diff options
| -rw-r--r-- | src/wallet/wallet.cpp | 224 |
1 files changed, 94 insertions, 130 deletions
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp index e848145a51..51ff683c2e 100644 --- a/src/wallet/wallet.cpp +++ b/src/wallet/wallet.cpp @@ -2834,7 +2834,6 @@ bool CWallet::CreateTransactionInternal( CMutableTransaction txNew; FeeCalculation feeCalc; - CAmount nFeeNeeded; std::pair<int64_t, int64_t> tx_sizes; int nBytes; { @@ -2919,7 +2918,6 @@ bool CWallet::CreateTransactionInternal( coin_selection_params.m_cost_of_change = coin_selection_params.m_discard_feerate.GetFee(coin_selection_params.change_spend_size) + coin_selection_params.m_change_fee; nFeeRet = 0; - bool pick_new_inputs = true; CAmount nValueIn = 0; // BnB selector is the only selector used when this is true. @@ -2932,7 +2930,6 @@ bool CWallet::CreateTransactionInternal( nChangePosInOut = nChangePosRequest; txNew.vin.clear(); txNew.vout.clear(); - bool fFirst = true; CAmount nValueToSelect = nValue; if (nSubtractFeeFromAmount == 0) @@ -2946,33 +2943,14 @@ bool CWallet::CreateTransactionInternal( { CTxOut txout(recipient.nAmount, recipient.scriptPubKey); - if (recipient.fSubtractFeeFromAmount) - { - assert(nSubtractFeeFromAmount != 0); - txout.nValue -= nFeeRet / nSubtractFeeFromAmount; // Subtract fee equally from each selected recipient - - if (fFirst) // first receiver pays the remainder not divisible by output count - { - fFirst = false; - txout.nValue -= nFeeRet % nSubtractFeeFromAmount; - } - } - // Include the fee cost for outputs. Note this is only used for BnB right now + // Include the fee cost for outputs. if (!coin_selection_params.m_subtract_fee_outputs) { coin_selection_params.tx_noinputs_size += ::GetSerializeSize(txout, PROTOCOL_VERSION); } if (IsDust(txout, chain().relayDustFee())) { - if (recipient.fSubtractFeeFromAmount && nFeeRet > 0) - { - if (txout.nValue < 0) - error = _("The transaction amount is too small to pay the fee"); - else - error = _("The transaction amount is too small to send after the fee has been deducted"); - } - else - error = _("Transaction amount too small"); + error = _("Transaction amount too small"); return false; } txNew.vout.push_back(txout); @@ -2980,58 +2958,40 @@ bool CWallet::CreateTransactionInternal( // Choose coins to use bool bnb_used = false; - if (pick_new_inputs) { - nValueIn = 0; - setCoins.clear(); - if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, coin_control, coin_selection_params, bnb_used)) - { - // If BnB was used, it was the first pass. No longer the first pass and continue loop with knapsack. - if (bnb_used) { - coin_selection_params.use_bnb = false; - continue; - } - else { - error = _("Insufficient funds"); - return false; - } + nValueIn = 0; + setCoins.clear(); + if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, coin_control, coin_selection_params, bnb_used)) + { + // If BnB was used, it was the first pass. No longer the first pass and continue loop with knapsack. + if (bnb_used) { + coin_selection_params.use_bnb = false; + continue; + } + else { + error = _("Insufficient funds"); + return false; } - } else { - bnb_used = false; } - const CAmount change_and_fee = nValueIn - nValueToSelect; - if (change_and_fee > 0) - { - // Fill a vout to ourself - CTxOut newTxOut(change_and_fee, scriptChange); - - // Never create dust outputs; if we would, just - // add the dust to the fee. - // The change_and_fee when BnB is used is always going to go to fees. - if (IsDust(newTxOut, coin_selection_params.m_discard_feerate) || bnb_used) - { - nChangePosInOut = -1; - nFeeRet += change_and_fee; - } - else - { - if (nChangePosInOut == -1) - { - // Insert change txn at random position: - nChangePosInOut = GetRandInt(txNew.vout.size()+1); - } - else if ((unsigned int)nChangePosInOut > txNew.vout.size()) - { - error = _("Change index out of range"); - return false; - } + // Always make a change output + // We will reduce the fee from this change output later, and remove the output if it is too small. + const CAmount change_and_fee = nValueIn - nValue; + assert(change_and_fee >= 0); + CTxOut newTxOut(change_and_fee, scriptChange); - std::vector<CTxOut>::iterator position = txNew.vout.begin()+nChangePosInOut; - txNew.vout.insert(position, newTxOut); - } - } else { - nChangePosInOut = -1; + if (nChangePosInOut == -1) + { + // Insert change txn at random position: + nChangePosInOut = GetRandInt(txNew.vout.size()+1); } + else if ((unsigned int)nChangePosInOut > txNew.vout.size()) + { + error = _("Change index out of range"); + return false; + } + + assert(nChangePosInOut != -1); + auto change_position = txNew.vout.insert(txNew.vout.begin() + nChangePosInOut, newTxOut); // Dummy fill vin for maximum size estimation // @@ -3039,76 +2999,80 @@ bool CWallet::CreateTransactionInternal( txNew.vin.push_back(CTxIn(coin.outpoint,CScript())); } + // Calculate the transaction fee tx_sizes = CalculateMaximumSignedTxSize(CTransaction(txNew), this, coin_control.fAllowWatchOnly); nBytes = tx_sizes.first; if (nBytes < 0) { error = _("Signing transaction failed"); return false; } + nFeeRet = coin_selection_params.m_effective_feerate.GetFee(nBytes); - nFeeNeeded = coin_selection_params.m_effective_feerate.GetFee(nBytes); - if (nFeeRet >= nFeeNeeded) { - // Reduce fee to only the needed amount if possible. This - // prevents potential overpayment in fees if the coins - // selected to meet nFeeNeeded result in a transaction that - // requires less fee than the prior iteration. - - // If we have no change and a big enough excess fee, then - // try to construct transaction again only without picking - // new inputs. We now know we only need the smaller fee - // (because of reduced tx size) and so we should add a - // change output. Only try this once. - if (nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 && pick_new_inputs) { - unsigned int tx_size_with_change = nBytes + coin_selection_params.change_output_size + 2; // Add 2 as a buffer in case increasing # of outputs changes compact size - CAmount fee_needed_with_change = coin_selection_params.m_effective_feerate.GetFee(tx_size_with_change); - CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, coin_selection_params.m_discard_feerate); - if (nFeeRet >= fee_needed_with_change + minimum_value_for_change) { - pick_new_inputs = false; - nFeeRet = fee_needed_with_change; - continue; - } - } - - // If we have change output already, just increase it - if (nFeeRet > nFeeNeeded && nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) { - CAmount extraFeePaid = nFeeRet - nFeeNeeded; - std::vector<CTxOut>::iterator change_position = txNew.vout.begin()+nChangePosInOut; - change_position->nValue += extraFeePaid; - nFeeRet -= extraFeePaid; - } - break; // Done, enough fee included. - } - else if (!pick_new_inputs) { - // This shouldn't happen, we should have had enough excess - // fee to pay for the new output and still meet nFeeNeeded - // Or we should have just subtracted fee from recipients and - // nFeeNeeded should not have changed - error = _("Transaction fee and change calculation failed"); - return false; + // Subtract fee from the change output if not subtrating it from recipient outputs + CAmount fee_needed = nFeeRet; + if (nSubtractFeeFromAmount == 0) { + change_position->nValue -= fee_needed; } - // Try to reduce change to include necessary fee - if (nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) { - CAmount additionalFeeNeeded = nFeeNeeded - nFeeRet; - std::vector<CTxOut>::iterator change_position = txNew.vout.begin()+nChangePosInOut; - // Only reduce change if remaining amount is still a large enough output. - if (change_position->nValue >= MIN_FINAL_CHANGE + additionalFeeNeeded) { - change_position->nValue -= additionalFeeNeeded; - nFeeRet += additionalFeeNeeded; - break; // Done, able to increase fee from change - } + // We want to drop the change to fees if: + // 1. The change output would be dust + // 2. The change is within the (almost) exact match window, i.e. it is less than or equal to the cost of the change output (cost_of_change) + CAmount change_amount = change_position->nValue; + if (IsDust(*change_position, coin_selection_params.m_discard_feerate) || change_amount <= coin_selection_params.m_cost_of_change) + { + nChangePosInOut = -1; + change_amount = 0; + txNew.vout.erase(change_position); + + // Because we have dropped this change, the tx size and required fee will be different, so let's recalculate those + tx_sizes = CalculateMaximumSignedTxSize(CTransaction(txNew), this, coin_control.fAllowWatchOnly); + nBytes = tx_sizes.first; + fee_needed = coin_selection_params.m_effective_feerate.GetFee(nBytes); } - // If subtracting fee from recipients, we now know what fee we - // need to subtract, we have no reason to reselect inputs - if (nSubtractFeeFromAmount > 0) { - pick_new_inputs = false; + // If the fee is covered, there's no need to loop or subtract from recipients + if (fee_needed <= change_and_fee - change_amount) { + nFeeRet = change_and_fee - change_amount; + break; } - // Include more fee and try again. - nFeeRet = nFeeNeeded; - coin_selection_params.use_bnb = false; - continue; + // Reduce output values for subtractFeeFromAmount + if (nSubtractFeeFromAmount != 0) { + CAmount to_reduce = fee_needed + change_amount - change_and_fee; + int i = 0; + bool fFirst = true; + for (const auto& recipient : vecSend) + { + if (i == nChangePosInOut) { + ++i; + } + CTxOut& txout = txNew.vout[i]; + + if (recipient.fSubtractFeeFromAmount) + { + txout.nValue -= to_reduce / nSubtractFeeFromAmount; // Subtract fee equally from each selected recipient + + if (fFirst) // first receiver pays the remainder not divisible by output count + { + fFirst = false; + txout.nValue -= to_reduce % nSubtractFeeFromAmount; + } + + // Error if this output is reduced to be below dust + if (IsDust(txout, chain().relayDustFee())) { + if (txout.nValue < 0) { + error = _("The transaction amount is too small to pay the fee"); + } else { + error = _("The transaction amount is too small to send after the fee has been deducted"); + } + return false; + } + } + ++i; + } + nFeeRet = fee_needed; + break; // The fee has been deducted from the recipients, nothing left to do here + } } // Give up if change keypool ran out and change is required @@ -3170,8 +3134,8 @@ bool CWallet::CreateTransactionInternal( reservedest.KeepDestination(); fee_calc_out = feeCalc; - WalletLogPrintf("Fee Calculation: Fee:%d Bytes:%u Needed:%d 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, nFeeNeeded, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay, + WalletLogPrintf("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, (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool) > 0.0 ? 100 * feeCalc.est.pass.withinTarget / (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool) : 0.0, feeCalc.est.pass.withinTarget, feeCalc.est.pass.totalConfirmed, feeCalc.est.pass.inMempool, feeCalc.est.pass.leftMempool, |