finish 2.1 and tests

Signed-off-by: Alex Chi Z <iskyzh@gmail.com>

mini-lsm/src/tests/harness.rs

@@ -5,7 +5,7 @@ use bytes::Bytes;
 
 use crate::{
     iterators::StorageIterator,
-    lsm_storage::BlockCache,
+    lsm_storage::{BlockCache, LsmStorageInner},
     table::{SsTable, SsTableBuilder},
 };
 
@@ -123,3 +123,11 @@ pub fn generate_sst(
     }
     builder.build(id, block_cache, path.as_ref()).unwrap()
 }
+
+
+pub fn sync(storage: &LsmStorageInner) {
+    storage
+        .force_freeze_memtable(&storage.state_lock.lock())
+        .unwrap();
+    storage.force_flush_next_imm_memtable().unwrap();
+}