void SendCoinsDialog::updateMinFeeLabel()
{
if (model && model->getOptionsModel())
ui->checkBoxMinimumFee->setText(tr("Pay only the required fee of %1").arg(
BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), GetRequiredFee(1000)) + "/kB")
);
}
CAmount GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc)
{
/* User control of how to calculate fee uses the following parameter precedence:
1. coin_control.m_feerate
2. coin_control.m_confirm_target
3. payTxFee (user-set global variable)
4. nTxConfirmTarget (user-set global variable)
The first parameter that is set is used.
*/
CAmount fee_needed;
if (coin_control.m_feerate) { // 1.
fee_needed = coin_control.m_feerate->GetFee(nTxBytes);
if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
// Allow to override automatic min/max check over coin control instance
if (coin_control.fOverrideFeeRate) return fee_needed;
}
else if (!coin_control.m_confirm_target && ::payTxFee != CFeeRate(0)) { // 3. TODO: remove magic value of 0 for global payTxFee
fee_needed = ::payTxFee.GetFee(nTxBytes);
if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
}
else { // 2. or 4.
// We will use smart fee estimation
unsigned int target = coin_control.m_confirm_target ? *coin_control.m_confirm_target : ::nTxConfirmTarget;
// By default estimates are economical iff we are signaling opt-in-RBF
bool conservative_estimate = !coin_control.signalRbf;
// Allow to override the default fee estimate mode over the CoinControl instance
if (coin_control.m_fee_mode == FeeEstimateMode::CONSERVATIVE) conservative_estimate = true;
else if (coin_control.m_fee_mode == FeeEstimateMode::ECONOMICAL) conservative_estimate = false;
fee_needed = estimator.estimateSmartFee(target, feeCalc, conservative_estimate).GetFee(nTxBytes);
if (fee_needed == 0) {
// if we don't have enough data for estimateSmartFee, then use fallbackFee
fee_needed = CWallet::fallbackFee.GetFee(nTxBytes);
if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
}
// Obey mempool min fee when using smart fee estimation
CAmount min_mempool_fee = pool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(nTxBytes);
if (fee_needed < min_mempool_fee) {
fee_needed = min_mempool_fee;
if (feeCalc) feeCalc->reason = FeeReason::MEMPOOL_MIN;
}
}
// prevent user from paying a fee below minRelayTxFee or minTxFee
CAmount required_fee = GetRequiredFee(nTxBytes);
if (required_fee > fee_needed) {
fee_needed = required_fee;
if (feeCalc) feeCalc->reason = FeeReason::REQUIRED;
}
// But always obey the maximum
if (fee_needed > maxTxFee) {
fee_needed = maxTxFee;
if (feeCalc) feeCalc->reason = FeeReason::MAXTXFEE;
}
return fee_needed;
}
void SendCoinsDialog::setMinimumFee()
{
ui->customFee->setValue(GetRequiredFee(1000));
}
void SendCoinsDialog::setModel(WalletModel *_model)
{
this->model = _model;
if(_model && _model->getOptionsModel())
{
for(int i = 0; i < ui->entries->count(); ++i)
{
SendCoinsEntry *entry = qobject_cast<SendCoinsEntry*>(ui->entries->itemAt(i)->widget());
if(entry)
{
entry->setModel(_model);
}
}
setBalance(_model->getBalance(), _model->getUnconfirmedBalance(), _model->getImmatureBalance(),
_model->getWatchBalance(), _model->getWatchUnconfirmedBalance(), _model->getWatchImmatureBalance());
connect(_model, SIGNAL(balanceChanged(CAmount,CAmount,CAmount,CAmount,CAmount,CAmount)), this, SLOT(setBalance(CAmount,CAmount,CAmount,CAmount,CAmount,CAmount)));
connect(_model->getOptionsModel(), SIGNAL(displayUnitChanged(int)), this, SLOT(updateDisplayUnit()));
updateDisplayUnit();
// Coin Control
connect(_model->getOptionsModel(), SIGNAL(displayUnitChanged(int)), this, SLOT(coinControlUpdateLabels()));
connect(_model->getOptionsModel(), SIGNAL(coinControlFeaturesChanged(bool)), this, SLOT(coinControlFeatureChanged(bool)));
ui->frameCoinControl->setVisible(_model->getOptionsModel()->getCoinControlFeatures());
coinControlUpdateLabels();
// fee section
for (const int n : confTargets) {
ui->confTargetSelector->addItem(tr("%1 (%2 blocks)").arg(GUIUtil::formatNiceTimeOffset(n*Params().GetConsensus().nPowTargetSpacing)).arg(n));
}
connect(ui->confTargetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(updateSmartFeeLabel()));
connect(ui->confTargetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(coinControlUpdateLabels()));
connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(updateFeeSectionControls()));
connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(coinControlUpdateLabels()));
connect(ui->customFee, SIGNAL(valueChanged()), this, SLOT(coinControlUpdateLabels()));
connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(setMinimumFee()));
connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(updateFeeSectionControls()));
connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
connect(ui->optInRBF, SIGNAL(stateChanged(int)), this, SLOT(updateSmartFeeLabel()));
connect(ui->optInRBF, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
ui->customFee->setSingleStep(GetRequiredFee(1000));
updateFeeSectionControls();
updateMinFeeLabel();
updateSmartFeeLabel();
// set default rbf checkbox state
ui->optInRBF->setCheckState(Qt::Checked);
// set the smartfee-sliders default value (wallets default conf.target or last stored value)
QSettings settings;
if (settings.value("nSmartFeeSliderPosition").toInt() != 0) {
// migrate nSmartFeeSliderPosition to nConfTarget
// nConfTarget is available since 0.15 (replaced nSmartFeeSliderPosition)
int nConfirmTarget = 25 - settings.value("nSmartFeeSliderPosition").toInt(); // 25 == old slider range
settings.setValue("nConfTarget", nConfirmTarget);
settings.remove("nSmartFeeSliderPosition");
}
if (settings.value("nConfTarget").toInt() == 0)
ui->confTargetSelector->setCurrentIndex(getIndexForConfTarget(model->getDefaultConfirmTarget()));
else
ui->confTargetSelector->setCurrentIndex(getIndexForConfTarget(settings.value("nConfTarget").toInt()));
}
}
Result CreateTransaction(const CWallet* wallet, const uint256& txid, const CCoinControl& coin_control, CAmount total_fee, std::vector<std::string>& errors,
CAmount& old_fee, CAmount& new_fee, CMutableTransaction& mtx)
{
LOCK2(cs_main, wallet->cs_wallet);
errors.clear();
auto it = wallet->mapWallet.find(txid);
if (it == wallet->mapWallet.end()) {
errors.push_back("Invalid or non-wallet transaction id");
return Result::INVALID_ADDRESS_OR_KEY;
}
const CWalletTx& wtx = it->second;
Result result = PreconditionChecks(wallet, wtx, errors);
if (result != Result::OK) {
return result;
}
if (!SignalsOptInRBF(*wtx.tx)) {
errors.push_back("Transaction is not BIP 125 replaceable");
return Result::WALLET_ERROR;
}
if (wtx.mapValue.count("replaced_by_txid")) {
errors.push_back(strprintf("Cannot bump transaction %s which was already bumped by transaction %s", txid.ToString(), wtx.mapValue.at("replaced_by_txid")));
return Result::WALLET_ERROR;
}
// check that original tx consists entirely of our inputs
// if not, we can't bump the fee, because the wallet has no way of knowing the value of the other inputs (thus the fee)
if (!wallet->IsAllFromMe(*wtx.tx, ISMINE_SPENDABLE)) {
errors.push_back("Transaction contains inputs that don't belong to this wallet");
return Result::WALLET_ERROR;
}
// figure out which output was change
// if there was no change output or multiple change outputs, fail
int nOutput = -1;
for (size_t i = 0; i < wtx.tx->vout.size(); ++i) {
if (wallet->IsChange(wtx.tx->vout[i])) {
if (nOutput != -1) {
errors.push_back("Transaction has multiple change outputs");
return Result::WALLET_ERROR;
}
nOutput = i;
}
}
if (nOutput == -1) {
errors.push_back("Transaction does not have a change output");
return Result::WALLET_ERROR;
}
// Calculate the expected size of the new transaction.
int64_t txSize = GetVirtualTransactionSize(*(wtx.tx));
const int64_t maxNewTxSize = CalculateMaximumSignedTxSize(*wtx.tx, wallet);
if (maxNewTxSize < 0) {
errors.push_back("Transaction contains inputs that cannot be signed");
return Result::INVALID_ADDRESS_OR_KEY;
}
// calculate the old fee and fee-rate
old_fee = wtx.GetDebit(ISMINE_SPENDABLE) - wtx.tx->GetValueOut();
CFeeRate nOldFeeRate(old_fee, txSize);
CFeeRate nNewFeeRate;
// The wallet uses a conservative WALLET_INCREMENTAL_RELAY_FEE value to
// future proof against changes to network wide policy for incremental relay
// fee that our node may not be aware of.
CFeeRate walletIncrementalRelayFee = CFeeRate(WALLET_INCREMENTAL_RELAY_FEE);
if (::incrementalRelayFee > walletIncrementalRelayFee) {
walletIncrementalRelayFee = ::incrementalRelayFee;
}
if (total_fee > 0) {
CAmount minTotalFee = nOldFeeRate.GetFee(maxNewTxSize) + ::incrementalRelayFee.GetFee(maxNewTxSize);
if (total_fee < minTotalFee) {
errors.push_back(strprintf("Insufficient totalFee, must be at least %s (oldFee %s + incrementalFee %s)",
FormatMoney(minTotalFee), FormatMoney(nOldFeeRate.GetFee(maxNewTxSize)), FormatMoney(::incrementalRelayFee.GetFee(maxNewTxSize))));
return Result::INVALID_PARAMETER;
}
CAmount requiredFee = GetRequiredFee(maxNewTxSize);
if (total_fee < requiredFee) {
errors.push_back(strprintf("Insufficient totalFee (cannot be less than required fee %s)",
FormatMoney(requiredFee)));
return Result::INVALID_PARAMETER;
}
new_fee = total_fee;
nNewFeeRate = CFeeRate(total_fee, maxNewTxSize);
} else {
new_fee = GetMinimumFee(maxNewTxSize, coin_control, mempool, ::feeEstimator, nullptr /* FeeCalculation */);
nNewFeeRate = CFeeRate(new_fee, maxNewTxSize);
// New fee rate must be at least old rate + minimum incremental relay rate
// walletIncrementalRelayFee.GetFeePerK() should be exact, because it's initialized
// in that unit (fee per kb).
// However, nOldFeeRate is a calculated value from the tx fee/size, so
// add 1 satoshi to the result, because it may have been rounded down.
if (nNewFeeRate.GetFeePerK() < nOldFeeRate.GetFeePerK() + 1 + walletIncrementalRelayFee.GetFeePerK()) {
nNewFeeRate = CFeeRate(nOldFeeRate.GetFeePerK() + 1 + walletIncrementalRelayFee.GetFeePerK());
new_fee = nNewFeeRate.GetFee(maxNewTxSize);
}
}
// Check that in all cases the new fee doesn't violate maxTxFee
if (new_fee > maxTxFee) {
errors.push_back(strprintf("Specified or calculated fee %s is too high (cannot be higher than maxTxFee %s)",
FormatMoney(new_fee), FormatMoney(maxTxFee)));
return Result::WALLET_ERROR;
}
// check that fee rate is higher than mempool's minimum fee
// (no point in bumping fee if we know that the new tx won't be accepted to the mempool)
// This may occur if the user set TotalFee or paytxfee too low, if fallbackfee is too low, or, perhaps,
// in a rare situation where the mempool minimum fee increased significantly since the fee estimation just a
// moment earlier. In this case, we report an error to the user, who may use total_fee to make an adjustment.
CFeeRate minMempoolFeeRate = mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000);
if (nNewFeeRate.GetFeePerK() < minMempoolFeeRate.GetFeePerK()) {
errors.push_back(strprintf(
"New fee rate (%s) is lower than the minimum fee rate (%s) to get into the mempool -- "
"the totalFee value should be at least %s or the settxfee value should be at least %s to add transaction",
FormatMoney(nNewFeeRate.GetFeePerK()),
FormatMoney(minMempoolFeeRate.GetFeePerK()),
FormatMoney(minMempoolFeeRate.GetFee(maxNewTxSize)),
FormatMoney(minMempoolFeeRate.GetFeePerK())));
return Result::WALLET_ERROR;
}
// Now modify the output to increase the fee.
// If the output is not large enough to pay the fee, fail.
CAmount nDelta = new_fee - old_fee;
assert(nDelta > 0);
mtx = *wtx.tx;
CTxOut* poutput = &(mtx.vout[nOutput]);
if (poutput->nValue < nDelta) {
errors.push_back("Change output is too small to bump the fee");
return Result::WALLET_ERROR;
}
// If the output would become dust, discard it (converting the dust to fee)
poutput->nValue -= nDelta;
if (poutput->nValue <= GetDustThreshold(*poutput, ::dustRelayFee)) {
LogPrint(BCLog::RPC, "Bumping fee and discarding dust output\n");
new_fee += poutput->nValue;
mtx.vout.erase(mtx.vout.begin() + nOutput);
}
// Mark new tx not replaceable, if requested.
if (!coin_control.signalRbf) {
for (auto& input : mtx.vin) {
if (input.nSequence < 0xfffffffe) input.nSequence = 0xfffffffe;
}
}
return Result::OK;
}
