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

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