address comments

Signed-off-by: tabokie <xy.tao@outlook.com>

components/engine_rocks/src/misc.rs

@@ -42,8 +42,7 @@ impl RocksEngine {
                 .as_ref()
                 .map_or(false, |key| key.as_slice() > r.start_key)
             {
-                self.delete_all_in_range_cf_by_key(wopts, cf, &r)?;
-                written = true;
+                written |= self.delete_all_in_range_cf_by_key(wopts, cf, &r)?;
                 continue;
             }
             last_end_key = Some(r.end_key.to_owned());

components/raftstore-v2/src/operation/command/write/mod.rs

@@ -310,8 +310,6 @@ impl<EK: KvEngine, R: ApplyResReporter> Apply<EK, R> {
         if index != u64::MAX && written {
             self.modifications_mut()[off] = index;
         }
-        // delete range is an unsafe operation and it cannot be rollbacked to replay, so
-        // we don't update modification index for this operation.
 
         Ok(())
     }

tests/integrations/raftstore/test_single.rs

@@ -92,7 +92,7 @@ fn test_delete() {
 }
 
 #[test_case(test_raftstore::new_node_cluster)]
-// v2 doesn't support.
+// v2 doesn't support RocksDB delete range.
 fn test_node_use_delete_range() {
     let mut cluster = new_cluster(0, 1);
     cluster.cfg.raft_store.use_delete_range = true;