sync starter code

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

mini-lsm-starter/src/manifest.rs

@@ -0,0 +1,42 @@
+use std::fs::File;
+use std::path::Path;
+use std::sync::Arc;
+
+use anyhow::Result;
+use parking_lot::{Mutex, MutexGuard};
+use serde::{Deserialize, Serialize};
+
+use crate::compact::CompactionTask;
+
+pub struct Manifest {
+    file: Arc<Mutex<File>>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub enum ManifestRecord {
+    Flush(usize),
+    NewMemtable(usize),
+    Compaction(CompactionTask, Vec<usize>),
+}
+
+impl Manifest {
+    pub fn create(path: impl AsRef<Path>) -> Result<Self> {
+        unimplemented!()
+    }
+
+    pub fn recover(path: impl AsRef<Path>) -> Result<(Self, Vec<ManifestRecord>)> {
+        unimplemented!()
+    }
+
+    pub fn add_record(
+        &self,
+        _state_lock_observer: &MutexGuard<()>,
+        record: ManifestRecord,
+    ) -> Result<()> {
+        self.add_record_when_init(record)
+    }
+
+    pub fn add_record_when_init(&self, record: ManifestRecord) -> Result<()> {
+        unimplemented!()
+    }
+}