Flush DB after the last index update

src/bin/bench_index.rs

@@ -22,6 +22,7 @@ impl ReadStore for FakeStore {
 
 impl WriteStore for FakeStore {
     fn write(&self, _rows: Vec<Row>) {}
+    fn flush(&self) {}
 }
 
 fn run() -> Result<()> {

src/index.rs

@@ -344,12 +344,14 @@ impl<'a> BufferedWriter<'a> {
     fn write(&mut self, mut rows: Vec<Row>) {
         self.batch.append(&mut rows);
         if self.batch.len() > 10_000_000 || self.start.elapsed() > Duration::from_secs(60) {
-            self.flush();
+            self.store.write(self.batch.split_off(0));
+            self.start = Instant::now();
         }
     }
 
     fn flush(&mut self) {
         self.store.write(self.batch.split_off(0));
         self.start = Instant::now();
+        self.store.flush(); // sync DB to disk
     }
 }

src/store.rs

@@ -20,6 +20,7 @@ pub trait ReadStore: Sync {
 
 pub trait WriteStore: Sync {
     fn write(&self, rows: Vec<Row>);
+    fn flush(&self);
 }
 
 pub struct DBStore {
@@ -95,7 +96,15 @@ impl WriteStore for DBStore {
             batch.put(row.key.as_slice(), row.value.as_slice()).unwrap();
         }
         let mut opts = rocksdb::WriteOptions::new();
-        opts.set_sync(true);
+        opts.set_sync(false);
         self.db.write_opt(batch, &opts).unwrap();
     }
+
+    fn flush(&self) {
+        let mut opts = rocksdb::WriteOptions::new();
+        opts.set_sync(true);
+        self.db
+            .write_opt(rocksdb::WriteBatch::default(), &opts)
+            .unwrap();
+    }
 }