ZoneRental

Major performance update implementing async chunk-based region scanning for improved server performance during rental expiration.

New Features

• MCCoroutine 2.21.0 Integration - Added Kotlin coroutine support for Bukkit

  • Plugin now extends SuspendingJavaPlugin for automatic coroutine lifecycle management
  • Enables non-blocking async operations during item/block scanning
  • TPS-aware throttling to prevent lag during large region scans

• ChunkSnapshot Pre-filtering - ~99% reduction in main thread getBlock() calls

  • Phase A: Scan ChunkSnapshot for container block types (async, off main thread)
  • Phase B: Access actual blocks only for found containers (main thread, minimal)
  • Dramatically reduces server impact for large rental regions

• Dynamic Chunk Batching - Batch size scales with region size

  • Tiny (<50 chunks): 15 chunks/batch, no delay
  • Small (<200 chunks): 10 chunks/batch, 25ms delay
  • Medium (<500 chunks): 8 chunks/batch, 50ms delay
  • Large (<1000 chunks): 4 chunks/batch, 100ms delay
  • Very Large (<2000 chunks): 2 chunks/batch, 150ms delay
  • Extreme (2000+ chunks): 1 chunk/batch, 200ms delay

• Y-Level Aware Scanning - Only scans actual region Y-bounds

  • Uses WorldGuard region min/max Y coordinates
  • Avoids scanning full world height (Y -64 to 320)
  • Significant performance improvement for regions with limited vertical extent

• TPS Monitoring with Auto-Throttling - Adaptive performance management

  • HEALTHY (TPS ≥ 19.5): Full speed scanning
  • WARNING (TPS ≥ 18.5): Reduced concurrency, doubled delays
  • CRITICAL (TPS < 18.5): Single chunk, 200ms delays, pause if TPS drops further

• Region Size Limits - Block rentals for excessively large regions

  • Configurable max-rental-chunks limit (default: 2000)
  • Prevents performance issues from extremely large regions
  • Clear error message when region exceeds limit

New Files

• src/main/kotlin/com/zonerental/async/ScanModels.kt - Data classes for async scanning

  • ScanRegion, ChunkCoord, BlockCoord, ChunkBatch
  • ScanStrategy sealed class (Tiny/Small/Medium/Large/VeryLarge/Extreme)
  • TpsLevel enum and AdjustedStrategy for TPS-based throttling

• src/main/kotlin/com/zonerental/async/TpsMonitor.kt - TPS monitoring utility

  • Uses Paper's Bukkit.getTPS() API
  • Provides strategy adjustment based on current server load
  • Estimates scan time for large regions

• src/main/kotlin/com/zonerental/async/AsyncScanService.kt - Core async scan service

  • createScanRegion() - Creates scan region from WorldGuard bounds
  • calculateChunkBatches() - Splits region into TPS-friendly batches
  • scanSnapshotForContainers() - Finds container blocks in ChunkSnapshot
  • scanSnapshotForChangedBlocks() - Detects player-placed blocks

Modified Files

• ZoneRental.java - Now extends SuspendingJavaPlugin for MCCoroutine
• StorageManager.kt - Added async ChunkSnapshot-based scanning methods
• WorldEditManager.kt - Added async file I/O for schematic operations
• RentalManager.kt - Added expireRentalAsync() suspend function
• ExpirationManager.kt - Uses plugin.launch {} for async expiration
• ConfigManager.kt - Added async-scanning configuration properties

New Configuration

async-scanning:
  enabled: true              # Enable async scanning for large regions
  min-chunks-for-async: 10   # Minimum chunks before using async
  tps-healthy-threshold: 19.5
  tps-warning-threshold: 18.5
  debug-async: false         # Enable debug logging for async operations
  max-rental-chunks: 2000    # Block rentals for regions larger than this

Technical Details

• Dependencies added:
  • mccoroutine-bukkit-api:2.21.0
  • mccoroutine-bukkit-core:2.21.0
  • kotlinx-coroutines-core:1.9.0
• All new dependencies are relocated via ShadowJar to avoid conflicts
• Backward compatible - small regions still use synchronous scanning
• No changes to data formats or API