net.mograsim.logic.core/src/net/mograsim/logic/core/timeline/Timeline.java

   1 package net.mograsim.logic.core.timeline;
   2
   3 import java.util.ArrayList;
   4 import java.util.List;
   5 import java.util.PriorityQueue;
   6 import java.util.function.BooleanSupplier;
   7 import java.util.function.Consumer;
   8 import java.util.function.LongSupplier;
   9
  10 /**
  11  * Orders Events by the time they are due to be executed. Can execute Events individually.
  12  *
  13  * @author Fabian Stemmler
  14  *
  15  */
  16 public class Timeline
  17 {
  18         private PriorityQueue<InnerEvent> events;
  19         private LongSupplier time;
  20         private long lastTimeUpdated = 0;
  21
  22         private final List<Consumer<TimelineEvent>> eventAddedListener;
  23
  24         public Timeline(int initCapacity)
  25         {
  26                 events = new PriorityQueue<InnerEvent>(initCapacity);
  27
  28                 eventAddedListener = new ArrayList<>();
  29                 time = () -> lastTimeUpdated;
  30         }
  31
  32         /**
  33          * @param timestamp exclusive
  34          * @return true if the first event is later than the timestamp
  35          */
  36         public BooleanSupplier laterThan(long timestamp)
  37         {
  38                 return () -> timeCmp(events.peek().getTiming(), timestamp) > 0;
  39         }
  40
  41         public boolean hasNext()
  42         {
  43                 return !events.isEmpty();
  44         }
  45
  46         /**
  47          * Executes all events at the next timestamp, at which there are any
  48          */
  49         public void executeNext()
  50         {
  51                 InnerEvent first = events.peek();
  52                 if (first != null)
  53                         executeUntil(laterThan(first.getTiming()), -1);
  54         }
  55
  56         public void executeAll()
  57         {
  58                 while (hasNext())
  59                         executeNext();
  60         }
  61
  62         /**
  63          * Executes all events until a given condition is met. The simulation process can be constrained by a real world timestamp.
  64          *
  65          * @param condition  the condition until which the events are be processed
  66          * @param stopMillis the System.currentTimeMillis() when simulation definitely needs to stop. A value of -1 means no timeout.
  67          * @return State of the event execution
  68          * @formatter:off
  69          * <code>NOTHING_DONE</code> if the {@link Timeline} was already empty
  70          * <code>EXEC_OUT_OF_TIME</code> if the given maximum time was reached
  71          * <code>EXEC_UNTIL_CONDITION</code> if the condition was met
  72          * <code>EXEC_UNTIL_EMPTY</code> if events were executed until the {@link Timeline} was empty
  73          * @formatter:on
  74          * @author Christian Femers, Fabian Stemmler
  75          */
  76         public ExecutionResult executeUntil(BooleanSupplier condition, long stopMillis)
  77         {
  78                 if (events.isEmpty())
  79                 {
  80                         lastTimeUpdated = getSimulationTime();
  81                         return ExecutionResult.NOTHING_DONE;
  82                 }
  83                 int checkStop = 0;
  84                 InnerEvent first = events.peek();
  85                 while (hasNext() && !condition.getAsBoolean())
  86                 {
  87                         events.remove();
  88                         lastTimeUpdated = first.getTiming();
  89                         first.run();
  90                         // Don't check after every run
  91                         checkStop = (checkStop + 1) % 10;
  92                         if (checkStop == 0 && System.currentTimeMillis() >= stopMillis)
  93                                 return ExecutionResult.EXEC_OUT_OF_TIME;
  94                         first = events.peek();
  95                 }
  96                 lastTimeUpdated = getSimulationTime();
  97                 return hasNext() ? ExecutionResult.EXEC_UNTIL_EMPTY : ExecutionResult.EXEC_UNTIL_CONDITION;
  98         }
  99
 100         public void setTimeFunction(LongSupplier time)
 101         {
 102                 this.time = time;
 103         }
 104
 105         public long getSimulationTime()
 106         {
 107                 return time.getAsLong();
 108         }
 109
 110         public long nextEventTime()
 111         {
 112                 if (!hasNext())
 113                         return -1;
 114                 return events.peek().getTiming();
 115         }
 116
 117         public void reset()
 118         {
 119                 events.clear();
 120                 lastTimeUpdated = 0;
 121         }
 122
 123         public void addEventAddedListener(Consumer<TimelineEvent> listener)
 124         {
 125                 eventAddedListener.add(listener);
 126         }
 127
 128         public void removeEventAddedListener(Consumer<TimelineEvent> listener)
 129         {
 130                 eventAddedListener.remove(listener);
 131         }
 132
 133         /**
 134          * Adds an Event to the {@link Timeline}
 135          *
 136          * @param function       The {@link TimelineEventHandler} that will be executed, when the {@link InnerEvent} occurs on the timeline.
 137          * @param relativeTiming The amount of MI ticks in which the {@link InnerEvent} is called, starting from the current time.
 138          */
 139         public void addEvent(TimelineEventHandler function, int relativeTiming)
 140         {
 141                 long timing = getSimulationTime() + relativeTiming;
 142                 TimelineEvent event = new TimelineEvent(timing);
 143                 events.add(new InnerEvent(function, event));
 144                 eventAddedListener.forEach(l -> l.accept(event));
 145         }
 146
 147         private class InnerEvent implements Runnable, Comparable<InnerEvent>
 148         {
 149                 private final TimelineEventHandler function;
 150                 private final TimelineEvent event;
 151
 152                 /**
 153                  * Creates an {@link InnerEvent}
 154                  *
 155                  * @param function {@link TimelineEventHandler} to be executed when the {@link InnerEvent} occurs
 156                  * @param timing   Point in the MI simulation {@link Timeline}, at which the {@link InnerEvent} is executed;
 157                  */
 158                 InnerEvent(TimelineEventHandler function, TimelineEvent event)
 159                 {
 160                         this.function = function;
 161                         this.event = event;
 162                 }
 163
 164                 public long getTiming()
 165                 {
 166                         return event.getTiming();
 167                 }
 168
 169                 @Override
 170                 public void run()
 171                 {
 172                         function.handle(event);
 173                 }
 174
 175                 @Override
 176                 public String toString()
 177                 {
 178                         return event.toString();
 179                 }
 180
 181                 @Override
 182                 public int compareTo(InnerEvent o)
 183                 {
 184                         return timeCmp(getTiming(), o.getTiming());
 185                 }
 186         }
 187
 188         public static int timeCmp(long a, long b)
 189         {
 190                 return Long.signum(a - b);
 191         }
 192
 193         @Override
 194         public String toString()
 195         {
 196                 return String.format("Simulation time: %s, Last update: %d, Events: %s", getSimulationTime(), lastTimeUpdated, events.toString());
 197         }
 198
 199         public enum ExecutionResult
 200         {
 201                 NOTHING_DONE, EXEC_UNTIL_EMPTY, EXEC_UNTIL_CONDITION, EXEC_OUT_OF_TIME
 202         }
 203 }