Avoid double reverse

relay-server/src/services/buffer/envelope_stack/sqlite.rs

@@ -120,7 +120,7 @@ impl SqliteEnvelopeStack {
  /// In case an envelope fails deserialization due to malformed data in the database, the affected
  /// envelope will not be unspooled and unspooling will continue with the remaining envelopes.
  async fn unspool_from_disk(&mut self) -> Result<(), SqliteEnvelopeStackError> {
- let mut envelopes = relay_statsd::metric!(timer(RelayTimers::BufferUnspool), {
+ let envelopes = relay_statsd::metric!(timer(RelayTimers::BufferUnspool), {
  self.envelope_store
  .delete_many(
  self.own_key,
@@ -139,11 +139,6 @@ impl SqliteEnvelopeStack {
  return Ok(());
  }
 
- // Since the store returns the envelopes sorted in descending order, we want to put them
- // in reverse into the vector in the buffer, because we want to pop the last element always,
- // which has to be the newest (aka with the biggest timestamp).
- envelopes.reverse();
-
  // We push in the back of the buffer, since we still want to give priority to
  // incoming envelopes that have a more recent timestamp.
  self.batches_buffer_size += envelopes.len();

relay-server/src/services/buffer/envelope_store/sqlite.rs

@@ -1,4 +1,3 @@
-use std::cmp::Reverse;
 use std::error::Error;
 use std::path::Path;
 use std::pin::pin;
@@ -371,12 +370,12 @@ impl SqliteEnvelopeStore {
  }
  }
 
- // We sort envelopes by `received_at`.
+ // We sort envelopes by `received_at` in ascending order.
  //
  // Unfortunately we have to do this because SQLite `DELETE` with `RETURNING` doesn't
  // return deleted rows in a specific order.
  extracted_envelopes.sort_by_key(|a| {
- Reverse(UnixTimestamp::from_datetime(a.received_at()).unwrap_or(UnixTimestamp::now()))
+ UnixTimestamp::from_datetime(a.received_at()).unwrap_or(UnixTimestamp::now())
  });
 
  Ok(extracted_envelopes)
@@ -553,10 +552,7 @@ mod tests {
  .unwrap();
  assert_eq!(extracted_envelopes.len(), 5);
  for (i, extracted_envelope) in extracted_envelopes.iter().enumerate().take(5) {
- assert_eq!(
- extracted_envelope.event_id(),
- envelopes[5..][4 - i].event_id()
- );
+ assert_eq!(extracted_envelope.event_id(), envelopes[5..][i].event_id());
  }
 
  // We check that if we load more than the envelopes stored on disk, we still get back at
@@ -567,10 +563,7 @@ mod tests {
  .unwrap();
  assert_eq!(extracted_envelopes.len(), 5);
  for (i, extracted_envelope) in extracted_envelopes.iter().enumerate().take(5) {
- assert_eq!(
- extracted_envelope.event_id(),
- envelopes[0..5][4 - i].event_id()
- );
+ assert_eq!(extracted_envelope.event_id(), envelopes[0..5][i].event_id());
  }
  }