| #include "rollback.h" |
| #include "../runtime/engine.h" |
|
|
| namespace unify { |
|
|
| void RollbackBuffer::advance(Engine& engine) { |
| uint64_t tick = engine.sim_clock().tick; |
| if (tick % interval_ == 0) snaps_.push_back({tick, engine.save_state(false)}); |
| engine.tick(); |
| log_.push_back(engine.input().frame()); |
| |
| while (!snaps_.empty() && tick - snaps_.front().tick > max_ticks_ && snaps_.size() > 1) snaps_.pop_front(); |
| while (!log_.empty() && !snaps_.empty() && log_.front().tick < snaps_.front().tick) log_.pop_front(); |
| } |
|
|
| bool RollbackBuffer::rewind_and_resimulate(Engine& engine, uint64_t tick, std::string& error) { |
| uint64_t now = engine.sim_clock().tick; |
| const Snap* base = nullptr; |
| for (const Snap& s : snaps_) if (s.tick <= tick) base = &s; |
| if (!base) { error = "tick is older than the rollback window"; return false; } |
| if (!engine.load_state(base->state, error)) return false; |
| for (const InputFrame& f : log_) { |
| if (f.tick < base->tick) continue; |
| if (f.tick >= now) break; |
| if (f.tick % interval_ == 0) { |
| for (Snap& s : snaps_) if (s.tick == f.tick) s.state = engine.save_state(false); |
| } |
| engine.replay_tick(f); |
| resimulated_++; |
| } |
| return engine.sim_clock().tick == now || (error = "resimulation ended at the wrong tick", false); |
| } |
|
|
| bool RollbackBuffer::correct(Engine& engine, uint64_t tick, const InputFrame& frame, std::string& error) { |
| for (InputFrame& f : log_) { |
| if (f.tick != tick) continue; |
| f = frame; |
| f.tick = tick; |
| return rewind_and_resimulate(engine, tick, error); |
| } |
| error = "no recorded input for that tick"; |
| return false; |
| } |
|
|
| } |
|
|
