feat: Allows disabling or delaying NetworkId recycle

Fixes: #214

Author: TwoTenPvP

MLAPI/Configuration/NetworkConfig.cs

@@ -122,6 +122,16 @@ public class NetworkConfig
                  "If false, Only non scene objects have to be prefabs. Scene objects will be matched using their PrefabInstanceId which can be precomputed globally for a scene at build time. Useful for single projects")]
         public bool UsePrefabSync = false;
         /// <summary>
+        /// If true, NetworkIds will be reused after the NetworkIdRecycleDelay.
+        /// </summary>
+        [Tooltip("If true, NetworkIds will be reused after the NetworkIdRecycleDelay")]
+        public bool RecycleNetworkIds = true;
+        /// <summary>
+        /// The amount of seconds a NetworkId has to be unused in order for it to be reused.
+        /// </summary>
+        [Tooltip("The amount of seconds a NetworkId has to unused in order for it to be reused")]
+        public float NetworkIdRecycleDelay = 120f;
+        /// <summary>
         /// Decides how many bytes to use for Rpc messaging. Leave this to 2 bytes unless you are facing hash collisions
         /// </summary>
         [Tooltip("The maximum amount of bytes to use for RPC messages. Leave this to 2 unless you are facing hash collisions")]

MLAPI/Spawning/ReleasedNetworkId.cs

@@ -0,0 +1,8 @@
+namespace MLAPI.Spawning
+{
+    internal struct ReleasedNetworkId
+    {
+        public ulong NetworkId;
+        public float ReleaseTime;
+    }
+}

MLAPI/Spawning/SpawnManager.cs

@@ -96,13 +96,13 @@ public static void RemoveCustomDestroyHandler(ulong prefabHash)
             customDestroyHandlers.Remove(prefabHash);
         }
 
-        internal static readonly Stack<ulong> releasedNetworkObjectIds = new Stack<ulong>();
+        internal static readonly Queue<ReleasedNetworkId> releasedNetworkObjectIds = new Queue<ReleasedNetworkId>();
         private static ulong networkObjectIdCounter;
         internal static ulong GetNetworkObjectId()
         {
-            if (releasedNetworkObjectIds.Count > 0)
+            if (releasedNetworkObjectIds.Count > 0 && NetworkingManager.Singleton.NetworkConfig.RecycleNetworkIds && (Time.unscaledTime - releasedNetworkObjectIds.Peek().ReleaseTime) >= NetworkingManager.Singleton.NetworkConfig.NetworkIdRecycleDelay)
             {
-                return releasedNetworkObjectIds.Pop();
+                return releasedNetworkObjectIds.Dequeue().NetworkId;
             }
             else
             {
@@ -522,7 +522,14 @@ internal static void OnDestroyObject(ulong networkId, bool destroyGameObject)
 
             if (NetworkingManager.Singleton != null && NetworkingManager.Singleton.IsServer)
             {
-                releasedNetworkObjectIds.Push(networkId);
+                if (NetworkingManager.Singleton.NetworkConfig.RecycleNetworkIds)
+                {
+                    releasedNetworkObjectIds.Enqueue(new ReleasedNetworkId()
+                    {
+                        NetworkId = networkId,
+                        ReleaseTime = Time.unscaledTime
+                    });   
+                }
 
                 if (SpawnedObjects[networkId] != null)
                 {