NOBUG cleanup

src/core/segment_meta.rs

@@ -14,41 +14,69 @@ struct DeleteMeta {
 #[derive(Clone, Debug, RustcDecodable,RustcEncodable)]
 pub struct SegmentMeta {
     segment_id: SegmentId,
-    num_docs: u32,
+    max_doc: u32,
     deletes: Option<DeleteMeta>, 
 }
 
 impl SegmentMeta {
+
+    /// Creates a new segment meta for 
+    /// a segment with no deletes and no documents.
     pub fn new(segment_id: SegmentId) -> SegmentMeta {
         SegmentMeta {
             segment_id: segment_id,
-            num_docs: 0,
+            max_doc: 0,
             deletes: None,
         }
     }
 
+    /// Returns the segment id.
     pub fn id(&self) -> SegmentId {
         self.segment_id
     }
 
-    pub fn num_docs(&self) -> u32 {
-        self.num_docs
-    } 
+    /// Returns the number of deleted documents.
+    pub fn num_deleted_docs(&self) -> u32 {
+        self.deletes
+            .as_ref()
+            .map(|delete_meta| delete_meta.num_deleted_docs)
+            .unwrap_or(0u32)
+    }
 
+    /// Return the highest doc id + 1
+    ///
+    /// If there are no deletes, then num_docs = max_docs
+    /// and all the doc ids contains in this segment
+    /// are exactly (0..max_doc).
+    pub fn max_doc(&self) -> u32 {
+        self.max_doc
+    }
+
+    /// Return the number of documents in the segment.
+    pub fn num_docs(&self) -> u32 {
+        self.max_doc() - self.num_deleted_docs()
+    }
+
+    /// Returns the opstamp of the last delete operation
+    /// taken in account in this segment.
     pub fn delete_opstamp(&self) -> Option<u64> {
         self.deletes
             .as_ref()
             .map(|delete_meta| delete_meta.opstamp)
     }
 
+    /// Returns true iff the segment meta contains
+    /// delete information.
     pub fn has_deletes(&self) -> bool {
         self.deletes.is_some()
     }
 
-    pub fn set_num_docs(&mut self, num_docs: u32) {
-        self.num_docs = num_docs;
+    #[doc(hidden)]
+    pub fn set_max_doc(&mut self, max_doc: u32) {
+        self.max_doc = max_doc;
     }
 
+    #[doc(hidden)]
     pub fn set_delete_meta(&mut self, num_deleted_docs: u32, opstamp: u64) {
         self.deletes = Some(DeleteMeta {
             num_deleted_docs: num_deleted_docs,