MemoryMaster — Server-Side Heap Memory Optimization Mod

For NeoForge 1.21.1, server-side only; no client installation required.

All 7 modules are enabled by default and can be disabled individually. Each module's mixins are kept in separate files, so a problem in one module won't affect the others.

Safety is a design prerequisite:

• The mixin plugin only validates target classes through resource lookup and does not load any classes (avoiding disruption of other mods' injection timing).
• All injections use require = 0, and the mixin config uses required = false.
• All optimization logic is wrapped in try-catch; on exception it falls back to vanilla behavior and logs it.
• There is a self-check at the transform stage and another after server startup to confirm whether injection points actually took effect; behavior-type injection points that didn't take effect are automatically downgraded.
• The mixin config uses priority = 9999, applied after other mods.
• After startup it scans other mods' mixins and proactively yields and writes to config when write-type overlap is found.
• /mmcmf panic disables all optimizations with one command.

Modules

• structures — Structure template cache LRU cap (default 30; the only write-type optimization enabled by default)
• diagnose — Read-only diagnostics: /mmcmf report, /mmcmf diagnose, JFR 96–128 byte allocation tracking
• guava — Guava immutable collection duplication measurement (write rewriting disabled by default)
• bytepool — byte[] bucketed pool (16/32/64/128 KB; pooling application disabled by default)
• objpool — Collection capacity pre-allocation based on historical peaks (disabled by default; cross-session learning)
• smallobj — Creation-count statistics for BlockPos / ItemStack / advancement objects
• secondopt — Conflict detection with FerriteCore/ModernFix/C2ME/Clumps, read-only leak observation, yielding

Commands

• /mmcmf status — Module status and injection point self-check
• /mmcmf report — JVM memory + memory-saving statistics (resident and allocation amounts calculated separately)
• /mmcmf diagnose [smallobj|leaks|mods]
• /mmcmf optimize|disable <module>|all
• /mmcmf panic | unpanic | reload

It should be noted: the only write-type optimization enabled by default is the structure template cache cap; the rest are measurement and optional experiments. The real memory hogs are still view distance / simulation distance, ModernFix's dynamic_resources, and FerriteCore — this mod does not replace them.