// looks for an edit at depth "depth"
// returns false and null in bestScript if no edit is found at depth "depth"
// returns false and not null in bestScript if found
// returns true if timeout
internal bool GetNFAEditScriptTimeout(
int depth, long lastEditHash,
Automaton <BDD> currentNfa2,
List <NFAEdit> editList, int scriptCost,
NFAEditScript bestScript)
{
// if timeout return true
if (sw.ElapsedMilliseconds > timeout)
{
return(true);
}
//Stop if no more moves left
if (depth == 0)
{
if (DFAUtilities.ApproximateMNEquivalent(tests, nfa1density, currentNfa2, al, solver) && currentNfa2.IsEquivalentWith(nfa1, solver))
{
//check if totalCost < finalScript cost and replace if needed
if (bestScript.script == null || scriptCost < bestScript.GetCost())
{
bestScript.script = ObjectCopier.Clone <List <NFAEdit> >(editList);
}
}
return(false);
}
NFAEdit edit = null;
long thisEditHash = 0;
#region Flip one state from fin to non fin
foreach (var state in currentNfa2.States)
{
thisEditHash = state;
if (CanAdd(thisEditHash, lastEditHash))
{
//flip its final non final status
var newFinalStates = new HashSet <int>(currentNfa2.GetFinalStates());
Automaton <BDD> nfa2new = null;
if (currentNfa2.GetFinalStates().Contains(state))
{
edit = new NFAEditState(state, false);
editList.Insert(0, edit);
newFinalStates.Remove(state);
nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, newFinalStates, currentNfa2.GetMoves());
}
else
{
edit = new NFAEditState(state, true);
editList.Insert(0, edit);
newFinalStates.Add(state);
nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, newFinalStates, currentNfa2.GetMoves());
}
if (GetNFAEditScriptTimeout(depth - 1, thisEditHash, nfa2new, editList, scriptCost + edit.GetCost(), bestScript))
{
return(true);
}
editList.RemoveAt(0);
}
}
#endregion
#region Change transition from source state
currentNfa2 = NFAUtilities.normalizeMoves(currentNfa2, solver);
foreach (var sourceState in currentNfa2.States)
{
HashSet <int> unreachedStates = new HashSet <int>(currentNfa2.States);
foreach (var moveFromSource in currentNfa2.GetMovesFrom(sourceState))
{
// take all chars in alphabet
foreach (var c in al)
{
long moveHash = currentNfa2.StateCount + IntegerUtil.TripleToInt(sourceState, moveFromSource.TargetState, alphabetMap[c]);
thisEditHash = currentNfa2.StateCount + moveHash;
if (CanAdd(thisEditHash, lastEditHash))
{
BDD cCond = solver.False;
BDD newCond = solver.False;
//skip epsilon moves
if (moveFromSource.Label != null)
{
// if c in move, remove it and recursion
if (solver.Contains(moveFromSource.Label, c))
{
cCond = solver.MkNot(solver.MkCharConstraint(false, c));
newCond = solver.MkAnd(moveFromSource.Label, cCond);
}
else // if c not in move, add it and recursion
{
cCond = solver.MkCharConstraint(false, c);
newCond = solver.MkOr(moveFromSource.Label, cCond);
}
var newMoves = new List <Move <BDD> >(currentNfa2.GetMoves());
newMoves.Remove(moveFromSource);
newMoves.Add(new Move <BDD>(sourceState, moveFromSource.TargetState, newCond));
var nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, currentNfa2.GetFinalStates(), newMoves);
edit = new NFAEditMove(sourceState, moveFromSource.TargetState, c);
editList.Insert(0, edit);
if (GetNFAEditScriptTimeout(depth - 1, thisEditHash, nfa2new, editList, scriptCost + edit.GetCost(), bestScript))
{
return(true);
}
editList.RemoveAt(0);
}
}
}
unreachedStates.Remove(moveFromSource.TargetState);
}
foreach (var targetState in unreachedStates)
{
//try adding a symbol not in transition
foreach (var c in al)
{
long moveHash = IntegerUtil.TripleToInt(sourceState, targetState, alphabetMap[c]);
thisEditHash = currentNfa2.StateCount + moveHash;
var moveCond = solver.MkCharConstraint(false, c);
var newMoves = new List <Move <BDD> >(currentNfa2.GetMoves());
newMoves.Add(new Move <BDD>(sourceState, targetState, moveCond));
var nfa2new = Automaton <BDD> .Create(currentNfa2.InitialState, currentNfa2.GetFinalStates(), newMoves);
edit = new NFAEditMove(sourceState, targetState, c);
editList.Insert(0, edit);
//TODO put correct hash
if (GetNFAEditScriptTimeout(depth - 1, thisEditHash, nfa2new, editList, scriptCost + edit.GetCost(), bestScript))
{
return(true);
}
editList.RemoveAt(0);
}
}
}
#endregion
return(false);
}
// looks for an edit at depth "depth"
// returns false and null in bestScript if no edit is found at depth "depth"
// returns false and not null in bestScript if found
// returns true if timeout
internal static bool GetDFAEditScriptTimeout(
Automaton <BDD> dfa1, Automaton <BDD> dfa2,
HashSet <char> al, CharSetSolver solver,
List <long> editScriptHash, List <DFAEdit> editList,
int depth, long timeout, Stopwatch sw,
Pair <IEnumerable <string>, IEnumerable <string> > tests,
double dfa1density,
int totalCost,
DFAEditScript bestScript, Dictionary <int, int> stateNamesMapping)
{
// check timer
if (sw.ElapsedMilliseconds > timeout)
{
return(true);
}
//Compute worst case distance, call finalScript with this value?
int dist = (dfa1.StateCount + dfa2.StateCount) * (al.Count + 1);
//Stop if no more moves left
if (depth == 0)
{
if (DFAUtilities.ApproximateMNEquivalent(tests, dfa1density, dfa2, al, solver) && dfa2.IsEquivalentWith(dfa1, solver))
{
//check if totalCost < finalScript cost and replace if needed
if (bestScript.script == null || totalCost < bestScript.GetCost())
{
bestScript.script = ObjectCopier.Clone <List <DFAEdit> >(editList);
}
}
return(false);
}
DFAEdit edit = null;
#region Flip one move target state
foreach (var move in dfa2.GetMoves())
{
//Creaty copy of the moves without current move
var movesWithoutCurrMove = dfa2.GetMoves().ToList();
movesWithoutCurrMove.Remove(move);
//Redirect every ch belonging to move condition
foreach (var c in solver.GenerateAllCharacters(move.Label, false))
{
long hash = IntegerUtil.PairToInt(move.SourceState, c - 97) + dfa2.StateCount;
if (CanAdd(hash, editScriptHash))
{
editScriptHash.Insert(0, hash);
//Local copy of moves
var newMoves = movesWithoutCurrMove.ToList();
var newMoveCondition = solver.MkCharConstraint(false, c);
#region Remove ch from current move
var andCond = solver.MkAnd(move.Label, solver.MkNot(newMoveCondition));
//add back move without ch iff satisfiable
if (solver.IsSatisfiable(andCond))
{
newMoves.Add(new Move <BDD>(move.SourceState, move.TargetState, andCond));
}
#endregion
#region Redirect c to a different state
foreach (var state in dfa2.States)
{
if (state != move.TargetState)
{
var newMovesComplete = newMoves.ToList();
newMovesComplete.Add(new Move <BDD>(move.SourceState, state, newMoveCondition));
var dfa2new = Automaton <BDD> .Create(dfa2.InitialState, dfa2.GetFinalStates(), newMovesComplete);
edit = new DFAEditMove(stateNamesMapping[move.SourceState], stateNamesMapping[state], c);
editList.Insert(0, edit);
if (GetDFAEditScriptTimeout(dfa1, dfa2new, al, solver, editScriptHash, editList, depth - 1, timeout, sw, tests, dfa1density, totalCost + edit.GetCost(), bestScript, stateNamesMapping))
{
return(true);
}
editList.RemoveAt(0);
}
}
#endregion
editScriptHash.RemoveAt(0);
}
}
}
#endregion
#region Flip one state from fin to non fin
foreach (var state in dfa2.States)
{
if (CanAdd(state, editScriptHash))
{
//flip its final non final status
editScriptHash.Insert(0, state);
var newFinalStates = new HashSet <int>(dfa2.GetFinalStates());
Automaton <BDD> dfa2new = null;
if (dfa2.GetFinalStates().Contains(state))
{
edit = new DFAEditState(stateNamesMapping[state], false);
editList.Insert(0, edit);
newFinalStates.Remove(state);
dfa2new = Automaton <BDD> .Create(dfa2.InitialState, newFinalStates, dfa2.GetMoves());
}
else
{
edit = new DFAEditState(stateNamesMapping[state], true);
editList.Insert(0, edit);
newFinalStates.Add(state);
dfa2new = Automaton <BDD> .Create(dfa2.InitialState, newFinalStates, dfa2.GetMoves());
}
if (GetDFAEditScriptTimeout(dfa1, dfa2new, al, solver, editScriptHash, editList, depth - 1, timeout, sw, tests, dfa1density, totalCost + edit.GetCost(), bestScript, stateNamesMapping))
{
return(true);
}
editScriptHash.RemoveAt(0);
editList.RemoveAt(0);
}
}
#endregion
return(false);
}
