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