1 files changed, 15 insertions, 14 deletions

diff --git a/src/indexer/index_writer.rs b/src/indexer/index_writer.rs
index 94961f5..3b4a01e 100644
--- a/src/indexer/index_writer.rs
+++ b/src/indexer/index_writer.rs
@@ -19,6 +19,7 @@ use indexer::doc_opstamp_mapping::DocToOpstampMapping;
 use indexer::operation::DeleteOperation;
 use indexer::stamper::Stamper;
 use indexer::MergePolicy;
+use indexer::Opstamp;
 use indexer::SegmentEntry;
 use indexer::SegmentWriter;
 use postings::compute_table_size;
@@ -99,7 +100,7 @@ pub struct IndexWriter {
     delete_queue: DeleteQueue,
 
     stamper: Stamper,
-    committed_opstamp: u64,
+    committed_opstamp: Opstamp,
 }
 
 /// Open a new index writer. Attempts to acquire a lockfile.
@@ -177,7 +178,7 @@ pub fn compute_deleted_bitset(
     segment_reader: &SegmentReader,
     delete_cursor: &mut DeleteCursor,
     doc_opstamps: &DocToOpstampMapping,
-    target_opstamp: u64,
+    target_opstamp: Opstamp,
 ) -> Result<bool> {
     let mut might_have_changed = false;
 
@@ -219,7 +220,7 @@ pub fn compute_deleted_bitset(
 pub fn advance_deletes(
     mut segment: Segment,
     segment_entry: &mut SegmentEntry,
-    target_opstamp: u64,
+    target_opstamp: Opstamp,
 ) -> Result<()> {
     {
         if segment_entry.meta().delete_opstamp() == Some(target_opstamp) {
@@ -299,11 +300,11 @@ fn index_documents(
     // the worker thread.
     assert!(num_docs > 0);
 
-    let doc_opstamps: Vec<u64> = segment_writer.finalize()?;
+    let doc_opstamps: Vec<Opstamp> = segment_writer.finalize()?;
 
     let segment_meta = SegmentMeta::new(segment_id, num_docs);
 
-    let last_docstamp: u64 = *(doc_opstamps.last().unwrap());
+    let last_docstamp: Opstamp = *(doc_opstamps.last().unwrap());
 
     let delete_bitset_opt = if delete_cursor.get().is_some() {
         let doc_to_opstamps = DocToOpstampMapping::from(doc_opstamps);
@@ -494,7 +495,7 @@ impl IndexWriter {
     /// state as it was after the last commit.
     ///
     /// The opstamp at the last commit is returned.
-    pub fn rollback(&mut self) -> Result<()> {
+    pub fn rollback(&mut self) -> Result<Opstamp> {
         info!("Rolling back to opstamp {}", self.committed_opstamp);
 
         // marks the segment updater as killed. From now on, all
@@ -529,7 +530,7 @@ impl IndexWriter {
         // was dropped with the index_writer.
         for _ in document_receiver.clone() {}
 
-        Ok(())
+        Ok(self.committed_opstamp)
     }
 
     /// Prepares a commit.
@@ -567,7 +568,7 @@ impl IndexWriter {
         info!("Preparing commit");
 
         // this will drop the current document channel
-        // and recreate a new one channels.
+        // and recreate a new one.
         self.recreate_document_channel();
 
         let former_workers_join_handle = mem::replace(&mut self.workers_join_handle, Vec::new());
@@ -601,7 +602,7 @@ impl IndexWriter {
     /// Commit returns the `opstamp` of the last document
     /// that made it in the commit.
     ///
-    pub fn commit(&mut self) -> Result<u64> {
+    pub fn commit(&mut self) -> Result<Opstamp> {
         self.prepare_commit()?.commit()
     }
 
@@ -617,7 +618,7 @@ impl IndexWriter {
     ///
     /// Like adds, the deletion itself will be visible
     /// only after calling `commit()`.
-    pub fn delete_term(&mut self, term: Term) -> u64 {
+    pub fn delete_term(&mut self, term: Term) -> Opstamp {
         let opstamp = self.stamper.stamp();
         let delete_operation = DeleteOperation { opstamp, term };
         self.delete_queue.push(delete_operation);
@@ -631,7 +632,7 @@ impl IndexWriter {
     ///
     /// This is also the opstamp of the commit that is currently
     /// available for searchers.
-    pub fn commit_opstamp(&self) -> u64 {
+    pub fn commit_opstamp(&self) -> Opstamp {
         self.committed_opstamp
     }
 
@@ -645,7 +646,7 @@ impl IndexWriter {
     ///
     /// Currently it represents the number of documents that
     /// have been added since the creation of the index.
-    pub fn add_document(&mut self, document: Document) -> u64 {
+    pub fn add_document(&mut self, document: Document) -> Opstamp {
         let opstamp = self.stamper.stamp();
         let add_operation = AddOperation { opstamp, document };
         let send_result = self.operation_sender.send(vec![add_operation]);
@@ -662,7 +663,7 @@ impl IndexWriter {
     /// The total number of stamps generated by this method is `count + 1`;
     /// each operation gets a stamp from the `stamps` iterator and `last_opstamp`
     /// is for the batch itself.
-    fn get_batch_opstamps(&mut self, count: u64) -> (u64, Range<u64>) {
+    fn get_batch_opstamps(&mut self, count: Opstamp) -> (Opstamp, Range<Opstamp>) {
         let Range { start, end } = self.stamper.stamps(count + 1u64);
         let last_opstamp = end - 1;
         let stamps = Range {
@@ -688,7 +689,7 @@ impl IndexWriter {
     /// Like adds and deletes (see `IndexWriter.add_document` and
     /// `IndexWriter.delete_term`), the changes made by calling `run` will be
     /// visible to readers only after calling `commit()`.
-    pub fn run(&mut self, user_operations: Vec<UserOperation>) -> u64 {
+    pub fn run(&mut self, user_operations: Vec<UserOperation>) -> Opstamp {
         let count = user_operations.len() as u64;
         if count == 0 {
             return self.stamper.stamp();