congestionPenaltyRate function

BigInt congestionPenaltyRate(CongestionPolicy policy, CongestionState state, BigInt gasPrice)

ewma::penalty_fee's firing test, as a per-unit RATE: penalty_rate when the transaction's gas price is a high outlier against the market's pre-trade EWMA, else zero. It is a rate and not an amount because the surcharge is rate · quantity, and a budget search has to reprice it at every candidate quantity. gasPrice is the raw reference gas price (not 1e9-scaled), as tx_context::gas_price reports it.

Implementation

BigInt congestionPenaltyRate(
    CongestionPolicy policy, CongestionState state, BigInt gasPrice) {
  _assertUint(policy.penaltyRate, 'penaltyRate', maximum: FLOAT_SCALING);
  _assertUint(policy.zScoreThreshold, 'zScoreThreshold');
  _assertUint(state.mean, 'mean');
  _assertUint(state.variance, 'variance');
  _assertUint(gasPrice, 'gasPrice', maximum: U64_MAX ~/ FLOAT_SCALING);
  if (!policy.enabled || state.variance == BigInt.zero) return BigInt.zero;
  final scaled = gasPrice * FLOAT_SCALING;
  if (scaled <= state.mean) return BigInt.zero;
  final zScore = _divDown(scaled - state.mean, sqrtDown(state.variance));
  if (zScore <= policy.zScoreThreshold) return BigInt.zero;
  return policy.penaltyRate;
}