Initial flame_lua_runtime package

lib/runtime/audio/runtime_audio_cache.dart

@@ -0,0 +1,90 @@
+part of 'runtime_audio_manager.dart';
+
+extension _RuntimeAudioManagerCache on RuntimeAudioManager {
+  void _releaseCachedAudio() {
+    _loadLimiter.clearPending();
+    for (final path in _audios.keys.toList(growable: false)) {
+      _removeAudioRecord(path);
+    }
+
+    _channels.clear();
+    final players = _players.toList(growable: false);
+    _players.clear();
+    final pooledPlayers = _sfxPool.toList(growable: false);
+    _sfxPool.clear();
+    for (final player in [...players, ...pooledPlayers]) {
+      player.dispose();
+    }
+  }
+
+  RuntimeAudioPlayer _takeSfxPlayer() {
+    if (_sfxPool.isNotEmpty) {
+      return _sfxPool.removeLast();
+    }
+    return _playerFactory();
+  }
+
+  Future<void> _releaseSfxPlayer(RuntimeAudioPlayer player) async {
+    if (_disposed || _sfxPool.length >= _maxSfxPoolSize) {
+      await player.dispose();
+      return;
+    }
+    _sfxPool.add(player);
+  }
+
+  void _touch(_AudioResourceRecord record) {
+    record.lastUsed = ++_accessCounter;
+  }
+
+  void _enforceAudioBudget() {
+    while (_isOverBudget()) {
+      final victim = _leastRecentlyUsedAudio();
+      if (victim == null || !_removeAudioRecord(victim)) {
+        return;
+      }
+    }
+  }
+
+  bool _isOverBudget() {
+    final maxBytes = _maxCacheBytes;
+    final maxEntries = _maxCacheEntries;
+    return (maxBytes != null && _cacheBytes > maxBytes) ||
+        (maxEntries != null && _readyAudioCount > maxEntries);
+  }
+
+  int get _readyAudioCount => _audios.values
+      .where((record) => record.state == GameResourceState.ready)
+      .length;
+
+  String? _leastRecentlyUsedAudio() {
+    String? victimPath;
+    _AudioResourceRecord? victim;
+    for (final entry in _audios.entries) {
+      final record = entry.value;
+      if (record.state != GameResourceState.ready) {
+        continue;
+      }
+      if (victim == null || record.lastUsed < victim.lastUsed) {
+        victim = record;
+        victimPath = entry.key;
+      }
+    }
+    return victimPath;
+  }
+
+  bool _removeAudioRecord(String path) {
+    final record = _audios.remove(path);
+    if (record == null) {
+      return false;
+    }
+    _cacheBytes -= record.bytes?.length ?? 0;
+    if (_cacheBytes < 0) {
+      _cacheBytes = 0;
+    }
+    record
+      ..state = GameResourceState.disposed
+      ..bytes = null
+      ..inflight = null;
+    return true;
+  }
+}