Commit e4ddde59 authored by Andrei Mihu's avatar Andrei Mihu
Browse files

Fix handling of leaderboard record writes that do not need to update the database.

parent 5559e8f7

CHANGELOG.md

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ The format is based on [keep a changelog](http://keepachangelog.com) and this pr 
### Fixed

- Gracefully close Lua matches when call queue fills up.

- Better handling for Lua runtime wallet update operation errors.

- Fix handling of leaderboard record writes that do not need to update the database.



## [3.9.0] - 2021-10-29

### Added

server/core_leaderboard.go

+28 −5
Original line number Diff line number Diff line
@@ -465,6 +465,9 @@ func LeaderboardRecordWrite(ctx context.Context, logger *zap.Logger, db *sql.DB, 
		params = append(params, scoreDelta, subscoreDelta)

	}



	// Track if the database record actually updates or not.

	var unchanged bool



	var dbUsername sql.NullString

	var dbScore int64

	var dbSubscore int64
@@ -475,15 +478,35 @@ func LeaderboardRecordWrite(ctx context.Context, logger *zap.Logger, db *sql.DB, 
	var dbUpdateTime pgtype.Timestamptz



	if err := db.QueryRowContext(ctx, query, params...).Scan(&dbUsername, &dbScore, &dbSubscore, &dbNumScore, &dbMaxNumScore, &dbMetadata, &dbCreateTime, &dbUpdateTime); err != nil {

		if err != sql.ErrNoRows {

			logger.Error("Error writing leaderboard record", zap.Error(err))

			return nil, err

		}



	// ensure we have the latest dbscore, dbsubscore

	newRank := rankCache.Insert(leaderboardId, expiryTime, leaderboard.SortOrder, uuid.Must(uuid.FromString(ownerID)), dbScore, dbSubscore)

		// If no rows were returned then both of these criteria must have been met:

		// 1. There was already a record for this leaderboard, user, and expiry time.

		// 2. This new update did not meet the criteria to be stored, so no update

		//    occurred. For example the new entry was not better in a "best" leaderboard.

		// In this case the user's record is unchanged, and we can just read it as is.

		query = "SELECT username, score, subscore, num_score, max_num_score, metadata, create_time, update_time FROM leaderboard_record WHERE leaderboard_id = $1 AND owner_id = $2 AND expiry_time = $3"

		err = db.QueryRowContext(ctx, query, leaderboardId, ownerID, time.Unix(expiryTime, 0).UTC()).Scan(&dbUsername, &dbScore, &dbSubscore, &dbNumScore, &dbMaxNumScore, &dbMetadata, &dbCreateTime, &dbUpdateTime)

		if err != nil {

			logger.Error("Error after writing leaderboard record", zap.Error(err))

			return nil, err

		}

		unchanged = true

	}



	var rank int64

	if unchanged {

		rank = rankCache.Get(leaderboardId, expiryTime, uuid.Must(uuid.FromString(ownerID)))

	} else {

		// Ensure we have the latest dbscore, dbsubscore if there was an update.

		rank = rankCache.Insert(leaderboardId, expiryTime, leaderboard.SortOrder, uuid.Must(uuid.FromString(ownerID)), dbScore, dbSubscore)

	}



	record := &api.LeaderboardRecord{

		Rank:          newRank,

		Rank:          rank,

		LeaderboardId: leaderboardId,

		OwnerId:       ownerID,

		Score:         dbScore,