
      }
    case ETCL_DISCRIMINANT:
      {
        // If the TCKind is not a union, the call to init() will
        // raise an exception, and the catch block will return -1;
        TAO_DynUnion_i dyn_union;
        dyn_union.init (this->current_value_.in ());

        DynamicAny::DynAny_var disc =
          dyn_union.get_discriminator ();

        CORBA::Any_var disc_any = disc->to_any ();

        TAO_ETCL_Literal_Constraint lit (disc_any.ptr ());
        this->queue_.enqueue_head (lit);
        return 0;
      }
    case ETCL_TYPE_ID:
      {
        const char *name = tc->name ();

        TAO_ETCL_Literal_Constraint lit (name);
        this->queue_.enqueue_head (lit);
        return 0;
      }
    case ETCL_REPOS_ID:
      {
        const char *id = tc->id ();

        TAO_ETCL_Literal_Constraint lit (id);
        this->queue_.enqueue_head (lit);
        return 0;
      }
    default:
      return -1;
    }
  }
  catch (const CORBA::Exception&)
  {
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_component (
    ETCL_Component *component
  )
{
  ETCL_Constraint *nested = component->component ();
  ETCL_Identifier *identifier = component->identifier ();
  ACE_CString component_name (identifier->value (),
                              0,
                              false);
  CORBA::Any *any_ptr = 0;
  int result =
    this->implicit_ids_.find (component_name, this->implicit_id_);

  if (result != 0)
    {
      this->implicit_id_ = TAO_Notify_Constraint_Visitor::EMPTY;
    }

  // If this component has no sub-component, only an identifier, then
  // we just visit the identifier, which puts a literal on the queue
  // to be handled upon returning from this method call.  If there is
  // a sub-component, we store the literal's value in our member _var
  // for possible examination at a more nested level, and visit the
  // sub-component. If the identifier matches one of the nested field
  // names in CosNotification::StructuredEvent, we just visit the
  // nested component, if any.
  if (this->implicit_id_ == TAO_Notify_Constraint_Visitor::EMPTY)
    {
      ACE_NEW_RETURN (any_ptr,
                      CORBA::Any,
                      -1);

      if (nested == 0)
        {
          // If this is the end of the line, we put the component name
          // into current_value_ so visit_exist can use it.
          (*any_ptr) <<= component_name.c_str ();
          this->current_value_ = any_ptr;
          return identifier->accept (this);
        }
      else
        {
          int result = identifier->accept (this);

          if (result != 0)
            {
              return result;
            }

          TAO_ETCL_Literal_Constraint id;
          this->queue_.dequeue_head (id);
                          
          any_ptr->replace (id);
          any_ptr->impl ()->_add_ref ();
          this->current_value_ = any_ptr;
        }
    }

  if (nested != 0)
    {
      return nested->accept (this);
    }
  else
    {
      switch (this->implicit_id_)
      {
      case TYPE_NAME:
        {
          TAO_ETCL_Literal_Constraint tn (this->type_name_.in ());
          this->queue_.enqueue_head (tn);
          return 0;
        }
      case EVENT_NAME:
        {
          TAO_ETCL_Literal_Constraint en (this->event_name_.in ());
          this->queue_.enqueue_head (en);
          return 0;
        }
      case DOMAIN_NAME:
        {
          TAO_ETCL_Literal_Constraint dn (this->domain_name_.in ());
          this->queue_.enqueue_head (dn);
          return 0;
        }
      case REMAINDER_OF_BODY:
        {
          TAO_ETCL_Literal_Constraint rob (&this->remainder_of_body_);
          this->queue_.enqueue_head (rob);
          return 0;
        }
        // The above cases are the leaves of the
        // CosNotification::StructuredEvent "tree". Anything else and we
        // should have a nested component. otherwise, it's an error.
      default:
        return -1;
      }
    }
}

int
TAO_Notify_Constraint_Visitor::visit_dot (ETCL_Dot *dot)
{
  // If we are here, we know we're headed for a more nested
  // level, so we just visit it, there's nothing else in this
  // constraint.
  return dot->component ()->accept (this);
}

int
TAO_Notify_Constraint_Visitor::visit_eval (ETCL_Eval *eval)
{
  // Nothing to do but visit the contained component.
  return eval->component ()->accept (this);
}

int
TAO_Notify_Constraint_Visitor::visit_default (ETCL_Default *def)
{
  ETCL_Constraint *comp = def->component ();

  if (comp == 0)
    {
      return -1;
    }

  if (comp->accept (this) != 0)
    {
      return -1;
    }

  try
  {
    CORBA::TypeCode_var tc = this->current_value_->type ();

    // If the current member is not a union, this call will throw
    // BadKind and the catch block will return -1.
    CORBA::Long default_index = tc->default_index ();

    // No default index.
    if (default_index == -1)
    {
      TAO_ETCL_Literal_Constraint result (false);
      this->queue_.enqueue_head (result);
      return 0;
    }

    // Okay, there's a default index, but is it active?
    TAO_ETCL_Literal_Constraint disc_value;
    this->queue_.dequeue_head (disc_value);
    TAO_ETCL_Literal_Constraint default_index_value (default_index);
    
    return (disc_value == default_index_value);
  }
  catch (const CORBA::Exception&)
  {
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_exist (ETCL_Exist *exist)
{
  ETCL_Constraint *component = exist->component ();

  if (component->accept (this) == 0)
    {
      const char *value = 0;
      CORBA::Boolean result = 0;

      // For the two cases below, we don't want the item at the top of
      // the queue, because it's the result of a hash table
      // lookup. For an existence test, we want the key value, which
      // is stored in the current_value_ member.
      if (this->implicit_id_ == FILTERABLE_DATA
          || this->implicit_id_ == VARIABLE_HEADER)
        {
          this->current_value_ >>= value;
        }
      else if (this->implicit_id_ == EMPTY)
        {
          // If the implicit id is empty, then we must default
          // it to the filterable data and set up the value pointer.
          
          ETCL_Identifier* ident =
            dynamic_cast<ETCL_Identifier*> (component);
            
          if (ident != 0)
            {
              this->implicit_id_ = FILTERABLE_DATA;
              value = ident->value ();
            }
        }

      switch (this->implicit_id_)
      {
      case FILTERABLE_DATA:
        result =
          (this->filterable_data_.find (ACE_CString (value, 0, false)) == 0);
        break;
      case VARIABLE_HEADER:
        result =
          (this->variable_header_.find (ACE_CString (value, 0, false)) == 0);
        break;
      case TYPE_NAME:
        result = (this->type_name_.in () != 0);
        break;
      case EVENT_NAME:
        result = (this->event_name_.in () != 0);
        break;
      case DOMAIN_NAME:
        result = (this->domain_name_.in () != 0);
        break;
        // Anything other than the above cases is an error.
      default:
        return -1;
      }

      this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));

      return 0;
    }

  return -1;
}

int
TAO_Notify_Constraint_Visitor::visit_unary_expr (
    ETCL_Unary_Expr *unary_expr
  )
{
  ETCL_Constraint *subexpr = unary_expr->subexpr ();

  if (subexpr->accept (this) == 0)
    {
      TAO_ETCL_Literal_Constraint subexpr_result;
      CORBA::Boolean result = false;
      int op_type = unary_expr->type ();

      switch (op_type)
      {
      case ETCL_NOT:
        this->queue_.dequeue_head (subexpr_result);
        result = ! (CORBA::Boolean) subexpr_result;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        return 0;
      case ETCL_MINUS:
        // The leading '-' was parsed separately, so we have to pull
        // the literal constraint off the queue, apply the class' own
        // unary minus operator, and put it back.
        this->queue_.dequeue_head (subexpr_result);
        this->queue_.enqueue_head (-subexpr_result);
        return 0;
      case ETCL_PLUS:
        // Leave the literal constraint on the queue. The leading
        // '+' was just syntactic sugar - no action is necessary.
        return 0;
      default:
        // The parser should never construct a ETCL_Unary_Constraint
        // behind any operators except the above three.
        return -1;
      }
    }

  return -1;
}

int
TAO_Notify_Constraint_Visitor::visit_binary_expr (
    ETCL_Binary_Expr *binary_expr
  )
{
  int bin_op_type = binary_expr->type ();

  switch (bin_op_type)
  {
  case ETCL_OR:
    return this->visit_or (binary_expr);
  case ETCL_AND:
    return this->visit_and (binary_expr);
  case ETCL_LT:
  case ETCL_LE:
  case ETCL_GT:
  case ETCL_GE:
  case ETCL_EQ:
  case ETCL_NE:
  case ETCL_PLUS:
  case ETCL_MINUS:
  case ETCL_MULT:
  case ETCL_DIV:
    return this->visit_binary_op (binary_expr, bin_op_type);
  case ETCL_TWIDDLE:
    return this->visit_twiddle (binary_expr);
  case ETCL_IN:
    return this->visit_in (binary_expr);
  default:
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_or (
    ETCL_Binary_Expr *binary
  )
{
  int return_value = -1;
  CORBA::Boolean result = false;
  ETCL_Constraint *lhs = binary->lhs ();

  if (lhs->accept (this) == 0)
    {
      TAO_ETCL_Literal_Constraint lhs_result;
      this->queue_.dequeue_head (lhs_result);
      result = (CORBA::Boolean) lhs_result;

      // Short-circuiting OR.
      if (result == 0)
        {
          ETCL_Constraint *rhs = binary->rhs ();

          if (rhs->accept (this) == 0)
            {
              TAO_ETCL_Literal_Constraint rhs_result;
              this->queue_.dequeue_head (rhs_result);
              result = (CORBA::Boolean) rhs_result;
              return_value = 0;
            }
        }
    else
      {
        return_value = 0;
      }
  }

  if (return_value == 0)
    {
      this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
    }

  return return_value;
}

int
TAO_Notify_Constraint_Visitor::visit_and (ETCL_Binary_Expr *binary)
{
  int return_value = -1;
  CORBA::Boolean result = false;
  ETCL_Constraint *lhs = binary->lhs ();

  if (lhs->accept (this) == 0)
    {
      TAO_ETCL_Literal_Constraint lhs_result;
      this->queue_.dequeue_head (lhs_result);
      result = (CORBA::Boolean) lhs_result;

      // Short-circuiting AND.
      if (result == true)
        {
          ETCL_Constraint *rhs = binary->rhs ();

          if (rhs->accept (this) == 0)
          {
            TAO_ETCL_Literal_Constraint rhs_result;
            this->queue_.dequeue_head (rhs_result);
            result = (CORBA::Boolean) rhs_result;
            return_value = 0;
          }
        }
      else
        {
          return_value = 0;
        }
    }

  if (return_value == 0)
    {
      this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
    }

  return return_value;
}

int
TAO_Notify_Constraint_Visitor::visit_binary_op (ETCL_Binary_Expr *binary,
                                                int op_type)
{
  int return_value = -1;
  ETCL_Constraint *lhs = binary->lhs ();
  CORBA::Boolean result = false;

  // Perform an operation on the results of evaluating the left and
  // right branches of this subtree.
  if (lhs->accept (this) == 0)
    {
      TAO_ETCL_Literal_Constraint left_operand;
      this->queue_.dequeue_head (left_operand);
      ETCL_Constraint *rhs = binary->rhs ();

      if (rhs->accept (this) == 0)
        {
          TAO_ETCL_Literal_Constraint right_operand;
          this->queue_.dequeue_head (right_operand);
          return_value = 0;

          switch (op_type)
          {
          case ETCL_LT:
            result = left_operand < right_operand;
            this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
            break;
          case ETCL_LE:
            result = left_operand <= right_operand;
            this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
            break;
          case ETCL_GT:
            result = left_operand > right_operand;
            this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
            break;
          case ETCL_GE:
            result = left_operand >= right_operand;
            this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
            break;
          case ETCL_EQ:
            result = left_operand == right_operand;
            this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
            break;
          case ETCL_NE:
            result = left_operand != right_operand;
            this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
            break;
          case ETCL_PLUS:
            this->queue_.enqueue_head (left_operand + right_operand);
            break;
          case ETCL_MINUS:
            this->queue_.enqueue_head (left_operand - right_operand);
            break;
          case ETCL_MULT:
            this->queue_.enqueue_head (left_operand * right_operand);
            break;
          case ETCL_DIV:
            this->queue_.enqueue_head (left_operand / right_operand);
            break;
          default:
            return_value = -1;
          }
        }
    }

  return return_value;
}

int
TAO_Notify_Constraint_Visitor::visit_twiddle (ETCL_Binary_Expr *binary)
{
  int return_value = -1;
  ETCL_Constraint *lhs = binary->lhs ();

  // Determine if the left operand is a substring of the right.
  if (lhs->accept (this) == 0)
    {
      TAO_ETCL_Literal_Constraint left;
      this->queue_.dequeue_head (left);
      ETCL_Constraint *rhs = binary->rhs ();

      if (rhs->accept (this) == 0)
        {
          TAO_ETCL_Literal_Constraint right;
          this->queue_.dequeue_head (right);
          CORBA::Boolean result =
            (ACE_OS::strstr ((const char *) right,
                             (const char *) left) != 0);
          this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
          return_value = 0;
        }
    }

  return return_value;
}

int
TAO_Notify_Constraint_Visitor::visit_in (ETCL_Binary_Expr *binary)
{
  int return_value = -1;
  ETCL_Constraint *lhs = binary->lhs ();

  // Determine if the left operand is contained in the right.
  if (lhs->accept (this) == 0)
    {
      TAO_ETCL_Literal_Constraint left;
      this->queue_.dequeue_head (left);

      ETCL_Constraint *rhs = binary->rhs ();

      if (rhs->accept (this) == 0)
        {
          TAO_ETCL_Literal_Constraint bag;
          this->queue_.dequeue_head (bag);

          if (bag.expr_type () == ETCL_COMPONENT)
            {
              CORBA::Any_ptr any_ptr = 0;
              ACE_NEW_RETURN (any_ptr,
                              CORBA::Any,
                              -1);
                              
              CORBA::Any_var component = any_ptr;
              component->replace (bag);
              component->impl ()->_add_ref ();
              CORBA::TCKind kind = CORBA::tk_null;

              try
              {
                CORBA::TypeCode_var tc = component->type ();
                kind = TAO_DynAnyFactory::unalias (tc.in ());
              }
              catch (const CORBA::Exception&)
              {
                return return_value;
              }

              CORBA::Boolean result = 0;

              switch (kind)
              {
              case CORBA::tk_sequence:
                result = this->sequence_does_contain (&component.in (),
                                                      left);
                break;
              case CORBA::tk_array:
                result = this->array_does_contain (&component.in (),
                                                   left);
                break;
              case CORBA::tk_struct:
                result = this->struct_does_contain (&component.in (),
                                                    left);
                break;
              case CORBA::tk_union:
                result = this->union_does_contain (&component.in (),
                                                   left);
                break;
              case CORBA::tk_any:
                result = this->any_does_contain (&component.in (),
                                                 left);
                break;
              default:
                return return_value;
              }

              this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
              return_value = 0;
            }
        }
    }

  return return_value;
}

int
TAO_Notify_Constraint_Visitor::visit_preference (ETCL_Preference *)
{
  // According to OMG 00-06-20 section 2.4.1, the Notification Service
  // does not use the preference operators. The method must be here
  // because it is called by the ETCL node, which may be used by other
  // CORBA services that do use the preference operators.
  return -1;
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::sequence_does_contain (
    const CORBA::Any *any,
    TAO_ETCL_Literal_Constraint &item
  )
{
  try
  {
    CORBA::TypeCode_var type = any->type ();
    CORBA::TypeCode_var base_type =
      TAO_DynAnyFactory::strip_alias (type.in ());
    CORBA::TypeCode_var content_type =
      base_type->content_type ();
    CORBA::TCKind kind =
      TAO_DynAnyFactory::unalias (content_type.in ());

    // The literal and the array elements must be
    // of the same simple type.
    CORBA::Boolean match =
      this->simple_type_match (item.expr_type (),
                               kind);

    if (!match)
      {
        return false;
      }

    TAO_DynSequence_i dyn_seq;
    dyn_seq.init (*any);

    DynamicAny::AnySeq_var any_seq = dyn_seq.get_elements ();

    CORBA::ULong length = any_seq->length ();

    for (CORBA::ULong i = 0; i < length; ++i)
      {
        TAO_ETCL_Literal_Constraint element (&any_seq[i]);

        if (item == element)
          {
            return true;
          }
      }
  }
  catch (const CORBA::Exception&)
  {
    return false;
  }

  return false;
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::array_does_contain (
    const CORBA::Any *any,
    TAO_ETCL_Literal_Constraint &item
  )
{
  try
  {
    CORBA::TypeCode_var type = any->type ();
    CORBA::TCKind kind = TAO_DynAnyFactory::unalias (type.in ());

    // The literal and the array elements must be
    // of the same simple type.
    CORBA::Boolean match =
      this->simple_type_match (item.expr_type (),
                               kind);

    if (!match)
      {
        return false;
      }

    TAO_DynArray_i dyn_array;
    dyn_array.init (*any);

    DynamicAny::AnySeq_var any_seq = dyn_array.get_elements ();

    CORBA::ULong length = any_seq->length ();

    for (CORBA::ULong i = 0; i < length; ++i)
      {
        TAO_ETCL_Literal_Constraint element (&any_seq[i]);

        if (item == element)
          {
            return true;
          }
      }
  }
  catch (const CORBA::Exception&)
  {
    return false;
  }

  return false;
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::struct_does_contain (
    const CORBA::Any *any,
    TAO_ETCL_Literal_Constraint &item
  )
{
  try
  {
    TAO_DynStruct_i dyn_struct;
    dyn_struct.init (*any);

    DynamicAny::NameValuePairSeq_var members =
      dyn_struct.get_members ();

    CORBA::ULong length = members->length ();
    CORBA::TypeCode_var tc;
    CORBA::TCKind kind;

    for (CORBA::ULong i = 0; i < length; ++i)
      {
        tc = members[i].value.type ();
        kind = TAO_DynAnyFactory::unalias (tc.in ());

        // The literal and the struct member must be
        // of the same simple type.
        CORBA::Boolean match =
          this->simple_type_match (item.expr_type (),
                                   kind);

        if (!match)
          {
            continue;
          }

        TAO_ETCL_Literal_Constraint element (&members[i].value);

        if (item == element)
          {
            return true;
          }
      }
  }
  catch (const CORBA::Exception&)
  {
    return false;
  }

  return false;
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::union_does_contain (
    const CORBA::Any *any,
    TAO_ETCL_Literal_Constraint &item
  )
{
  try
  {
    TAO_DynUnion_i dyn_union;
    dyn_union.init (*any);

    DynamicAny::DynAny_var cc =
      dyn_union.current_component ();

    CORBA::Any_var member = cc->to_any ();

    CORBA::TypeCode_var tc = member->type ();
    CORBA::TCKind kind = TAO_DynAnyFactory::unalias (tc.in ());

    // The literal and the union member must be
    // of the same simple type.
    CORBA::Boolean match =
      this->simple_type_match (item.expr_type (),
                               kind);

    if (!match)
      {
        return false;
      }

    TAO_ETCL_Literal_Constraint element (&member.inout ());

    return (item == element);
  }
  catch (const CORBA::Exception&)
  {
    return false;
  }
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::any_does_contain (
    const CORBA::Any *any,
    TAO_ETCL_Literal_Constraint &item
  )
{
  const CORBA::Any *result = 0;
  *any >>= result;

  TAO_ETCL_Literal_Constraint element (const_cast<CORBA::Any *>(result));
  return item == element;
}

CORBA::Boolean
TAO_Notify_Constraint_Visitor::simple_type_match (int expr_type,
                                                  CORBA::TCKind tc_kind)
{
  switch (expr_type)
  {
  case ETCL_STRING:
    if (tc_kind != CORBA::tk_string)
      {
        return false;
      }
    break;
  case ETCL_DOUBLE:
    if (tc_kind != CORBA::tk_double && tc_kind != CORBA::tk_float)
      {
        return false;
      }
    break;
  case ETCL_INTEGER:
  case ETCL_SIGNED:
    if (tc_kind != CORBA::tk_short
        && tc_kind != CORBA::tk_long
        && tc_kind != CORBA::tk_longlong)
      {
        return false;
      }
    break;
  case ETCL_UNSIGNED:
    if (tc_kind != CORBA::tk_ushort
        && tc_kind != CORBA::tk_ulong
        && tc_kind != CORBA::tk_ulonglong)
      {
        return false;
      }
    break;
  case ETCL_BOOLEAN:
    if (tc_kind != CORBA::tk_boolean)
      {
        return false;
      }
    break;
  default:
    return false;
  }
  
  return true;
}

const size_t TAO_Notify_Constraint_Visitor::implicit_ids_size_ = 27;
const size_t TAO_Notify_Constraint_Visitor::filterable_data_size_ = 31;
const size_t TAO_Notify_Constraint_Visitor::variable_header_size_ = 31;

TAO_END_VERSIONED_NAMESPACE_DECL

---