era.mi/src/era/mi/logic/timeline/Timeline.java

   1 package era.mi.logic.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.Consumer;\r
   7 \r
   8 /**\r
   9  * Orders Events by the time they are due to be executed. Can execute Events individually.\r
  10  * \r
  11  * @author Fabian Stemmler\r
  12  *\r
  13  */\r
  14 public class Timeline\r
  15 {\r
  16         private PriorityQueue<InnerEvent> events;\r
  17         private long currentTime = 0;\r
  18 \r
  19         private final List<Consumer<TimelineEvent>> eventAddedListener;\r
  20 \r
  21         public Timeline(int initCapacity)\r
  22         {\r
  23                 events = new PriorityQueue<InnerEvent>(initCapacity, (a, b) ->\r
  24                 {\r
  25                         long difference = a.getTiming() - b.getTiming();\r
  26                         if (difference == 0)\r
  27                                 return 0;\r
  28                         return difference < 0 ? -1 : 1;\r
  29                 });\r
  30 \r
  31                 eventAddedListener = new ArrayList<>();\r
  32         }\r
  33 \r
  34         public boolean hasNext()\r
  35         {\r
  36                 return !events.isEmpty();\r
  37         }\r
  38 \r
  39         public void executeNext()\r
  40         {\r
  41                 InnerEvent first = events.poll();\r
  42                 currentTime = first.getTiming();\r
  43                 first.run();\r
  44         }\r
  45 \r
  46         public void executeAll()\r
  47         {\r
  48                 while (hasNext())\r
  49                         executeNext();\r
  50         }\r
  51 \r
  52         /**\r
  53          * Executes all events up to a given simulation timestamp. The simulation process can be constrained by a real world timestamp.\r
  54          * \r
  55          * @param timestamp  the simulation timestamp up to which the events will be processed\r
  56          * @param stopMillis the System.currentTimeMillis() when simulation definitely needs to stop.\r
  57          * @return if it was possible to fulfil the goal in the given real world time.\r
  58          * @author Christian Femers\r
  59          */\r
  60         public ExecutionResult executeUpTo(long timestamp, long stopMillis)\r
  61         {\r
  62                 if (events.isEmpty())\r
  63                 {\r
  64                         currentTime = timestamp;\r
  65                         return ExecutionResult.NOTHING_DONE;\r
  66                 }\r
  67                 int checkStop = 0;\r
  68                 InnerEvent first = events.peek();\r
  69                 while (first != null && first.getTiming() <= timestamp)\r
  70                 {\r
  71                         events.remove();\r
  72                         currentTime = first.getTiming();\r
  73                         first.run();\r
  74                         // Don't check after every run\r
  75                         checkStop = (checkStop + 1) % 10;\r
  76                         if (checkStop == 0 && System.currentTimeMillis() >= stopMillis)\r
  77                                 return ExecutionResult.RAN_OUT_OF_TIME;\r
  78                         first = events.peek();\r
  79                 }\r
  80                 currentTime = timestamp;\r
  81                 return ExecutionResult.DONE_IN_TIME;\r
  82         }\r
  83 \r
  84         public long getSimulationTime()\r
  85         {\r
  86                 return currentTime;\r
  87         }\r
  88 \r
  89         public long nextEventTime()\r
  90         {\r
  91                 if (!hasNext())\r
  92                         return -1;\r
  93                 return events.peek().timing;\r
  94         }\r
  95 \r
  96         public void reset()\r
  97         {\r
  98                 events.clear();\r
  99                 currentTime = 0;\r
 100         }\r
 101 \r
 102         public void addEventAddedListener(Consumer<TimelineEvent> listener)\r
 103         {\r
 104                 eventAddedListener.add(listener);\r
 105         }\r
 106 \r
 107         public void removeEventAddedListener(Consumer<TimelineEvent> listener)\r
 108         {\r
 109                 eventAddedListener.remove(listener);\r
 110         }\r
 111 \r
 112         /**\r
 113          * Adds an Event to the {@link Timeline}\r
 114          * \r
 115          * @param function       The {@link TimelineEventHandler} that will be executed, when the {@link InnerEvent} occurs on the timeline.\r
 116          * @param relativeTiming The amount of MI ticks in which the {@link InnerEvent} is called, starting from the current time.\r
 117          */\r
 118         public void addEvent(TimelineEventHandler function, int relativeTiming)\r
 119         {\r
 120                 long timing = currentTime + relativeTiming;\r
 121                 TimelineEvent event = new TimelineEvent(timing);\r
 122                 events.add(new InnerEvent(function, event, timing));\r
 123                 eventAddedListener.forEach(l -> l.accept(event));\r
 124         }\r
 125 \r
 126         private class InnerEvent\r
 127         {\r
 128 \r
 129                 final long timing;\r
 130                 private final TimelineEventHandler function;\r
 131                 private final TimelineEvent event;\r
 132 \r
 133                 /**\r
 134                  * Creates an {@link InnerEvent}\r
 135                  * \r
 136                  * @param function {@link TimelineEventHandler} to be executed when the {@link InnerEvent} occurs\r
 137                  * @param timing   Point in the MI simulation {@link Timeline}, at which the {@link InnerEvent} is executed;\r
 138                  */\r
 139                 InnerEvent(TimelineEventHandler function, TimelineEvent event, long timing)\r
 140                 {\r
 141                         this.function = function;\r
 142                         this.event = event;\r
 143                         this.timing = timing;\r
 144                 }\r
 145 \r
 146                 public long getTiming()\r
 147                 {\r
 148                         return timing;\r
 149                 }\r
 150 \r
 151                 public void run()\r
 152                 {\r
 153                         function.handle(event);\r
 154                 }\r
 155 \r
 156                 @Override\r
 157                 public String toString()\r
 158                 {\r
 159                         return event.toString();\r
 160                 }\r
 161         }\r
 162 \r
 163         @Override\r
 164         public String toString()\r
 165         {\r
 166                 return "simulation time: " + currentTime + ", " + events.toString();\r
 167         }\r
 168 \r
 169         public static long toNanoseconds(long ticks)\r
 170         {\r
 171                 return ticks; // TODO: Alter this when it has been determined how ticks should relate to real time.\r
 172         }\r
 173 \r
 174         public enum ExecutionResult\r
 175         {\r
 176                 NOTHING_DONE, DONE_IN_TIME, RAN_OUT_OF_TIME\r
 177         }\r
 178 }