refactor: remove unnecessary Arc in SessionAllocator (#38)

### Description
Previously the `SessionAllocator` was designed to have an `Arc<dyn
StringStore>`, which caused a [Clippy issue regarding internal of Arc
not being Send or
Sync](https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync).
For the use case of `SessionAllocator`, it doesn't need to have an
internal `Arc` to the `StringStore`, a simple reference seems to be
enough.

linkup-cli/src/local_server.rs

@@ -22,8 +22,6 @@ async fn linkup_config_handler(
     string_store: web::Data<MemoryStringStore>,
     req_body: web::Bytes,
 ) -> impl Responder {
-    let sessions = SessionAllocator::new(string_store.into_inner());
-
     let input_json_conf = match String::from_utf8(req_body.to_vec()) {
         Ok(input_json_conf) => input_json_conf,
         Err(_) => {
@@ -35,6 +33,7 @@ async fn linkup_config_handler(
 
     match update_session_req_from_json(input_json_conf) {
         Ok((desired_name, server_conf)) => {
+            let sessions = SessionAllocator::new(string_store.as_ref());
             let session_name = sessions
                 .store_session(server_conf, NameKind::Animal, desired_name)
                 .await;
@@ -59,7 +58,7 @@ async fn linkup_ws_request_handler(
     req: HttpRequest,
     req_stream: web::Payload,
 ) -> impl Responder {
-    let sessions = SessionAllocator::new(string_store.into_inner());
+    let sessions = SessionAllocator::new(string_store.as_ref());
 
     let url = format!("http://localhost:{}{}", LINKUP_LOCALSERVER_PORT, req.uri());
     let mut headers = LinkupHeaderMap::from_actix_request(&req);
@@ -161,7 +160,7 @@ async fn linkup_request_handler(
     req: HttpRequest,
     req_body: web::Bytes,
 ) -> impl Responder {
-    let sessions = SessionAllocator::new(string_store.into_inner());
+    let sessions = SessionAllocator::new(string_store.as_ref());
 
     let url = format!("http://localhost:{}{}", LINKUP_LOCALSERVER_PORT, req.uri());
     let mut headers = LinkupHeaderMap::from_actix_request(&req);

linkup/src/lib.rs

@@ -271,8 +271,6 @@ fn extrace_tracestate(tracestate: &str, linkup_key: String) -> String {
 
 #[cfg(test)]
 mod tests {
-    use std::sync::Arc;
-
     use super::*;
 
     const CONF_STR: &str = r#"
@@ -325,7 +323,8 @@ mod tests {
 
     #[tokio::test]
     async fn test_get_request_session_by_subdomain() {
-        let sessions = SessionAllocator::new(Arc::new(MemoryStringStore::new()));
+        let string_store = MemoryStringStore::new();
+        let sessions = SessionAllocator::new(&string_store);
 
         let config_value: serde_json::Value = serde_json::from_str(CONF_STR).unwrap();
         let config: Session = config_value.try_into().unwrap();
@@ -455,7 +454,8 @@ mod tests {
 
     #[tokio::test]
     async fn test_get_target_url() {
-        let sessions = SessionAllocator::new(Arc::new(MemoryStringStore::new()));
+        let string_store = MemoryStringStore::new();
+        let sessions = SessionAllocator::new(&string_store);
 
         let input_config_value: serde_json::Value = serde_json::from_str(CONF_STR).unwrap();
         let input_config: Session = input_config_value.try_into().unwrap();
@@ -544,7 +544,8 @@ mod tests {
 
     #[tokio::test]
     async fn test_repeatable_rewritten_routes() {
-        let sessions = SessionAllocator::new(Arc::new(MemoryStringStore::new()));
+        let string_store = MemoryStringStore::new();
+        let sessions = SessionAllocator::new(&string_store);
 
         let input_config_value: serde_json::Value = serde_json::from_str(CONF_STR).unwrap();
         let input_config: Session = input_config_value.try_into().unwrap();

linkup/src/session_allocator.rs

@@ -1,17 +1,15 @@
-use std::sync::Arc;
-
 use crate::{
     extract_tracestate_session, first_subdomain, headers::HeaderName, random_animal,
     random_six_char, session_to_json, ConfigError, HeaderMap, NameKind, Session, SessionError,
     StringStore,
 };
 
-pub struct SessionAllocator {
-    store: Arc<dyn StringStore>,
+pub struct SessionAllocator<'a> {
+    store: &'a dyn StringStore,
 }
 
-impl SessionAllocator {
-    pub fn new(store: Arc<dyn StringStore>) -> Self {
+impl<'a> SessionAllocator<'a> {
+    pub fn new(store: &'a dyn StringStore) -> Self {
         Self { store }
     }
 

worker/src/lib.rs

@@ -1,13 +1,7 @@
-// TODO(augustoccesar)[2023-10-16]: We need to revisit the session allocator and how we are using Arc.
-//   It seems that `CfWorkerStringStore` is not really Send or Sync, which is making so that clippy warn about this.
-//   For more info check: https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync
-#![allow(clippy::arc_with_non_send_sync)]
-
 use http_util::*;
 use kv_store::CfWorkerStringStore;
 use linkup::{HeaderMap as LinkupHeaderMap, *};
 use regex::Regex;
-use std::sync::Arc;
 use worker::*;
 use ws::linkup_ws_handler;
 
@@ -16,7 +10,10 @@ mod kv_store;
 mod utils;
 mod ws;
 
-async fn linkup_session_handler(mut req: Request, sessions: SessionAllocator) -> Result<Response> {
+async fn linkup_session_handler<'a>(
+    mut req: Request,
+    sessions: &'a SessionAllocator<'a>,
+) -> Result<Response> {
     let body_bytes = match req.bytes().await {
         Ok(bytes) => bytes,
         Err(_) => return plaintext_error("Bad or missing request body", 400),
@@ -84,7 +81,10 @@ async fn set_cached_req(
     Ok(resp)
 }
 
-async fn linkup_request_handler(mut req: Request, sessions: SessionAllocator) -> Result<Response> {
+async fn linkup_request_handler<'a>(
+    mut req: Request,
+    sessions: &'a SessionAllocator<'a>,
+) -> Result<Response> {
     let url = match req.url() {
         Ok(url) => url.to_string(),
         Err(_) => return plaintext_error("Bad or missing request url", 400),
@@ -154,17 +154,17 @@ pub async fn main(req: Request, env: Env, _ctx: worker::Context) -> Result<Respo
 
     let string_store = CfWorkerStringStore::new(kv);
 
-    let sessions = SessionAllocator::new(Arc::new(string_store));
+    let sessions = SessionAllocator::new(&string_store);
 
     if let Ok(Some(upgrade)) = req.headers().get("upgrade") {
         if upgrade == "websocket" {
-            return linkup_ws_handler(req, sessions).await;
+            return linkup_ws_handler(req, &sessions).await;
         }
     }
 
     if req.method() == Method::Post && req.path() == "/linkup" {
-        return linkup_session_handler(req, sessions).await;
+        return linkup_session_handler(req, &sessions).await;
     }
 
-    linkup_request_handler(req, sessions).await
+    linkup_request_handler(req, &sessions).await
 }

worker/src/ws.rs

@@ -8,7 +8,10 @@ use futures::{
 
 use crate::http_util::plaintext_error;
 
-pub async fn linkup_ws_handler(req: Request, sessions: SessionAllocator) -> Result<Response> {
+pub async fn linkup_ws_handler<'a>(
+    req: Request,
+    sessions: &'a SessionAllocator<'a>,
+) -> Result<Response> {
     let url = match req.url() {
         Ok(url) => url.to_string(),
         Err(_) => return plaintext_error("Bad or missing request url", 400),