Include event domain in GenericEvent kind (#69)

* Include event domain in GenericEvent kind (ID is not unique across domains)

Co-authored-by: Mark Keinz <makei@microsoft.com>

Author: markkeinz

LTTngDataExtensions/DataOutputTypes/LTTngGenericEvent.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 
+using System;
 using System.Collections.Generic;
 using CtfPlayback;
 using CtfPlayback.FieldValues;
@@ -11,12 +12,44 @@ namespace LTTngDataExtensions.DataOutputTypes
 {
     public class EventKind
     {
-        public static readonly Dictionary<uint, EventKind> RegisteredKinds = new Dictionary<uint, EventKind>();
+        private class Key
+        {
+            private string domain;
+            private uint id;
+
+            public Key(string domain, uint id)
+            {
+                this.domain = domain ?? string.Empty;
+                this.id = id;
+            }
+
+            public override bool Equals(object obj)
+            {
+                if (obj is Key key)
+                {
+                    return domain.Equals(key.domain) && id.Equals(key.id);
+                }
+                else
+                {
+                    return false;
+                }
+            }
+
+            public override int GetHashCode()
+            {
+                int h1 = domain.GetHashCode();
+                int h2 = id.GetHashCode();
+                return ((h1 << 5) + h1) ^ h2;
+            }
+        }
+
+        public string Domain { get; }
         public uint Id { get; }
         public string EventName { get; }
         public readonly List<string> FieldNames;
-        public EventKind(uint id, string name, IReadOnlyList<CtfFieldValue> fields)
+        public EventKind(string domain, uint id, string name, IReadOnlyList<CtfFieldValue> fields)
         {
+            this.Domain = domain;
             this.Id = id;
             this.EventName = name;
             this.FieldNames = new List<string>(fields.Count);
@@ -25,6 +58,20 @@ public EventKind(uint id, string name, IReadOnlyList<CtfFieldValue> fields)
                 this.FieldNames.Add(field.FieldName);
             }
         }
+
+        private static readonly Dictionary<Key, EventKind> RegisteredKinds = new Dictionary<Key, EventKind>();
+
+        public static bool TryGetRegisteredKind(string domain, uint id, out EventKind kind)
+        {
+            return RegisteredKinds.TryGetValue(new Key(domain, id), out kind);
+        }
+
+        public static EventKind RegisterKind(string domain, uint id, string name, IReadOnlyList<CtfFieldValue> fields)
+        {
+            EventKind kind = new EventKind(domain, id, name, fields);
+            RegisteredKinds.Add(new Key(domain, id), kind);
+            return kind;
+        }
     }
 
     public struct LTTngGenericEvent
@@ -43,10 +90,9 @@ public LTTngGenericEvent(LTTngEvent data, LTTngContext context)
             this.CpuId = context.CurrentCpu;
             this.DiscardedEvents = data.DiscardedEvents;
 
-            if (!EventKind.RegisteredKinds.TryGetValue(data.Id, out this.kind))
+            if (!EventKind.TryGetRegisteredKind(context.Domain, data.Id, out this.kind))
             {
-                this.kind = new EventKind(data.Id, data.Name, payload.Fields);
-                EventKind.RegisteredKinds.Add(data.Id, this.kind);
+                this.kind = EventKind.RegisterKind(context.Domain, data.Id, data.Name, payload.Fields);
             }
 
             // As this is being written, all columns are of type 'T', so all rows are the same. For generic events,