Module diff_pool 

WavDiff + DiffPool + RollbackBuffer — 18-byte diff protocol with pre-allocated ring buffers for deterministic rollback.

All world mutations flow through WavDiff. The DiffPool is a 1.1MB pre-allocated ring buffer that never grows. The RollbackBuffer stores exactly 120 frames (1.0 second at 120Hz) of FrameSnapshot metadata for prediction/correction rollback.

Zero heap allocation. Integer-only. Bitwise deterministic.

Structs

DiffPool

Pre-allocated 1.1MB ring buffer of WavDiff entries.

FrameDiffIter

Forward iterator over a frame’s diffs in the DiffPool.

FrameDiffReverseIter

Reverse iterator over a frame’s diffs in the DiffPool.

FrameRangeIter

Forward iterator over frames in a tick range.

FrameRangeReverseIter

Reverse iterator over frames in a tick range.

FrameSnapshot

Metadata snapshot for a single simulation frame.

RollbackBuffer

120-frame ring buffer for prediction/correction rollback.

WavDiff

18-byte diff record for a single state mutation.

Constants

POOL_CAPACITY

Pre-allocated DiffPool capacity. 18 bytes × 64000 ≈ 1.125 MB — fits the 1.1MB budget with margin.

ROLLBACK_FRAMES

Rollback window: exactly 120 frames = 1.0 second at 120Hz. Architecturally locked — do not change.

Functions

compute_tick_checksum

Compute a Blake3 checksum of a frame’s diffs in the DiffPool.

replay

Replay diffs forward (old→new) to restore state after rewind.

rewind

Rewind state by applying diffs in reverse (new→old).