issue/232 added unit test. (#233)

src/postings/mod.rs

@@ -76,6 +76,58 @@ mod tests {
         assert!(read.len() <= 140);
     }
 
+    #[test]
+    pub fn test_skip_positions() {
+        let mut schema_builder = SchemaBuilder::new();
+        let title = schema_builder.add_text_field("title", TEXT);
+        let schema = schema_builder.build();
+        let index = Index::create_in_ram(schema);
+        let mut index_writer = index.writer_with_num_threads(1, 30_000_000).unwrap();
+        index_writer.add_document(doc!(title => r#"abc abc abc"#));
+        index_writer.add_document(doc!(title => r#"abc be be be be abc"#));
+        for _ in 0..1_000 {
+            index_writer.add_document(doc!(title => r#"abc abc abc"#));
+        }
+        index_writer.add_document(doc!(title => r#"abc be be be be abc"#));
+        index_writer.commit().unwrap();
+        index.load_searchers().unwrap();
+        let searcher = index.searcher();
+        let query = TermQuery::new(Term::from_field_text(title, "abc"), IndexRecordOption::WithFreqsAndPositions);
+        let weight = query.specialized_weight(&*searcher);
+        {
+            let mut scorer = weight.specialized_scorer(searcher.segment_reader(0u32)).unwrap();
+            scorer.advance();
+            assert_eq!(&[0,1,2], scorer.postings().positions());
+            scorer.advance();
+            assert_eq!(&[0,5], scorer.postings().positions());
+        }
+        {
+            let mut scorer = weight.specialized_scorer(searcher.segment_reader(0u32)).unwrap();
+            scorer.advance();
+            scorer.advance();
+            assert_eq!(&[0,5], scorer.postings().positions());
+        }
+        {
+            let mut scorer = weight.specialized_scorer(searcher.segment_reader(0u32)).unwrap();
+            assert_eq!(scorer.skip_next(1), SkipResult::Reached);
+            assert_eq!(scorer.doc(), 1);
+            assert_eq!(&[0,5], scorer.postings().positions());
+        }
+        {
+            let mut scorer = weight.specialized_scorer(searcher.segment_reader(0u32)).unwrap();
+            assert_eq!(scorer.skip_next(1002), SkipResult::Reached);
+            assert_eq!(scorer.doc(), 1002);
+            assert_eq!(&[0,5], scorer.postings().positions());
+        }
+        {
+            let mut scorer = weight.specialized_scorer(searcher.segment_reader(0u32)).unwrap();
+            assert_eq!(scorer.skip_next(100), SkipResult::Reached);
+            assert_eq!(scorer.skip_next(1002), SkipResult::Reached);
+            assert_eq!(scorer.doc(), 1002);
+            assert_eq!(&[0,5], scorer.postings().positions());
+        }
+    }
+
     #[test]
     pub fn test_position_and_fieldnorm1() {
         let mut schema_builder = SchemaBuilder::default();

src/postings/segment_postings.rs

@@ -40,7 +40,6 @@ impl PositionComputer {
     pub fn positions(&mut self, term_freq: usize) -> &[u32] {
         if let Some(num_skip) = self.position_to_skip {
             self.positions.resize(term_freq, 0u32);
-
             self.positions_stream.skip(num_skip);
             self.positions_stream.read(&mut self.positions[..term_freq]);
 
@@ -116,6 +115,7 @@ impl DocSet for SegmentPostings {
     #[inline]
     fn advance(&mut self) -> bool {
         loop {
+            self.position_add_skip(|| self.term_freq() as usize);
             self.cur += 1;
             if self.cur >= self.block_cursor.block_len() {
                 self.cur = 0;
@@ -124,7 +124,6 @@ impl DocSet for SegmentPostings {
                     return false;
                 }
             }
-            self.position_add_skip(|| self.term_freq() as usize);
             if !self.delete_bitset.is_deleted(self.doc()) {
                 return true;
             }