chore(sdk): Fix comments and rename variables.

Author: Hywan

crates/matrix-sdk-common/src/linked_chunk/builder.rs

@@ -61,7 +61,7 @@ impl LinkedChunkBuilder {
 
         // Create the `LinkedChunk` from a single chunk.
         {
-            // This is the only chunk. Pretend it has no previous chunk if any.
+            // Take the `previous` chunk and consider it becomes the `lazy_previous`.
             let lazy_previous = chunk.previous.take();
 
             // Transform the `RawChunk` into a `Chunk`.
@@ -184,7 +184,7 @@ impl LinkedChunkBuilder {
             }
         }
 
-        // Emit the updates..
+        // Emit the updates.
         if let Some(updates) = linked_chunk.updates.as_mut() {
             let first_chunk = linked_chunk.links.first_chunk();
 

crates/matrix-sdk/src/event_cache/pagination.rs

@@ -238,7 +238,7 @@ impl RoomPagination {
             // Reverse the order of the events as `/messages` has been called with `dir=b`
             // (backwards). The `RoomEvents` API expects the first event to be the oldest.
             // Let's re-order them for this block.
-            let events = events
+            let reversed_events = events
                 .iter()
                 .rev()
                 .cloned()
@@ -258,7 +258,7 @@ impl RoomPagination {
                     trace!("replacing previous gap with the back-paginated events");
 
                     // Replace the gap with the events we just deduplicated.
-                    room_events.replace_gap_at(events.clone(), gap_id)
+                    room_events.replace_gap_at(reversed_events.clone(), gap_id)
                         .expect("gap_identifier is a valid chunk id we read previously")
                 }
             } else if let Some(pos) = first_event_pos {
@@ -267,15 +267,15 @@ impl RoomPagination {
                 trace!("inserted events before the first known event");
 
                 room_events
-                    .insert_events_at(events.clone(), pos)
+                    .insert_events_at(reversed_events.clone(), pos)
                     .expect("pos is a valid position we just read above");
 
                 Some(pos)
             } else {
                 // No prior gap, and no prior events: push the events.
                 trace!("pushing events received from back-pagination");
 
-                room_events.push_events(events.clone());
+                room_events.push_events(reversed_events.clone());
 
                 // A new gap may be inserted before the new events, if there are any.
                 room_events.events().next().map(|(item_pos, _)| item_pos)
@@ -299,7 +299,7 @@ impl RoomPagination {
                 debug!("not storing previous batch token, because we deduplicated all new back-paginated events");
             }
 
-            room_events.on_new_events(&self.inner.room_version, events.iter());
+            room_events.on_new_events(&self.inner.room_version, reversed_events.iter());
         })
         .await?;
 

crates/matrix-sdk/src/event_cache/room/mod.rs

@@ -657,10 +657,6 @@ mod private {
         }
 
         /// Load more events backwards if the last chunk is **not** a gap.
-        ///
-        /// Return `Ok(Some((events, reached_start), _))` if events have been
-        /// inserted, `Ok(None)` if a gap has been inserted or if the
-        /// store is disabled.
         #[must_use = "Updates as `VectorDiff` must probably be propagated via `RoomEventCacheUpdate`"]
         pub(in super::super) async fn load_more_events_backwards(
             &mut self,