support force full compaction

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

mini-lsm/src/bin/minilsm_cli.rs

@@ -1,5 +1,3 @@
-use std::time::Duration;
-
 use anyhow::Result;
 use mini_lsm::compact::{CompactionOptions, SimpleLeveledCompactionOptions};
 use mini_lsm::lsm_storage::{LsmStorageOptions, MiniLsm};

mini-lsm/src/compact.rs

@@ -184,6 +184,40 @@ impl LsmStorageInner {
         Ok(new_sst)
     }
 
+    pub fn force_full_compaction(&self) -> Result<()> {
+        let CompactionOptions::NoCompaction = self.options.compaction_options else {
+            panic!("full compaction can only be called with compaction is not enabled")
+        };
+        let snapshot = {
+            let state = self.state.read();
+            state.clone()
+        };
+        let original_sstables = snapshot.l0_sstables.clone();
+        let sstables = self.compact(&CompactionTask::ForceFullCompaction(
+            original_sstables.clone(),
+        ))?;
+        {
+            let _state_lock = self.state_lock.lock();
+            let mut state = self.state.read().as_ref().clone();
+            for sst in original_sstables.iter() {
+                let result = state.sstables.remove(sst);
+                assert!(result.is_some());
+            }
+            let mut ids = Vec::with_capacity(sstables.len());
+            for new_sst in sstables {
+                ids.push(new_sst.sst_id());
+                let result = state.sstables.insert(new_sst.sst_id(), new_sst);
+                assert!(result.is_none());
+            }
+            state.l0_sstables = ids;
+            *self.state.write() = Arc::new(state);
+        }
+        for sst in original_sstables {
+            std::fs::remove_file(self.path_of_sst(sst))?;
+        }
+        Ok(())
+    }
+
     fn trigger_compaction(&self) -> Result<()> {
         let snapshot = {
             let state = self.state.read();