[router] minor code clean up and and refactoring (#8711)

sgl-router/src/routers/pd_router.rs

@@ -35,7 +35,7 @@ pub struct PDRouter {
     pub interval_secs: u64,
     pub worker_loads: Arc<tokio::sync::watch::Receiver<HashMap<String, isize>>>,
     pub load_monitor_handle: Option<Arc<tokio::task::JoinHandle<()>>>,
-    pub http_client: reqwest::Client,
+    pub http_client: Client,
     _prefill_health_checker: Option<HealthChecker>,
     _decode_health_checker: Option<HealthChecker>,
 }
@@ -206,51 +206,17 @@ impl PDRouter {
         }
 
         // Initialize cache-aware components if needed for prefill policy
-        let prefill_tree = if prefill_policy.name() == "cache_aware" {
-            // Initialize the policy's internal tree with prefill workers
-            if let Some(cache_policy) = prefill_policy
-                .as_any()
-                .downcast_ref::<crate::policies::CacheAwarePolicy>()
-            {
-                cache_policy.init_workers(&prefill_workers);
-            }
-
-            let tree = Arc::new(Mutex::new(Tree::new()));
-            // Initialize tree with prefill workers
-            for worker in &prefill_workers {
-                tree.lock().unwrap().insert("", worker.url());
-            }
-            Some(tree)
-        } else {
-            None
-        };
+        let prefill_tree = Self::initialize_radix_tree(&prefill_policy, &prefill_workers)?;
 
         // Initialize cache-aware components if needed for decode policy
-        let decode_tree = if decode_policy.name() == "cache_aware" {
-            // Initialize the policy's internal tree with decode workers
-            if let Some(cache_policy) = decode_policy
-                .as_any()
-                .downcast_ref::<crate::policies::CacheAwarePolicy>()
-            {
-                cache_policy.init_workers(&decode_workers);
-            }
-
-            let tree = Arc::new(Mutex::new(Tree::new()));
-            // Initialize tree with decode workers
-            for worker in &decode_workers {
-                tree.lock().unwrap().insert("", worker.url());
-            }
-            Some(tree)
-        } else {
-            None
-        };
+        let decode_tree = Self::initialize_radix_tree(&decode_policy, &decode_workers)?;
 
         // Set up background load monitoring for power-of-two selection
         let (tx, rx) = tokio::sync::watch::channel(HashMap::new());
         let worker_loads = Arc::new(rx);
 
         // Create a shared HTTP client for all operations
-        let http_client = reqwest::Client::builder()
+        let http_client = Client::builder()
             .timeout(Duration::from_secs(timeout_secs))
             .build()
             .map_err(|e| format!("Failed to create HTTP client: {}", e))?;
@@ -304,6 +270,35 @@ impl PDRouter {
         })
     }
 
+    // Helper function to initialize radix tree for cache-aware policies
+    fn initialize_radix_tree(
+        policy: &Arc<dyn LoadBalancingPolicy>,
+        workers: &[Box<dyn Worker>],
+    ) -> Result<Option<Arc<Mutex<Tree>>>, String> {
+        if let Some(cache_policy) = policy
+            .as_any()
+            .downcast_ref::<crate::policies::CacheAwarePolicy>()
+        {
+            // Initialize the policy's internal tree with workers
+            cache_policy.init_workers(workers);
+
+            let tree = Arc::new(Mutex::new(Tree::new()));
+
+            {
+                let tree_guard = tree
+                    .lock()
+                    .map_err(|e| format!("Failed to lock tree: {}", e))?;
+                for worker in workers {
+                    tree_guard.insert("", worker.url());
+                }
+            }
+
+            Ok(Some(tree))
+        } else {
+            Ok(None)
+        }
+    }
+
     // Route a typed generate request
     pub async fn route_generate(
         &self,
@@ -329,7 +324,7 @@ impl PDRouter {
         });
 
         // Select servers
-        let (prefill, decode) = match self.select_pd_pair(client, request_text).await {
+        let (prefill, decode) = match self.select_pd_pair(request_text).await {
             Ok(pair) => pair,
             Err(e) => {
                 error!("Failed to select PD pair error={}", e);
@@ -417,7 +412,7 @@ impl PDRouter {
             .and_then(|content| content.as_str());
 
         // Select servers
-        let (prefill, decode) = match self.select_pd_pair(client, request_text).await {
+        let (prefill, decode) = match self.select_pd_pair(request_text).await {
             Ok(pair) => pair,
             Err(e) => {
                 error!("Failed to select PD pair error={}", e);
@@ -498,7 +493,7 @@ impl PDRouter {
         };
 
         // Select servers
-        let (prefill, decode) = match self.select_pd_pair(client, request_text).await {
+        let (prefill, decode) = match self.select_pd_pair(request_text).await {
             Ok(pair) => pair,
             Err(e) => {
                 error!("Failed to select PD pair error={}", e);
@@ -833,7 +828,6 @@ impl PDRouter {
     // Select a pair of prefill and decode servers
     async fn select_pd_pair(
         &self,
-        _client: &Client,
         request_text: Option<&str>,
     ) -> Result<(Box<dyn Worker>, Box<dyn Worker>), String> {
         // Get read locks for both worker lists
@@ -998,7 +992,7 @@ impl PDRouter {
         // Note: This endpoint actually causes the model to generate tokens, so we only test one pair
 
         // Select a random worker pair using the policy
-        let (prefill, decode) = match self.select_pd_pair(client, None).await {
+        let (prefill, decode) = match self.select_pd_pair(None).await {
             Ok(pair) => pair,
             Err(e) => {
                 return (
@@ -1921,8 +1915,7 @@ mod tests {
         router.prefill_workers.write().unwrap().push(healthy_worker);
         router.decode_workers.write().unwrap().push(decode_worker);
 
-        let client = reqwest::Client::new();
-        let result = router.select_pd_pair(&client, None).await;
+        let result = router.select_pd_pair(None).await;
 
         assert!(result.is_ok());
         let (prefill, _decode) = result.unwrap();
@@ -1936,8 +1929,7 @@ mod tests {
     async fn test_empty_worker_lists() {
         let router = create_test_pd_router();
 
-        let client = reqwest::Client::new();
-        let result = router.select_pd_pair(&client, None).await;
+        let result = router.select_pd_pair(None).await;
 
         assert!(result.is_err());
         assert!(result.unwrap_err().contains("No prefill workers available"));