[router] move radix tree to policy crate and addreses some code styles (#13131)

sgl-router/src/lib.rs

@@ -19,7 +19,6 @@ pub mod server;
 pub mod service_discovery;
 pub mod tokenizer;
 pub mod tool_parser;
-pub mod tree;
 use crate::metrics::PrometheusConfig;
 
 #[pyclass(eq)]

sgl-router/src/policies/bucket.rs

@@ -672,7 +672,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(34)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(10)).await;
+        tokio::time::sleep(Duration::from_secs(11)).await;
         {
             let model_key = "default";
 
@@ -844,7 +844,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(26)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(3)).await;
+        tokio::time::sleep(Duration::from_secs(4)).await;
         // Verify boundaries adjusted to: [0, 20], [21, 26], [27, MAX]
         {
             let model_key = "default";
@@ -889,7 +889,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(57)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(3)).await;
+        tokio::time::sleep(Duration::from_secs(4)).await;
         // Verify boundaries adjusted to: [0, 40], [41, 57], [58, MAX]
         {
             let model_key = "default";
@@ -974,7 +974,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(20)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(3)).await;
+        tokio::time::sleep(Duration::from_secs(4)).await;
         {
             let model_key = "default";
 
@@ -1001,7 +1001,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(7)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(3)).await;
+        tokio::time::sleep(Duration::from_secs(4)).await;
         {
             let model_key = "default";
 
@@ -1099,7 +1099,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(26)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(3)).await;
+        tokio::time::sleep(Duration::from_secs(4)).await;
         {
             let model_key = "default";
 
@@ -1141,7 +1141,7 @@ mod tests {
             .select_worker(&prefill_workers, Some(&*"a".repeat(55)))
             .unwrap();
 
-        tokio::time::sleep(Duration::from_secs(3)).await;
+        tokio::time::sleep(Duration::from_secs(4)).await;
         {
             let model_key = "default";
 

sgl-router/src/policies/cache_aware.rs

@@ -65,8 +65,8 @@ use dashmap::DashMap;
 use rand::Rng;
 use tracing::debug;
 
-use super::{get_healthy_worker_indices, CacheAwareConfig, LoadBalancingPolicy};
-use crate::{core::Worker, metrics::RouterMetrics, tree::Tree};
+use super::{get_healthy_worker_indices, tree::Tree, CacheAwareConfig, LoadBalancingPolicy};
+use crate::{core::Worker, metrics::RouterMetrics};
 
 /// Cache-aware routing policy
 ///
@@ -346,30 +346,6 @@ impl LoadBalancingPolicy for CacheAwarePolicy {
         }
     }
 
-    fn name(&self) -> &'static str {
-        "cache_aware"
-    }
-
-    fn needs_request_text(&self) -> bool {
-        true // Cache-aware policy needs request text for cache affinity
-    }
-
-    fn on_request_complete(&self, worker_url: &str, success: bool) {
-        // Could track success rates per worker for more intelligent routing
-        if !success {
-            // Optionally reduce affinity for failed requests
-            tracing::debug!(
-                "Request to {} completed with success={}",
-                worker_url,
-                success
-            );
-        }
-    }
-
-    fn as_any(&self) -> &dyn std::any::Any {
-        self
-    }
-
     fn select_worker_pair(
         &self,
         prefill_workers: &[Arc<dyn Worker>],
@@ -400,6 +376,30 @@ impl LoadBalancingPolicy for CacheAwarePolicy {
 
         Some((prefill_idx, decode_idx))
     }
+
+    fn on_request_complete(&self, worker_url: &str, success: bool) {
+        // Could track success rates per worker for more intelligent routing
+        if !success {
+            // Optionally reduce affinity for failed requests
+            tracing::debug!(
+                "Request to {} completed with success={}",
+                worker_url,
+                success
+            );
+        }
+    }
+
+    fn name(&self) -> &'static str {
+        "cache_aware"
+    }
+
+    fn needs_request_text(&self) -> bool {
+        true // Cache-aware policy needs request text for cache affinity
+    }
+
+    fn as_any(&self) -> &dyn std::any::Any {
+        self
+    }
 }
 
 impl Default for CacheAwarePolicy {

sgl-router/src/policies/mod.rs

@@ -14,6 +14,7 @@ mod power_of_two;
 mod random;
 mod registry;
 mod round_robin;
+mod tree;
 
 pub use bucket::BucketPolicy;
 pub use cache_aware::CacheAwarePolicy;

sgl-router/src/policies/tree.rs

@@ -321,7 +321,7 @@ impl Tree {
         (ret_text, tenant)
     }
 
-    #[allow(unused_assignments)]
+    #[allow(unused_assignments, dead_code)]
     pub fn prefix_match_tenant(&self, text: &str, tenant: &str) -> String {
         let mut curr = Arc::clone(&self.root);
         let mut curr_idx = 0;
@@ -529,6 +529,7 @@ impl Tree {
         self.tenant_char_count.remove(&tenant.to_string());
     }
 
+    #[allow(dead_code)]
     pub fn get_tenant_char_count(&self) -> HashMap<String, usize> {
         self.tenant_char_count
             .iter()
@@ -560,6 +561,7 @@ impl Tree {
         min_tenant.unwrap_or_else(|| "empty".to_string())
     }
 
+    #[allow(dead_code)]
     pub fn get_used_size_per_tenant(&self) -> HashMap<String, usize> {
         // perform a DFS to traverse all nodes and calculate the total size used by each tenant
 
@@ -584,6 +586,7 @@ impl Tree {
         used_size_per_tenant
     }
 
+    #[allow(dead_code)]
     fn node_to_string(node: &NodeRef, prefix: &str, is_last: bool) -> String {
         let mut result = String::new();
 
@@ -641,6 +644,7 @@ impl Tree {
         result
     }
 
+    #[allow(dead_code)]
     pub fn pretty_print(&self) {
         if self.root.children.is_empty() {
             return;