Line data    Source code

       1             : // Copyright (c) 2009-2010 Satoshi Nakamoto
       2             : // Copyright (c) 2009-2022 The Bitcoin Core developers
       3             : // Distributed under the MIT software license, see the accompanying
       4             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       5             : 
       6             : #ifndef BITCOIN_POLICY_FEERATE_H
       7             : #define BITCOIN_POLICY_FEERATE_H
       8             : 
       9             : #include <consensus/amount.h>
      10             : #include <serialize.h>
      11             : 
      12             : 
      13             : #include <cstdint>
      14             : #include <string>
      15             : #include <type_traits>
      16             : 
      17             : const std::string CURRENCY_UNIT = "BTC"; // One formatted unit
      18             : const std::string CURRENCY_ATOM = "sat"; // One indivisible minimum value unit
      19             : 
      20             : /* Used to determine type of fee estimation requested */
      21             : enum class FeeEstimateMode {
      22             :     UNSET,        //!< Use default settings based on other criteria
      23             :     ECONOMICAL,   //!< Force estimateSmartFee to use non-conservative estimates
      24             :     CONSERVATIVE, //!< Force estimateSmartFee to use conservative estimates
      25             :     BTC_KVB,      //!< Use BTC/kvB fee rate unit
      26             :     SAT_VB,       //!< Use sat/vB fee rate unit
      27             : };
      28             : 
      29             : /**
      30             :  * Fee rate in satoshis per kilovirtualbyte: CAmount / kvB
      31             :  */
      32             : class CFeeRate
      33             : {
      34             : private:
      35             :     /** Fee rate in sat/kvB (satoshis per 1000 virtualbytes) */
      36             :     CAmount nSatoshisPerK;
      37             : 
      38             : public:
      39             :     /** Fee rate of 0 satoshis per kvB */
      40        1343 :     CFeeRate() : nSatoshisPerK(0) { }
      41             :     template<typename I>
      42       66844 :     explicit CFeeRate(const I _nSatoshisPerK): nSatoshisPerK(_nSatoshisPerK) {
      43             :         // We've previously had bugs creep in from silent double->int conversion...
      44             :         static_assert(std::is_integral<I>::value, "CFeeRate should be used without floats");
      45       66844 :     }
      46             : 
      47             :     /**
      48             :      * Construct a fee rate from a fee in satoshis and a vsize in vB.
      49             :      *
      50             :      * param@[in]   nFeePaid    The fee paid by a transaction, in satoshis
      51             :      * param@[in]   num_bytes   The vsize of a transaction, in vbytes
      52             :      */
      53             :     CFeeRate(const CAmount& nFeePaid, uint32_t num_bytes);
      54             : 
      55             :     /**
      56             :      * Return the fee in satoshis for the given vsize in vbytes.
      57             :      * If the calculated fee would have fractional satoshis, then the
      58             :      * returned fee will always be rounded up to the nearest satoshi.
      59             :      */
      60             :     CAmount GetFee(uint32_t num_bytes) const;
      61             : 
      62             :     /**
      63             :      * Return the fee in satoshis for a vsize of 1000 vbytes
      64             :      */
      65         375 :     CAmount GetFeePerK() const { return nSatoshisPerK; }
      66         404 :     friend bool operator<(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK < b.nSatoshisPerK; }
      67        8198 :     friend bool operator>(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK > b.nSatoshisPerK; }
      68           0 :     friend bool operator==(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK == b.nSatoshisPerK; }
      69         132 :     friend bool operator<=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK <= b.nSatoshisPerK; }
      70           0 :     friend bool operator>=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK >= b.nSatoshisPerK; }
      71           0 :     friend bool operator!=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK != b.nSatoshisPerK; }
      72         184 :     CFeeRate& operator+=(const CFeeRate& a) { nSatoshisPerK += a.nSatoshisPerK; return *this; }
      73             :     std::string ToString(const FeeEstimateMode& fee_estimate_mode = FeeEstimateMode::BTC_KVB) const;
      74             : 
      75           0 :     SERIALIZE_METHODS(CFeeRate, obj) { READWRITE(obj.nSatoshisPerK); }
      76             : };
      77             : 
      78             : #endif // BITCOIN_POLICY_FEERATE_H