async/examples/periodic-leaderboard

periodic-leaderboard

Recomputes a top-5 leaderboard every minute by reading PlayerStats.level from every online player in parallel, sorting, and broadcasting.

What it shows

• pluginScope(this).launch { while (isActive) { delay(60.seconds); … } } — a plugin-lifetime periodic task. Cancels cleanly on shutdown via Async.shutdown().
• Parallel read over players via async { … }.awaitAll(). Each read switches to its player's owning world dispatcher independently — reads on different worlds run concurrently, reads on the same world serialize.
• runCatching { … } around the body so a single bad read doesn't kill the loop.

This is the shape for any plugin-wide background recompute: leaderboards, periodic backups of derived state, quest sync, etc.

Build

./gradlew shadowJar
# → build/libs/periodic-leaderboard.jar

Run

1. Drop in mods/, wire PlayerStatsBinding.componentType() and onlinePlayers().
2. For a faster demo while testing, change delay(60.seconds) to delay(5.seconds) and rebuild.
3. Connect 2+ players. The top-5 logs every loop tick.

If you want per-world leaderboards instead, swap pluginScope(this) for worldScope(world) and run one loop per world. Cancellation flows through WorldScopes.cancel(uuid).