MiniGameScoreMapper

Info

MyBatis mapper interface for mini-game high-score CRUD operations with atomic CAS upsert semantics.

Overview

MiniGameScoreMapper provides the data access layer for mini_game_score. The write path follows a three-step pattern inside ScoreUpsertConsumer: insertIfAbsent -> updateBestIfGreater -> incrementPlaysCount.

Methods

Method	Description	Returns
selectByUserAndGame(userId, gameId)	Query high-score record by user and game	MiniGameScore or null
insertIfAbsent(score)	Insert only if (user_id, game_id) does not exist (INSERT IGNORE)	1 = inserted, 0 = already exists
updateBestIfGreater(userId, gameId, highScore, bestDurationMs, bestMoves, achievedAt, updatedAt)	Atomic CAS: update only when new score > current high_score	1 = updated, 0 = no change
incrementPlaysCount(userId, gameId, lastPlayedAt, updatedAt)	Increment plays_count and refresh last_played_at	1 = success, 0 = not found
selectTopByGame(gameId, limit)	Top-N records by high_score DESC for leaderboard backfill	List<MiniGameScore>

Write Flow

ScoreUpsertConsumer.onMessage()
  ├─ insertIfAbsent()      → first-time (user, game) pair
  ├─ updateBestIfGreater()  → atomic CAS for new high score
  └─ incrementPlaysCount()  → always called for non-new rows

Tips

updateBestIfGreater uses a SQL WHERE high_score < #{highScore} clause to ensure atomic compare-and-swap without application-level locking.