consider merge width for tiered trigger + mvcc compaction

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

mini-lsm/src/debug.rs

@@ -1,8 +1,8 @@
-use crate::lsm_storage::MiniLsm;
+use crate::lsm_storage::{LsmStorageInner, MiniLsm};
 
-impl MiniLsm {
+impl LsmStorageInner {
     pub fn dump_structure(&self) {
-        let snapshot = self.inner.state.read();
+        let snapshot = self.state.read();
         if !snapshot.l0_sstables.is_empty() {
             println!(
                 "L0 ({}): {:?}",
@@ -15,3 +15,9 @@ impl MiniLsm {
         }
     }
 }
+
+impl MiniLsm {
+    pub fn dump_structure(&self) {
+        self.inner.dump_structure()
+    }
+}