# MsgTrans for rust

## Server sample code

Using MsgTrans to create multiple protocol server.

```rust
let mut server = MessageTransportServer::new();

// Add TCP channel
server.add_channel(TcpServerChannel::new("0.0.0.0", 9001)).await;

// Add WebSocket channel
server.add_channel(WebSocketServerChannel::new("0.0.0.0", 9002, "/ws")).await;

// Add QUIC channel
server.add_channel(QuicServerChannel::new(
    "0.0.0.0",
    9003,
    "certs/cert.pem",
    "certs/key.pem",
)).await;

// set some callback handler for server

server.start().await;
```

## Run example for server

```bash
cargo run --example server
```

## Run example for client

```bash
# for tcp
cargo run --example client_tcp
# for websocket
cargo run --example client_websocket
# for quic
cargo run --example client_quic
```

## Generate cert and key for test

```bash
openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365000 -nodes -subj "/CN=localhost"
```

## Packet Structure

```text
+--------------------------------+
|         Packet Header          |
|  +--------------------------+  |
|  |  Message ID (4 bytes)    |  |
|  +--------------------------+  |
|  |  Message Length (4 bytes)|  |
|  +--------------------------+  |
|  | Compression Type (1 byte)|  |
|  +--------------------------+  |
|  |  Extend Length (4 bytes) |  |
|  +--------------------------+  |
|  |  Reserved (3 bytes)      |  |
|  +--------------------------+  |
+--------------------------------+
              |
              v
+--------------------------------+
|    Extended Header Content     |
|  (variable length, Extend      |
|   Length specifies size)       |
+--------------------------------+
              |
              v
+--------------------------------+
|        Payload Content         |
|    (variable length, Message   |
|     Length specifies size)     |
+--------------------------------+
```

Structure Explanation:

 1. Header Content: Contains fixed-length header information, including Message ID, Message Length, Compression Type, and Extend Length.
 2. Extended Header Content: Variable-length extended header content, with its size specified by the Extend Length field.
 3. Payload Content: Variable-length payload content, with its size specified by the Message Length field.