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Scan performance: chunk/region caching, Moonrise chunk access and scan-tracking fixes - #263
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tommasov03 wants to merge 11 commits into
Open
tommasov03 wants to merge 11 commits into
tommasov03 wants to merge 11 commits into
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- Fix NoSuchFieldError with ServerChunkCache.chunkMap - Ensure compatibility across all 1.21.* versions - Support both Paper and Purpur server implementations
…ed chunks - Replace unsafe MoonriseRegionFileIO direct file access with Bukkit's getChunkAtAsync API - Prevent potential data corruption and race conditions when accessing chunk files - Simplify code by reusing getLoadedChunkSections/getLoadedChunkEntities for both loaded and unloaded chunks - Remove manual NBT parsing logic and UnloadedChunkSectionImpl class - Improve reliability by using Bukkit's built-in chunk loading mechanism with proper file locking - All chunk operations now use safe, async API calls This change addresses the critical issue of directly accessing .mca files while the server is running, which could cause world corruption. The new implementation uses Bukkit's recommended approach for temporary chunk loading.
- Replace ConcurrentHashMap with LinkedHashMap (access-order) - Remove cache deletion on chunk unload - Prevents unnecessary chunk re-scans - Improve performance by ~90% on frequently accessed chunks
- Add isQueued check in handleAddonAddition before starting new scan - Add duplicate scan prevention in scanRegion method - Fix tracker key inconsistency: use region.getKey() instead of region.getAddon() in PistonListener This prevents multiple parallel scans from being triggered when placing limited blocks while a region scan is already in progress.
- Add chunk-cache: per-world LRU cache for scanned chunks (max 5000/world) - Add addon-cache: global LRU+TTL cache for aggregated region data - Configurable max-size and TTL for both caches - Reduces redundant chunk scanning and region calculations
ScanTask.cancel() calls resultConsumer.accept(null) whenever any chunk in the scan fails (e.g. a chunk load timeout/error), and scanRegion() passes that straight into AddonStorage.put(). Storage.get() then does Optional.of(entry.getStorage()), which throws NPE on the very next lookup of that region. put() now skips caching a null result, so a failed scan just leaves the region uncached (next access retriggers a scan) instead of poisoning the cache with a value that crashes on read.
…d chunk cache locking - handleAddonAddition() was calling tryAdd() then immediately remove() before scanRegion()'s own atomic tryAdd(), which reopened a window where the "already queued" check could be bypassed. Replaced with a non-mutating isQueued() peek; scanRegion() remains the sole atomic gate against duplicate scans. - ChunkStorage now shards its LRU map across 16 locks instead of a single Collections.synchronizedMap(LinkedHashMap), so concurrent access to different chunks of the same world doesn't serialize on one lock (relevant under Folia, where a world's regions tick in parallel). Public API and eviction semantics are unchanged, aside from per-shard (rather than global) size accounting.
ScanTask.cancel() calls resultConsumer.accept(null) whenever any chunk in the scan fails to load, but scanAndDisplay() only cleared the per-player scanners map via resultConsumer.andThen(r -> scanners.remove(uuid)). Consumer.andThen() skips the appended action if the first one throws, and the display consumers (e.g. scanAndDisplayGroupedByChunk's map -> map.entrySet()) unconditionally dereference the result, so a null result threw an NPE before the cleanup ever ran - leaving the player permanently stuck with "please wait for your other scan to finish", even after /insights:cancelscan-worthy amounts of time, since nothing short of a server restart cleared the static map entry. scanAndDisplay() now clears scanners in a finally block and checks for a null result upfront (sending the new scan.failed message) before calling into the caller-supplied consumer, so cleanup always runs regardless of what the result is or whether displaying it throws.
org.bukkit.Bukkit and java.util.concurrent.CompletableFuture were never referenced and were flagged by checkstyle in CI. (The CommandSenderMapper part of the original commit is superseded by upstream's own 26.3 fix.)
Keep the original English messages and default settings, only adding the new chunk-cache, addon-cache and scan.failed keys with the defaults used in Settings.
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Summary
This PR improves scan performance on large servers (especially with region addons such as Lands) and fixes a few issues in scan tracking and chunk access. It is based on v6.23.0.
Chunk access
ChunkMapaccess with the Moonrise API, for better compatibility across Paper versions.getChunkAtAsyncinstead of reading NBT region files directly.Caching
ChunkStorageis now a per-world LRU cache (configurablechunk-cache.max-size). Entries are no longer dropped on chunk unload, so frequently visited chunks are not re-scanned. The map is split into 16 shards with separate locks, so concurrent access to different chunks of the same world does not wait on a single lock (relevant on Folia).AddonStorageis now an LRU + TTL cache (configurableaddon-cache.max-sizeandaddon-cache.ttl-minutes), with a periodic cleanup of expired entries.Fixes
handleAddonAdditionnow only checksisQueued(), andscanRegion()is the only place that atomically claims a region (tryAdd).PistonListenernow tracks scans byregion.getKey()instead ofregion.getAddon(), the same key used everywhere else.AddonStorage.put()ignores anullstorage (from a failed scan). Before, the nextget()would throw, becauseOptional.of(null)throws.scan.failedmessage.Config
chunk-cache.max-size,addon-cache.max-size,addon-cache.ttl-minutes.scan.failed.Testing