import java.util.ArrayList;
import java.util.List;
import java.util.PriorityQueue;
+import java.util.function.BooleanSupplier;
import java.util.function.Consumer;
+import java.util.function.LongSupplier;
/**
* Orders Events by the time they are due to be executed. Can execute Events individually.
+ *
* @author Fabian Stemmler
*
*/
public class Timeline
{
private PriorityQueue<InnerEvent> events;
- private long currentTime = 0;
-
+ private LongSupplier time;
+ private long lastTimeUpdated = 0;
+
private final List<Consumer<TimelineEvent>> eventAddedListener;
-
+
public Timeline(int initCapacity)
{
- events = new PriorityQueue<InnerEvent>(initCapacity, (a, b) -> {
- long difference = a.getTiming() - b.getTiming();
- if(difference == 0)
- return 0;
- return difference < 0 ? -1 : 1;
- });
-
+ events = new PriorityQueue<InnerEvent>(initCapacity);
+
eventAddedListener = new ArrayList<>();
+ time = () -> lastTimeUpdated;
+ }
+
+ /**
+ * @param timestamp exclusive
+ * @return true if the first event is later than the timestamp
+ */
+ public BooleanSupplier laterThan(long timestamp)
+ {
+ return () -> timeCmp(events.peek().getTiming(), timestamp) > 0;
}
-
+
public boolean hasNext()
{
return !events.isEmpty();
}
+ /**
+ * Executes all events at the next timestamp, at which there are any
+ */
public void executeNext()
{
- InnerEvent first = events.poll();
- currentTime = first.getTiming();
- first.run();
+ InnerEvent first = events.peek();
+ if (first != null)
+ executeUntil(laterThan(first.getTiming()), -1);
}
-
+
public void executeAll()
{
while (hasNext())
executeNext();
}
-
+
/**
- * Executes all events up to a given simulation timestamp. The simulation
- * process can be constrained by a real world timestamp.
+ * Executes all events until a given condition is met. The simulation process can be constrained by a real world timestamp.
*
- * @param timestamp the simulation timestamp up to which the events will be
- * processed
- * @param stopMillis the System.currentTimeMillis() when simulation definitely
- * needs to stop.
- * @return if it was possible to fulfil the goal in the given real world time.
- * @author Christian Femers
+ * @param condition the condition until which the events are be processed
+ * @param stopMillis the System.currentTimeMillis() when simulation definitely needs to stop. A value of -1 means no timeout.
+ * @return State of the event execution
+ * @formatter:off
+ * <code>NOTHING_DONE</code> if the {@link Timeline} was already empty
+ * <code>EXEC_OUT_OF_TIME</code> if the given maximum time was reached
+ * <code>EXEC_UNTIL_CONDITION</code> if the condition was met
+ * <code>EXEC_UNTIL_EMPTY</code> if events were executed until the {@link Timeline} was empty
+ * @formatter:on
+ * @author Christian Femers, Fabian Stemmler
*/
- public ExecutionResult executeUpTo(long timestamp, long stopMillis)
+ public ExecutionResult executeUntil(BooleanSupplier condition, long stopMillis)
{
if (events.isEmpty())
{
- currentTime = timestamp;
+ lastTimeUpdated = getSimulationTime();
return ExecutionResult.NOTHING_DONE;
}
int checkStop = 0;
InnerEvent first = events.peek();
- while (first != null && first.getTiming() <= timestamp)
+ while (hasNext() && !condition.getAsBoolean())
{
events.remove();
- currentTime = first.getTiming();
+ lastTimeUpdated = first.getTiming();
first.run();
// Don't check after every run
checkStop = (checkStop + 1) % 10;
if (checkStop == 0 && System.currentTimeMillis() >= stopMillis)
- return ExecutionResult.RAN_OUT_OF_TIME;
+ return ExecutionResult.EXEC_OUT_OF_TIME;
first = events.peek();
}
- currentTime = timestamp;
- return ExecutionResult.DONE_IN_TIME;
+ lastTimeUpdated = getSimulationTime();
+ return hasNext() ? ExecutionResult.EXEC_UNTIL_EMPTY : ExecutionResult.EXEC_UNTIL_CONDITION;
+ }
+
+ public void setTimeFunction(LongSupplier time)
+ {
+ this.time = time;
}
public long getSimulationTime()
{
- return currentTime;
+ return time.getAsLong();
}
public long nextEventTime()
{
- if(!hasNext())
+ if (!hasNext())
return -1;
- else
- return events.peek().timing;
+ return events.peek().getTiming();
}
-
+
public void reset()
{
events.clear();
- currentTime = 0;
+ lastTimeUpdated = 0;
}
public void addEventAddedListener(Consumer<TimelineEvent> listener)
{
eventAddedListener.add(listener);
}
+
public void removeEventAddedListener(Consumer<TimelineEvent> listener)
{
eventAddedListener.remove(listener);
}
-
+
/**
* Adds an Event to the {@link Timeline}
- * @param function The {@link TimelineEventHandler} that will be executed, when the {@link InnerEvent} occurs on the timeline.
+ *
+ * @param function The {@link TimelineEventHandler} that will be executed, when the {@link InnerEvent} occurs on the timeline.
* @param relativeTiming The amount of MI ticks in which the {@link InnerEvent} is called, starting from the current time.
*/
public void addEvent(TimelineEventHandler function, int relativeTiming)
{
- long timing = currentTime + relativeTiming;
+ long timing = getSimulationTime() + relativeTiming;
TimelineEvent event = new TimelineEvent(timing);
- events.add(new InnerEvent(function, event, timing));
+ events.add(new InnerEvent(function, event));
eventAddedListener.forEach(l -> l.accept(event));
}
-
- private class InnerEvent
- {
- private final long timing;
+ private class InnerEvent implements Runnable, Comparable<InnerEvent>
+ {
private final TimelineEventHandler function;
private final TimelineEvent event;
-
+
/**
* Creates an {@link InnerEvent}
+ *
* @param function {@link TimelineEventHandler} to be executed when the {@link InnerEvent} occurs
- * @param timing Point in the MI simulation {@link Timeline}, at which the {@link InnerEvent} is executed;
+ * @param timing Point in the MI simulation {@link Timeline}, at which the {@link InnerEvent} is executed;
*/
- InnerEvent(TimelineEventHandler function, TimelineEvent event, long timing)
+ InnerEvent(TimelineEventHandler function, TimelineEvent event)
{
this.function = function;
this.event = event;
- this.timing = timing;
}
public long getTiming()
{
- return timing;
+ return event.getTiming();
}
-
+
+ @Override
public void run()
{
function.handle(event);
}
-
+
@Override
public String toString()
{
return event.toString();
}
+
+ @Override
+ public int compareTo(InnerEvent o)
+ {
+ return timeCmp(getTiming(), o.getTiming());
+ }
}
-
- @Override
- public String toString()
+
+ private static int timeCmp(long a, long b)
{
- return "simulation time: " + currentTime + ", " + events.toString();
+ return Long.signum(a - b);
}
-
- public static long toNanoseconds(long ticks)
+
+ @Override
+ public String toString()
{
- return ticks; //TODO: Alter this when it has been determined how ticks should relate to real time.
+ return String.format("Simulation time: %s, Last update: %d, Events: %s", getSimulationTime(), lastTimeUpdated, events.toString());
}
-
+
public enum ExecutionResult
{
- NOTHING_DONE, DONE_IN_TIME, RAN_OUT_OF_TIME
+ NOTHING_DONE, EXEC_UNTIL_EMPTY, EXEC_UNTIL_CONDITION, EXEC_OUT_OF_TIME
}
}
\ No newline at end of file