sync starter code

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

mini-lsm-starter/src/compact/leveled.rs

@@ -0,0 +1,58 @@
+use std::collections::HashSet;
+
+use serde::{Deserialize, Serialize};
+
+use crate::lsm_storage::LsmStorageState;
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct LeveledCompactionTask {
+    // if upper_level is `None`, then it is L0 compaction
+    pub upper_level: Option<usize>,
+    pub upper_level_sst_ids: Vec<usize>,
+    pub lower_level: usize,
+    pub lower_level_sst_ids: Vec<usize>,
+    pub is_lower_level_bottom_level: bool,
+}
+
+#[derive(Debug, Clone)]
+pub struct LeveledCompactionOptions {
+    pub level_size_multiplier: usize,
+    pub level0_file_num_compaction_trigger: usize,
+    pub max_levels: usize,
+    pub base_level_size_mb: usize,
+}
+
+pub struct LeveledCompactionController {
+    options: LeveledCompactionOptions,
+}
+
+impl LeveledCompactionController {
+    pub fn new(options: LeveledCompactionOptions) -> Self {
+        Self { options }
+    }
+
+    fn find_overlapping_ssts(
+        &self,
+        snapshot: &LsmStorageState,
+        sst_ids: &[usize],
+        in_level: usize,
+    ) -> Vec<usize> {
+        unimplemented!()
+    }
+
+    pub fn generate_compaction_task(
+        &self,
+        snapshot: &LsmStorageState,
+    ) -> Option<LeveledCompactionTask> {
+        unimplemented!()
+    }
+
+    pub fn apply_compaction_result(
+        &self,
+        snapshot: &LsmStorageState,
+        task: &LeveledCompactionTask,
+        output: &[usize],
+    ) -> (LsmStorageState, Vec<usize>) {
+        unimplemented!()
+    }
+}