Function EstimateFeeRate

src/wallet/feebumper.cpp:121–146

}

static CFeeRate EstimateFeeRate(const CWallet& wallet, const CWalletTx& wtx, const CAmount old_fee, const CCoinControl& coin_control)
{
    // Get the fee rate of the original transaction. This is calculated from
    // the tx fee/vsize, so it may have been rounded down. Add 1 satoshi to the
    // result.
    int64_t txSize = GetVirtualTransactionSize(*(wtx.tx));
    CFeeRate feerate(old_fee, txSize);
    feerate += CFeeRate(1);

    // The node has a configurable incremental relay fee. Increment the fee by
    // the minimum of that and the wallet's conservative
    // WALLET_INCREMENTAL_RELAY_FEE value to future proof against changes to
    // network wide policy for incremental relay fee that our node may not be
    // aware of. This ensures we're over the required relay fee rate
    // (BIP 125 rule 4).  The replacement tx will be at least as large as the
    // original tx, so the total fee will be greater (BIP 125 rule 3)
    CFeeRate node_incremental_relay_fee = wallet.chain().relayIncrementalFee();
    CFeeRate wallet_incremental_relay_fee = CFeeRate(WALLET_INCREMENTAL_RELAY_FEE);
    feerate += std::max(node_incremental_relay_fee, wallet_incremental_relay_fee);

    // Fee rate must also be at least the wallet's GetMinimumFeeRate
    CFeeRate min_feerate(GetMinimumFeeRate(wallet, coin_control, /* feeCalc */ nullptr));

    // Set the required fee rate for the replacement transaction in coin control.
    return std::max(feerate, min_feerate);
}

namespace feebumper {