ENet

Implementation of the ENet Protocol in C#

Raison D'être

Looking for a C# ENet implementation yielded many projects but those where either incomplete or abandoned. The requirements are managed code, no dll wrapper and compatible to the original C source.

About

This project is inspired by the C implementation of (https://github.com/lsalzman/enet). The reason being is to achieve feature compability and increase testability, as it allows to reason about the flow while comparing it with the original.
However this might be suboptimal in terms of performance, the second step would be to optimize the code to take advantage of C# features and increase readability where possible.

Status

• enet_host_create (server = new ENetHost(address, x, x, x, x))
• enet_host_service (server.Service(event, timeout))
• enet_host_create (client = new ENetHost(null, x, x, x, x))
• enet_host_connect (peer = client.Connect(address, 2, 0); )
• enet_host_service (client.Service(event, timeout))
• enet_peer_send (peer.Send(channel, packet)
• enet_host_broadcast
• enet_peer_reset (peer.Reset()) (50%; enet_peer_on_disconnect function need to be called from peer)
• ENET_PROTOCOL_COMMAND_ACKNOWLEDGE
• ENET_PROTOCOL_COMMAND_CONNECT
• ENET_PROTOCOL_COMMAND_VERIFY_CONNECT
• ENET_PROTOCOL_COMMAND_DISCONNECT
• ENET_PROTOCOL_COMMAND_PING
• ENET_PROTOCOL_COMMAND_SEND_RELIABLE
• ENET_PROTOCOL_COMMAND_SEND_UNRELIABLE
• ENET_PROTOCOL_COMMAND_SEND_FRAGMENT
• ENET_PROTOCOL_COMMAND_SEND_UNSEQUENCED
• ENET_PROTOCOL_COMMAND_BANDWIDTH_LIMIT
• ENET_PROTOCOL_COMMAND_THROTTLE_CONFIGURE
• ENET_PROTOCOL_COMMAND_SEND_UNRELIABLE_FRAGMENT
• move enet_peer-functions from ENetHost.cs -> ENetPeer.cs
• move enet_protocol-functions from ENetHost.cs -> ? or keep them ?
• shorten + rename Flags names, ex.: ENetProtocolCommand.ENET_PROTOCOL_COMMAND_SEND_RELIABLE -> ENetProtocolCommand.SendReliable
• shorten + rename functions, ex.: ENetHost::enet_host_bandwidth_throttle -> ENetHost::BandwidthThrottle
• shorten + rename constants, ex.: ENetHost::ENET_HOST_DEFAULT_MAXIMUM_PACKET_SIZE -> ENetHost::DefaultMaximumPacketSize
• surround _logger.Debug with #if DEBUG / #endif
• reduce usage of new-keyword / use a pool where acceptable (due to translation from c++ to C# some behaviour might be suboptimal)
• reduce coping of byte[] where possible, utilize Span<T> (due to translation from c++ to C# some behaviour might be suboptimal)
• inspect existing object pools / ensure proper use / remove unnecessary copy (due to translation from c++ to C# some behaviour might be suboptimal)
• add xml method documentation to all methods
• arrange functions / code in similar way / order as C source
• implementation of the default compressor
• implementation of the default checksum calculator
• create unit tests
• provide usage examples

Version

The major and minor fields are used to denote the ENet version. The patch field is used for updates of this project. ex.: 1.314.0 -> ENet Version 1.3.14

Example

Server

ENetHost eNetHost = new ENetHost(new IPEndPoint(IPAddress.Loopback, 10000), 32, 2, 0, 0);
ENetEvent eNetEvent = new ENetEvent();
while (true)
{
    int result = eNetHost.Service(eNetEvent, 1000);
    Console.WriteLine($"Result: {result}");
    switch (eNetEvent.Type)
    {
        case ENetEventType.ENET_EVENT_TYPE_CONNECT:
            Console.WriteLine($"A new client connected from: {eNetEvent.Peer.Address.Address}:{eNetEvent.Peer.Address.Port}");
            break;
        case ENetEventType.ENET_EVENT_TYPE_RECEIVE:
            Console.WriteLine($"A packet of length {eNetEvent.Packet.DataLength} was received from {eNetEvent.Peer.Address.Address}:{eNetEvent.Peer.Address.Port} on channel {eNetEvent.ChannelId}");
            break;
        case ENetEventType.ENET_EVENT_TYPE_DISCONNECT:
            Console.WriteLine($"Client {eNetEvent.Peer.Address.Address}:{eNetEvent.Peer.Address.Port} disconnected");
            break;
    }
}

Contributors

• @sebastian-heinz

3rd Parties and Libraries

• .NET Standard (https://github.com/dotnet/standard)