Alive doc iterator.

src/core/index.rs

@@ -24,10 +24,8 @@ use crate::IndexWriter;
 use std::borrow::BorrowMut;
 use std::collections::HashSet;
 use std::fmt;
-
 #[cfg(feature = "mmap")]
-use std::path::Path;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 fn load_metas(

src/core/segment_reader.rs

@@ -295,8 +295,8 @@ impl SegmentReader {
     }
 
     /// Returns an iterator that will iterate over the alive document ids
-    pub fn doc_ids_alive(&self) -> SegmentReaderAliveDocsIterator<'_> {
-        SegmentReaderAliveDocsIterator::new(&self)
+    pub fn doc_ids_alive<'a>(&'a self) -> impl Iterator<Item = DocId> + 'a {
+        (0u32..self.max_doc).filter(move |doc| !self.is_deleted(*doc))
     }
 
     /// Summarize total space usage of this segment.
@@ -324,52 +324,6 @@ impl fmt::Debug for SegmentReader {
     }
 }
 
-/// Implements the iterator trait to allow easy iteration
-/// over non-deleted ("alive") DocIds in a SegmentReader
-pub struct SegmentReaderAliveDocsIterator<'a> {
-    reader: &'a SegmentReader,
-    max_doc: DocId,
-    current: DocId,
-}
-
-impl<'a> SegmentReaderAliveDocsIterator<'a> {
-    pub fn new(reader: &'a SegmentReader) -> SegmentReaderAliveDocsIterator<'a> {
-        SegmentReaderAliveDocsIterator {
-            reader,
-            max_doc: reader.max_doc(),
-            current: 0,
-        }
-    }
-}
-
-impl<'a> Iterator for SegmentReaderAliveDocsIterator<'a> {
-    type Item = DocId;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        // TODO: Use TinySet (like in BitSetDocSet) to speed this process up
-        if self.current >= self.max_doc {
-            return None;
-        }
-
-        // find the next alive doc id
-        while self.reader.is_deleted(self.current) {
-            self.current += 1;
-
-            if self.current >= self.max_doc {
-                return None;
-            }
-        }
-
-        // capture the current alive DocId
-        let result = Some(self.current);
-
-        // move down the chain
-        self.current += 1;
-
-        result
-    }
-}
-
 #[cfg(test)]
 mod test {
     use crate::core::Index;

src/indexer/merger.rs

@@ -589,45 +589,48 @@ impl IndexMerger {
             // of all of the segments containing the given term.
             //
             // These segments are non-empty and advance has already been called.
-            if segment_postings.is_empty() {
-                continue;
-            }
-            // If not, the `term` will be entirely removed.
+            if !segment_postings.is_empty() {
+                // If not, the `term` will be entirely removed.
 
-            // We know that there is at least one document containing
-            // the term, so we add it.
-            let to_term_ord = field_serializer.new_term(term_bytes)?;
+                // We know that there is at least one document containing
+                // the term, so we add it.
+                let to_term_ord = field_serializer.new_term(term_bytes)?;
 
-            if let Some(ref mut term_ord_mapping) = term_ord_mapping_opt {
-                for (segment_ord, from_term_ord) in merged_terms.matching_segments() {
-                    term_ord_mapping.register_from_to(segment_ord, from_term_ord, to_term_ord);
-                }
-            }
-
-            // We can now serialize this postings, by pushing each document to the
-            // postings serializer.
-            for (segment_ord, mut segment_postings) in segment_postings {
-                let old_to_new_doc_id = &merged_doc_id_map[segment_ord];
-
-                let mut doc = segment_postings.doc();
-                while doc != TERMINATED {
-                    // deleted doc are skipped as they do not have a `remapped_doc_id`.
-                    if let Some(remapped_doc_id) = old_to_new_doc_id[doc as usize] {
-                        // we make sure to only write the term iff
-                        // there is at least one document.
-                        let term_freq = segment_postings.term_freq();
-                        segment_postings.positions(&mut positions_buffer);
-
-                        let delta_positions = delta_computer.compute_delta(&positions_buffer);
-                        field_serializer.write_doc(remapped_doc_id, term_freq, delta_positions)?;
+                if let Some(ref mut term_ord_mapping) = term_ord_mapping_opt {
+                    for (segment_ord, from_term_ord) in merged_terms.matching_segments() {
+                        term_ord_mapping.register_from_to(segment_ord, from_term_ord, to_term_ord);
                     }
-
-                    doc = segment_postings.advance();
                 }
-            }
 
-            // closing the term.
-            field_serializer.close_term()?;
+                // We can now serialize this postings, by pushing each document to the
+                // postings serializer.
+                for (segment_ord, mut segment_postings) in segment_postings {
+                    let old_to_new_doc_id = &merged_doc_id_map[segment_ord];
+
+                    let mut doc = segment_postings.doc();
+                    while doc != TERMINATED {
+                        // deleted doc are skipped as they do not have a `remapped_doc_id`.
+                        if let Some(remapped_doc_id) = old_to_new_doc_id[doc as usize] {
+                            // we make sure to only write the term iff
+                            // there is at least one document.
+                            let term_freq = segment_postings.term_freq();
+                            segment_postings.positions(&mut positions_buffer);
+
+                            let delta_positions = delta_computer.compute_delta(&positions_buffer);
+                            field_serializer.write_doc(
+                                remapped_doc_id,
+                                term_freq,
+                                delta_positions,
+                            )?;
+                        }
+
+                        doc = segment_postings.advance();
+                    }
+                }
+
+                // closing the term.
+                field_serializer.close_term()?;
+            }
         }
         field_serializer.close()?;
         Ok(term_ord_mapping_opt)