public void IsEmpty_NotEmptyQueue_ReturnsFalse()
{
var queue = new FastEquivalenceQueue <int>(new ModuloIntegerEqualityComparer(3, 2));
queue.Enqueue(2);
Assert.IsFalse(queue.IsEmpty);
}
public void Equeue_EqueueOne_Enqueues()
{
var queue = new FastEquivalenceQueue <int>(EqualityComparer <int> .Default);
queue.Enqueue(1);
var result = queue.DequeueEquivalenceSet().ToList();
Assert.AreEqual(1, result.Single());
}
public void Count_TwoEquivalenceClasses_ReturnsTotalNumberOfItems()
{
var queue = new FastEquivalenceQueue <int>(new ModuloIntegerEqualityComparer(2));
queue.Enqueue(1);
queue.Enqueue(2);
queue.Enqueue(3);
Assert.AreEqual(3, queue.Count);
}
public void DequeueEquivalenceSet_EqueueNonUniqueItem_EnqueuesOnlyOnce()
{
var queue = new FastEquivalenceQueue <int>(EqualityComparer <int> .Default);
queue.Enqueue(1);
queue.Enqueue(2);
queue.Enqueue(1);
var result = queue.DequeueEquivalenceSet().ToList();
Assert.AreEqual(1, result.Count);
}
public void DequeueEquivalenceSet_TwoEquivalenceClasses_ReturnsOnlyItemsFromFirstClass()
{
var queue = new FastEquivalenceQueue <int>(new ModuloIntegerEqualityComparer(2));
queue.Enqueue(1);
queue.Enqueue(2);
queue.Enqueue(3);
queue.Enqueue(4);
var result = queue.DequeueEquivalenceSet().ToList();
Assert.That(result, Is.EquivalentTo(new[] { 1, 3 }));
}
public void DequeueEquivalenceSet_ThreeEquivalenceClassesWithTwoHashesThirdDequeue_ReturnsOnlyItemsFromThirdClass()
{
var queue = new FastEquivalenceQueue <int>(new ModuloIntegerEqualityComparer(3, 2));
queue.Enqueue(1);
queue.Enqueue(2);
queue.Enqueue(3);
queue.Enqueue(4);
queue.Enqueue(5);
queue.Enqueue(6);
var a = queue.DequeueEquivalenceSet();
var b = queue.DequeueEquivalenceSet();
var result = queue.DequeueEquivalenceSet().ToList();
Assert.That(result, Is.EquivalentTo(new[] { 3, 6 }));
}
/// <summary>
/// Optimizes the specified input machine.
/// </summary>
/// <param name="inputMachine">The input machine. Must have transitions in a common order. Must be in format as generated by the <see cref="StateMachineBuilder"/> (no loops other than regular back-transitions within a single path).</param>
/// <returns>State machine with all equivalent states merged into one state.</returns>
public StateMachine OptimizeSortedMachine(StateMachine inputMachine)
{
var parentStateMap = this.BuildParentStateMap(inputMachine);
var finalStates = this.GetFinalStates(inputMachine);
var transitionComparer = new TransitionNonrecursiveEqualityComparer();
var queue = new FastEquivalenceQueue <State>(new TransitionCountStateEqualityComparer());
var oldToNewMap = new Dictionary <State, State>();
var waitingForBacktransitionConfirmationMap = new Dictionary <State, WaitingForConfirmationInfo>();
var backtTransitionsByState = this.GetBackTransitionsByState(inputMachine);
foreach (var finalState in finalStates)
{
queue.Enqueue(finalState);
}
//int i = 0;
while (!queue.IsEmpty)
{
//i++;
var currentSet = queue.DequeueEquivalenceSet().ToList();
/*Console.WriteLine("=======================");
* Console.WriteLine(i + " T " + queue.Count + ") " + string.Join(", ", currentSet.Select(p => p)));*/
// First state is the "template" for the equivalency class (all the other states in the group have to be equivalent
// to this state to be in its group)
var firstState = currentSet.First();
foreach (var state in currentSet)
{
//Console.WriteLine("Current: " + state);
// If the previous template state was kicked out due to not having all its children processed,
// try to use the next state as a template.
if (firstState == null)
{
firstState = state;
}
var currentStateBackTransition = backtTransitionsByState.GetValueOrDefault(state);
var firstStateBackTransition = backtTransitionsByState.GetValueOrDefault(firstState);
// Were all children of this state already processed? (skip back-transitions)
if (!state.Transitions.Where(p => currentStateBackTransition != p).All(p => oldToNewMap.ContainsKey(p.TargetState)))
{
// Another state will have to become the template.
if (state == firstState)
{
firstState = null;
}
//Console.WriteLine("Requeueing because children not processed");
queue.Enqueue(state);
continue;
}
// By now, at least one state is still in the equivalency class (and is the template).
// The template is obviously auto-included in the group.
if (firstState != state)
{
if (firstState.Transitions.Count != state.Transitions.Count)
{
//Console.WriteLine("Requeueing because not same number of transitions as template");
queue.Enqueue(state);
continue;
}
// Do a rough check of the back-transition (we can discard obviously non-equivalent back-transitions)
if (
!transitionComparer.Equals(currentStateBackTransition, firstStateBackTransition) ||
((currentStateBackTransition != null) != (firstStateBackTransition != null)))
{
//Console.WriteLine("Requeueing because preliminary backtransition check failed");
queue.Enqueue(state);
continue;
}
// Check if the children states of the current state (and transitions leading to them) match the template.
var transitionPairs = state.Transitions.Where(p => currentStateBackTransition != p).Zip(
firstState.Transitions.Where(p => backtTransitionsByState.GetValueOrDefault(firstState) != p),
(currentStateTransition, firstStateTransition) => new { currentStateTransition, firstStateTransition }
);
if (transitionPairs.Any(pair =>
{
//Console.WriteLine("Compare transition: first " + pair.firstStateTransition.SortingKey + " current" + pair.firstStateTransition.SortingKey);
// The transitions must match either way (whether there is backtransition going around current state or not).
if (!transitionComparer.Equals(pair.currentStateTransition, pair.firstStateTransition))
{
return(true);
}
var waitingForConfirmationFirstStateInfo = waitingForBacktransitionConfirmationMap.GetValueOrDefault(pair.firstStateTransition.TargetState);
var waitingForConfirmationCurrentStateInfo = waitingForBacktransitionConfirmationMap.GetValueOrDefault(pair.currentStateTransition.TargetState);
/*Console.WriteLine(
* "Waiting template: first " +
* (waitingForConfirmationFirstStateInfo != null ?
* waitingForConfirmationFirstStateInfo.TemplateState.HeadShift.ToString() : "x") +
* " current " +
* (waitingForConfirmationCurrentStateInfo != null ?
* waitingForConfirmationCurrentStateInfo.TemplateState.HeadShift.ToString() : "x"));*/
if (waitingForConfirmationFirstStateInfo == null && waitingForConfirmationCurrentStateInfo == null)
{
return(oldToNewMap[pair.firstStateTransition.TargetState] != oldToNewMap[pair.currentStateTransition.TargetState]);
}
else if (waitingForConfirmationFirstStateInfo == null || waitingForConfirmationCurrentStateInfo == null)
{
return(true);
}
else
{
// Equivalent template state in the waiting-for-conf info means the children were processed and that they are equivalent.
return(waitingForConfirmationFirstStateInfo.TemplateState != waitingForConfirmationCurrentStateInfo.TemplateState);
}
}
//oldToNewMap[pair.firstStateTransition.TargetState] != oldToNewMap[pair.currentStateTransition.TargetState] /*&&
//waitingForBacktransitionConfirmationMap.GetValueOrDefault().TemplateState
))
{
//Console.WriteLine("Requeueing because children (or transitions to children) don't match");
queue.Enqueue(state);
continue;
}
}
// Were children of this state waiting for backtransition confirmation?
// TODO: Check if children are waiting for the same state (opposite would mean a bug in Compiler)
var childrenWaitingForConfirmationInfo = state.Transitions
.Where(p => currentStateBackTransition != p && waitingForBacktransitionConfirmationMap.ContainsKey(p.TargetState))
.Select(p => p.TargetState)
.Select(childState => waitingForBacktransitionConfirmationMap[childState])
.ToList();
// If there is a backtransition loop going from this state to this state, consider the state to be a child of itself for purpose
// of back-transition handling (to avoid having to handle this as a special case later).
var hasSelfBacktransition = currentStateBackTransition != null && currentStateBackTransition.TargetState == state;
if (hasSelfBacktransition)
{
childrenWaitingForConfirmationInfo.Add(new WaitingForConfirmationInfo
{
TemplateState = firstState,
ConfirmingState = state,
StatesWithBacktransitions = new List <State> {
state
}
});
}
/*Console.WriteLine("Following waiting for confirmation infos were passed by children:");
* foreach (var waitingForConfirmationInfo in childrenWaitingForConfirmationInfo)
* {
* Console.WriteLine("\t" + waitingForConfirmationInfo);
* }*/
var isWaitingBacktransitionTarget =
childrenWaitingForConfirmationInfo.Count > 0 &&
childrenWaitingForConfirmationInfo.First().ConfirmingState == state;
/*Console.WriteLine("Reuse template?");
* Console.WriteLine("\tIs NOT the template:" + (state != firstState));
* Console.WriteLine("\tHas no backtransition:" + (currentStateBackTransition == null) + " OR it is self-backtransition :" + hasSelfBacktransition);
* Console.WriteLine("\tChildren have no open backtransitions:" + (childrenWaitingForConfirmationInfo.Count == 0) + " OR It is the target :" + isWaitingBacktransitionTarget);*/
// Merge this state's subtree into the template state's subtree, if it matches following conditions
State newState;
if (
state != firstState && // Always create a new subree for the template state.
(currentStateBackTransition == null || hasSelfBacktransition) && // If the state has backtransition, it must its target.
(childrenWaitingForConfirmationInfo.Count == 0 || isWaitingBacktransitionTarget) // There are no backtransitions going around it
)
{
newState = oldToNewMap[firstState];
//Console.WriteLine("Reusing template");
}
else
{
newState = new State();
newState.Transitions = state.Transitions.Where(p => p != currentStateBackTransition).Select(t =>
{
var newTransition = t.Clone();
newTransition.TargetState = oldToNewMap[t.TargetState];
return(newTransition);
}).ToList();
//Console.WriteLine("Creating new state");
}
oldToNewMap[state] = newState;
if (currentStateBackTransition != null && currentStateBackTransition.TargetState != state)
{
waitingForBacktransitionConfirmationMap.Add(
state,
new WaitingForConfirmationInfo
{
ConfirmingState = currentStateBackTransition.TargetState,
TemplateState = firstState,
StatesWithBacktransitions = new List <State> {
state
}
});
//Console.WriteLine("wrote waiting for template " + firstState + " because has backtrans");
}
if (childrenWaitingForConfirmationInfo.Count > 0)
{
if (!isWaitingBacktransitionTarget && currentStateBackTransition == null /*!stateComparer.Equals(childrenWaitingForConfirmationInfo.First().ConfirmingState, state)*/) // TODO: Co tady?
{
// This is not the state these states are waiting for -> forward the waiting for confirmation info further
waitingForBacktransitionConfirmationMap.Add(
state,
new WaitingForConfirmationInfo
{
ConfirmingState = childrenWaitingForConfirmationInfo.First().ConfirmingState,
TemplateState = firstState,
StatesWithBacktransitions = childrenWaitingForConfirmationInfo.SelectMany(p => p.StatesWithBacktransitions).ToList()
});
//Console.WriteLine("wrote waiting for template " + firstState + " not which waiting for");
}
else
{
// This is the state the unconfirmed states are waiting for!
// Add back-transitions from these states to the current state.
foreach (var stateWaitingForBacktransition in childrenWaitingForConfirmationInfo.SelectMany(p => p.StatesWithBacktransitions))
{
var backTransitionOrigin = oldToNewMap[stateWaitingForBacktransition];
backTransitionOrigin.Transitions.Add(new AlwaysTransition
{
TargetState = newState,
HeadShift = backTransitionOrigin == newState ? 1 : 0 // Do not loop in place
});
}
//Console.WriteLine("skipped forwarding waiting for template " + firstState + " , is backtrans target (backtrans created)");
}
}
foreach (var parentState in parentStateMap[state])
{
// Parent map also includes backtransition -> exclude them now.
var parentBackTransition = backtTransitionsByState.GetValueOrDefault(parentState);
if (parentBackTransition != null && parentBackTransition.TargetState == state)
{
continue;
}
//Console.WriteLine("Enqueued parent state " + parentState);
// Tady bude treba resit, aby se do fronty vrcholy nepridavaly vicekrat
queue.Enqueue(parentState);
}
}
}
return(new StateMachine(oldToNewMap[inputMachine.EntryState]));
}
