Branch data     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                 :            : #include <wallet/fees.h>
       7                 :            : 
       8                 :            : #include <wallet/coincontrol.h>
       9                 :            : #include <wallet/wallet.h>
      10                 :            : 
      11                 :            : 
      12                 :            : namespace wallet {
      13                 :          0 : CAmount GetRequiredFee(const CWallet& wallet, unsigned int nTxBytes)
      14                 :            : {
      15                 :          0 :     return GetRequiredFeeRate(wallet).GetFee(nTxBytes);
      16                 :            : }
      17         [ +  - ]:          2 : 
      18         [ +  - ]:          2 : 
      19                 :          0 : CAmount GetMinimumFee(const CWallet& wallet, unsigned int nTxBytes, const CCoinControl& coin_control, FeeCalculation* feeCalc)
      20                 :            : {
      21                 :          0 :     return GetMinimumFeeRate(wallet, coin_control, feeCalc).GetFee(nTxBytes);
      22                 :            : }
      23                 :            : 
      24                 :          0 : CFeeRate GetRequiredFeeRate(const CWallet& wallet)
      25                 :            : {
      26                 :          0 :     return std::max(wallet.m_min_fee, wallet.chain().relayMinFee());
      27                 :          2 : }
      28                 :            : 
      29                 :          0 : CFeeRate GetMinimumFeeRate(const CWallet& wallet, const CCoinControl& coin_control, FeeCalculation* feeCalc)
      30                 :            : {
      31                 :            :     /* User control of how to calculate fee uses the following parameter precedence:
      32                 :            :        1. coin_control.m_feerate
      33                 :            :        2. coin_control.m_confirm_target
      34                 :            :        3. m_pay_tx_fee (user-set member variable of wallet)
      35                 :            :        4. m_confirm_target (user-set member variable of wallet)
      36                 :            :        The first parameter that is set is used.
      37                 :            :     */
      38                 :          0 :     CFeeRate feerate_needed;
      39         [ #  # ]:          0 :     if (coin_control.m_feerate) { // 1.
      40                 :          0 :         feerate_needed = *(coin_control.m_feerate);
      41         [ #  # ]:          0 :         if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
      42                 :            :         // Allow to override automatic min/max check over coin control instance
      43         [ #  # ]:          0 :         if (coin_control.fOverrideFeeRate) return feerate_needed;
      44                 :          0 :     }
      45 [ #  # ][ #  # ]:          0 :     else if (!coin_control.m_confirm_target && wallet.m_pay_tx_fee != CFeeRate(0)) { // 3. TODO: remove magic value of 0 for wallet member m_pay_tx_fee
      46                 :          0 :         feerate_needed = wallet.m_pay_tx_fee;
      47         [ #  # ]:          0 :         if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
      48                 :          0 :     }
      49                 :            :     else { // 2. or 4.
      50                 :            :         // We will use smart fee estimation
      51         [ #  # ]:          0 :         unsigned int target = coin_control.m_confirm_target ? *coin_control.m_confirm_target : wallet.m_confirm_target;
      52                 :            :         // By default estimates are economical iff we are signaling opt-in-RBF
      53         [ #  # ]:          0 :         bool conservative_estimate = !coin_control.m_signal_bip125_rbf.value_or(wallet.m_signal_rbf);
      54                 :            :         // Allow to override the default fee estimate mode over the CoinControl instance
      55         [ #  # ]:          0 :         if (coin_control.m_fee_mode == FeeEstimateMode::CONSERVATIVE) conservative_estimate = true;
      56         [ #  # ]:          0 :         else if (coin_control.m_fee_mode == FeeEstimateMode::ECONOMICAL) conservative_estimate = false;
      57                 :            : 
      58                 :          0 :         feerate_needed = wallet.chain().estimateSmartFee(target, conservative_estimate, feeCalc);
      59         [ #  # ]:          0 :         if (feerate_needed == CFeeRate(0)) {
      60                 :            :             // if we don't have enough data for estimateSmartFee, then use fallback fee
      61                 :          0 :             feerate_needed = wallet.m_fallback_fee;
      62         [ #  # ]:          0 :             if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
      63                 :            : 
      64                 :            :             // directly return if fallback fee is disabled (feerate 0 == disabled)
      65         [ #  # ]:          0 :             if (wallet.m_fallback_fee == CFeeRate(0)) return feerate_needed;
      66                 :          0 :         }
      67                 :            :         // Obey mempool min fee when using smart fee estimation
      68                 :          0 :         CFeeRate min_mempool_feerate = wallet.chain().mempoolMinFee();
      69         [ #  # ]:          0 :         if (feerate_needed < min_mempool_feerate) {
      70                 :          0 :             feerate_needed = min_mempool_feerate;
      71         [ #  # ]:          0 :             if (feeCalc) feeCalc->reason = FeeReason::MEMPOOL_MIN;
      72                 :          0 :         }
      73                 :            :     }
      74                 :            : 
      75                 :            :     // prevent user from paying a fee below the required fee rate
      76                 :          0 :     CFeeRate required_feerate = GetRequiredFeeRate(wallet);
      77         [ #  # ]:          0 :     if (required_feerate > feerate_needed) {
      78                 :          0 :         feerate_needed = required_feerate;
      79         [ #  # ]:          0 :         if (feeCalc) feeCalc->reason = FeeReason::REQUIRED;
      80                 :          0 :     }
      81                 :          0 :     return feerate_needed;
      82                 :          0 : }
      83                 :            : 
      84                 :          0 : CFeeRate GetDiscardRate(const CWallet& wallet)
      85                 :            : {
      86                 :          0 :     unsigned int highest_target = wallet.chain().estimateMaxBlocks();
      87                 :          0 :     CFeeRate discard_rate = wallet.chain().estimateSmartFee(highest_target, /*conservative=*/false);
      88                 :            :     // Don't let discard_rate be greater than longest possible fee estimate if we get a valid fee estimate
      89         [ #  # ]:          0 :     discard_rate = (discard_rate == CFeeRate(0)) ? wallet.m_discard_rate : std::min(discard_rate, wallet.m_discard_rate);
      90                 :            :     // Discard rate must be at least dust relay feerate
      91                 :          2 :     discard_rate = std::max(discard_rate, wallet.chain().relayDustFee());
      92                 :          0 :     return discard_rate;
      93                 :            : }
      94                 :            : } // namespace wallet