Add has_merging_threads function to IndexWriter

src/indexer/index_writer.rs

@@ -328,6 +328,12 @@ impl<D: Document> IndexWriter<D> {
         &self.index
     }
 
+    /// Check if there are any merging threads
+    /// Does not block
+    pub fn has_merging_threads(&self) -> bool {
+        self.segment_updater.has_merging_threads()
+    }
+
     /// If there are some merging threads, blocks until they all finish their work and
     /// then drop the `IndexWriter`.
     pub fn wait_merging_threads(mut self) -> crate::Result<()> {

src/indexer/segment_updater.rs

@@ -645,6 +645,11 @@ impl SegmentUpdater {
         Ok(after_merge_segment_meta)
     }
 
+    /// Check if there are still pending merges without blocking
+    pub fn has_merging_threads(&self) -> bool {
+        self.merge_operations.len() > 0
+    }
+
     /// Wait for current merging threads.
     ///
     /// Upon termination of the current merging threads,