fix: Fix Rust clippy warnings

rust/Cargo.toml

@@ -5,9 +5,9 @@
 # The ASF licenses this file to You under the Apache License, Version 2.0
 # (the "License"); you may not use this file except in compliance with
 # the License.  You may obtain a copy of the License at
-# 
+#
 #     http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -23,6 +23,7 @@ edition = "2021"
 tokio = { version = "1", features = ["full"] }
 tokio-rustls = {version = "0.24.0", features = ["default", "dangerous_configuration"] }
 async-trait = "0.1.68"
+lazy_static = "1.4"
 tonic = {version = "0.9.0", features = ["tls", "default", "channel", "tls-roots"]}
 prost = "0.11.8"
 prost-types = "0.11.8"
@@ -50,4 +51,4 @@ tonic-build = "0.9.0"
 
 [dev-dependencies]
 wiremock-grpc = "0.0.3-alpha2"
-futures = "0.3"
+futures = "0.3"

rust/src/client.rs

@@ -28,8 +28,7 @@ use crate::pb::{
 };
 use crate::session::{RPCClient, Session, SessionManager};
 
-pub trait Foo {}
-
+#[derive(Debug)]
 pub(crate) struct Client {
     logger: Logger,
     option: ClientOption,
@@ -39,7 +38,9 @@ pub(crate) struct Client {
     endpoints: Endpoints,
 }
 
-static CLIENT_ID_SEQUENCE: AtomicUsize = AtomicUsize::new(0);
+lazy_static::lazy_static! {
+    static ref CLIENT_ID_SEQUENCE: AtomicUsize = AtomicUsize::new(0);
+}
 
 impl Client {
     const OPERATION_CLIENT_NEW: &'static str = "client.new";
@@ -50,7 +51,7 @@ impl Client {
         let id = Self::generate_client_id();
         let endpoints = Endpoints::from_access_url(option.access_url().to_string())
             .map_err(|e| e.with_operation(Self::OPERATION_CLIENT_NEW))?;
-        let session_manager = SessionManager::new(&logger, id.clone(), &option);
+        let session_manager = SessionManager::new(logger, id.clone(), &option);
         Ok(Client {
             logger: logger.new(o!("component" => "client")),
             option,
@@ -250,12 +251,23 @@ impl Client {
 
 #[cfg(test)]
 mod tests {
+    use std::sync::atomic::Ordering;
+
     use crate::client::Client;
     use crate::conf::ClientOption;
     use crate::log::terminal_logger;
     use crate::pb::{Code, MessageQueue, QueryRouteResponse, Resource, Status};
     use crate::session;
 
+    use super::CLIENT_ID_SEQUENCE;
+
+    #[test]
+    fn test_client_id_sequence() {
+        let v1 = CLIENT_ID_SEQUENCE.fetch_add(1, Ordering::Relaxed);
+        let v2 = CLIENT_ID_SEQUENCE.fetch_add(1, Ordering::Relaxed);
+        assert!(v2 > v1, "Client ID sequence should be increasing");
+    }
+
     #[tokio::test]
     async fn client_query_route() {
         let logger = terminal_logger();

rust/src/lib.rs

@@ -23,8 +23,13 @@ mod log;
 
 mod client;
 mod model;
+
+#[allow(clippy::all)]
 #[path = "pb/apache.rocketmq.v2.rs"]
 mod pb;
 mod session;
 
-mod producer;
+pub(crate) mod producer;
+
+// Export structs that are part of crate API.
+pub use producer::Producer;

rust/src/model.rs

@@ -34,6 +34,7 @@ pub(crate) enum RouteStatus {
     Found(Arc<Route>),
 }
 
+#[derive(Debug)]
 pub(crate) struct Endpoints {
     access_url: String,
     scheme: AddressScheme,

rust/src/producer.rs

@@ -14,15 +14,24 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-use slog::{info, Logger};
+
+//! Publish messages of various types to brokers.
+//!
+//! `Producer` is a thin wrapper of internal `Client` struct that shoulders the actual workloads.
+//! Most of its methods take shared reference so that application developers may use it at will.
 
 use crate::client::Client;
 use crate::conf::{ClientOption, ProducerOption};
 use crate::error::ClientError;
 use crate::log;
 use crate::pb::{Message, SendResultEntry};
+use slog::{info, Logger};
 
-struct Producer {
+/// `Producer` is the core struct, to which application developers should turn, when publishing messages to brokers.
+///
+/// `Producer` is `Send` and `Sync` by design, so that developers may get started easily.
+#[derive(Debug)]
+pub struct Producer {
     option: ProducerOption,
     logger: Logger,
     client: Client,

rust/src/session.rs

@@ -64,7 +64,7 @@ impl Session {
         client_id: String,
         option: &ClientOption,
     ) -> Result<Self, ClientError> {
-        let peer = endpoints.access_url().clone();
+        let peer = endpoints.access_url().to_owned();
         debug!(logger, "creating session, peer={}", peer);
 
         let mut channel_endpoints = Vec::new();
@@ -78,7 +78,7 @@ impl Session {
                 "No endpoint available.".to_string(),
                 Self::OPERATION_CREATE,
             )
-            .with_context("peer", peer));
+            .with_context("peer", peer.clone()));
         }
 
         let channel = if channel_endpoints.len() == 1 {
@@ -89,7 +89,7 @@ impl Session {
                     Self::OPERATION_CREATE,
                 )
                 .set_source(e)
-                .with_context("peer", peer)
+                .with_context("peer", peer.clone())
             })?
         } else {
             Channel::balance_list(channel_endpoints.into_iter())
@@ -104,7 +104,7 @@ impl Session {
         );
 
         Ok(Session {
-            logger: logger.new(o!("component" => "session", "peer" => peer.to_owned())),
+            logger: logger.new(o!("component" => "session", "peer" => peer.clone())),
             client_id,
             stub,
         })