perf: cache display item names to eliminate per-search skull construction#92
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Problem: FilterType.BY_DISPLAY_ITEM_NAME called getDisplayRecipes() live on every Slimefun machine during each player search. getDisplayRecipes() clones SlimefunItemStacks, which triggers CraftMetaSkull.applyToItem and CraftPlayerProfile.<init> for every skull-based display item. CraftPlayerProfile construction fires HTTP requests to Mojang sessionserver, causing 429 rate-limit errors and TPS drops on the server thread. Spark profiler confirmed CraftPlayerProfile.<init> (91 nodes) and CraftMetaSkull (390 nodes) were all rooted in SearchGroup.filterItems via the BY_DISPLAY_ITEM_NAME filter. Fix: - SearchGroup: add DISPLAY_ITEM_NAMES_CACHE (Map<String,List<String>>), a hard-reference map from Slimefun item ID to lower-cased display names from getDisplayRecipes(). Populated once during init() alongside CACHE2. - FilterType.BY_DISPLAY_ITEM_NAME: replace live getDisplayRecipes() calls with a lookup against DISPLAY_ITEM_NAMES_CACHE. No ItemStack clone, no CraftMetaSkull, no CraftPlayerProfile, no Mojang HTTP request at search. - Removed unused imports from FilterType (AContainer, MultiBlockMachine, RecipeDisplayItem, SpecialMenuProvider, Debug). - pom.xml: bump Lombok 1.18.34 -> 1.18.38 for JDK 25 compatibility.
Fixes NoClassDefFoundError on Leaf 1.21.11 (modern Paper, no versioned CraftBukkit packages). 1.10.13-SNAPSHOT ships Wrapper26_R1 which uses the un-versioned org.bukkit.craftbukkit.* import path that Leaf uses.
balugaq
approved these changes
May 23, 2026
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Changes
SearchGroup: addDISPLAY_ITEM_NAMES_CACHE(Map<String, List<String>>), populated once duringinit()alongsideCACHE2. Stores lower-cased display names fromgetDisplayRecipes()per item ID.FilterType.BY_DISPLAY_ITEM_NAME: replace livegetDisplayRecipes()calls with a lookup against the cache. EliminatesCraftMetaSkull/CraftPlayerProfileconstruction at search time, which was firing Mojang sessionserver HTTP requests and causing 429 rate-limit errors.Root cause
Every player search triggered
BY_DISPLAY_ITEM_NAME, which calledgetDisplayRecipes()live per item. For skull-based display items this clones aSlimefunItemStack, constructsCraftMetaSkullandCraftPlayerProfile, and fires an HTTP request tosessionserver.mojang.com. Under load this saturates Mojang's rate limit (HTTP 429) and stalls the server thread.Spark profiler confirmed
CraftPlayerProfile.<init>(91 call-tree nodes) andCraftMetaSkull(390 nodes) were all rooted inSearchGroup.filterItemsvia this filter.After
Display name lookup is a plain
Map.get+ stringcontains-- no object allocation, no HTTP, no Mojang round-trip.Live-tested on production server
Deployed on a Leaf 1.21.11 server with ~133 plugins (heavy Slimefun ecosystem including SlimeAE, NetworksExpansion, LogiTech, InfinityExpansion). All addon integrations verified working after the fix.