Output Fee Estimation Calculations in CreateTransaction

3 files changed, 31 insertions, 11 deletions

diff --git a/src/wallet/feebumper.cpp b/src/wallet/feebumper.cpp
index 46ef87b7b1..6a9e6cf9ff 100644
--- a/src/wallet/feebumper.cpp
+++ b/src/wallet/feebumper.cpp
@@ -165,7 +165,7 @@ CFeeBumper::CFeeBumper(const CWallet *pWallet, const uint256 txidIn, int newConf
         nNewFee = totalFee;
         nNewFeeRate = CFeeRate(totalFee, maxNewTxSize);
     } else {
-        nNewFee = CWallet::GetMinimumFee(maxNewTxSize, newConfirmTarget, mempool, ::feeEstimator, ignoreGlobalPayTxFee);
+        nNewFee = CWallet::GetMinimumFee(maxNewTxSize, newConfirmTarget, mempool, ::feeEstimator, nullptr, ignoreGlobalPayTxFee);
         nNewFeeRate = CFeeRate(nNewFee, maxNewTxSize);
 
         // New fee rate must be at least old rate + minimum incremental relay rate
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index b2706d09f6..796580728e 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2524,7 +2524,8 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
 
     assert(txNew.nLockTime <= (unsigned int)chainActive.Height());
     assert(txNew.nLockTime < LOCKTIME_THRESHOLD);
-
+    FeeCalculation feeCalc;
+    unsigned int nBytes;
     {
         std::set<CInputCoin> setCoins;
         LOCK2(cs_main, cs_wallet);
@@ -2696,7 +2697,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                     return false;
                 }
 
-                unsigned int nBytes = GetVirtualTransactionSize(txNew);
+                nBytes = GetVirtualTransactionSize(txNew);
 
                 CTransaction txNewConst(txNew);
 
@@ -2711,7 +2712,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                 if (coinControl && coinControl->nConfirmTarget > 0)
                     currentConfirmationTarget = coinControl->nConfirmTarget;
 
-                CAmount nFeeNeeded = GetMinimumFee(nBytes, currentConfirmationTarget, ::mempool, ::feeEstimator);
+                CAmount nFeeNeeded = GetMinimumFee(nBytes, currentConfirmationTarget, ::mempool, ::feeEstimator, &feeCalc);
                 if (coinControl && coinControl->fOverrideFeeRate)
                     nFeeNeeded = coinControl->nFeeRate.GetFee(nBytes);
 
@@ -2808,6 +2809,15 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
             return false;
         }
     }
+
+    LogPrintf("Fee Calculation: Fee:%d Bytes:%u Tgt:%d (requested %d) Reason:\"%s\" Decay %.5f: Estimation: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out) Fail: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out)\n",
+              nFeeRet, nBytes, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
+              feeCalc.est.pass.start, feeCalc.est.pass.end,
+              100 * feeCalc.est.pass.withinTarget / (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool),
+              feeCalc.est.pass.withinTarget, feeCalc.est.pass.totalConfirmed, feeCalc.est.pass.inMempool, feeCalc.est.pass.leftMempool,
+              feeCalc.est.fail.start, feeCalc.est.fail.end,
+              100 * feeCalc.est.fail.withinTarget / (feeCalc.est.fail.totalConfirmed + feeCalc.est.fail.inMempool + feeCalc.est.fail.leftMempool),
+              feeCalc.est.fail.withinTarget, feeCalc.est.fail.totalConfirmed, feeCalc.est.fail.inMempool, feeCalc.est.fail.leftMempool);
     return true;
 }
 
@@ -2882,23 +2892,32 @@ CAmount CWallet::GetRequiredFee(unsigned int nTxBytes)
     return std::max(minTxFee.GetFee(nTxBytes), ::minRelayTxFee.GetFee(nTxBytes));
 }
 
-CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, bool ignoreGlobalPayTxFee)
+CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc, bool ignoreGlobalPayTxFee)
 {
     // payTxFee is the user-set global for desired feerate
     CAmount nFeeNeeded = payTxFee.GetFee(nTxBytes);
     // User didn't set: use -txconfirmtarget to estimate...
     if (nFeeNeeded == 0 || ignoreGlobalPayTxFee) {
-        int estimateFoundTarget = nConfirmTarget;
-        nFeeNeeded = estimator.estimateSmartFee(nConfirmTarget, &estimateFoundTarget, pool).GetFee(nTxBytes);
+        nFeeNeeded = estimator.estimateSmartFee(nConfirmTarget, feeCalc, pool, true).GetFee(nTxBytes);
         // ... unless we don't have enough mempool data for estimatefee, then use fallbackFee
-        if (nFeeNeeded == 0)
+        if (nFeeNeeded == 0) {
             nFeeNeeded = fallbackFee.GetFee(nTxBytes);
+            if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
+        }
+    } else {
+        if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
     }
     // prevent user from paying a fee below minRelayTxFee or minTxFee
-    nFeeNeeded = std::max(nFeeNeeded, GetRequiredFee(nTxBytes));
+    CAmount requiredFee = GetRequiredFee(nTxBytes);
+    if (requiredFee > nFeeNeeded) {
+        nFeeNeeded = requiredFee;
+        if (feeCalc) feeCalc->reason = FeeReason::REQUIRED;
+    }
     // But always obey the maximum
-    if (nFeeNeeded > maxTxFee)
+    if (nFeeNeeded > maxTxFee) {
         nFeeNeeded = maxTxFee;
+        if (feeCalc) feeCalc->reason = FeeReason::MAXTXFEE;
+    }
     return nFeeNeeded;
 }
 
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index a9c50aee4d..f0bf2c5afb 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -76,6 +76,7 @@ class CScheduler;
 class CTxMemPool;
 class CBlockPolicyEstimator;
 class CWalletTx;
+class FeeCalculation;
 
 /** (client) version numbers for particular wallet features */
 enum WalletFeature
@@ -956,7 +957,7 @@ public:
      * Estimate the minimum fee considering user set parameters
      * and the required fee
      */
-    static CAmount GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, bool ignoreGlobalPayTxFee = false);
+    static CAmount GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc = nullptr, bool ignoreGlobalPayTxFee = false);
     /**
      * Return the minimum required fee taking into account the
      * floating relay fee and user set minimum transaction fee