fix unnecessary cookie creation when updating the session data

Author: fa-sharp

src/options.rs

@@ -8,7 +8,7 @@ pub struct RocketFlexSessionOptions {
     /// The session cookie's `HttpOnly` attribute (default: `true`)
     pub http_only: bool,
     /// The session cookie's `Max-Age` attribute, in seconds. This also determines
-    /// the session storage TTL, unless you specify a different `ttl` setting. (default: 14 days)
+    /// the session storage TTL, unless you specify a different `ttl` setting. (default: 2 weeks)
     pub max_age: u32,
     /// The session cookie's `Path` attribute (default: `"/"`)
     pub path: String,

src/session.rs

@@ -223,9 +223,11 @@ where
             return;
         };
 
-        // Generate new cookie
-        self.cookie_jar
-            .add_private(create_session_cookie(id, self.options));
+        // Generate new session cookie if needed
+        if inner.is_new() {
+            let session_cookie = create_session_cookie(id, self.options);
+            self.cookie_jar.add_private(session_cookie);
+        }
 
         // Notify any cookie-based storage
         let save_result = self.storage.save_cookie(

src/session_inner.rs

@@ -12,6 +12,8 @@ struct ActiveSession<T> {
     pending_data: Option<T>,
     /// Time-to-live in seconds
     ttl: u32,
+    /// Whether this is a new session that hasn't been stored yet
+    new: bool,
 }
 impl<T: Clone> ActiveSession<T> {
     /// Create a new active session with a generated ID, to be saved in storage
@@ -21,6 +23,7 @@ impl<T: Clone> ActiveSession<T> {
             data: new_data.clone(),
             pending_data: Some(new_data),
             ttl,
+            new: true,
         }
     }
     /// Active session that already exists in storage
@@ -30,6 +33,7 @@ impl<T: Clone> ActiveSession<T> {
             data,
             pending_data: None,
             ttl,
+            new: false,
         }
     }
 }
@@ -79,6 +83,10 @@ where
         self.current.as_ref().map(|s| s.ttl)
     }
 
+    pub(crate) fn is_new(&self) -> bool {
+        self.current.as_ref().map(|s| s.new).unwrap_or(false)
+    }
+
     pub(crate) fn set_data(&mut self, new_data: T, default_ttl: u32) {
         match &mut self.current {
             Some(current) => current.pending_data = Some(new_data),