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Diffstat (limited to 'TAO/orbsvcs/orbsvcs/Trader/Constraint_Visitors.h')
-rw-r--r-- | TAO/orbsvcs/orbsvcs/Trader/Constraint_Visitors.h | 366 |
1 files changed, 0 insertions, 366 deletions
diff --git a/TAO/orbsvcs/orbsvcs/Trader/Constraint_Visitors.h b/TAO/orbsvcs/orbsvcs/Trader/Constraint_Visitors.h deleted file mode 100644 index d8653f45cea..00000000000 --- a/TAO/orbsvcs/orbsvcs/Trader/Constraint_Visitors.h +++ /dev/null @@ -1,366 +0,0 @@ -/* -*- C++ -*- */ - -// ======================================================================== -// $Id$ -// -// = LIBRARY -// orbsvcs -// -// = FILENAME -// Constraint_Visitor.h -// -// = AUTHOR -// Seth Widoff <sbw1@cs.wustl.edu> -// -// ======================================================================== - -#ifndef TAO_CONSTRAINT_VISITOR_H -#define TAO_CONSTRAINT_VISITOR_H - -#include "Trader.h" - - // ************************************************************* - // TAO_Constraint_Visitor - // ************************************************************* - -class TAO_Constraint; -class TAO_Unary_Constraint; -class TAO_Binary_Constraint; -class TAO_Literal_Constraint; -class TAO_Property_Constraint; -class TAO_Noop_Constraint; - -class TAO_Constraint_Visitor -// -// = TITLE -// This is the base class for all visitors who wish to preform -// some operation from the state of the expression tree. Using -// double dispatching, subclasses of Constraint expression call -// back to the InterpreterVisitor subclass from the accept method. -// -// = DESCRIPTION -// Traversal of the expression tree uses the "Visitor" pattern. To -// "visit" a node, a client invokes the "accept" method on a -// subclass of ConstraintExpression, which, in turn, invokes the -// appropriate method on the visitor passed to it, based on its -// own type. So, the Constraint_Visitor has a method to deal with -// each possible type of node in an expression tree; one for each -// operator in the grammar. -{ -public: - - virtual ~TAO_Constraint_Visitor (void) {} - - virtual int visit_constraint (TAO_Unary_Constraint* constraint) = 0; - - virtual int visit_with (TAO_Unary_Constraint* unary_with) = 0; - virtual int visit_min (TAO_Unary_Constraint* unary_min) = 0; - virtual int visit_max (TAO_Unary_Constraint* unary_max) = 0; - virtual int visit_first (TAO_Noop_Constraint* noop_first) = 0; - virtual int visit_random (TAO_Noop_Constraint* noop_random) = 0; - - virtual int visit_and (TAO_Binary_Constraint* boolean_and) = 0; - virtual int visit_or (TAO_Binary_Constraint* boolean_or) = 0; - virtual int visit_not (TAO_Unary_Constraint* unary_not) = 0; - - virtual int visit_exist (TAO_Unary_Constraint* unary_exist) = 0; - virtual int visit_unary_minus (TAO_Unary_Constraint* unary_minus) = 0; - - virtual int visit_add (TAO_Binary_Constraint* boolean_add) = 0; - virtual int visit_sub (TAO_Binary_Constraint* boolean_sub) = 0; - virtual int visit_mult (TAO_Binary_Constraint* boolean_mult) = 0; - virtual int visit_div (TAO_Binary_Constraint* boolean_div) = 0; - - virtual int visit_twiddle (TAO_Binary_Constraint* binary_twiddle) = 0; - virtual int visit_in (TAO_Binary_Constraint* binary_in) = 0; - - virtual int visit_less_than (TAO_Binary_Constraint* boolean_lt) = 0; - virtual int visit_less_than_equal (TAO_Binary_Constraint* boolean_lte) = 0; - virtual int visit_greater_than (TAO_Binary_Constraint* boolean_gt) = 0; - virtual int visit_greater_than_equal (TAO_Binary_Constraint* boolean_gte) = 0; - virtual int visit_equal (TAO_Binary_Constraint* boolean_eq) = 0; - virtual int visit_not_equal (TAO_Binary_Constraint* boolean_neq) = 0; - - virtual int visit_literal (TAO_Literal_Constraint* literal) = 0; - virtual int visit_property (TAO_Property_Constraint* literal) = 0; -}; - - -CORBA::Boolean TAO_find_string (CosTradingSequences::StringSeq& sequence, const char* element); - - // ************************************************************* - // TAO_Constraint_Validator - // ************************************************************* - -#include "Constraint_Nodes.h" - -class TAO_Constraint_Validator : public TAO_Constraint_Visitor - // - // = TITLE - // TAO_Constraint_Validator ensures that in an expression tree - // passed to it, the operands of each operation match the - // correct types. - // - // = DESCRIPTION - // TAO_Constraint_Validator uses the visitor pattern to - // traverse all the nodes in an expression tree, checking that - // for each operator node the operands are of the proper data - // type it they're literals, or that they exist in the service - // type definition _and_ have the proper type, if they're - // property names. The algorithm for type - // checking is as follows: ensure that operand expression(s) - // return the correct types using expr_returns* methods. If they - // (or it) return the correct types, call accept - // on each operand until all return true or one returns false, - // at which point we can back out of the traversal and indicate - // failure. -{ -public: - - TAO_Constraint_Validator - (const CosTradingRepos::ServiceTypeRepository::TypeStruct& type_struct); - // The constructor creates a map of property names to their values - // from the Type Description retrieved from the - // ServiceTypeRepository. The ServiceTypeRepository throws - // exceptions when it's displeased with the type name provided to - // it. The map allows O(lg n) associative access, rather than the - // O(n) sequential lookup from the CORBA data structures. - - virtual ~TAO_Constraint_Validator (void); - // Desctructor. - - int validate (TAO_Constraint* root); - // Validate returns 1 if the expression tree whose root is <root> - // makes semantic sense, in that the operands for each operation - // comply with each other and the types accepted by the operator. - - // = Visitor Methods - - virtual int visit_constraint (TAO_Unary_Constraint* constraint); - - virtual int visit_with (TAO_Unary_Constraint* unary_with); - virtual int visit_min (TAO_Unary_Constraint* unary_min); - virtual int visit_max (TAO_Unary_Constraint* unary_max); - virtual int visit_first (TAO_Noop_Constraint* noop_first); - virtual int visit_random (TAO_Noop_Constraint* noop_random); - - virtual int visit_and (TAO_Binary_Constraint* boolean_and); - virtual int visit_or (TAO_Binary_Constraint* boolean_or); - // The two operands must return a boolean value. - - virtual int visit_not (TAO_Unary_Constraint* unary_not); - // The operand must return a boolean value. - - virtual int visit_exist (TAO_Unary_Constraint* unary_exist); - // The operand must return a valid (i.e., present in the service - // type description) property name. - - virtual int visit_unary_minus (TAO_Unary_Constraint* unary_minus); - // The operand must return a number to be negated. - - virtual int visit_add (TAO_Binary_Constraint* boolean_add); - virtual int visit_sub (TAO_Binary_Constraint* boolean_sub); - virtual int visit_mult (TAO_Binary_Constraint* boolean_mult); - virtual int visit_div (TAO_Binary_Constraint* boolean_div); - // Both operands must return numeric results. - - virtual int visit_twiddle (TAO_Binary_Constraint* binary_twiddle); - // Both operands must return strings. - - virtual int visit_in (TAO_Binary_Constraint* binary_in); - // The right operand must be a sequence of the same simple type as - // the left operand. - - virtual int visit_less_than (TAO_Binary_Constraint* boolean_lt); - virtual int visit_less_than_equal (TAO_Binary_Constraint* boolean_lte); - virtual int visit_greater_than (TAO_Binary_Constraint* boolean_gt); - virtual int visit_greater_than_equal (TAO_Binary_Constraint* boolean_gte); - virtual int visit_equal (TAO_Binary_Constraint* boolean_eq); - virtual int visit_not_equal (TAO_Binary_Constraint* boolean_neq); - // The left and right operands must both be of the same simple type. - - virtual int visit_literal (TAO_Literal_Constraint* literal); - virtual int visit_property (TAO_Property_Constraint* literal); - // The property must be defined in the service type description. - -private: - - TAO_Typecode_Table type_map_; - // A map gleaned from the ServiceTypeStruct, which correlates - // property names with their types. - - CORBA::TypeCode* extract_type (TAO_Constraint* expr_type, - TAO_Expression_Type& type); - - int expr_returns_boolean (TAO_Expression_Type expr_type); - // expr_returns_boolean returns 1 if <expr_type>, when evaluated, will - // return a boolean. - - int expr_returns_number (TAO_Expression_Type expr_type); - // expr_returns_boolean returns 1 if <expr_type>, when evaluated, will - // return a number. - - int expr_returns_string (TAO_Expression_Type expr_type); - // expr_returns_boolean returns 1 if <expr_type>, when evaluated, will - // return a string. - - TAO_Constraint_Validator (const TAO_Constraint_Validator&); - TAO_Constraint_Validator& operator= (const TAO_Constraint_Validator&); -}; - - // ************************************************************* - // TAO_Constraint_Evaluator - // ************************************************************* - -#include "Trader_Utils.h" - -class TAO_Constraint_Evaluator : public TAO_Constraint_Visitor -// -// = TITLE -// TAO_Constraint_Evaluator traverse a constraint expression tree, -// and determines whether an offer fits the constraints -// represented by the tree -// -// = DESCRIPTION -// Using the Visitor pattern, the TAO_Constraint_Evaluator has each -// node of the expression tree call back to it with the method -// designated for its type. In that method, the visitor will -// evaluate its operands and perform the operation designated by -// that node's type, and return the result. Note: the -// TAO_Constraint_Evaluator assumes the tree is semantically correct, -// that is, the validate method on TAO_Constraint_Validator return -// true. The only possible evaluation time errors are a divide by a -// property whose value is zero and undefined properties. -{ -public: - - TAO_Constraint_Evaluator (CosTrading::Offer* offer, - CORBA::Boolean supports_dynamic_properties = 1); - - CORBA::Boolean evaluate_constraint (TAO_Constraint* root); - // Evaluate returns 1 if the offer satisfies the constraints - // represented by the the expression tree rooted at <root>, 0 if it - // doesn't. If an error occurs during process, the constraint - // automatically fails. - - int evaluate_preference (TAO_Constraint* root, - TAO_Literal_Constraint& result); - // The result of the preference evaluation is stored in result. The - // method returns 0 upon success, -1 upon failure. - - // = Visitor Methods - - virtual int visit_constraint (TAO_Unary_Constraint* constraint); - - virtual int visit_with (TAO_Unary_Constraint* unary_with); - virtual int visit_min (TAO_Unary_Constraint* unary_min); - virtual int visit_max (TAO_Unary_Constraint* unary_max); - virtual int visit_first (TAO_Noop_Constraint* noop_first); - virtual int visit_random (TAO_Noop_Constraint* noop_random); - - virtual int visit_and (TAO_Binary_Constraint* boolean_and); - // Takes the logical and of the results of both operands. Note that - // in the case where the left operand returns zero, the result is - // immediately known. - - virtual int visit_or (TAO_Binary_Constraint* boolean_or); - // Takes the logical or of the results of both operands. Note that - // in the case where the left operand returns one, the result is - // immediately known. - - virtual int visit_not (TAO_Unary_Constraint* unary_not); - // Logically negates the value of the operand. - - virtual int visit_exist (TAO_Unary_Constraint* unary_exist); - // The property exists if its name is bound to a value in the - // <props_> map. - - virtual int visit_unary_minus (TAO_Unary_Constraint* unary_minus); - // Mathematically negates the return value the operand. - - virtual int visit_add (TAO_Binary_Constraint* boolean_add); - // Add the results of evaluating the left and right operands. - - virtual int visit_sub (TAO_Binary_Constraint* boolean_sub); - // Subtract the results of evaluating the left and right operands. - - virtual int visit_mult (TAO_Binary_Constraint* boolean_mult); - // Multiply the results of evaluating the left and right operands. - - virtual int visit_div (TAO_Binary_Constraint* boolean_div); - // Divide the results of evaluating the left and right operands. - - virtual int visit_twiddle (TAO_Binary_Constraint* binary_twiddle); - // Determines if the right operand is a substring of the left. - - virtual int visit_in (TAO_Binary_Constraint* binary_in); - // Determines if the sequence represented by the right operand - // contains the left operand. - - // = Compare the results of evaluating left and right operands. - virtual int visit_less_than (TAO_Binary_Constraint* boolean_lt); - virtual int visit_less_than_equal (TAO_Binary_Constraint* boolean_lte); - virtual int visit_greater_than (TAO_Binary_Constraint* boolean_gt); - virtual int visit_greater_than_equal (TAO_Binary_Constraint* boolean_gte); - virtual int visit_equal (TAO_Binary_Constraint* boolean_eq); - virtual int visit_not_equal (TAO_Binary_Constraint* boolean_neq); - - virtual int visit_literal (TAO_Literal_Constraint* literal); - // Copy the value of the literal into the result container. - - virtual int visit_property (TAO_Property_Constraint* literal); - // Copy the value of the property into the result container. - -private: - - class Operand_Queue : - public ACE_Unbounded_Queue <TAO_Literal_Constraint> - // = TITLE - // A queue adapter with methods to setting and getting operands - // from the expression evaluation results. - { - public: - - Operand_Queue (void); - - TAO_Literal_Constraint& get_left_operand (void); - // In a binary operation, obtain the left operand. - - TAO_Literal_Constraint& get_right_operand (void); - // In a binary operation, obtain the right operand. - - TAO_Literal_Constraint& get_operand (void); - // In a unary operation, obtain the only operand. - - void dequeue_operand (void); - // Remove an operand from the queue. - }; - - void do_the_op (int operation); - // Method for performing a arithmetic or comparison operation. - - int visit_bin_op (TAO_Binary_Constraint* op, int operation); - // Method for evaluating a binary operation. - - CORBA::Boolean sequence_does_contain (CORBA::Any* sequence, - TAO_Literal_Constraint& element); - // Determine if sequence contains <element>, a literal of the same - // simple type as <sequence_type>. Return 1 in this eventuality. - - TAO_Constraint_Evaluator (const TAO_Constraint_Evaluator&); - TAO_Constraint_Evaluator& operator= (const TAO_Constraint_Evaluator&); - // Disallow copying. - - TAO_Lookup_Table props_; - // The map of property names to their values for a property. - - TAO_Property_Evaluator prop_eval_; - // Utility with which to evaluate the properties of an offer, be - // they dyanmic or static. - - Operand_Queue queue_; - // The result of a non_boolean operation. -}; - - -#endif /* CONSTRAINT_VISITORS_H */ |