@colyseus/schema: improve instance sharing and ref count tracking.

Author: endel

Assets/Colyseus/Runtime/Colyseus/Serializer/Schema/Decoder.cs

@@ -124,17 +124,17 @@ protected void DecodeValue(byte[] bytes, Iterator it, IRef _ref, int fieldIndex,
 			//
 			if ((operation & (byte)OPERATION.DELETE) == (byte)OPERATION.DELETE)
 			{
-				if (operation != (byte)OPERATION.DELETE_AND_ADD)
-				{
-					_ref.DeleteByIndex(fieldIndex);
-				}
-
 				// Flag `refId` for garbage collection.
 				if (previousValue != null && previousValue is IRef)
 				{
 					Refs.Remove(((IRef)previousValue).__refId);
 				}
 
+				if (operation != (byte)OPERATION.DELETE_AND_ADD)
+				{
+					_ref.DeleteByIndex(fieldIndex);
+				}
+
 				value = null;
 			}
 
@@ -152,20 +152,6 @@ protected void DecodeValue(byte[] bytes, Iterator it, IRef _ref, int fieldIndex,
 				var __refId = Convert.ToInt32(Utils.Decode.DecodeNumber(bytes, it));
 				value = Refs.Get(__refId);
 
-				if (previousValue != null)
-				{
-					var previousRefId = ((IRef)previousValue).__refId;
-					if (
-						previousRefId > 0 &&
-						__refId != previousRefId &&
-						// FIXME: we may need to check for REPLACE operation as well
-						((operation & (byte)OPERATION.DELETE) == (byte)OPERATION.DELETE)
-					)
-					{
-						Refs.Remove(previousRefId);
-					}
-				}
-
 				if ((operation & (byte)OPERATION.ADD) == (byte)OPERATION.ADD)
 				{
 					System.Type concreteChildType = GetSchemaType(bytes, it, childType);
@@ -210,9 +196,11 @@ protected void DecodeValue(byte[] bytes, Iterator it, IRef _ref, int fieldIndex,
 						__refId != ((IRef)previousValue).__refId
 					)
 					{
-						Refs.Remove(((IRef)previousValue).__refId);
-
 						((ISchemaCollection)previousValue).ForEach((key, value) => {
+							if (value is IRef) {
+								Refs.Remove(((IRef)value).__refId);
+							}
+
 							AllChanges.Add(new DataChange
 							{
 								RefId = __refId,
@@ -225,7 +213,10 @@ protected void DecodeValue(byte[] bytes, Iterator it, IRef _ref, int fieldIndex,
 					}
 				}
 
-				Refs.Add(__refId, (IRef)value, valueRef != previousValue);
+				Refs.Add(__refId, (IRef)value, (
+					valueRef != previousValue || // increment ref count if value has changed
+					(operation == (byte)OPERATION.DELETE_AND_ADD && valueRef == previousValue) // increment ref count if the same instance is being added again
+				));
 			}
 		}
 

Assets/Colyseus/Runtime/Colyseus/Serializer/Schema/ReferenceTracker.cs

@@ -1,6 +1,6 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
+using UnityEngine;
 
 namespace Colyseus.Schema
 {
@@ -80,18 +80,20 @@ public bool Has(int refId)
         ///     Remove a reference by ID
         /// </summary>
         /// <param name="refId">The ID of the reference to remove</param>
-        /// <returns>True if successful, false otherwise</returns>
-        public bool Remove(int refId)
+        public void Remove(int refId)
         {
+            if (!refCounts.ContainsKey(refId))
+            {
+                Debug.Log("trying to remove refId that doesn't exist: " + refId);
+                return;
+            }
+
             refCounts[refId] = refCounts[refId] - 1;
 
-            if (!deletedRefs.Contains(refId))
+            if (refCounts[refId] <= 0)
             {
                 deletedRefs.Add(refId);
-                return true;
             }
-
-            return false;
         }
 
         /// <summary>
@@ -110,31 +112,36 @@ public void GarbageCollection()
                     IRef _ref = refs[refId];
                     if (_ref is Schema)
                     {
-                        foreach (KeyValuePair<string, System.Type> field in ((Schema) _ref).GetFieldChildTypes())
+                        foreach (KeyValuePair<string, System.Type> field in ((Schema)_ref).GetFieldChildTypes())
                         {
-                            object fieldValue = ((Schema) _ref)[field.Key];
-                            if (
-                                fieldValue is IRef &&
-                                Remove(((IRef) fieldValue).__refId))
+                            object fieldValue = ((Schema)_ref)[field.Key];
+                            if (fieldValue is IRef)
                             {
-                                totalDeletedRefs++;
+                                int childRefId = ((IRef)fieldValue).__refId;
+                                if (!deletedRefs.Contains(childRefId))
+                                {
+                                    Remove(childRefId);
+                                    totalDeletedRefs++;
+                                }
                             }
                         }
                     }
-                    else if (_ref is ISchemaCollection && ((ISchemaCollection) _ref).HasSchemaChild)
+                    else if (_ref is ISchemaCollection && ((ISchemaCollection)_ref).HasSchemaChild)
                     {
-						((ISchemaCollection)_ref).ForEach((key, value) =>
-						{
-							if (Remove(((IRef)value).__refId))
-							{
-								totalDeletedRefs++;
-							}
-						});
+                        ((ISchemaCollection)_ref).ForEach((key, value) =>
+                        {
+                            int childRefId = ((IRef)value).__refId;
+                            if (!deletedRefs.Contains(childRefId))
+                            {
+                                Remove(childRefId);
+                                totalDeletedRefs++;
+                            }
+                        });
                     }
 
                     refs.Remove(refId);
                     refCounts.Remove(refId);
-					callbacks.Remove(refId);
+                    callbacks.Remove(refId);
                 }
             }
 

Assets/Colyseus/Tests/Editor/ColyseusTests/SchemaDeserializerTest.cs

@@ -417,7 +417,7 @@ public void InstanceSharingTypesTest()
 		var previousArraySchemaRefId = state.arrayOfPlayers.__refId;
 
 		// Replacing ArraySchema
-		decoder.Decode(new byte[] { 130, 9, 255, 9, 128, 0, 10, 255, 10, 128, 11, 255, 11, 128, 10, 129, 20 });
+		decoder.Decode(new byte[] { 194, 9, 255, 9, 128, 0, 10, 255, 10, 128, 11, 255, 11, 128, 10, 129, 20 });
 		Assert.AreEqual(false, refs.refs.ContainsKey(previousArraySchemaRefId));
 		Assert.AreEqual(1, state.arrayOfPlayers.Count);
 		Assert.AreEqual(5, refs.refs.Count);

Assets/Colyseus/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "io.colyseus.sdk",
-	"version": "0.16.4",
+	"version": "0.16.5",
 	"displayName": "Colyseus SDK",
 	"description": "Colyseus Multiplayer SDK for Unity",
 	"unity": "2019.1",

Server/src/rooms/MyRoom.ts

@@ -1,4 +1,4 @@
-import { Room, Client } from "colyseus";
+import { Room, Client, AuthContext } from "colyseus";
 import { MyRoomState, Player } from "./schema/MyRoomState";
 
 export type PositionMessage = {
@@ -12,6 +12,10 @@ export class MyRoom extends Room<MyRoomState> {
     this.setState(new MyRoomState());
   }
 
+  onAuth(client: Client, options: any, context: AuthContext) {
+    return false;
+  }
+
   onJoin (client: Client, options: any) {
     console.log(client.sessionId, "joined!");