improve session config allocation footprint

src/service.rs

@@ -1,5 +1,6 @@
 //! A middleware that provides [`Session`] as a request extension.
 use std::{
+ borrow::Cow,
  future::Future,
  pin::Pin,
  sync::Arc,
@@ -19,59 +20,59 @@
 };
 
 #[derive(Debug, Clone)]
-struct SessionConfig {
- name: String,
+struct SessionConfig<'a> {
+ name: Cow<'a, str>,
  http_only: bool,
  same_site: SameSite,
  expiry: Option<Expiry>,
  secure: bool,
- path: String,
- domain: Option<String>,
+ path: Cow<'a, str>,
+ domain: Option<Cow<'a, str>>,
 }
 
-impl SessionConfig {
- fn build_cookie<'c>(&self, session_id: session::Id, expiry_age: Duration) -> Cookie<'c> {
- let mut cookie_builder = Cookie::build((self.name.clone(), session_id.to_string()))
+impl<'a> SessionConfig<'a> {
+ fn build_cookie(self, session_id: session::Id, expiry_age: Duration) -> Cookie<'a> {
+ let mut cookie_builder = Cookie::build((self.name, session_id.to_string()))
  .http_only(self.http_only)
  .same_site(self.same_site)
  .secure(self.secure)
- .path(self.path.clone());
+ .path(self.path);
 
  if !matches!(self.expiry, Some(Expiry::OnSessionEnd) | None) {
  cookie_builder = cookie_builder.max_age(expiry_age);
  }
 
- if let Some(domain) = &self.domain {
- cookie_builder = cookie_builder.domain(domain.clone());
+ if let Some(domain) = self.domain {
+ cookie_builder = cookie_builder.domain(domain);
  }
 
  cookie_builder.build()
  }
 }
 
-impl Default for SessionConfig {
+impl<'a> Default for SessionConfig<'a> {
  fn default() -> Self {
  Self {
- name: String::from("id"), /* See: https://cheatsheetseries.owasp.org/cheatsheets/Session_Management_Cheat_Sheet.html#session-id-name-fingerprinting */
+ name: "id".into(), /* See: https://cheatsheetseries.owasp.org/cheatsheets/Session_Management_Cheat_Sheet.html#session-id-name-fingerprinting */
  http_only: true,
  same_site: SameSite::Strict,
  expiry: None, // TODO: Is `Max-Age: "Session"` the right default?
  secure: true,
- path: String::from("/"),
+ path: "/".into(),
  domain: None,
  }
  }
 }
 
 /// A middleware that provides [`Session`] as a request extension.
 #[derive(Debug, Clone)]
-pub struct SessionManager<S, Store: SessionStore> {
+pub struct SessionManager<'a, S, Store: SessionStore> {
  inner: S,
  session_store: Arc<Store>,
- session_config: SessionConfig,
+ session_config: SessionConfig<'a>,
 }
 
-impl<S, Store: SessionStore> SessionManager<S, Store> {
+impl<'a, S, Store: SessionStore> SessionManager<'a, S, Store> {
  /// Create a new [`SessionManager`].
  pub fn new(inner: S, session_store: Store) -> Self {
  Self {
@@ -83,7 +84,7 @@
 }
 
 impl<ReqBody, ResBody, S, Store: SessionStore> Service<Request<ReqBody>>
- for SessionManager<S, Store>
+ for SessionManager<'static, S, Store>
 where
  S: Service<Request<ReqBody>, Response = Response<ResBody>> + Clone + Send + 'static,
  S::Future: Send,
@@ -202,7 +203,7 @@
 #[derive(Debug, Clone)]
 pub struct SessionManagerLayer<Store: SessionStore> {
  session_store: Arc<Store>,
- session_config: SessionConfig,
+ session_config: SessionConfig<'static>,
 }
 
 impl<Store: SessionStore> SessionManagerLayer<Store> {
@@ -217,8 +218,8 @@
  /// let session_store = MemoryStore::default();
  /// let session_service = SessionManagerLayer::new(session_store).with_name("my.sid");
  /// ```
- pub fn with_name(mut self, name: &str) -> Self {
- self.session_config.name = name.to_string();
+ pub fn with_name<N: Into<Cow<'static, str>>>(mut self, name: N) -> Self {
+ self.session_config.name = name.into();
  self
  }
 
@@ -304,11 +305,10 @@
  /// use tower_sessions::{MemoryStore, SessionManagerLayer};
  ///
  /// let session_store = MemoryStore::default();
- /// let session_service =
- /// SessionManagerLayer::new(session_store).with_path("/some/path".to_string());
+ /// let session_service = SessionManagerLayer::new(session_store).with_path("/some/path");
  /// ```
- pub fn with_path(mut self, path: String) -> Self {
- self.session_config.path = path;
+ pub fn with_path<P: Into<Cow<'static, str>>>(mut self, path: P) -> Self {
+ self.session_config.path = path.into();
  self
  }
 
@@ -321,11 +321,10 @@
  /// use tower_sessions::{MemoryStore, SessionManagerLayer};
  ///
  /// let session_store = MemoryStore::default();
- /// let session_service =
- /// SessionManagerLayer::new(session_store).with_domain("localhost".to_string());
+ /// let session_service = SessionManagerLayer::new(session_store).with_domain("localhost");
  /// ```
- pub fn with_domain(mut self, domain: String) -> Self {
- self.session_config.domain = Some(domain);
+ pub fn with_domain<D: Into<Cow<'static, str>>>(mut self, domain: D) -> Self {
+ self.session_config.domain = Some(domain.into());
  self
  }
 }
@@ -353,7 +352,7 @@
 }
 
 impl<S, Store: SessionStore> Layer<S> for SessionManagerLayer<Store> {
- type Service = CookieManager<SessionManager<S, Store>>;
+ type Service = CookieManager<SessionManager<'static, S, Store>>;
 
  fn layer(&self, inner: S) -> Self::Service {
  let session_manager = SessionManager {