Notify_Constraint_Visitors.cpp

Go to the documentation of this file.

// $Id: Notify_Constraint_Visitors.cpp 77889 2007-04-03 16:13:57Z elliott_c $

#include "orbsvcs/Notify/Notify_Constraint_Visitors.h"
#include "orbsvcs/ETCL/ETCL_Constraint.h"
#include "orbsvcs/ETCL/ETCL_y.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 (
  TAO_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 (
  TAO_ETCL_Literal_Constraint *literal
  )
{
  this->queue_.enqueue_head (*literal);
  return 0;
}

int
TAO_Notify_Constraint_Visitor::visit_identifier (TAO_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 (
  TAO_ETCL_Union_Value *union_value
  )
{
  switch (union_value->sign ())
  {
    case 0:
      this->queue_.enqueue_head (*union_value->string ());
      break;
    case -1:
      this->queue_.enqueue_head (-(*union_value->integer ()));
      break;
    case 1:
      this->queue_.enqueue_head (*union_value->integer ());
      break;
    default:
      return -1;
  }

  return 0;
}

int
TAO_Notify_Constraint_Visitor::visit_union_pos (
  TAO_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 TAO_ETCL_INTEGER:
      case TAO_ETCL_SIGNED:
      case TAO_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 TAO_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 TAO_ETCL_Union_Value that was put on the queue
        // shouldn't have any other type.
      default:
        return -1;
      }

      TAO_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 (
  TAO_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 == 0)
          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 == 0)
          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 ();

    TAO_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 (
  TAO_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;
  }

  TAO_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 (TAO_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 == 0)
          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 == 0)
          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 ();

    TAO_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 (TAO_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 TAO_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 TAO_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 TAO_ETCL_TYPE_ID:
      {
        const char *name = tc->name ();

        TAO_ETCL_Literal_Constraint lit (name);
        this->queue_.enqueue_head (lit);
        return 0;
      }
    case TAO_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 (
  TAO_ETCL_Component *component
  )
{
  TAO_ETCL_Constraint *nested = component->component ();
  TAO_ETCL_Identifier *identifier = component->identifier ();
  ACE_CString component_name (identifier->value (),
    0,
    false);
  CORBA::Any *any_ptr = 0;

  if (this->implicit_ids_.find (component_name, this->implicit_id_) != 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)
  {
    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.
      ACE_NEW_RETURN (any_ptr,
        CORBA::Any,
        -1);
      (*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);
      ACE_NEW_RETURN (any_ptr,
        CORBA::Any (),
        -1);
      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 (TAO_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 (TAO_ETCL_Eval *eval)
{
  // Nothing to do but visit the contained component.
  return eval->component ()->accept (this);
}

int
TAO_Notify_Constraint_Visitor::visit_default (TAO_ETCL_Default *def)
{
  TAO_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 ((CORBA::Boolean) 0);
      this->queue_.enqueue_head (result);
      return 0;
    }

    // Okay, there's a default index, but is it active?

    TAO_ETCL_Literal_Constraint disc;
    this->queue_.dequeue_head (disc);
    TAO_ETCL_Literal_Constraint default_index_value (default_index);
    return (disc == default_index_value);
  }
  catch (const CORBA::Exception&)
  {
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_exist (TAO_ETCL_Exist *exist)
{
  TAO_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;
    }
    // If the implicit id is empty, then we must default
    // it to the filterable data and set up the value pointer
    else if (this->implicit_id_ == EMPTY)
      {
        TAO_ETCL_Identifier* ident =
          dynamic_cast<TAO_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 (
  TAO_ETCL_Unary_Expr *unary_expr
  )
{
  TAO_ETCL_Constraint *subexpr = unary_expr->subexpr ();

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

    switch (op_type)
    {
    case TAO_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 TAO_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 TAO_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 TAO_ETCL_Unary_Constraint
      // behind any operators except the above three.
      return -1;
    }
  }

  return -1;
}

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

  switch (bin_op_type)
  {
  case TAO_ETCL_OR:
    return this->visit_or (binary_expr);
  case TAO_ETCL_AND:
    return this->visit_and (binary_expr);
  case TAO_ETCL_LT:
  case TAO_ETCL_LE:
  case TAO_ETCL_GT:
  case TAO_ETCL_GE:
  case TAO_ETCL_EQ:
  case TAO_ETCL_NE:
  case TAO_ETCL_PLUS:
  case TAO_ETCL_MINUS:
  case TAO_ETCL_MULT:
  case TAO_ETCL_DIV:
    return this->visit_binary_op (binary_expr,
      bin_op_type);
  case TAO_ETCL_TWIDDLE:
    return this->visit_twiddle (binary_expr);
  case TAO_ETCL_IN:
    return this->visit_in (binary_expr);
  default:
    return -1;
  }
}

int
TAO_Notify_Constraint_Visitor::visit_or (
  TAO_ETCL_Binary_Expr *binary
  )
{
  int return_value = -1;
  CORBA::Boolean result = 0;
  TAO_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)
    {
      TAO_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 (TAO_ETCL_Binary_Expr *binary)
{
  int return_value = -1;
  CORBA::Boolean result = 0;
  TAO_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 == 1)
    {
      TAO_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 (TAO_ETCL_Binary_Expr *binary,
                                                int op_type)
{
  int return_value = -1;
  TAO_ETCL_Constraint *lhs = binary->lhs ();
  CORBA::Boolean result = 0;

  // 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);
    TAO_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 TAO_ETCL_LT:
        result = left_operand < right_operand;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        break;
      case TAO_ETCL_LE:
        result = left_operand <= right_operand;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        break;
      case TAO_ETCL_GT:
        result = left_operand > right_operand;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        break;
      case TAO_ETCL_GE:
        result = left_operand >= right_operand;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        break;
      case TAO_ETCL_EQ:
        result = left_operand == right_operand;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        break;
      case TAO_ETCL_NE:
        result = left_operand != right_operand;
        this->queue_.enqueue_head (TAO_ETCL_Literal_Constraint (result));
        break;
      case TAO_ETCL_PLUS:
        this->queue_.enqueue_head (left_operand + right_operand);
        break;
      case TAO_ETCL_MINUS:
        this->queue_.enqueue_head (left_operand - right_operand);
        break;
      case TAO_ETCL_MULT:
        this->queue_.enqueue_head (left_operand * right_operand);
        break;
      case TAO_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 (TAO_ETCL_Binary_Expr *binary)
{
  int return_value = -1;
  TAO_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);
    TAO_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 (TAO_ETCL_Binary_Expr *binary)
{
  int return_value = -1;
  TAO_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);

    TAO_ETCL_Constraint *rhs = binary->rhs ();

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

      if (bag.expr_type () == TAO_ETCL_COMPONENT)
      {
        CORBA::Any_var component = new CORBA::Any ();
        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 (TAO_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 == 0)
      return 0;

    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 1;
    }
  }
  catch (const CORBA::Exception&)
  {
    return 0;
  }

  return 0;
}

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 == 0)
      return 0;

    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 1;
    }
  }
  catch (const CORBA::Exception&)
  {
    return 0;
  }

  return 0;
}

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 == 0)
        continue;

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

      if (item == element)
        return 1;
    }
  }
  catch (const CORBA::Exception&)
  {
    return 0;
  }

  return 0;
}

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 == 0)
      return 0;

    TAO_ETCL_Literal_Constraint element (&member.inout ());

    return (item == element);
  }
  catch (const CORBA::Exception&)
  {
    return 0;
  }
}

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 TAO_ETCL_STRING:
    if (tc_kind != CORBA::tk_string)
      return 0;
    break;
  case TAO_ETCL_DOUBLE:
    if (tc_kind != CORBA::tk_double
      && tc_kind != CORBA::tk_float)
      return 0;
    break;
  case TAO_ETCL_INTEGER:
  case TAO_ETCL_SIGNED:
    if (tc_kind != CORBA::tk_short
      && tc_kind != CORBA::tk_long
      && tc_kind != CORBA::tk_longlong)
      return 0;
    break;
  case TAO_ETCL_UNSIGNED:
    if (tc_kind != CORBA::tk_ushort
      && tc_kind != CORBA::tk_ulong
      && tc_kind != CORBA::tk_ulonglong)
      return 0;
    break;
  case TAO_ETCL_BOOLEAN:
    if (tc_kind != CORBA::tk_boolean)
      return 0;
    break;
  default:
    return 0;
  }
  return 1;
}

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

---