Class CFeeRate

src/policy/feerate.h:31–80

* Fee rate in satoshis per virtualbyte: CAmount / vB * the feerate is represented internally as FeeFrac */

 * the feerate is represented internally as FeeFrac
 */
class CFeeRate
{
private:
    /** Fee rate in sats/vB (satoshis per N virtualbytes) */
    FeePerVSize m_feerate;

public:
    /** Fee rate of 0 satoshis per 0 vB */
    CFeeRate() = default;
    template<std::integral I> // Disallow silent float -> int conversion
    explicit CFeeRate(const I m_feerate_kvb) : m_feerate(FeePerVSize(m_feerate_kvb, 1000)) {}

    /**
     * Construct a fee rate from a fee in satoshis and a vsize in vB.
     *
     * Passing any virtual_bytes less than or equal to 0 will result in 0 fee rate per 0 size.
     */
    CFeeRate(const CAmount& nFeePaid, int32_t virtual_bytes);

    /**
     * Return the fee in satoshis for the given vsize in vbytes.
     * If the calculated fee would have fractional satoshis, then the
     * returned fee will always be rounded up to the nearest satoshi.
     */
    CAmount GetFee(int32_t virtual_bytes) const;

    FeePerVSize GetFeePerVSize() const { return m_feerate; }

    /**
     * Return the fee in satoshis for a vsize of 1000 vbytes
     */
    CAmount GetFeePerK() const { return CAmount(m_feerate.EvaluateFeeDown(1000)); }
    friend std::strong_ordering operator<=>(const CFeeRate& a, const CFeeRate& b) noexcept
    {
        return ByRatio{a.m_feerate} <=> ByRatio{b.m_feerate};
    }
    friend bool operator==(const CFeeRate& a, const CFeeRate& b) noexcept
    {
        return ByRatio{a.m_feerate} == ByRatio{b.m_feerate};
    }
    CFeeRate& operator+=(const CFeeRate& a) {
        m_feerate = FeePerVSize(GetFeePerK() + a.GetFeePerK(), 1000);
        return *this;
    }
    std::string ToString(FeeRateFormat fee_rate_format = FeeRateFormat::BTC_KVB) const;
    friend CFeeRate operator*(const CFeeRate& f, int a) { return CFeeRate(a * f.m_feerate.fee, f.m_feerate.size); }
    friend CFeeRate operator*(int a, const CFeeRate& f) { return CFeeRate(a * f.m_feerate.fee, f.m_feerate.size); }

    SERIALIZE_METHODS(CFeeRate, obj) { READWRITE(obj.m_feerate.fee, obj.m_feerate.size); }
};

#endif // BITCOIN_POLICY_FEERATE_H