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