/// <summary>
/// Sends a message, but notify when it is delivered or lost
/// </summary>
/// <typeparam name="T">type of message to send</typeparam>
/// <param name="message">message to send</param>
/// <param name="token">a arbitrary object that the sender will receive with their notification</param>
public void SendNotify <T>(T message, object token, int channelId = Channel.Unreliable)
{
if (sendWindow.Count == WINDOW_SIZE)
{
NotifyLost?.Invoke(this, token);
return;
}
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
var notifyPacket = new NotifyPacket
{
Sequence = (ushort)sequencer.Next(),
ReceiveSequence = receiveSequence,
AckMask = receiveMask
};
sendWindow.Enqueue(new PacketEnvelope
{
Sequence = notifyPacket.Sequence,
Token = token
});
MessagePacker.Pack(notifyPacket, writer);
MessagePacker.Pack(message, writer);
NetworkDiagnostics.OnSend(message, channelId, writer.Length, 1);
Send(writer.ToArraySegment(), channelId);
lastNotifySentTime = Time.unscaledTime;
}
}
/// <summary>
/// Send a message to all connected clients.
/// </summary>
/// <typeparam name="T">Message type</typeparam>
/// <param name="msg">Message</param>
/// <param name="channelId">Transport channel to use</param>
public void SendToAll <T>(T msg, int channelId = Channel.Reliable)
{
if (logger.LogEnabled())
{
logger.Log("Server.SendToAll id:" + typeof(T));
}
using (var writer = NetworkWriterPool.GetWriter())
{
// pack message into byte[] once
MessagePacker.Pack(msg, writer);
var segment = writer.ToArraySegment();
var count = 0;
// using SendToMany (with IEnumerable) will cause Enumerator to be boxed and create GC/alloc
// instead we can use while loop and MoveNext to avoid boxing
var enumerator = _connections.Values.GetEnumerator();
while (enumerator.MoveNext())
{
var player = enumerator.Current;
player.Send(segment, channelId);
count++;
}
enumerator.Dispose();
NetworkDiagnostics.OnSend(msg, segment.Count, count);
}
}
private static NetworkMessageDelegate MessageHandler <T>(Action <INetworkPlayer, T> handler)
{
void AdapterFunction(INetworkPlayer player, NetworkReader reader, int channelId)
{
// protect against DOS attacks if attackers try to send invalid
// data packets to crash the server/client. there are a thousand
// ways to cause an exception in data handling:
// - invalid headers
// - invalid message ids
// - invalid data causing exceptions
// - negative ReadBytesAndSize prefixes
// - invalid utf8 strings
// - etc.
//
// let's catch them all and then disconnect that connection to avoid
// further attacks.
var message = default(T);
try
{
message = reader.Read <T>();
}
finally
{
NetworkDiagnostics.OnReceive(message, channelId, reader.Length);
}
handler(player, message);
}
return(AdapterFunction);
}
/// <summary>
/// This sends a network message to the connection.
/// </summary>
/// <typeparam name="T">The message type</typeparam>
/// <param name="msg">The message to send.</param>
/// <param name="channelId">The transport layer channel to send on.</param>
/// <returns></returns>
public void Send <T>(T message, int channelId = Channel.Reliable)
{
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
// pack message and send allocation free
MessagePacker.Pack(message, writer);
NetworkDiagnostics.OnSend(message, channelId, writer.Length, 1);
Send(writer.ToArraySegment(), channelId);
}
}
/// <summary>
/// This sends a network message to the connection. You can await it to check for errors
/// </summary>
/// <typeparam name="T">The message type</typeparam>
/// <param name="msg">The message to send.</param>
/// <param name="channelId">The transport layer channel to send on.</param>
/// <returns></returns>
public virtual UniTask SendAsync <T>(T msg, int channelId = Channel.Reliable)
{
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
// pack message and send allocation free
MessagePacker.Pack(msg, writer);
NetworkDiagnostics.OnSend(msg, channelId, writer.Length, 1);
return(SendAsync(writer.ToArraySegment(), channelId));
}
}
private static NetworkMessageDelegate MessageWrapper <T>(MessageDelegateWithPlayer <T> handler)
{
void AdapterFunction(INetworkPlayer player, NetworkReader reader)
{
T message = NetworkDiagnostics.ReadWithDiagnostics <T>(reader);
handler.Invoke(player, message);
}
return(AdapterFunction);
}
/// <summary>
/// This sends a network message to the connection.
/// </summary>
/// <typeparam name="T">The message type</typeparam>
/// <param name="msg">The message to send.</param>
/// <param name="channelId">The transport layer channel to send on.</param>
/// <returns></returns>
public void Send <T>(T message, INotifyCallBack token)
{
if (isDisconnected)
{
return;
}
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
MessagePacker.Pack(message, writer);
var segment = writer.ToArraySegment();
NetworkDiagnostics.OnSend(message, segment.Count, 1);
connection.SendNotify(segment, token);
}
}
/// <summary>
/// This sends a network message to the connection.
/// </summary>
/// <typeparam name="T">The message type</typeparam>
/// <param name="msg">The message to send.</param>
/// <param name="channelId">The transport layer channel to send on.</param>
/// <returns></returns>
public void Send <T>(T message, int channelId = Channel.Reliable)
{
if (isDisconnected)
{
return;
}
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
MessagePacker.Pack(message, writer);
var segment = writer.ToArraySegment();
NetworkDiagnostics.OnSend(message, segment.Count, 1);
Send(segment, channelId);
}
}
/// <summary>
/// Sends a message to many connections
/// <para>
/// Same as <see cref="SendToMany{T}(IEnumerable{INetworkPlayer}, T, int)"/> but uses for loop to avoid allocations
/// </para>
/// </summary>
/// <remarks>
/// Using list in foreach loop causes Unity's mono version to box the struct which causes allocations, <see href="https://docs.unity3d.com/2019.4/Documentation/Manual/BestPracticeUnderstandingPerformanceInUnity4-1.html">Understanding the managed heap</see>
/// </remarks>
public static void SendToMany <T>(IReadOnlyList <INetworkPlayer> players, T msg, int channelId = Channel.Reliable)
{
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
// pack message into byte[] once
MessagePacker.Pack(msg, writer);
var segment = writer.ToArraySegment();
int count = players.Count;
for (int i = 0; i < count; i++)
{
players[i].Send(segment, channelId);
}
NetworkDiagnostics.OnSend(msg, segment.Count, count);
}
}
/// <summary>
/// Sends a message to many connections
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="players"></param>
/// <param name="msg"></param>
/// <param name="channelId"></param>
public static void SendToMany <T>(IEnumerable <INetworkPlayer> players, T msg, int channelId = Channel.Reliable)
{
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
// pack message into byte[] once
MessagePacker.Pack(msg, writer);
var segment = writer.ToArraySegment();
int count = 0;
foreach (INetworkPlayer player in players)
{
player.Send(segment, channelId);
count++;
}
NetworkDiagnostics.OnSend(msg, segment.Count, count);
}
}
public static void Send <T>(IEnumerable <INetworkConnection> connections, T msg, int channelId = Channel.Reliable)
{
using (PooledNetworkWriter writer = NetworkWriterPool.GetWriter())
{
// pack message into byte[] once
MessagePacker.Pack(msg, writer);
var segment = writer.ToArraySegment();
int count = 0;
foreach (INetworkConnection conn in connections)
{
// send to all connections, but don't wait for them
conn.Send(segment, channelId);
count++;
}
NetworkDiagnostics.OnSend(msg, channelId, segment.Count, count);
}
}
/// <summary>
/// Calls <see cref="Reader{T}.Read"/> and measures number of bytes read
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="reader"></param>
/// <returns></returns>
internal static T ReadWithDiagnostics <T>(NetworkReader reader)
{
var message = default(T);
// record start position for NetworkDiagnostics because reader might contain multiple messages if using batching
int startPos = reader.BitPosition;
try
{
message = reader.Read <T>();
}
finally
{
int endPos = reader.BitPosition;
int byteLength = (endPos - startPos) / 8;
NetworkDiagnostics.OnReceive(message, byteLength);
}
return(message);
}