little change

src/brpc/couchbase_channel.cpp

@@ -375,49 +375,39 @@ void CouchbaseChannel::CallMethod(const google::protobuf::MethodDescriptor* meth
     const CouchbaseRequest* req = reinterpret_cast<const CouchbaseRequest*>(request);
     Controller* cntl = static_cast<Controller*>(controller);
     Channel* channel = nullptr;
-    do {
+    ClosureGuard done_guard(done);
     std::string key;
     policy::MemcacheBinaryCommand command;
     // Do not support Flush/Version
     if (req->ParseRequest(&key, &command) != 0) {
         cntl->SetFailed("failed to parse key and command from request");
-            break;
+        return;
     }
     {
         butil::DoublyBufferedData<VBucketServerMap>::ScopedPtr vb_map;
         if(_vbucket_map.Read(&vb_map) != 0) {
             cntl->SetFailed(ENOMEM, "failed to read vbucket map");
-                break;
+            return;
         }
         if (vb_map->_version == 0) {
             cntl->SetFailed(ENODATA, "vbucket map is not initialize");
-                break;
+            return;
         } 
         const size_t vb_index = Hash(key, vb_map->_vbucket.size());
         channel = SelectMasterChannel(vb_map.get(), vb_index);
         if (channel == nullptr) {
             cntl->SetFailed(ENODATA,"failed to get mapped channel");
-                break;
+            return;
         }
         CouchbaseRequest new_req;
         if (!req->BuildNewWithVBucketId(&new_req, vb_index)) {
             cntl->SetFailed("failed to add vbucket id");
-                break;
+            return;
         }
+        done_guard.release();
         channel->CallMethod(nullptr, cntl, &new_req, response, done);
     }
-
-        while(FLAGS_retry_during_rebalance) {
-            // TODO: retry in case of rebalance/failover
-            break;
-        }
     return;
-    } while (false);
-    if (cntl->FailedInline()) {
-        if (done) {
-            done->Run();
-        }
-    }
 }
 
 Channel* CouchbaseChannel::SelectMasterChannel(