Introduce an Index mathod to retrieve the currently processed update

meilidb-core/src/database.rs

@@ -23,8 +23,7 @@ fn update_awaiter(
     rkv: Arc<RwLock<rkv::Rkv>>,
     update_fn: Arc<ArcSwapFn>,
     index: Index,
-)
+) {
-{
     for () in receiver {
         // consume all updates in order (oldest first)
         loop {

meilidb-core/src/store/mod.rs

@@ -186,6 +186,13 @@ impl Index {
         )
     }
 
+    pub fn current_update_id<T: rkv::Readable>(&self, reader: &T) -> MResult<Option<u64>> {
+        match self.updates.last_update_id(reader)? {
+            Some((id, _)) => Ok(Some(id)),
+            None => Ok(None),
+        }
+    }
+
     pub fn update_status<T: rkv::Readable>(
         &self,
         reader: &T,