Update READMEs

README.md

@@ -2,7 +2,7 @@
 Promul is a simple, lightweight, and easy-to-use relay server and session management implementation for [Unity Netcode for GameObjects](https://docs-multiplayer.unity3d.com/netcode/current/about/). 
 
 Promul uses a heavily-modified version of the [LibNetLib](https://github.com/RevenantX/LiteNetLib) library for its internal networking, converting the library from a thread-based non-async model to a Task-based Asynchronous Programming (TAP)-based implementation.
-Technical details of the networking are explained in [the networking documentation](Common/Networking/README.md).
+Technical details of the networking are explained in engineering section below.
 
 Promul is intended to be a free and open-source alternative to [Unity Relay](https://unity.com/products/relay). It supports join secret-based session management, with a REST API for creating and deleting sessions, and an admin UI for managing active sessions.
 
@@ -25,8 +25,37 @@ Example:
 You should now be ready to use Promul as a relay server for your Unity project. You can call `NetworkManager`'s `StartHost`/`StartClient`/`StartServer` methods as normal.
 
 ## Engineering
-### Protocol
-Promul uses its own wire protocol over LibNetLib. The protocol is shown in the following diagram:
+### Transit layer
+Promul's included networking solution is a very heavily modified version of the amazing [LibNetLib](https://github.com/RevenantX/LiteNetLib) by Ruslan Pyrch.
+
+Promul is *probably* compatible with LibNetLib clients and servers. I don't know, and I don't check.  
+Compatibility with LibNetLib is not a goal of Promul.
+
+#### Differences from LibNetLib
+Among other differences:
+- The library requires .NET Standard 2.1.
+    - This limits the Unity versions that can use the library, but also
+      allows the library to use newer constructs such as `ArraySegment<T>`.
+- The `NetDataReader` and `NetDataWriter` classes have been removed in favour of `BinaryReader` and `BinaryWriter` from `System.IO`.
+    - This means support for `INetSerializable` has been removed. Clients are expected to create extension overloads for `BinaryWriter.Write` and `BinaryReader.Read{Type}`.
+- The logic and receive threads have been removed, in favour of a long-running `Task` spawned by the `NetManager`.
+- Most of the library's blocking methods have been replaced with Task-based Asynchronous Programming (TAP) methods, using `Task`. This requires
+  a significant rewrite of most parts of the library.
+- NAT punch-through and manual mode have both been removed.
+    - The transport will now put transport events onto a queue,
+      and `NetworkTransport#PollEvents` will dequeue events and pass them to Unity Netcode.
+- `NetManager#Start` has been replaced by `PromulManager#ListenAsync`, which will begin infinitely looping, waiting for incoming messages.
+    - This method will block, so in the Unity transport, it is spawned on an un-awaited `Task`.
+    - Servers are expected to use a paradigm such as `BackgroundService` to run the long-running `Task`.
+- Documentation has been improved.
+- `NetPacket` no longer has jurisdiction over its data. It is a wrapper around an `ArraySegment<byte>`.
+- Most (if not all) usages of `byte[] data, int offset, int count` have been replaced with `ArraySegment<byte>`.
+- `INetBasedListener` and related classes have been removed. All events
+  are invoked on the `PromulManager` class as
+  regular CLR `event` types.
+- In many classes, extraneous overloads have been removed in favour of default parameters.
+### Protocol layer
+Promul's Unity relay uses its own wire protocol over the transit layer. The protocol is shown in the following diagram:
 ```mermaid
 sequenceDiagram
     autonumber
@@ -59,6 +88,24 @@ sequenceDiagram
     Host (ID 0)--xRelay: Connection lost
     Relay->>Relay API: Destroys session
 ```
+
+## Roadmap
+### Engineering &mdash; Transit/Protocol
+- [x] Task-based asynchronous programming rewrite
+- [x] Authentication and binding tests
+- [x] MTU negotation tests
+- [ ] Replace logging with a better solution
+- [ ] Restore merged sending support
+- [ ] Restore NAT punch-through(?)
+- [ ] Improve memory and throughput performance
+- [ ] More real-world replications in tests
+- [ ] More uses of `ValueTask<T>` over regular tasks
+### Relay Server
+- [x] Basic create/join session by join code
+  - [x] Update session manager
+- [x] Basic web interface
+  - [ ] Further development of web interface
+- [ ] Multicast(?)
 ## Copyright
 &copy; 2023 Firework Eyes Studio (NZBN 9429048922678) under the MIT License.