fix a few bugs

src/lib.rs

@@ -173,9 +173,9 @@ impl TryFrom<u8> for OldNodeMode {
 
     fn try_from(v: u8) -> std::result::Result<Self, Self::Error> {
         match v {
-            v if v == NodeMode::Item as u8 => Ok(OldNodeMode::Item),
-            v if v == NodeMode::Tree as u8 => Ok(OldNodeMode::Tree),
-            v if v == NodeMode::Metadata as u8 => Ok(OldNodeMode::Metadata),
+            v if v == OldNodeMode::Item as u8 => Ok(OldNodeMode::Item),
+            v if v == OldNodeMode::Tree as u8 => Ok(OldNodeMode::Tree),
+            v if v == OldNodeMode::Metadata as u8 => Ok(OldNodeMode::Metadata),
             v => Err(format!("Could not convert {v} as a `NodeMode`.")),
         }
     }
@@ -185,24 +185,24 @@ impl TryFrom<u8> for OldNodeMode {
 /// /!\ This is only valid if the arroy database was generated by Meilisearch. Do not try to use it yourself.
 pub fn ugrade_from_prev_version(
     rtxn: &RoTxn,
+    read_database: heed::Database<Unspecified, Unspecified>,
     wtxn: &mut RwTxn,
-    database: heed::Database<Unspecified, Unspecified>,
+    write_database: heed::Database<Unspecified, Unspecified>,
 ) -> Result<()> {
     // We need to update EVERY single nodes, thus we can clear the whole DB initially
-    database.clear(wtxn)?;
+    write_database.clear(wtxn)?;
 
     // Then we **must** iterate over everything in the database to be sure we don't miss anything.
-    for ret in database.remap_types::<internals::KeyCodec, LazyDecode<Bytes>>().iter(rtxn)? {
+    for ret in read_database.remap_types::<internals::KeyCodec, LazyDecode<Bytes>>().iter(rtxn)? {
         let (mut key, value) = ret?;
         let old_mode = OldNodeMode::try_from(key.node.mode as u8)
             .map_err(|_| Error::CannotDecodeKeyMode { mode: key.node.mode })?;
 
-        // All the modes have been remapped
         match old_mode {
             OldNodeMode::Item => {
                 key.node.mode = NodeMode::Item;
                 // In case of an item there is nothing else to do
-                database.remap_types::<KeyCodec, Bytes>().put(
+                write_database.remap_types::<KeyCodec, Bytes>().put(
                     wtxn,
                     &key,
                     value.remap::<Bytes>().decode().unwrap(),
@@ -230,7 +230,7 @@ pub fn ugrade_from_prev_version(
                         OldNodeMode::Metadata => NodeMode::Metadata,
                     };
                 }
-                database
+                write_database
                     .remap_types::<KeyCodec, NodeCodec<Cosine>>()
                     .put(wtxn, &key, &tree_node)?;
             }
@@ -241,21 +241,22 @@ pub fn ugrade_from_prev_version(
                         // The distance has been renamed
                         let mut metadata = value.remap::<MetadataCodec>().decode().unwrap();
                         metadata.distance = Cosine::name();
-                        database
+                        write_database
                             .remap_types::<KeyCodec, MetadataCodec>()
                             .put(wtxn, &key, &metadata)?;
                     }
                     1 => {
                         key.node.mode = NodeMode::Updated;
                         // In this case we have a roaring bitmap of document id
                         // that we must re-insert as multiple values
-                        let updated = value.remap::<RoaringBitmapCodec>().decode().unwrap();
+                        let updated =
+                            value.remap::<RoaringBitmapCodec>().decode().unwrap_or_default();
                         for item in updated {
                             key.node.item = item;
-                            database.remap_types::<KeyCodec, Unit>().put(wtxn, &key, &())?;
+                            write_database.remap_types::<KeyCodec, Unit>().put(wtxn, &key, &())?;
                         }
                     }
-                    _ => unreachable!(),
+                    _ => (),
                 }
             }
         };