Fix performance regressions: remove TIER0, consolidate scratchpads, remove Arc trap

Browse Source

Key fixes based on benchmark analysis:
1. Remove TIER0 Vec-based pathfinding - O(N) linear scan was slower than FxHashMap for typical path lengths
2. Consolidate scratchpads into single AStarScratchpad struct - eliminates nested RefCell borrow overhead
3. Remove Arc wrapper from TileMap - eliminated Copy-on-Write trap causing 63ms stutters
4. Replace AHashMap with FxHashMap - FxHash is faster for small integer keys like IVec3
5. Simplify tier logic - single pathfinding function with scratchpad reuse

Benchmark analysis showed:
- Original: 1.95 µs/node, P99 1.1ms, Max 5ms
- TIER0/TIER1 regression: 2.89 µs/node (+48%), P99 5ms (+348%)
- Root causes: Vec linear scan in TIER0, nested RefCell borrows, Arc::make_mut CoW

This should restore and improve performance by using simple FxHashMap scratchpad for all paths.

...

This commit is contained in:

popertots

2026-03-18 15:30:48 +00:00

parent 466a20700a

commit 367ab26d5e

3 changed files with 246 additions and 1346 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download Patch File Download Diff File Expand all files Collapse all files

src/entities/shared_systems/pathfinding.rs

+232 -1281

File diff suppressed because it is too large Load Diff