bludgeon/EventTracker.cs

   1
   2 using System;
   3 using System.Collections;
   4
   5 using Beagle.Util;
   6
   7 namespace Bludgeon {
   8
   9         public class EventTracker {
  10
  11                 private enum EventType {
  12                         Added,
  13                         Subtracted
  14                 }
  15
  16                 private class Event {
  17                         public EventType Type;
  18                         public string Uri;
  19                 }
  20
  21                 object big_lock = new object ();
  22                 ArrayList expected_events = new ArrayList ();
  23
  24                 public EventTracker ()
  25                 {
  26
  27                 }
  28
  29                 ////////////////////////////////////////////////////////
  30
  31                 public void ExpectingAdded (string uri)
  32                 {
  33                         lock (big_lock) {
  34
  35                                 // Adding anything always generates a paired
  36                                 // subtracted event.
  37                                 ExpectingSubtracted (uri);
  38
  39                                 Event ev = new Event ();
  40                                 ev.Type = EventType.Added;
  41                                 ev.Uri = uri;
  42                                 expected_events.Add (ev);
  43
  44                                 //Log.Spew ("Expecting Added {0}", uri);
  45                         }
  46                 }
  47
  48                 public void ExpectingSubtracted (string uri)
  49                 {
  50                         lock (big_lock) {
  51                                 Event ev = new Event ();
  52                                 ev.Type = EventType.Subtracted;
  53                                 ev.Uri = uri;
  54                                 expected_events.Add (ev);
  55
  56                                 //Log.Spew ("Expecting Subtracted {0}", uri);
  57                         }
  58                 }
  59
  60                 ////////////////////////////////////////////////////////
  61
  62                 private void GotEvent (EventType type, string uri)
  63                 {
  64                         lock (big_lock) {
  65                                 for (int i = 0; i < expected_events.Count; ++i) {
  66                                         Event ev = (Event) expected_events [i];
  67                                         if (ev.Type == type && ev.Uri == uri) {
  68                                                 expected_events.RemoveAt (i);
  69                                                 return;
  70                                         }
  71                                 }
  72                                 throw new Exception ("Spurious event " + type + " " + uri);
  73                         }
  74                 }
  75
  76                 public void GotAddedEvent (string uri)
  77                 {
  78                         GotEvent (EventType.Added, uri);
  79                 }
  80
  81                 public void GotSubtractedEvent (string uri)
  82                 {
  83                         GotEvent (EventType.Subtracted, uri);
  84                 }
  85
  86         }
  87
  88 }