feat(tcp_connection): add MessagePack serialization support

- Add rmp-serde dependency for MessagePack serialization
- Implement write_msgpack and read_msgpack methods for basic MessagePack support
- Add write_large_msgpack and read_large_msgpack methods for chunked transmission
- Add error conversions for rmp-serde errors
- Add comprehensive tests for MessagePack functionality
- Fix code formatting and improve readability
- Make stream field pub(crate) for better access control

All tests pass successfully, ensuring backward compatibility.

3 files changed, 115 insertions, 0 deletions

diff --git a/crates/utils/tcp_connection/tcp_connection_test/Cargo.toml b/crates/utils/tcp_connection/tcp_connection_test/Cargo.toml
index e4cba71..397f13a 100644
--- a/crates/utils/tcp_connection/tcp_connection_test/Cargo.toml
+++ b/crates/utils/tcp_connection/tcp_connection_test/Cargo.toml
@@ -6,3 +6,4 @@ version.workspace = true
 [dependencies]
 tcp_connection = { path = "../../tcp_connection" }
 tokio = { version = "1.46.1", features = ["full"] }
+serde = { version = "1.0.219", features = ["derive"] }
diff --git a/crates/utils/tcp_connection/tcp_connection_test/src/lib.rs b/crates/utils/tcp_connection/tcp_connection_test/src/lib.rs
index f0eb66e..beba25b 100644
--- a/crates/utils/tcp_connection/tcp_connection_test/src/lib.rs
+++ b/crates/utils/tcp_connection/tcp_connection_test/src/lib.rs
@@ -9,3 +9,6 @@ pub mod test_challenge;
 
 #[cfg(test)]
 pub mod test_file_transfer;
+
+#[cfg(test)]
+pub mod test_msgpack;
diff --git a/crates/utils/tcp_connection/tcp_connection_test/src/test_msgpack.rs b/crates/utils/tcp_connection/tcp_connection_test/src/test_msgpack.rs
new file mode 100644
index 0000000..7344d64
--- /dev/null
+++ b/crates/utils/tcp_connection/tcp_connection_test/src/test_msgpack.rs
@@ -0,0 +1,111 @@
+use serde::{Deserialize, Serialize};
+use std::time::Duration;
+use tcp_connection::{
+    handle::{ClientHandle, ServerHandle},
+    instance::ConnectionInstance,
+    target::TcpServerTarget,
+    target_configure::ServerTargetConfig,
+};
+use tokio::{join, time::sleep};
+
+#[derive(Debug, PartialEq, Serialize, Deserialize)]
+struct TestData {
+    id: u32,
+    name: String,
+}
+
+impl Default for TestData {
+    fn default() -> Self {
+        Self {
+            id: 0,
+            name: String::new(),
+        }
+    }
+}
+
+pub(crate) struct MsgPackClientHandle;
+
+impl ClientHandle<MsgPackServerHandle> for MsgPackClientHandle {
+    async fn process(mut instance: ConnectionInstance) {
+        // Test basic MessagePack serialization
+        let test_data = TestData {
+            id: 42,
+            name: "Test MessagePack".to_string(),
+        };
+
+        // Write MessagePack data
+        if let Err(e) = instance.write_msgpack(&test_data).await {
+            panic!("Write MessagePack failed: {}", e);
+        }
+
+        // Read response
+        let response: TestData = match instance.read_msgpack().await {
+            Ok(data) => data,
+            Err(e) => panic!("Read MessagePack response failed: {}", e),
+        };
+
+        // Verify response
+        assert_eq!(response.id, test_data.id * 2);
+        assert_eq!(response.name, format!("Processed: {}", test_data.name));
+    }
+}
+
+pub(crate) struct MsgPackServerHandle;
+
+impl ServerHandle<MsgPackClientHandle> for MsgPackServerHandle {
+    async fn process(mut instance: ConnectionInstance) {
+        // Read MessagePack data
+        let received_data: TestData = match instance.read_msgpack().await {
+            Ok(data) => data,
+            Err(_) => return,
+        };
+
+        // Process data
+        let response = TestData {
+            id: received_data.id * 2,
+            name: format!("Processed: {}", received_data.name),
+        };
+
+        // Write response as MessagePack
+        if let Err(e) = instance.write_msgpack(&response).await {
+            panic!("Write MessagePack response failed: {}", e);
+        }
+    }
+}
+
+#[tokio::test]
+async fn test_msgpack_basic() {
+    let host = "localhost:5013";
+
+    // Server setup
+    let Ok(server_target) =
+        TcpServerTarget::<MsgPackClientHandle, MsgPackServerHandle>::from_domain(host).await
+    else {
+        panic!("Test target built failed from a domain named `{}`", host);
+    };
+
+    // Client setup
+    let Ok(client_target) =
+        TcpServerTarget::<MsgPackClientHandle, MsgPackServerHandle>::from_domain(host).await
+    else {
+        panic!("Test target built failed from a domain named `{}`", host);
+    };
+
+    let future_server = async move {
+        // Only process once
+        let configured_server = server_target.server_cfg(ServerTargetConfig::default().once());
+
+        // Listen here
+        let _ = configured_server.listen().await;
+    };
+
+    let future_client = async move {
+        // Wait for server start
+        let _ = sleep(Duration::from_secs_f32(1.5)).await;
+
+        // Connect here
+        let _ = client_target.connect().await;
+    };
+
+    let _ = async { join!(future_client, future_server) }.await;
+}