NetworkBehaviour.cs

using System;
using System.Collections.Generic;
using Unity.Collections;
using UnityEngine;

namespace Unity.Netcode
{
    /// <summary>
    /// Exception thrown when an RPC (Remote Procedure Call) encounters an error during execution
    /// </summary>
    public class RpcException : Exception
    {
        /// <summary>
        /// Initializes a new instance of the RpcException class with a specified error message
        /// </summary>
        /// <param name="message">The message that describes the error</param>
        public RpcException(string message) : base(message)
        {

        }
    }

    /// <summary>
    /// The base class to override to write network code. Inherits MonoBehaviour.
    /// </summary>
    public abstract class NetworkBehaviour : MonoBehaviour
    {
#if UNITY_EDITOR
        [HideInInspector]
        [SerializeField]
        internal bool ShowTopMostFoldoutHeaderGroup = true;
#endif

#pragma warning disable IDE1006 // disable naming rule violation check

        // RuntimeAccessModifiersILPP will make this `public`
        internal delegate void RpcReceiveHandler(NetworkBehaviour behaviour, FastBufferReader reader, __RpcParams parameters);

        // RuntimeAccessModifiersILPP will make this `public`
        internal static readonly Dictionary<Type, Dictionary<uint, RpcReceiveHandler>> __rpc_func_table = new Dictionary<Type, Dictionary<uint, RpcReceiveHandler>>();
        internal static readonly Dictionary<Type, Dictionary<uint, RpcInvokePermission>> __rpc_permission_table = new Dictionary<Type, Dictionary<uint, RpcInvokePermission>>();

#if DEVELOPMENT_BUILD || UNITY_EDITOR || UNITY_MP_TOOLS_NET_STATS_MONITOR_ENABLED_IN_RELEASE
        // RuntimeAccessModifiersILPP will make this `public`
        internal static readonly Dictionary<Type, Dictionary<uint, string>> __rpc_name_table = new Dictionary<Type, Dictionary<uint, string>>();
#endif

        // RuntimeAccessModifiersILPP will make this `protected`
        internal enum __RpcExecStage
        {
            // Technically will overlap with None and Server
            // but it doesn't matter since we don't use None and Server
            Send = 0,
            Execute = 1,

            // Backward compatibility, not used...
            None = 0,
            Server = 1,
            Client = 2,
        }
        // NetworkBehaviourILPP will override this in derived classes to return the name of the concrete type
        internal virtual string __getTypeName() => nameof(NetworkBehaviour);

        [NonSerialized]
        // RuntimeAccessModifiersILPP will make this `protected`
        internal __RpcExecStage __rpc_exec_stage = __RpcExecStage.Send;
#pragma warning restore IDE1006 // restore naming rule violation check

        private const int k_RpcMessageDefaultSize = 1024; // 1k
        private const int k_RpcMessageMaximumSize = 1024 * 64; // 64k

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal FastBufferWriter __beginSendServerRpc(uint rpcMethodId, ServerRpcParams serverRpcParams, RpcDelivery rpcDelivery)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            if (m_NetworkObject == null && !IsSpawned)
            {
                throw new RpcException("The NetworkBehaviour must be spawned before calling this method.");
            }

            return new FastBufferWriter(k_RpcMessageDefaultSize, Allocator.Temp, k_RpcMessageMaximumSize);
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal void __endSendServerRpc(ref FastBufferWriter bufferWriter, uint rpcMethodId, ServerRpcParams serverRpcParams, RpcDelivery rpcDelivery)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            var networkManager = m_NetworkManager;
            var serverRpcMessage = new ServerRpcMessage
            {
                Metadata = new RpcMetadata
                {
                    NetworkObjectId = NetworkObjectId,
                    NetworkBehaviourId = NetworkBehaviourId,
                    NetworkRpcMethodId = rpcMethodId,
                },
                WriteBuffer = bufferWriter
            };

            NetworkDelivery networkDelivery;
            switch (rpcDelivery)
            {
                default:
                case RpcDelivery.Reliable:
                    networkDelivery = MessageDeliveryType<ServerRpcMessage>.DefaultDelivery;
                    break;
                case RpcDelivery.Unreliable:
                    if (bufferWriter.Length > networkManager.MessageManager.NonFragmentedMessageMaxSize)
                    {
                        throw new OverflowException("RPC parameters are too large for unreliable delivery.");
                    }
                    networkDelivery = NetworkDelivery.Unreliable;
                    break;
            }

            var rpcWriteSize = 0;
            // Authority just no ops and sends to itself
            // Client-Server: Only the server-host sends to self
            if (IsServer)
            {
                using var tempBuffer = new FastBufferReader(bufferWriter, Allocator.Temp);
                var context = new NetworkContext
                {
                    SenderId = NetworkManager.ServerClientId,
                    Timestamp = networkManager.RealTimeProvider.RealTimeSinceStartup,
                    SystemOwner = networkManager,
                    // header information isn't valid since it's not a real message.
                    // RpcMessage doesn't access this stuff so it's just left empty.
                    Header = new NetworkMessageHeader(),
                    SerializedHeaderSize = 0,
                    MessageSize = 0
                };
                serverRpcMessage.ReadBuffer = tempBuffer;
                serverRpcMessage.Handle(ref context);
                rpcWriteSize = tempBuffer.Length;
            }
            else
            {
                rpcWriteSize = networkManager.ConnectionManager.SendMessage(ref serverRpcMessage, networkDelivery, NetworkManager.ServerClientId);
            }

            bufferWriter.Dispose();
#if DEVELOPMENT_BUILD || UNITY_EDITOR || UNITY_MP_TOOLS_NET_STATS_MONITOR_ENABLED_IN_RELEASE
            if (__rpc_name_table[GetType()].TryGetValue(rpcMethodId, out var rpcMethodName))
            {
                networkManager.NetworkMetrics.TrackRpcSent(
                    NetworkManager.ServerClientId,
                    m_NetworkObject,
                    rpcMethodName,
                    __getTypeName(),
                    rpcWriteSize);
            }
#endif
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal FastBufferWriter __beginSendClientRpc(uint rpcMethodId, ClientRpcParams clientRpcParams, RpcDelivery rpcDelivery)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            if (m_NetworkObject == null && !IsSpawned)
            {
                throw new RpcException("The NetworkBehaviour must be spawned before calling this method.");
            }

            return new FastBufferWriter(k_RpcMessageDefaultSize, Allocator.Temp, k_RpcMessageMaximumSize);
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal void __endSendClientRpc(ref FastBufferWriter bufferWriter, uint rpcMethodId, ClientRpcParams clientRpcParams, RpcDelivery rpcDelivery)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            var networkManager = m_NetworkManager;
            var clientRpcMessage = new ClientRpcMessage
            {
                Metadata = new RpcMetadata
                {
                    NetworkObjectId = NetworkObjectId,
                    NetworkBehaviourId = NetworkBehaviourId,
                    NetworkRpcMethodId = rpcMethodId,
                },
                WriteBuffer = bufferWriter
            };

            NetworkDelivery networkDelivery;
            switch (rpcDelivery)
            {
                default:
                case RpcDelivery.Reliable:
                    networkDelivery = MessageDeliveryType<ClientRpcMessage>.DefaultDelivery;
                    break;
                case RpcDelivery.Unreliable:
                    if (bufferWriter.Length > networkManager.MessageManager.NonFragmentedMessageMaxSize)
                    {
                        throw new OverflowException("RPC parameters are too large for unreliable delivery.");
                    }
                    networkDelivery = NetworkDelivery.Unreliable;
                    break;
            }

            var rpcWriteSize = 0;

            // We check to see if we need to shortcut for the case where we are the host/server and we can send a clientRPC
            // to ourself. Sadly we have to figure that out from the list of clientIds :(
            bool shouldInvokeLocally = false;
            if (clientRpcParams.Send.TargetClientIds != null)
            {
                foreach (var targetClientId in clientRpcParams.Send.TargetClientIds)
                {
                    if (targetClientId == NetworkManager.ServerClientId)
                    {
                        shouldInvokeLocally = true;
                        continue;
                    }
                    // Check to make sure we are sending to only observers, if not log an error.
                    if (networkManager.LogLevel >= LogLevel.Error && !m_NetworkObject.Observers.Contains(targetClientId))
                    {
                        NetworkLog.LogError(GenerateObserverErrorMessage(clientRpcParams, targetClientId));
                    }
                }
                rpcWriteSize = m_NetworkManager.ConnectionManager.SendMessage(ref clientRpcMessage, networkDelivery, in clientRpcParams.Send.TargetClientIds);
            }
            else if (clientRpcParams.Send.TargetClientIdsNativeArray != null)
            {
                foreach (var targetClientId in clientRpcParams.Send.TargetClientIdsNativeArray)
                {
                    if (targetClientId == NetworkManager.ServerClientId)
                    {
                        shouldInvokeLocally = true;
                        continue;
                    }
                    // Check to make sure we are sending to only observers, if not log an error.
                    if (networkManager.LogLevel >= LogLevel.Error && !m_NetworkObject.Observers.Contains(targetClientId))
                    {
                        NetworkLog.LogError(GenerateObserverErrorMessage(clientRpcParams, targetClientId));
                    }
                }
                rpcWriteSize = networkManager.ConnectionManager.SendMessage(ref clientRpcMessage, networkDelivery, clientRpcParams.Send.TargetClientIdsNativeArray.Value);
            }
            else
            {
                var observerEnumerator = m_NetworkObject.Observers.GetEnumerator();
                while (observerEnumerator.MoveNext())
                {
                    // Skip over the host
                    if (IsHost && observerEnumerator.Current == networkManager.LocalClientId)
                    {
                        shouldInvokeLocally = true;
                        continue;
                    }
                    rpcWriteSize = networkManager.ConnectionManager.SendMessage(ref clientRpcMessage, networkDelivery, observerEnumerator.Current);
                }
            }

            // If we are a server/host then we just no op and send to ourself
            if (shouldInvokeLocally)
            {
                using var tempBuffer = new FastBufferReader(bufferWriter, Allocator.Temp);
                var context = new NetworkContext
                {
                    SenderId = NetworkManager.ServerClientId,
                    Timestamp = networkManager.RealTimeProvider.RealTimeSinceStartup,
                    SystemOwner = networkManager,
                    // header information isn't valid since it's not a real message.
                    // RpcMessage doesn't access this stuff so it's just left empty.
                    Header = new NetworkMessageHeader(),
                    SerializedHeaderSize = 0,
                    MessageSize = 0
                };
                clientRpcMessage.ReadBuffer = tempBuffer;
                clientRpcMessage.Handle(ref context);
            }

            bufferWriter.Dispose();
#if DEVELOPMENT_BUILD || UNITY_EDITOR || UNITY_MP_TOOLS_NET_STATS_MONITOR_ENABLED_IN_RELEASE
            if (__rpc_name_table[GetType()].TryGetValue(rpcMethodId, out var rpcMethodName))
            {
                if (clientRpcParams.Send.TargetClientIds != null)
                {
                    foreach (var targetClientId in clientRpcParams.Send.TargetClientIds)
                    {
                        networkManager.NetworkMetrics.TrackRpcSent(
                            targetClientId,
                            m_NetworkObject,
                            rpcMethodName,
                            __getTypeName(),
                            rpcWriteSize);
                    }
                }
                else if (clientRpcParams.Send.TargetClientIdsNativeArray != null)
                {
                    foreach (var targetClientId in clientRpcParams.Send.TargetClientIdsNativeArray)
                    {
                        networkManager.NetworkMetrics.TrackRpcSent(
                            targetClientId,
                            m_NetworkObject,
                            rpcMethodName,
                            __getTypeName(),
                            rpcWriteSize);
                    }
                }
                else
                {
                    var observerEnumerator = m_NetworkObject.Observers.GetEnumerator();
                    while (observerEnumerator.MoveNext())
                    {
                        networkManager.NetworkMetrics.TrackRpcSent(
                            observerEnumerator.Current,
                            m_NetworkObject,
                            rpcMethodName,
                            __getTypeName(),
                            rpcWriteSize);
                    }
                }
            }
#endif
        }


#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal FastBufferWriter __beginSendRpc(uint rpcMethodId, RpcParams rpcParams, RpcAttribute.RpcAttributeParams attributeParams, SendTo defaultTarget, RpcDelivery rpcDelivery)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            if (m_NetworkObject == null && !IsSpawned)
            {
                throw new RpcException("The NetworkBehaviour must be spawned before calling this method.");
            }

            if (attributeParams.InvokePermission == RpcInvokePermission.Server && !IsServer)
            {
                throw new RpcException("This RPC can only be sent by the server.");
            }

#pragma warning disable CS0618 // Type or member is obsolete
            var requireOwnership = attributeParams.RequireOwnership;
#pragma warning restore CS0618 // Type or member is obsolete

            if ((requireOwnership || attributeParams.InvokePermission == RpcInvokePermission.Owner) && !IsOwner)
            {
                throw new RpcException("This RPC can only be sent by its owner.");
            }
            return new FastBufferWriter(k_RpcMessageDefaultSize, Allocator.Temp, k_RpcMessageMaximumSize);
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal void __endSendRpc(ref FastBufferWriter bufferWriter, uint rpcMethodId, RpcParams rpcParams, RpcAttribute.RpcAttributeParams attributeParams, SendTo defaultTarget, RpcDelivery rpcDelivery)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            var rpcMessage = new RpcMessage
            {
                Metadata = new RpcMetadata
                {
                    NetworkObjectId = NetworkObjectId,
                    NetworkBehaviourId = NetworkBehaviourId,
                    NetworkRpcMethodId = rpcMethodId,
                },
                SenderClientId = m_NetworkManager.LocalClientId,
                WriteBuffer = bufferWriter
            };

            NetworkDelivery networkDelivery;
            switch (rpcDelivery)
            {
                default:
                case RpcDelivery.Reliable:
                    networkDelivery = MessageDeliveryType<RpcMessage>.DefaultDelivery;
                    break;
                case RpcDelivery.Unreliable:
                    if (bufferWriter.Length > m_NetworkManager.MessageManager.NonFragmentedMessageMaxSize)
                    {
                        throw new OverflowException("RPC parameters are too large for unreliable delivery.");
                    }
                    networkDelivery = NetworkDelivery.Unreliable;
                    break;
            }

            if (rpcParams.Send.Target == null)
            {
                switch (defaultTarget)
                {
                    case SendTo.Everyone:
                        rpcParams.Send.Target = RpcTarget.Everyone;
                        break;
                    case SendTo.Owner:
                        rpcParams.Send.Target = RpcTarget.Owner;
                        break;
                    case SendTo.Server:
                        rpcParams.Send.Target = RpcTarget.Server;
                        break;
                    case SendTo.NotServer:
                        rpcParams.Send.Target = RpcTarget.NotServer;
                        break;
                    case SendTo.NotMe:
                        rpcParams.Send.Target = RpcTarget.NotMe;
                        break;
                    case SendTo.NotOwner:
                        rpcParams.Send.Target = RpcTarget.NotOwner;
                        break;
                    case SendTo.Me:
                        rpcParams.Send.Target = RpcTarget.Me;
                        break;
                    case SendTo.ClientsAndHost:
                        rpcParams.Send.Target = RpcTarget.ClientsAndHost;
                        break;
                    case SendTo.Authority:
                        rpcParams.Send.Target = RpcTarget.Authority;
                        break;
                    case SendTo.NotAuthority:
                        rpcParams.Send.Target = RpcTarget.NotAuthority;
                        break;
                    case SendTo.SpecifiedInParams:
                        throw new RpcException("This method requires a runtime-specified send target.");
                }
            }
            else if (defaultTarget != SendTo.SpecifiedInParams && !attributeParams.AllowTargetOverride)
            {
                throw new RpcException("Target override is not allowed for this method.");
            }

            if (rpcParams.Send.LocalDeferMode == LocalDeferMode.Default)
            {
                rpcParams.Send.LocalDeferMode = attributeParams.DeferLocal ? LocalDeferMode.Defer : LocalDeferMode.SendImmediate;
            }

            rpcParams.Send.Target.Send(this, ref rpcMessage, networkDelivery, rpcParams);

            bufferWriter.Dispose();
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal static NativeList<T> __createNativeList<T>() where T : unmanaged
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            return new NativeList<T>(Allocator.Temp);
        }

        internal string GenerateObserverErrorMessage(ClientRpcParams clientRpcParams, ulong targetClientId)
        {
            var containerNameHoldingId = clientRpcParams.Send.TargetClientIds != null ? nameof(ClientRpcParams.Send.TargetClientIds) : nameof(ClientRpcParams.Send.TargetClientIdsNativeArray);
            return $"Sending ClientRpc to non-observer! {containerNameHoldingId} contains clientId {targetClientId} that is not an observer!";
        }

        private NetworkManager m_NetworkManager;

        /// <summary>
        /// Gets the NetworkManager that owns this NetworkBehaviour instance.
        /// See `NetworkObject` note for how there is a chicken/egg problem when not initialized.
        /// </summary>
        public NetworkManager NetworkManager
        {
            get
            {
                if (m_NetworkManager != null)
                {
                    return m_NetworkManager;
                }

                if (NetworkObject?.NetworkManager != null)
                {
                    return NetworkObject.NetworkManager;
                }

                return NetworkManager.Singleton;
            }
        }

        // This erroneously tries to simplify these method references but the docs do not pick it up correctly
        // because they try to resolve it on the field rather than the class of the same name.
#pragma warning disable IDE0001
        /// <summary>
        /// Provides access to the various <see cref="SendTo"/> targets at runtime, as well as
        /// runtime-bound targets like <see cref="Unity.Netcode.RpcTarget.Single"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Group(NativeArray{ulong})"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Group(NativeList{ulong})"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Group(ulong[])"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Group{T}(T)"/>, <see cref="Unity.Netcode.RpcTarget.Not(ulong)"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Not(NativeArray{ulong})"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Not(NativeList{ulong})"/>,
        /// <see cref="Unity.Netcode.RpcTarget.Not(ulong[])"/>, and
        /// <see cref="Unity.Netcode.RpcTarget.Not{T}(T)"/>.
        /// </summary>
#pragma warning restore IDE0001
        public RpcTarget RpcTarget { get; private set; }

        /// <summary>
        /// If a NetworkObject is assigned, returns whether the NetworkObject
        /// is the local player object. If no NetworkObject is assigned, returns false.
        /// </summary>
        public bool IsLocalPlayer { get; private set; }

        /// <summary>
        /// Gets whether the object is owned by the local player or if the object is the local player object.
        /// </summary>
        public bool IsOwner { get; internal set; }

        /// <summary>
        /// Gets whether executing as a server.
        /// </summary>
        public bool IsServer { get; private set; }

        /// <summary>
        /// Determines if the local client has authority over the associated NetworkObject.
        /// <list type="bullet">
        /// <item>In client-server contexts: returns true if `IsServer` or `IsHost`.</item>
        /// <item>In distributed authority contexts: returns true if `IsOwner`.</item>
        /// </list>
        /// </summary>
        public bool HasAuthority { get; internal set; }


        /// <summary>
        /// Gets whether the client is the distributed authority mode session owner.
        /// </summary>
        public bool IsSessionOwner { get; private set; }

        /// <summary>
        /// Gets whether the server (local or remote) is a host.
        /// </summary>
        public bool ServerIsHost { get; private set; }

        /// <summary>
        /// Gets whether executing as a client.
        /// </summary>
        public bool IsClient { get; private set; }


        /// <summary>
        /// Gets whether executing as a host (both server and client).
        /// </summary>
        public bool IsHost { get; private set; }

        /// <summary>
        /// Gets whether the object has an owner.
        /// </summary>
        public bool IsOwnedByServer { get; internal set; }

        /// <summary>
        /// Determines whether it's safe to access a NetworkObject and NetworkManager from within a NetworkBehaviour component.
        /// Primarily useful when checking NetworkObject or NetworkManager properties within FixedUpate.
        /// </summary>
        public bool IsSpawned { get; internal set; }

        internal bool IsBehaviourEditable()
        {
            if (!m_NetworkObject || !m_NetworkManager || !m_NetworkManager.IsListening)
            {
                return true;
            }

            // Only the authority can MODIFY. So allow modification if network is either not running or we are the authority.
            return HasAuthority;
        }

        internal void SetNetworkObject(NetworkObject networkObject, ushort behaviourId)
        {
            m_NetworkObject = networkObject;
            NetworkBehaviourId = behaviourId;
        }

        //  TODO: this needs an overhaul.  It's expensive, it's ja little naive in how it looks for networkObject in
        //  its parent and worst, it creates a puzzle if you are a NetworkBehaviour wanting to see if you're live or not
        //  (e.g. editor code).  All you want to do is find out if NetworkManager is null, but to do that you
        //  need NetworkObject, but if you try and grab NetworkObject and NetworkManager isn't up you'll get
        //  the warning below.  This is why IsBehaviourEditable had to be created.  Matt was going to re-do
        //  how NetworkObject works but it was close to the release and too risky to change
        /// <summary>
        /// Gets the NetworkObject that owns this NetworkBehaviour instance.
        /// </summary>
        public NetworkObject NetworkObject
        {
            get
            {
                if (m_NetworkObject != null)
                {
                    return m_NetworkObject;
                }

                try
                {
                    m_NetworkObject = GetComponentInParent<NetworkObject>();
                }
                catch (Exception)
                {
                    return null;
                }

                // ShutdownInProgress check:
                // This prevents an edge case scenario where the NetworkManager is shutting down but user code
                // in Update and/or in FixedUpdate could still be checking NetworkBehaviour.NetworkObject directly (i.e. does it exist?)
                // or NetworkBehaviour.IsSpawned (i.e. to early exit if not spawned) which, in turn, could generate several Warning messages
                // per spawned NetworkObject.  Checking for ShutdownInProgress prevents these unnecessary LogWarning messages.
                // We must check IsSpawned, otherwise a warning will be logged under certain valid conditions (see OnDestroy)
                if (IsSpawned && m_NetworkObject == null && (m_NetworkManager == null || !m_NetworkManager.ShutdownInProgress))
                {
                    if (NetworkLog.CurrentLogLevel <= LogLevel.Normal)
                    {
                        NetworkLog.LogWarning($"Could not get {nameof(NetworkObject)} for the {nameof(NetworkBehaviour)}. Are you missing a {nameof(NetworkObject)} component?");
                    }
                }

                return m_NetworkObject;
            }
        }

        /// <summary>
        /// Gets whether this NetworkBehaviour instance has a NetworkObject owner.
        /// </summary>
        public bool HasNetworkObject => NetworkObject != null;

        private NetworkObject m_NetworkObject;

        /// <summary>
        /// Gets the NetworkId of the NetworkObject that owns this NetworkBehaviour instance.
        /// </summary>
        public ulong NetworkObjectId { get; internal set; }

        /// <summary>
        /// Gets NetworkId for this NetworkBehaviour from the owner NetworkObject.
        /// </summary>
        public ushort NetworkBehaviourId { get; internal set; }

        /// <summary>
        /// Internally caches the Id of this behaviour in a NetworkObject. Makes look-up faster
        /// </summary>
        internal ushort NetworkBehaviourIdCache = 0;

        /// <summary>
        /// Returns the NetworkBehaviour with a given BehaviourId for the current NetworkObject.
        /// </summary>
        /// <param name="behaviourId">The behaviourId to return</param>
        /// <returns>Returns NetworkBehaviour with given behaviourId</returns>
        protected NetworkBehaviour GetNetworkBehaviour(ushort behaviourId)
        {
            return NetworkObject.GetNetworkBehaviourAtOrderIndex(behaviourId);
        }

        /// <summary>
        /// Gets the ClientId that owns this NetworkObject.
        /// </summary>
        public ulong OwnerClientId { get; internal set; }

        /// <summary>
        /// Updates properties with network session related
        /// dependencies such as a NetworkObject's spawned
        /// state or NetworkManager's session state.
        /// </summary>
        internal void UpdateNetworkProperties()
        {
            var networkObject = m_NetworkObject;
            var networkManager = m_NetworkManager;

            // Set identification related properties
            NetworkObjectId = networkObject.NetworkObjectId;
            IsLocalPlayer = networkObject.IsLocalPlayer;

            // Set ownership related properties
            IsOwnedByServer = networkObject.IsOwnedByServer;
            IsOwner = networkObject.IsOwner;
            OwnerClientId = networkObject.OwnerClientId;

            // Set NetworkManager dependent properties
            if (networkManager != null)
            {
                IsHost = networkManager.IsListening && networkManager.IsHost;
                IsClient = networkManager.IsListening && networkManager.IsClient;
                IsServer = networkManager.IsListening && networkManager.IsServer;
                IsSessionOwner = networkManager.IsListening && networkManager.LocalClient.IsSessionOwner;
                HasAuthority = networkObject.HasAuthority;
                ServerIsHost = networkManager.IsListening && networkManager.ServerIsHost;
            }
        }

        /// <summary>
        /// Only for use in distributed authority mode.
        /// Invoked only on the authority instance when a <see cref="NetworkObject"/> is deferring its despawn on non-authoritative instances.
        /// </summary>
        /// <remarks>
        /// See also: <see cref="NetworkObject.DeferDespawn(int, bool)"/>
        /// </remarks>
        /// <param name="despawnTick">The future network tick that the <see cref="NetworkObject"/> will be despawned on non-authoritative instances</param>
        public virtual void OnDeferringDespawn(int despawnTick) { }

        /// <summary>
        /// Gets called after the <see cref="NetworkObject"/> is spawned. No NetworkBehaviours associated with the NetworkObject will have had <see cref="OnNetworkSpawn"/> invoked yet.
        /// A reference to <see cref="NetworkManager"/> is passed in as a parameter to determine the context of execution (`IsServer` or `IsClient`).
        /// </summary>
        /// <param name="networkManager">a ref to the <see cref="NetworkManager"/> since this is not yet set on the <see cref="NetworkBehaviour"/></param>
        /// <remarks>
        /// The <see cref="NetworkBehaviour"/> will not have anything assigned to it at this point in time.
        /// Settings like ownership, NetworkBehaviourId, NetworkManager, and most other spawn-related properties will not be set.
        /// This can be used to handle things like initializing a NetworkVariable.
        /// </remarks>
        protected virtual void OnNetworkPreSpawn(ref NetworkManager networkManager) { }

        /// <summary>
        /// Gets called when the <see cref="NetworkObject"/> gets spawned, message handlers are ready to be registered, and the network is set up.
        /// </summary>
        public virtual void OnNetworkSpawn() { }

        /// <summary>
        /// Gets called after the <see cref="NetworkObject"/> is spawned. All NetworkBehaviours associated with the NetworkObject will have had <see cref="OnNetworkSpawn"/> invoked.
        /// </summary>
        /// <remarks>
        /// Will be invoked on each <see cref="NetworkBehaviour"/> associated with the <see cref="NetworkObject"/> being spawned.
        /// All associated <see cref="NetworkBehaviour"/> components will have had <see cref="OnNetworkSpawn"/> invoked on the spawned <see cref="NetworkObject"/>.
        /// </remarks>
        protected virtual void OnNetworkPostSpawn() { }

        /// <summary>
        /// Internal implementation of post-spawn functionality. Called after OnNetworkSpawn to handle internal post-spawn operations.
        /// </summary>
        protected internal virtual void InternalOnNetworkPostSpawn() { }

        /// <summary>
        /// This method is only available client-side.
        /// When a new client joins it's synchronized with all spawned NetworkObjects and scenes loaded for the session joined. At the end of the synchronization process, when all
        /// <see cref="NetworkObject"/>s and scenes (if scene management is enabled) have finished synchronizing, all NetworkBehaviour components associated with spawned <see cref="NetworkObject"/>s
        /// will have this method invoked.
        /// </summary>
        /// <remarks>
        /// This can be used to handle post-synchronization actions where you might need to access a different NetworkObject and/or NetworkBehaviour not local to the current NetworkObject context.
        /// This is only invoked on clients during a client-server network topology session.
        /// </remarks>
        protected virtual void OnNetworkSessionSynchronized() { }

        /// <summary>
        /// Internal implementation of network session synchronization. Handles the internal processing of session synchronization events.
        /// </summary>
        protected internal virtual void InternalOnNetworkSessionSynchronized() { }

        /// <summary>
        /// When a scene is loaded and in-scene placed NetworkObjects are finished spawning, this method is invoked on all of the newly spawned in-scene placed NetworkObjects.
        /// This method runs both client and server side.
        /// </summary>
        /// <remarks>
        /// This method can be used to handle post-scene loaded actions for in-scene placed NetworkObjcts where you might need to access a different NetworkObject and/or NetworkBehaviour not local to the current NetworkObject context.
        /// </remarks>
        protected virtual void OnInSceneObjectsSpawned() { }

        /// <summary>
        /// Gets called when the <see cref="NetworkObject"/> gets despawned. This method runs both client and server side.
        /// </summary>
        public virtual void OnNetworkDespawn() { }

        /// <summary>
        /// Gets called before <see cref="OnNetworkDespawn"/> has been invoked for all <see cref="NetworkBehaviour"/>s associated with the currently spawned <see cref="NetworkObject"/> instance.
        /// </summary>
        public virtual void OnNetworkPreDespawn() { }

        internal void NetworkPreSpawn(ref NetworkManager networkManager, NetworkObject networkObject)
        {
            m_NetworkObject = networkObject;
            m_NetworkManager = networkManager;
            RpcTarget = networkManager.RpcTarget;

            UpdateNetworkProperties();

            try
            {
                OnNetworkPreSpawn(ref networkManager);
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }
        }

        internal void InternalOnNetworkSpawn()
        {
            IsSpawned = true;
            // Initialize the NetworkVariables so they are accessible in OnNetworkSpawn;
            InitializeVariables();
            UpdateNetworkProperties();

            try
            {
                OnNetworkSpawn();
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }

            // Initialize again in case the user's OnNetworkSpawn changed something
            InitializeVariables();

            if (m_NetworkObject.HasAuthority)
            {
                // Since we just spawned the object and since user code might have modified their NetworkVariable, esp.
                // NetworkList, we need to mark the object as free of updates.
                // This should happen for all objects on the machine triggering the spawn.
                PostNetworkVariableWrite(true);
            }
        }

        internal void NetworkPostSpawn()
        {
            try
            {
                InternalOnNetworkPostSpawn();
                OnNetworkPostSpawn();
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }
        }

        internal void NetworkSessionSynchronized()
        {
            try
            {
                InternalOnNetworkSessionSynchronized();
                OnNetworkSessionSynchronized();
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }
        }

        internal void InSceneNetworkObjectsSpawned()
        {
            try
            {
                OnInSceneObjectsSpawned();
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }
        }

        internal void InternalOnNetworkPreDespawn()
        {
            try
            {
                OnNetworkPreDespawn();
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }
        }

        internal void InternalOnNetworkDespawn()
        {
            IsSpawned = false;
            UpdateNetworkProperties();
            try
            {
                OnNetworkDespawn();
            }
            catch (Exception e)
            {
                Debug.LogException(e);
            }

            // Deinitialize all NetworkVariables in the event the associated
            // NetworkObject is recylced (in-scene placed or pooled).
            for (int i = 0; i < NetworkVariableFields.Count; i++)
            {
                NetworkVariableFields[i].Deinitialize();
            }
        }

        /// <summary>
        /// In client-server contexts, this method is invoked on both the server and the local client of the owner when <see cref="Netcode.NetworkObject"/> ownership is assigned.
        /// In distributed authority contexts, this method is invoked on all clients connected to the session.
        /// </summary>
        public virtual void OnGainedOwnership() { }

        internal void InternalOnGainedOwnership()
        {
            // New owners need to assure any NetworkVariables they have write permissions
            // to are updated so the previous and original values are aligned with the
            // current value (primarily for collections).
            if (IsOwner)
            {
                UpdateNetworkVariableOnOwnershipChanged();
            }
            OnGainedOwnership();
        }

        /// <summary>
        /// Invoked on all clients. Override this method to be notified of any
        /// ownership changes (even if the instance was neither the previous or
        /// newly assigned current owner).
        /// </summary>
        /// <param name="previous">the previous owner</param>
        /// <param name="current">the current owner</param>
        protected virtual void OnOwnershipChanged(ulong previous, ulong current)
        {

        }

        internal void InternalOnOwnershipChanged(ulong previous, ulong current)
        {
            OnOwnershipChanged(previous, current);
        }

        /// <summary>
        /// In client-server contexts, this method is invoked on the local client when it loses ownership of the associated <see cref="Netcode.NetworkObject"/>
        /// and on the server when any client loses ownership.
        /// In distributed authority contexts, this method is invoked on all clients connected to the session.
        /// </summary>
        public virtual void OnLostOwnership() { }

        /// <summary>
        /// Gets called when the parent NetworkObject of this NetworkBehaviour's NetworkObject has changed.
        /// </summary>
        /// <param name="parentNetworkObject">the new <see cref="NetworkObject"/> parent</param>
        public virtual void OnNetworkObjectParentChanged(NetworkObject parentNetworkObject) { }

        internal virtual void InternalOnNetworkObjectParentChanged(NetworkObject parentNetworkObject) { }

        private bool m_VarInit = false;

        private readonly List<HashSet<int>> m_DeliveryMappedNetworkVariableIndices = new List<HashSet<int>>();
        private readonly List<NetworkDelivery> m_DeliveryTypesForNetworkVariableGroups = new List<NetworkDelivery>();

        // RuntimeAccessModifiersILPP will make this `protected`
        internal readonly List<NetworkVariableBase> NetworkVariableFields = new List<NetworkVariableBase>();

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal virtual void __initializeVariables()
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            // ILPP generates code for all NetworkBehaviour subtypes to initialize each type's network variables.
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        internal virtual void __initializeRpcs()
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            // ILPP generates code for all NetworkBehaviour subtypes to initialize each type's RPCs.
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // This is needed to add the RpcInvokePermission as even with an optional parameter, the change counts as a breaking change.
        internal void __registerRpc(uint hash, RpcReceiveHandler handler, string rpcMethodName) => __registerRpc(hash, handler, rpcMethodName, RpcInvokePermission.Everyone);
        // RuntimeAccessModifiersILPP will make this `protected`
        internal void __registerRpc(uint hash, RpcReceiveHandler handler, string rpcMethodName, RpcInvokePermission permission)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            __rpc_func_table[GetType()][hash] = handler;
            __rpc_permission_table[GetType()][hash] = permission;
#if DEVELOPMENT_BUILD || UNITY_EDITOR || UNITY_MP_TOOLS_NET_STATS_MONITOR_ENABLED_IN_RELEASE
            __rpc_name_table[GetType()][hash] = rpcMethodName;
#endif
        }

#pragma warning disable IDE1006 // disable naming rule violation check
        // RuntimeAccessModifiersILPP will make this `protected`
        // Using this method here because ILPP doesn't seem to let us do visibility modification on properties.
        internal void __nameNetworkVariable(NetworkVariableBase variable, string varName)
#pragma warning restore IDE1006 // restore naming rule violation check
        {
            variable.Name = varName;
        }

        /// <summary>
        /// Does a first pass initialization for RPCs and NetworkVariables
        /// If already initialized, then it just re-initializes the NetworkVariables.
        /// </summary>
        internal void InitializeVariables()
        {
            if (m_VarInit)
            {
                // If the primary initialization has already been done, then go ahead
                // and re-initialize each NetworkVariable in the event it is an in-scene
                // placed NetworkObject in an already loaded scene that has already been
                // used within a network session =or= if this is a pooled NetworkObject
                // that is being repurposed.
                for (int i = 0; i < NetworkVariableFields.Count; i++)
                {
                    // If already initialized, then skip
                    if (NetworkVariableFields[i].HasBeenInitialized)
                    {
                        continue;
                    }
                    NetworkVariableFields[i].Initialize(this);
                }
                // Exit early as we don't need to run through the rest of this initialization
                // process
                return;
            }

            m_VarInit = true;

            if (!__rpc_func_table.ContainsKey(GetType()))
            {
                __rpc_func_table[GetType()] = new Dictionary<uint, RpcReceiveHandler>();
                __rpc_permission_table[GetType()] = new Dictionary<uint, RpcInvokePermission>();
#if UNITY_EDITOR || DEVELOPMENT_BUILD || UNITY_MP_TOOLS_NET_STATS_MONITOR_ENABLED_IN_RELEASE
                __rpc_name_table[GetType()] = new Dictionary<uint, string>();
#endif
                __initializeRpcs();
            }
            __initializeVariables();

            {
                // Create index map for delivery types
                var firstLevelIndex = new Dictionary<NetworkDelivery, int>();
                int secondLevelCounter = 0;

                for (int i = 0; i < NetworkVariableFields.Count; i++)
                {
                    var networkDelivery = MessageDeliveryType<NetworkVariableDeltaMessage>.DefaultDelivery;
                    if (!firstLevelIndex.ContainsKey(networkDelivery))
                    {
                        firstLevelIndex.Add(networkDelivery, secondLevelCounter);
                        m_DeliveryTypesForNetworkVariableGroups.Add(networkDelivery);
                        secondLevelCounter++;
                    }

                    if (firstLevelIndex[networkDelivery] >= m_DeliveryMappedNetworkVariableIndices.Count)
                    {
                        m_DeliveryMappedNetworkVariableIndices.Add(new HashSet<int>());
                    }

                    m_DeliveryMappedNetworkVariableIndices[firstLevelIndex[networkDelivery]].Add(i);
                }
            }
        }

        internal void PreNetworkVariableWrite()
        {
            // reset our "which variables got written" data
            NetworkVariableIndexesToReset.Clear();
            NetworkVariableIndexesToResetSet.Clear();
        }

        internal void PostNetworkVariableWrite(bool forced = false)
        {
            if (forced)
            {
                // Mark every variable as no longer dirty. We just spawned the object and whatever the game code did
                // during OnNetworkSpawn has been sent and needs to be cleared
                for (int i = 0; i < NetworkVariableFields.Count; i++)
                {
                    var networkVariable = NetworkVariableFields[i];
                    if (networkVariable.IsDirty())
                    {
                        if (networkVariable.CanSend())
                        {
                            networkVariable.UpdateLastSentTime();
                            networkVariable.ResetDirty();
                            networkVariable.SetDirty(false);
                        }
                    }
                }
            }
            else
            {
                // mark any variables we wrote as no longer dirty
                for (int i = 0; i < NetworkVariableIndexesToReset.Count; i++)
                {
                    var networkVariable = NetworkVariableFields[NetworkVariableIndexesToReset[i]];
                    if (networkVariable.IsDirty())
                    {
                        if (networkVariable.CanSend())
                        {
                            networkVariable.UpdateLastSentTime();
                            networkVariable.ResetDirty();
                            networkVariable.SetDirty(false);
                        }
                    }
                }
            }

            MarkVariablesDirty(false);
        }

        internal void PreVariableUpdate()
        {
            if (!m_VarInit)
            {
                InitializeVariables();
            }

            PreNetworkVariableWrite();
        }

        internal readonly List<int> NetworkVariableIndexesToReset = new List<int>();
        internal readonly HashSet<int> NetworkVariableIndexesToResetSet = new HashSet<int>();

        /// <summary>
        /// Determines if a NetworkVariable should have any changes to state sent out
        /// </summary>
        /// <param name="targetClientId">target to send the updates to</param>
        /// <param name="forceSend">specific to change in ownership</param>
        internal void NetworkVariableUpdate(ulong targetClientId, bool forceSend = false)
        {
            if (!forceSend && !CouldHaveDirtyNetworkVariables())
            {
                return;
            }

            // Getting these ahead of time actually improves performance
            var networkManager = m_NetworkManager;
            var networkObject = m_NetworkObject;
            var messageManager = networkManager.MessageManager;
            var connectionManager = networkManager.ConnectionManager;

            for (int j = 0; j < m_DeliveryMappedNetworkVariableIndices.Count; j++)
            {
                var networkVariable = (NetworkVariableBase)null;
                var shouldSend = false;
                for (int k = 0; k < NetworkVariableFields.Count; k++)
                {
                    networkVariable = NetworkVariableFields[k];
                    if (networkVariable.IsDirty() && networkVariable.CanClientRead(targetClientId))
                    {
                        if (networkVariable.CanSend())
                        {
                            shouldSend = true;
                            break;
                        }
                    }
                }
                // All of this is just to prevent the DA Host from re-sending a NetworkVariable update it received from the client owner
                // If this NetworkManager is running as a DAHost:
                // - Only when the write permissions is owner (to pass existing integration tests running as DAHost)
                // - If the target client ID is the owner and the owner is not the local NetworkManager instance
                // - **Special** As long as ownership did not just change and we are sending the new owner any dirty/updated NetworkVariables
                // Under these conditions we should not send to the client
                if (shouldSend && networkManager.DAHost && networkVariable.WritePerm == NetworkVariableWritePermission.Owner &&
                    networkObject.OwnerClientId == targetClientId && networkObject.OwnerClientId != networkManager.LocalClientId &&
                    networkObject.PreviousOwnerId == networkObject.OwnerClientId)
                {
                    shouldSend = false;
                }

                if (!shouldSend)
                {
                    continue;
                }
                var message = new NetworkVariableDeltaMessage
                {
                    NetworkObjectId = NetworkObjectId,
                    NetworkBehaviourIndex = NetworkBehaviourId,
                    NetworkBehaviour = this,
                    TargetClientId = targetClientId,
                    DeliveryMappedNetworkVariableIndex = m_DeliveryMappedNetworkVariableIndices[j],
                    // By sending the network delivery we can forward messages immediately as opposed to processing them
                    // at the end. While this will send updates to clients that cannot read, the handler will ignore anything
                    // sent to a client that does not have read permissions.
                    NetworkDelivery = m_DeliveryTypesForNetworkVariableGroups[j]
                };
                // TODO: Serialization is where the IsDirty flag gets changed.
                // Messages don't get sent from the server to itself, so if we're host and sending to ourselves,
                // we still have to actually serialize the message even though we're not sending it, otherwise
                // the dirty flag doesn't change properly. These two pieces should be decoupled at some point
                // so we don't have to do this serialization work if we're not going to use the result.
                if (IsServer && targetClientId == NetworkManager.ServerClientId)
                {
                    var tmpWriter = new FastBufferWriter(messageManager.NonFragmentedMessageMaxSize, Allocator.Temp, messageManager.FragmentedMessageMaxSize);
                    using (tmpWriter)
                    {
                        message.Serialize(tmpWriter, message.Version);
                    }
                }
                else
                {
                    connectionManager.SendMessage(ref message, m_DeliveryTypesForNetworkVariableGroups[j], targetClientId);
                }
            }
        }

        internal static bool LogSentVariableUpdateMessage;

        private bool CouldHaveDirtyNetworkVariables()
        {
            // TODO: There should be a better way by reading one dirty variable vs. 'n'
            for (int i = 0; i < NetworkVariableFields.Count; i++)
            {
                var networkVariable = NetworkVariableFields[i];
                if (networkVariable.IsDirty())
                {
                    if (networkVariable.CanSend())
                    {
                        return true;
                    }
                    // If it's dirty but can't be sent yet, we have to keep monitoring it until one of the
                    // conditions blocking its send changes.
                    m_NetworkManager.BehaviourUpdater.AddForUpdate(m_NetworkObject);
                }
            }

            return false;
        }

        /// <summary>
        /// Invoked on a new client to assure the previous and original values
        /// are synchronized with the current known value.
        /// </summary>
        /// <remarks>
        /// Primarily for collections to assure the previous value(s) is/are the
        /// same as the current value(s) in order to not re-send already known entries.
        /// </remarks>
        internal void UpdateNetworkVariableOnOwnershipChanged()
        {
            for (int j = 0; j < NetworkVariableFields.Count; j++)
            {
                // Only invoke OnInitialize on NetworkVariables the owner can write to
                if (NetworkVariableFields[j].CanClientWrite(OwnerClientId))
                {
                    NetworkVariableFields[j].OnInitialize();
                }
            }
        }

        internal void MarkVariablesDirty(bool dirty)
        {
            for (int j = 0; j < NetworkVariableFields.Count; j++)
            {
                NetworkVariableFields[j].SetDirty(dirty);
            }
        }

        /// <summary>
        /// For owner read permissions, when changing ownership we need to do a full synchronization
        /// of all NetworkVariables that are owner read permission based since the owner is the only
        /// instance that knows what the most current values are.
        /// </summary>
        internal void MarkOwnerReadDirtyAndCheckOwnerWriteIsDirty()
        {
            for (int j = 0; j < NetworkVariableFields.Count; j++)
            {
                if (NetworkVariableFields[j].ReadPerm == NetworkVariableReadPermission.Owner)
                {
                    NetworkVariableFields[j].SetDirty(true);
                }
                if (NetworkVariableFields[j].WritePerm == NetworkVariableWritePermission.Owner)
                {
                    NetworkVariableFields[j].OnCheckIsDirtyState();
                }
            }
        }

        /// <summary>
        /// Synchronizes by setting only the NetworkVariable field values that the client has permission to read.
        /// Note: This is only invoked when first synchronizing a NetworkBehaviour (i.e. late join or spawned NetworkObject)
        /// </summary>
        /// <remarks>
        /// When NetworkConfig.EnsureNetworkVariableLengthSafety is enabled each NetworkVariable field will be preceded
        /// by the number of bytes written for that specific field.
        /// </remarks>
        internal void WriteNetworkVariableData(FastBufferWriter writer, ulong targetClientId)
        {
            // Create any values that require accessing the NetworkManager locally (it is expensive to access it in NetworkBehaviour)
            var networkManager = m_NetworkManager;
            var ensureLengthSafety = networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety;

            foreach (var field in NetworkVariableFields)
            {
                // Client-Server: Try to write values only for clients that have read permissions.
                // Distributed Authority: All clients have read permissions, always try to write the value.
                if (field.CanClientRead(targetClientId))
                {
                    // Write additional NetworkVariable information when length safety is enabled
                    if (ensureLengthSafety)
                    {
                        var writePos = writer.Position;
                        // Note: This value can't be packed because we don't know how large it will be in advance
                        // we reserve space for it, then write the data, then come back and write the final size value
                        writer.WriteValueSafe(0);
                        var startPos = writer.Position;

                        // Write the NetworkVariable field value
                        field.WriteFieldSynchronization(writer);

                        // Write the NetworkVariable field value size
                        var size = writer.Position - startPos;
                        writer.Seek(writePos);
                        writer.WriteValueSafe(size);
                        writer.Seek(startPos + size);
                    }
                    else
                    {
                        // Write the NetworkVariable field value
                        field.WriteFieldSynchronization(writer);
                    }
                }
                else if (ensureLengthSafety)
                {
                    // Client-Server Only: If the client cannot read this field, then skip it but write a 0 for this NetworkVariable's position
                    {
                        writer.WriteValueSafe(0);
                    }
                }
            }
        }

        /// <summary>
        /// Synchronizes by setting only the NetworkVariable field values that the client has permission to read.
        /// Note: This is only invoked when first synchronizing a NetworkBehaviour (i.e. late join or spawned NetworkObject)
        /// </summary>
        /// <remarks>
        /// When NetworkConfig.EnsureNetworkVariableLengthSafety is enabled each NetworkVariable field will be preceded
        /// by the number of bytes written for that specific field.
        /// </remarks>
        internal void SetNetworkVariableData(FastBufferReader reader, ulong clientId)
        {
            // Stack cache any values that requires accessing the NetworkManager (it is expensive to access it in NetworkBehaviour)
            var networkManager = m_NetworkManager;
            var ensureLengthSafety = networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety;

            foreach (var field in NetworkVariableFields)
            {
                int expectedBytesToRead = 0;
                var readStartPos = 0;
                // Client-Server: Clients that only have read permissions will try to read the value
                // Distributed Authority: All clients have read permissions, always try to read the value
                if (field.CanClientRead(clientId))
                {
                    if (ensureLengthSafety)
                    {
                        reader.ReadValueSafe(out expectedBytesToRead);
                        if (expectedBytesToRead == 0)
                        {
                            Debug.LogError($"[{name}][NetworkObjectId: {NetworkObjectId}][NetworkBehaviourId: {NetworkBehaviourId}][{field.Name}] Expected non-zero size readable NetworkVariable! (Skipping)");
                            continue;
                        }
                        readStartPos = reader.Position;
                    }
                }
                else // Client-Server Only: If the client cannot read this field, then skip it
                {
                    // If skipping and length safety, then fill in a 0 size for this one spot
                    if (ensureLengthSafety)
                    {
                        reader.ReadValueSafe(out expectedBytesToRead);
                        if (expectedBytesToRead != 0)
                        {
                            Debug.LogError($"[{name}][NetworkObjectId: {NetworkObjectId}][NetworkBehaviourId: {NetworkBehaviourId}][{field.Name}] Expected zero size for non-readable NetworkVariable when EnsureNetworkVariableLengthSafety is enabled! (Skipping)");
                        }
                    }
                    continue;
                }

                // Read the NetworkVariable value
                field.ReadField(reader);

                // When EnsureNetworkVariableLengthSafety always do a bounds check
                if (ensureLengthSafety)
                {
                    var totalBytesRead = reader.Position - readStartPos;
                    if (totalBytesRead != expectedBytesToRead)
                    {
                        if (networkManager.LogLevel <= LogLevel.Normal)
                        {
                            NetworkLog.LogWarning($"[{name}][NetworkObjectId: {NetworkObjectId}][NetworkBehaviourId: {NetworkBehaviourId}][{field.Name}] NetworkVariable read {totalBytesRead} bytes but was expected to read {expectedBytesToRead} bytes during synchronization deserialization!");
                        }
                        reader.Seek(readStartPos + expectedBytesToRead);
                    }
                }
            }
        }

        /// <summary>
        /// Gets the local instance of a NetworkObject with a given NetworkId.
        /// </summary>
        /// <param name="networkId">The unique network identifier of the NetworkObject to retrieve</param>
        /// <returns>The NetworkObject instance if found, null if no object exists with the specified networkId</returns>
        protected NetworkObject GetNetworkObject(ulong networkId)
        {
            return m_NetworkManager.SpawnManager.SpawnedObjects.GetValueOrDefault(networkId);
        }

        /// <summary>
        /// Override this method if your derived NetworkBehaviour requires custom synchronization data.
        /// Use of this method is only for the initial client synchronization of NetworkBehaviours
        /// and will increase the payload size for client synchronization and dynamically spawned
        /// <see cref="NetworkObject"/>s.
        /// </summary>
        /// <remarks>
        /// When serializing (writing), this method is invoked during the client synchronization period and
        /// when spawning new NetworkObjects.
        /// When deserializing (reading), this method is invoked prior to the NetworkBehaviour's associated
        /// NetworkObject being spawned.
        /// </remarks>
        /// <param name="serializer">The serializer to use to read and write the data.</param>
        /// <typeparam name="T">
        /// Either BufferSerializerReader or BufferSerializerWriter, depending whether the serializer
        /// is in read mode or write mode.
        /// </typeparam>
        protected virtual void OnSynchronize<T>(ref BufferSerializer<T> serializer) where T : IReaderWriter
        {

        }

        /// <summary>
        /// Called when network conditions require reanticipation of game state.
        /// Override this method to handle adjustments needed when network latency changes.
        /// </summary>
        /// <param name="lastRoundTripTime">The most recent round trip time measurement in seconds</param>
        public virtual void OnReanticipate(double lastRoundTripTime)
        {

        }

        /// <summary>
        /// The relative client identifier targeted for the serialization of this <see cref="NetworkBehaviour"/> instance.
        /// </summary>
        /// <remarks>
        /// This value is set prior to <see cref="OnSynchronize{T}(ref BufferSerializer{T})"/> being invoked.
        /// For writing (server-side), this is useful to know which client will receive the serialized data.
        /// For reading (client-side), this will be the <see cref="NetworkManager.LocalClientId"/>.
        /// When synchronization of this instance is complete, this value is reset to 0.
        /// </remarks>
        protected ulong m_TargetIdBeingSynchronized { get; private set; }

        /// <summary>
        /// Internal method that determines if a NetworkBehaviour has additional synchronization data to
        /// be synchronized when first instantiated prior to its associated NetworkObject being spawned.
        /// </summary>
        /// <remarks>
        /// This includes try-catch blocks to recover from exceptions that might occur and continue to
        /// synchronize any remaining NetworkBehaviours.
        /// </remarks>
        /// <returns>true if it wrote synchronization data and false if it did not</returns>
        internal bool Synchronize<T>(ref BufferSerializer<T> serializer, ulong targetClientId = 0) where T : IReaderWriter
        {
            m_TargetIdBeingSynchronized = targetClientId;
            if (serializer.IsWriter)
            {
                // Get the writer to handle seeking and determining how many bytes were written
                var writer = serializer.GetFastBufferWriter();
                // Save our position before we attempt to write anything so we can seek back to it (i.e. error occurs)
                var positionBeforeWrite = writer.Position;
                writer.WriteValueSafe(NetworkBehaviourId);

                // Save our position where we will write the final size being written so we can skip over it in the
                // event an exception occurs when deserializing.
                var sizePosition = writer.Position;
                writer.WriteValueSafe(0);

                // Save our position before synchronizing to determine how much was written
                var positionBeforeSynchronize = writer.Position;
                var threwException = false;
                try
                {
                    OnSynchronize(ref serializer);
                }
                catch (Exception ex)
                {
                    threwException = true;
                    if (m_NetworkManager.LogLevel <= LogLevel.Normal)
                    {
                        NetworkLog.LogWarning($"{name} threw an exception during synchronization serialization, this {nameof(NetworkBehaviour)} is being skipped and will not be synchronized!");
                        if (m_NetworkManager.LogLevel == LogLevel.Developer)
                        {
                            NetworkLog.LogError($"{ex.Message}\n {ex.StackTrace}");
                        }
                    }
                }
                var finalPosition = writer.Position;

                // Reset before exiting
                m_TargetIdBeingSynchronized = default;
                // If we wrote nothing then skip writing anything for this NetworkBehaviour
                if (finalPosition == positionBeforeSynchronize || threwException)
                {
                    writer.Seek(positionBeforeWrite);
                    // Truncate back to the size before
                    writer.Truncate();
                    return false;
                }
                else
                {
                    // Write the number of bytes serialized to handle exceptions on the deserialization side
                    var bytesWritten = finalPosition - positionBeforeSynchronize;
                    writer.Seek(sizePosition);
                    writer.WriteValueSafe(bytesWritten);
                    writer.Seek(finalPosition);
                }
                return true;
            }
            else
            {
                var reader = serializer.GetFastBufferReader();
                // We will always read the expected byte count
                reader.ReadValueSafe(out int expectedBytesToRead);

                // Save our position before we begin synchronization deserialization
                var positionBeforeSynchronize = reader.Position;
                var synchronizationError = false;
                try
                {
                    // Invoke synchronization
                    OnSynchronize(ref serializer);
                }
                catch (Exception ex)
                {
                    if (m_NetworkManager.LogLevel <= LogLevel.Normal)
                    {
                        NetworkLog.LogWarning($"{name} threw an exception during synchronization deserialization, this {nameof(NetworkBehaviour)} is being skipped and will not be synchronized!");
                        if (m_NetworkManager.LogLevel == LogLevel.Developer)
                        {
                            NetworkLog.LogError($"{ex.Message}\n {ex.StackTrace}");
                        }
                    }
                    synchronizationError = true;
                }

                var totalBytesRead = reader.Position - positionBeforeSynchronize;
                if (totalBytesRead != expectedBytesToRead)
                {
                    if (m_NetworkManager.LogLevel <= LogLevel.Normal)
                    {
                        NetworkLog.LogWarning($"{name} read {totalBytesRead} bytes but was expected to read {expectedBytesToRead} bytes during synchronization deserialization! This {nameof(NetworkBehaviour)}({GetType().Name})is being skipped and will not be synchronized!");
                    }
                    synchronizationError = true;
                }

                // Reset before exiting
                m_TargetIdBeingSynchronized = default;

                // Skip over the entry if deserialization fails
                if (synchronizationError)
                {
                    var skipToPosition = positionBeforeSynchronize + expectedBytesToRead;
                    reader.Seek(skipToPosition);
                    return false;
                }
                return true;
            }
        }

        /// <summary>
        /// Use to assure a helper component invokes script during destroy in the
        /// event that a derived class does not invoke base.OnDestroy.
        /// </summary>
        internal virtual void InternalOnDestroy()
        {

        }

        /// <summary>
        /// Invoked when the <see cref="GameObject"/> the <see cref="NetworkBehaviour"/> is attached to is destroyed.
        /// If you override this, you must always invoke the base class version of this <see cref="OnDestroy"/> method.
        /// </summary>
        public virtual void OnDestroy()
        {
            try
            {
                InternalOnDestroy();
            }
            catch (Exception ex)
            {
                Debug.LogException(ex);
            }

            if (m_NetworkObject != null && m_NetworkObject.IsSpawned && IsSpawned)
            {
                // If the associated NetworkObject is still spawned then this
                // NetworkBehaviour will be removed from the NetworkObject's
                // ChildNetworkBehaviours list.
                m_NetworkObject.OnNetworkBehaviourDestroyed(this);
            }

            // this seems odd to do here, but in fact especially in tests we can find ourselves
            //  here without having called InitializedVariables, which causes problems if any
            //  of those variables use native containers (e.g. NetworkList) as they won't be
            //  registered here and therefore won't be cleaned up.
            //
            // we should study to understand the initialization patterns
            if (!m_VarInit)
            {
                InitializeVariables();
            }


            foreach (var networkVar in NetworkVariableFields)
            {
                networkVar.Dispose();
            }
        }
    }
}