fix: make max-txn-ops limit valid (#3481)

src/common/meta/src/kv_backend/chroot.rs

@@ -45,6 +45,10 @@ impl TxnService for ChrootKvBackend {
         let txn_res = self.inner.txn(txn).await?;
         Ok(self.chroot_txn_response(txn_res))
     }
+
+    fn max_txn_ops(&self) -> usize {
+        self.inner.max_txn_ops()
+    }
 }
 
 #[async_trait::async_trait]

src/common/meta/src/kv_backend/memory.rs

@@ -323,6 +323,10 @@ impl<T: ErrorExt + Send + Sync> TxnService for MemoryKvBackend<T> {
             responses,
         })
     }
+
+    fn max_txn_ops(&self) -> usize {
+        usize::MAX
+    }
 }
 
 impl<T: ErrorExt + Send + Sync + 'static> ResettableKvBackend for MemoryKvBackend<T> {

src/common/meta/src/kv_backend/txn.rs

@@ -30,7 +30,7 @@ pub trait TxnService: Sync + Send {
 
     /// Maximum number of operations permitted in a transaction.
     fn max_txn_ops(&self) -> usize {
-        usize::MAX
+        unimplemented!("txn is not implemented")
     }
 }
 

src/log-store/src/raft_engine/backend.rs

@@ -152,6 +152,10 @@ impl TxnService for RaftEngineBackend {
             responses,
         })
     }
+
+    fn max_txn_ops(&self) -> usize {
+        usize::MAX
+    }
 }
 
 #[async_trait::async_trait]

src/meta-srv/src/service/store/cached_kv.rs

@@ -380,6 +380,10 @@ impl TxnService for LeaderCachedKvBackend {
 
         Ok(res)
     }
+
+    fn max_txn_ops(&self) -> usize {
+        self.store.max_txn_ops()
+    }
 }
 
 impl ResettableKvBackend for LeaderCachedKvBackend {