public abstract class StoppingConditionConstraintEvaluator extends Object implements IEvaluator
StoppingConditionConstraint.
This evaluator will be checked at one of two times and return a boolean
indicating if the state checked can be used to stop propagation (if the
StoppingConditionEvaluator also determines if propagation should stop).
Often there are times when a StoppingCondition
needs additional criteria to truly stop on the desired event. Simply combining
StoppingConditions usually wouldn't work; if you would AND two conditions
together, they both must have their own relevant at the exact same time. It is more reasonable to add
constraints to a stopping condition that could, instead of stopping at some particular event, could instead
signal that some other event has gone by, or has not happened yet. This is the evaluator for such an object.
Note that most cases are sampling some single double value from the state at the current propagation time.
If that is the general behavior of your constraint, consider using
ThresholdStoppingConditionConstraintEvaluator instead,
which allows for the more general case for deciding upon the satisfaction of this constraint by any
means of determining true or false based on the passed in
state.
| Modifier | Constructor and Description |
|---|---|
protected |
StoppingConditionConstraintEvaluator(EvaluatorGroup group,
StoppingConditionConstraint definition)
Initializes a new instance.
|
protected |
StoppingConditionConstraintEvaluator(StoppingConditionConstraintEvaluator existingInstance,
CopyContext context)
Initializes a new instance as a copy of an existing instance.
|
| Modifier and Type | Method and Description |
|---|---|
static boolean |
areConstraintsSatisfied(List<StoppingConditionConstraintEvaluator> constraints,
ITimeBasedState state,
WhenToCheckConstraint whenCheckIsOccurring)
Loop through the
Constraints (get)
and see if their constraints are satisfied by the
state given when a relevant event is detected. |
void |
checkCurrentState(ITimeBasedState currentState)
This method gets called every time a new
ITimeBasedState is checked
by the parent StoppingConditionEvaluator. |
abstract Object |
clone(CopyContext context)
Clones this object using the specified context.
|
void |
dispose()
Releases any resources associated with this instance.
|
protected void |
dispose(boolean disposing)
Releases any resources associated with this instance.
|
TimeIntervalCollection |
getAvailabilityIntervals(TimeIntervalCollection consideredIntervals)
Gets the intervals over which data is available.
|
IEvaluator |
getCachingWrapper()
Gets a version of this evaluator that caches the previously computed value so that if it is evaluated
twice at the same date the computation is done only once.
|
EvaluatorGroup |
getGroup()
Gets the group that contains this evaluator.
|
abstract boolean |
getIsThreadSafe()
Gets a value indicating whether the methods on this instance are safe to call from
multiple threads simultaneously.
|
String |
getName()
Gets an optional name for this
StoppingConditionConstraintEvaluator. |
WhenToCheckConstraint |
getWhenToCheck()
Gets when to check the constraint (when an event is detected or exactly found).
|
void |
initialize(ITimeBasedState initialState)
Initialize the
constraint with the
initialState. |
boolean |
isAvailable(JulianDate date)
Determines if valid data is available for the given
JulianDate. |
abstract boolean |
isConstraintSatisfied(ITimeBasedState state)
This method will examine from the state and return
true if this
constraint is satisfied, and false
if not. |
void |
updateEvaluatorReferences(CopyContext context)
Updates the evaluator references held by this object using the reference-to-reference
mapping in the specified
CopyContext. |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitcloseprotected StoppingConditionConstraintEvaluator(@Nonnull EvaluatorGroup group, @Nonnull StoppingConditionConstraint definition)
group - The group that contains this evaluator.definition - The StoppingConditionConstraint that is creating this evaluator.ArgumentNullException - Thrown when group or definition is null.protected StoppingConditionConstraintEvaluator(@Nonnull StoppingConditionConstraintEvaluator existingInstance, @Nonnull CopyContext context)
See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor
in a derived class.
existingInstance - The existing instance to copy.context - A CopyContext that controls the depth of the copy.ArgumentNullException - Thrown when existingInstance or context is null.public void updateEvaluatorReferences(CopyContext context)
CopyContext.
The following example shows how to implement this method for an evaluator that contains a nested evaluator:
@Override
public final void updateEvaluatorReferences(CopyContext context) {
m_nestedEvaluator = context.updateReference(m_nestedEvaluator);
}
This method is called by EvaluatorGroup and usually does not need to be
called directly by users. EvaluatorGroup uses this method to replace references
to shared evaluators with references to caching versions of the evaluators.
To implement this method, call CopyContext.updateReference(T) on each evaluator reference
held by your evaluator and assign the return value back to the field.
updateEvaluatorReferences in interface IEvaluatorcontext - The context that specifies the reference mapping.public abstract Object clone(CopyContext context)
This method should be implemented to call a copy constructor on the class of the
object being cloned. The copy constructor should take the CopyContext as a parameter
in addition to the existing instance to copy. The copy constructor should first call
CopyContext.addObjectMapping(T, T) to identify the newly constructed instance
as a copy of the existing instance. It should then copy all fields, using
CopyContext.updateReference(T) to copy any reference fields.
A typical implementation of ICloneWithContext:
public static class MyClass implements ICloneWithContext {
public MyClass(MyClass existingInstance, CopyContext context) {
context.addObjectMapping(existingInstance, this);
someReference = context.updateReference(existingInstance.someReference);
}
@Override
public final Object clone(CopyContext context) {
return new MyClass(this, context);
}
private Object someReference;
}
In general, all fields that are reference types should be copied with a call to
CopyContext.updateReference(T). There are a couple of exceptions:
If one of these exceptions applies, the CopyContext should be given an opportunity
to update the reference before the reference is copied explicitly. Use
CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns
the original object, indicating that the context does not have a replacement registered,
then copy the object manually by invoking a Clone method, a copy constructor, or by manually
constructing a new instance and copying the values.
alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}
If you are implementing an evaluator (a class that implements IEvaluator), the
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the
copy context constructor. Code duplication can be avoided by doing the following:
CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to
non-evaluators.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the
same CopyContext passed to the constructor.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.
public MyClass(MyClass existingInstance, CopyContext context) {
super(existingInstance, context);
someReference = context.updateReference(existingInstance.someReference);
evaluatorReference = existingInstance.evaluatorReference;
updateEvaluatorReferences(context);
}
@Override
public void updateEvaluatorReferences(CopyContext context) {
evaluatorReference = context.updateReference(evaluatorReference);
}
@Override
public Object clone(CopyContext context) {
return new MyClass(this, context);
}
private Object someReference;
private IEvaluator evaluatorReference;clone in interface ICloneWithContextcontext - The context to use to perform the copy.public final void dispose()
dispose in interface IDisposableprotected void dispose(boolean disposing)
disposing - true to release both managed and unmanaged resources;
false to release only unmanaged resources.public TimeIntervalCollection getAvailabilityIntervals(TimeIntervalCollection consideredIntervals)
getAvailabilityIntervals in interface IAvailabilityconsideredIntervals - The intervals over which availability information is needed. Note that the returned availability
intervals may indicate availability outside of these intervals of consideration.public boolean isAvailable(@Nonnull JulianDate date)
JulianDate.isAvailable in interface IAvailabilitydate - The date for which to check availability.true if valid data is available for this date; otherwise false.public abstract boolean getIsThreadSafe()
If this property is true, all methods and properties are guaranteed to be thread safe.
Conceptually, an object that returns true for this method acts as if there is a lock
protecting each method and property such that only one thread at a time can be inside any method or
property in the class. In reality, such locks are generally not used and are in fact discouraged. However,
the user must not experience any exceptions or inconsistent behavior that would not be experienced if such
locks were used.
If this property is false, the behavior when using this class from multiple threads
simultaneously is undefined and may include inconsistent results and exceptions. Clients wishing to use
multiple threads should call CopyForAnotherThread.copy(T) to get a separate instance of the
object for each thread.
getIsThreadSafe in interface IThreadAwarepublic final EvaluatorGroup getGroup()
getGroup in interface IEvaluatorpublic final IEvaluator getCachingWrapper()
This method is called by EvaluatorGroup to create a caching version of an evaluator
that is shared between multiple computations.
To implement this method in your own evaluator, construct and return a caching version of the evaluator's base class.
For example, if your evaluator implements IEvaluator1 directly, return an instance of
CachingEvaluator. In many cases, such as when implementing a PointEvaluator
this method does not need to be overridden because the default implementation returns an appropriate
caching wrapper already. If you do not want the last value computed by your evaluator to ever be cached, or
if your evaluator does its own caching internally, this method can return this.
Shows an example implementation in an evaluator that implements IEvaluator1
directly, where T is double.
@Override
public IEvaluator getCachingWrapper() {
return new CachingEvaluator<Double>(this);
}getCachingWrapper in interface IEvaluatorthis should be returned by this method.public static boolean areConstraintsSatisfied(List<StoppingConditionConstraintEvaluator> constraints, ITimeBasedState state, @Nonnull WhenToCheckConstraint whenCheckIsOccurring)
Constraints (get)
and see if their constraints are satisfied by the
state given when a relevant event is detected.constraints - The constraints to check.state - The state to check.whenCheckIsOccurring - Specifies when this method was called during propagation. Only the
constraints with the matching setting will be checked.true if all of the constraints that
should be checked will work with the state, and propagation should stop.
Otherwise, false, and propagation should continue.public abstract boolean isConstraintSatisfied(ITimeBasedState state)
true if this
constraint is satisfied, and false
if not.state - The state to check.true if this constraint is satisfied; otherwise false.
When all constraints return true, then the
stopping condition may stop propagation if it too is satisfied.@Nonnull public final WhenToCheckConstraint getWhenToCheck()
WhenToCheckConstraint to help decide which one to pick.public void initialize(ITimeBasedState initialState)
constraint with the
initialState. This is useful for when the
constraint is comparing the current
value with the initial (such as something related to the duration of propagation).initialState - The state to initialize with.public final String getName()
StoppingConditionConstraintEvaluator.public void checkCurrentState(ITimeBasedState currentState)
ITimeBasedState is checked
by the parent StoppingConditionEvaluator. This method
should be used when the criteria of your StoppingConditionConstraintEvaluator
needs to check every computed state. For example,
ThresholdStoppingConditionConstraintEvaluator needs to keep track of extrema if its
InequalityCriteria (get / set) is set to
InequalityCondition.GREATER_THAN_MINIMUM or InequalityCondition.LESS_THAN_MAXIMUM.currentState - The state to check at every step of propagation.