req debug log

Signed-off-by: Ping Yu <yuping@pingcap.com>

src/request/mod.rs

@@ -42,7 +42,7 @@ mod shard;
 #[async_trait]
 pub trait KvRequest: Request + Sized + Clone + Sync + Send + 'static {
     /// The expected response to the request.
-    type Response: HasKeyErrors + HasLocks + Clone + Send + 'static;
+    type Response: HasKeyErrors + HasLocks + Clone + Send + std::fmt::Debug + 'static;
 
     // TODO: fn encode_request()
     // TODO: fn decode_response()
@@ -114,7 +114,7 @@ mod test {
 
     #[tokio::test]
     async fn test_region_retry() {
-        #[derive(Clone)]
+        #[derive(Clone, Debug)]
         struct MockRpcResponse;
 
         impl HasKeyErrors for MockRpcResponse {

src/request/plan.rs

@@ -62,6 +62,9 @@ impl<Req: KvRequest> Plan for Dispatch<Req> {
 
     async fn execute(&self) -> Result<Self::Result> {
         let stats = tikv_stats(self.request.label());
+        if self.request.label() == "kv_prewrite" || self.request.label() == "kv_commit" {
+            info!("req {}", self.request.to_str())
+        }
         let result = self
             .kv_client
             .as_ref()
@@ -70,8 +73,13 @@ impl<Req: KvRequest> Plan for Dispatch<Req> {
             .await;
         let result = stats.done(result);
         result.map(|r| {
-            *r.downcast()
+            let resp = *r
-                .expect("Downcast failed: request and response type mismatch")
+                .downcast()
+                .expect("Downcast failed: request and response type mismatch");
+            if self.request.label() == "kv_prewrite" || self.request.label() == "kv_commit" {
+                info!("resp {:?}", resp);
+            }
+            resp
         })
     }
 }

src/store/request.rs

@@ -25,6 +25,9 @@ pub trait Request: Any + Sync + Send + 'static {
     /// Should always use `set_context` other than modify the `self.context` directly.
     fn set_context(&mut self, context: kvrpcpb::Context);
     fn set_api_version(&mut self, api_version: kvrpcpb::ApiVersion);
+    fn to_str(&self) -> String {
+        "".to_string()
+    }
 }
 
 macro_rules! impl_request {
@@ -68,6 +71,10 @@ macro_rules! impl_request {
                 let context = self.context.get_or_insert(kvrpcpb::Context::default());
                 context.api_version = api_version.into();
             }
+
+            fn to_str(&self) -> String {
+                format!("{:?}", self)
+            }
         }
     };
 }