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Add sane fallback for fee estimation
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Add new commandline option "-fallbackfee" to use when fee estimation does not have sufficient data.
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morcos committed Jan 5, 2016
1 parent 995b9f3 commit e420a1b
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Showing 4 changed files with 27 additions and 2 deletions.
11 changes: 11 additions & 0 deletions src/init.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -393,6 +393,8 @@ std::string HelpMessage(HelpMessageMode mode)
strUsage += HelpMessageGroup(_("Wallet options:"));
strUsage += HelpMessageOpt("-disablewallet", _("Do not load the wallet and disable wallet RPC calls"));
strUsage += HelpMessageOpt("-keypool=<n>", strprintf(_("Set key pool size to <n> (default: %u)"), DEFAULT_KEYPOOL_SIZE));
strUsage += HelpMessageOpt("-fallbackfee=<amt>", strprintf(_("A fee rate (in %s/kB) that will be used when fee estimation has insufficient data (default: %s)"),
CURRENCY_UNIT, FormatMoney(DEFAULT_FALLBACK_FEE)));
strUsage += HelpMessageOpt("-mintxfee=<amt>", strprintf(_("Fees (in %s/kB) smaller than this are considered zero fee for transaction creation (default: %s)"),
CURRENCY_UNIT, FormatMoney(DEFAULT_TRANSACTION_MINFEE)));
strUsage += HelpMessageOpt("-paytxfee=<amt>", strprintf(_("Fee (in %s/kB) to add to transactions you send (default: %s)"),
Expand Down Expand Up @@ -947,6 +949,15 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
else
return InitError(strprintf(_("Invalid amount for -mintxfee=<amount>: '%s'"), mapArgs["-mintxfee"]));
}
if (mapArgs.count("-fallbackfee"))
{
CAmount nFeePerK = 0;
if (!ParseMoney(mapArgs["-fallbackfee"], nFeePerK))
return InitError(strprintf(_("Invalid amount for -fallbackfee=<amount>: '%s'"), mapArgs["-fallbackfee"]));
if (nFeePerK > nHighTransactionFeeWarning)
InitWarning(_("-fallbackfee is set very high! This is the transaction fee you may pay when fee estimates are not available."));
CWallet::fallbackFee = CFeeRate(nFeePerK);
}
if (mapArgs.count("-paytxfee"))
{
CAmount nFeePerK = 0;
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6 changes: 4 additions & 2 deletions src/qt/sendcoinsdialog.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -640,13 +640,15 @@ void SendCoinsDialog::updateSmartFeeLabel()
CFeeRate feeRate = mempool.estimateSmartFee(nBlocksToConfirm, &estimateFoundAtBlocks);
if (feeRate <= CFeeRate(0)) // not enough data => minfee
{
ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::GetRequiredFee(1000)) + "/kB");
ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(),
std::max(CWallet::fallbackFee.GetFeePerK(), CWallet::GetRequiredFee(1000))) + "/kB");
ui->labelSmartFee2->show(); // (Smart fee not initialized yet. This usually takes a few blocks...)
ui->labelFeeEstimation->setText("");
}
else
{
ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kB");
ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(),
std::max(feeRate.GetFeePerK(), CWallet::GetRequiredFee(1000))) + "/kB");
ui->labelSmartFee2->hide();
ui->labelFeeEstimation->setText(tr("Estimated to begin confirmation within %n block(s).", "", estimateFoundAtBlocks));
}
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9 changes: 9 additions & 0 deletions src/wallet/wallet.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,12 @@ bool fSendFreeTransactions = DEFAULT_SEND_FREE_TRANSACTIONS;
* Override with -mintxfee
*/
CFeeRate CWallet::minTxFee = CFeeRate(DEFAULT_TRANSACTION_MINFEE);
/**
* If fee estimation does not have enough data to provide estimates, use this fee instead.
* Has no effect if not using fee estimation
* Override with -fallbackfee
*/
CFeeRate CWallet::fallbackFee = CFeeRate(DEFAULT_FALLBACK_FEE);

/** @defgroup mapWallet
*
Expand Down Expand Up @@ -2223,6 +2229,9 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarge
if (nFeeNeeded == 0) {
int estimateFoundTarget = nConfirmTarget;
nFeeNeeded = pool.estimateSmartFee(nConfirmTarget, &estimateFoundTarget).GetFee(nTxBytes);
// ... unless we don't have enough mempool data for estimatefee, then use fallbackFee
if (nFeeNeeded == 0)
nFeeNeeded = fallbackFee.GetFee(nTxBytes);
}
// prevent user from paying a fee below minRelayTxFee or minTxFee
nFeeNeeded = std::max(nFeeNeeded, GetRequiredFee(nTxBytes));
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3 changes: 3 additions & 0 deletions src/wallet/wallet.h
Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,8 @@ static const unsigned int DEFAULT_KEYPOOL_SIZE = 100;
static const CAmount DEFAULT_TRANSACTION_FEE = 0;
//! -paytxfee will warn if called with a higher fee than this amount (in satoshis) per KB
static const CAmount nHighTransactionFeeWarning = 0.01 * COIN;
//! -fallbackfee default
static const CAmount DEFAULT_FALLBACK_FEE = 20000;
//! -mintxfee default
static const CAmount DEFAULT_TRANSACTION_MINFEE = 1000;
//! -maxtxfee default
Expand Down Expand Up @@ -666,6 +668,7 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
bool AddAccountingEntry(const CAccountingEntry&, CWalletDB & pwalletdb);

static CFeeRate minTxFee;
static CFeeRate fallbackFee;
/**
* Estimate the minimum fee considering user set parameters
* and the required fee
Expand Down

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