feat: add packet_size configuration for LOGIN7 message

src/client/config.rs

@@ -32,6 +32,7 @@ pub struct Config {
     pub(crate) trust: TrustConfig,
     pub(crate) auth: AuthMethod,
     pub(crate) readonly: bool,
+    pub(crate) packet_size: Option<u32>,
 }
 
 #[derive(Clone, Debug)]
@@ -65,6 +66,7 @@ impl Default for Config {
             trust: TrustConfig::Default,
             auth: AuthMethod::None,
             readonly: false,
+            packet_size: None,
         }
     }
 }
@@ -115,6 +117,22 @@ impl Config {
         self.application_name = Some(name.to_string());
     }
 
+    /// Sets the TDS packet size for the connection.
+    ///
+    /// Larger packet sizes can improve bulk insert performance by reducing
+    /// the number of network round-trips. Valid values are 512 to 32767.
+    /// The server may negotiate a different size.
+    ///
+    /// - Defaults to 4096 bytes.
+    pub fn packet_size(&mut self, size: u32) {
+        self.packet_size = Some(size);
+    }
+
+    /// Gets the configured packet size, if set.
+    pub fn get_packet_size(&self) -> Option<u32> {
+        self.packet_size
+    }
+
     /// Set the preferred encryption level.
     ///
     /// - With `tls` feature, defaults to `Required`.

src/client/connection.rs

@@ -106,6 +106,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin + Send> Connection<S> {
                 config.host,
                 config.application_name,
                 config.readonly,
+                config.packet_size,
                 prelogin,
             )
             .await?;
@@ -293,6 +294,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin + Send> Connection<S> {
         server_name: Option<String>,
         application_name: Option<String>,
         readonly: bool,
+        packet_size: Option<u32>,
         prelogin: PreloginMessage,
     ) -> crate::Result<Self> {
         let mut login_message = LoginMessage::new();
@@ -311,6 +313,10 @@ impl<S: AsyncRead + AsyncWrite + Unpin + Send> Connection<S> {
 
         login_message.readonly(readonly);
 
+        if let Some(size) = packet_size {
+            login_message.packet_size(size);
+        }
+
         match auth {
             #[cfg(all(windows, feature = "winauth"))]
             AuthMethod::Integrated => {

src/tds/codec/login.rs

@@ -240,6 +240,14 @@ impl<'a> LoginMessage<'a> {
             self.type_flags.remove(LoginTypeFlag::ReadOnlyIntent);
         }
     }
+
+    /// Sets the requested TDS packet size.
+    ///
+    /// Valid values are 512 to 32767. The server may negotiate a different size.
+    /// Larger packet sizes can improve bulk insert performance.
+    pub fn packet_size(&mut self, size: u32) {
+        self.packet_size = size;
+    }
 }
 
 impl<'a> Encode<BytesMut> for LoginMessage<'a> {