diff options
| -rw-r--r-- | src/init.cpp | 2 | ||||
| -rw-r--r-- | src/policy/policy.cpp | 10 | ||||
| -rw-r--r-- | src/policy/policy.h | 4 | ||||
| -rw-r--r-- | src/test/transaction_tests.cpp | 10 | ||||
| -rw-r--r-- | src/wallet/wallet.cpp | 31 | ||||
| -rw-r--r-- | src/wallet/wallet.h | 3 |
6 files changed, 46 insertions, 14 deletions
diff --git a/src/init.cpp b/src/init.cpp index d9b98be739..f0dbdb47c6 100644 --- a/src/init.cpp +++ b/src/init.cpp @@ -479,7 +479,7 @@ std::string HelpMessage(HelpMessageMode mode) if (showDebug) { strUsage += HelpMessageOpt("-acceptnonstdtxn", strprintf("Relay and mine \"non-standard\" transactions (%sdefault: %u)", "testnet/regtest only; ", defaultChainParams->RequireStandard())); strUsage += HelpMessageOpt("-incrementalrelayfee=<amt>", strprintf("Fee rate (in %s/kB) used to define cost of relay, used for mempool limiting and BIP 125 replacement. (default: %s)", CURRENCY_UNIT, FormatMoney(DEFAULT_INCREMENTAL_RELAY_FEE))); - strUsage += HelpMessageOpt("-dustrelayfee=<amt>", strprintf("Fee rate (in %s/kB) used to defined dust, the value of an output such that it will cost about 1/3 of its value in fees at this fee rate to spend it. (default: %s)", CURRENCY_UNIT, FormatMoney(DUST_RELAY_TX_FEE))); + strUsage += HelpMessageOpt("-dustrelayfee=<amt>", strprintf("Fee rate (in %s/kB) used to defined dust, the value of an output such that it will cost more than its value in fees at this fee rate to spend it. (default: %s)", CURRENCY_UNIT, FormatMoney(DUST_RELAY_TX_FEE))); } strUsage += HelpMessageOpt("-bytespersigop", strprintf(_("Equivalent bytes per sigop in transactions for relay and mining (default: %u)"), DEFAULT_BYTES_PER_SIGOP)); strUsage += HelpMessageOpt("-datacarrier", strprintf(_("Relay and mine data carrier transactions (default: %u)"), DEFAULT_ACCEPT_DATACARRIER)); diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp index 9f2d623e76..605e3e0696 100644 --- a/src/policy/policy.cpp +++ b/src/policy/policy.cpp @@ -19,16 +19,18 @@ CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFeeIn) { // "Dust" is defined in terms of dustRelayFee, // which has units satoshis-per-kilobyte. - // If you'd pay more than 1/3 in fees + // If you'd pay more in fees than the value of the output // to spend something, then we consider it dust. // A typical spendable non-segwit txout is 34 bytes big, and will // need a CTxIn of at least 148 bytes to spend: // so dust is a spendable txout less than - // 546*dustRelayFee/1000 (in satoshis). + // 182*dustRelayFee/1000 (in satoshis). + // 546 satoshis at the default rate of 3000 sat/kB. // A typical spendable segwit txout is 31 bytes big, and will // need a CTxIn of at least 67 bytes to spend: // so dust is a spendable txout less than - // 294*dustRelayFee/1000 (in satoshis). + // 98*dustRelayFee/1000 (in satoshis). + // 294 satoshis at the default rate of 3000 sat/kB. if (txout.scriptPubKey.IsUnspendable()) return 0; @@ -44,7 +46,7 @@ CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFeeIn) nSize += (32 + 4 + 1 + 107 + 4); // the 148 mentioned above } - return 3 * dustRelayFeeIn.GetFee(nSize); + return dustRelayFeeIn.GetFee(nSize); } bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFeeIn) diff --git a/src/policy/policy.h b/src/policy/policy.h index 2c2ea9d5b8..c06820f84e 100644 --- a/src/policy/policy.h +++ b/src/policy/policy.h @@ -40,12 +40,12 @@ static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100; static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80; /** The maximum size of a standard witnessScript */ static const unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600; -/** Min feerate for defining dust. Historically this has been the same as the +/** Min feerate for defining dust. Historically this has been based on the * minRelayTxFee, however changing the dust limit changes which transactions are * standard and should be done with care and ideally rarely. It makes sense to * only increase the dust limit after prior releases were already not creating * outputs below the new threshold */ -static const unsigned int DUST_RELAY_TX_FEE = 1000; +static const unsigned int DUST_RELAY_TX_FEE = 3000; /** * Standard script verification flags that standard transactions will comply * with. However scripts violating these flags may still be present in valid diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp index 39f9f58604..6654634bf1 100644 --- a/src/test/transaction_tests.cpp +++ b/src/test/transaction_tests.cpp @@ -692,7 +692,7 @@ BOOST_AUTO_TEST_CASE(test_IsStandard) BOOST_CHECK(IsStandardTx(t, reason)); // Check dust with default relay fee: - CAmount nDustThreshold = 182 * dustRelayFee.GetFeePerK()/1000 * 3; + CAmount nDustThreshold = 182 * dustRelayFee.GetFeePerK()/1000; BOOST_CHECK_EQUAL(nDustThreshold, 546); // dust: t.vout[0].nValue = nDustThreshold - 1; @@ -702,13 +702,13 @@ BOOST_AUTO_TEST_CASE(test_IsStandard) BOOST_CHECK(IsStandardTx(t, reason)); // Check dust with odd relay fee to verify rounding: - // nDustThreshold = 182 * 1234 / 1000 * 3 - dustRelayFee = CFeeRate(1234); + // nDustThreshold = 182 * 3702 / 1000 + dustRelayFee = CFeeRate(3702); // dust: - t.vout[0].nValue = 672 - 1; + t.vout[0].nValue = 673 - 1; BOOST_CHECK(!IsStandardTx(t, reason)); // not dust: - t.vout[0].nValue = 672; + t.vout[0].nValue = 673; BOOST_CHECK(IsStandardTx(t, reason)); dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE); diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp index c56fd05d7e..7a0aac5f53 100644 --- a/src/wallet/wallet.cpp +++ b/src/wallet/wallet.cpp @@ -57,6 +57,8 @@ CFeeRate CWallet::minTxFee = CFeeRate(DEFAULT_TRANSACTION_MINFEE); */ CFeeRate CWallet::fallbackFee = CFeeRate(DEFAULT_FALLBACK_FEE); +CFeeRate CWallet::m_discard_rate = CFeeRate(DEFAULT_DISCARD_FEE); + const uint256 CMerkleTx::ABANDON_HASH(uint256S("0000000000000000000000000000000000000000000000000000000000000001")); /** @defgroup mapWallet @@ -2524,6 +2526,17 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC return true; } +static CFeeRate GetDiscardRate(const CBlockPolicyEstimator& estimator) +{ + unsigned int highest_target = estimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE); + CFeeRate discard_rate = estimator.estimateSmartFee(highest_target, nullptr /* FeeCalculation */, false /* conservative */); + // Don't let discard_rate be greater than longest possible fee estimate if we get a valid fee estimate + discard_rate = (discard_rate == CFeeRate(0)) ? CWallet::m_discard_rate : std::min(discard_rate, CWallet::m_discard_rate); + // Discard rate must be at least dustRelayFee + discard_rate = std::max(discard_rate, ::dustRelayFee); + return discard_rate; +} + bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, const CCoinControl& coin_control, bool sign) { @@ -2623,6 +2636,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT CTxOut change_prototype_txout(0, scriptChange); size_t change_prototype_size = GetSerializeSize(change_prototype_txout, SER_DISK, 0); + CFeeRate discard_rate = GetDiscardRate(::feeEstimator); nFeeRet = 0; bool pick_new_inputs = true; CAmount nValueIn = 0; @@ -2690,7 +2704,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT // Never create dust outputs; if we would, just // add the dust to the fee. - if (IsDust(newTxOut, ::dustRelayFee)) + if (IsDust(newTxOut, discard_rate)) { nChangePosInOut = -1; nFeeRet += nChange; @@ -2770,7 +2784,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT // (because of reduced tx size) and so we should add a // change output. Only try this once. CAmount fee_needed_for_change = GetMinimumFee(change_prototype_size, coin_control, ::mempool, ::feeEstimator, nullptr); - CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, ::dustRelayFee); + CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, discard_rate); CAmount max_excess_fee = fee_needed_for_change + minimum_value_for_change; if (nFeeRet > nFeeNeeded + max_excess_fee && nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 && pick_new_inputs) { pick_new_inputs = false; @@ -3811,6 +3825,9 @@ std::string CWallet::GetWalletHelpString(bool showDebug) 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("-discardfee=<amt>", strprintf(_("The fee rate (in %s/kB) used to discard change (to fee) if it would be dust at this fee rate (default: %s) " + "Note: We will always discard up to the dust relay fee and a discard fee above that is limited by the longest target fee estimate"), + CURRENCY_UNIT, FormatMoney(DEFAULT_DISCARD_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)"), @@ -4136,6 +4153,16 @@ bool CWallet::ParameterInteraction() _("This is the transaction fee you may pay when fee estimates are not available.")); CWallet::fallbackFee = CFeeRate(nFeePerK); } + if (IsArgSet("-discardfee")) + { + CAmount nFeePerK = 0; + if (!ParseMoney(GetArg("-discardfee", ""), nFeePerK)) + return InitError(strprintf(_("Invalid amount for -discardfee=<amount>: '%s'"), GetArg("-discardfee", ""))); + if (nFeePerK > HIGH_TX_FEE_PER_KB) + InitWarning(AmountHighWarn("-discardfee") + " " + + _("This is the transaction fee you may discard if change is smaller than dust at this level")); + CWallet::m_discard_rate = CFeeRate(nFeePerK); + } if (IsArgSet("-paytxfee")) { CAmount nFeePerK = 0; diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h index bf09b040f6..bcd7e4b4ee 100644 --- a/src/wallet/wallet.h +++ b/src/wallet/wallet.h @@ -45,6 +45,8 @@ static const unsigned int DEFAULT_KEYPOOL_SIZE = 1000; static const CAmount DEFAULT_TRANSACTION_FEE = 0; //! -fallbackfee default static const CAmount DEFAULT_FALLBACK_FEE = 20000; +//! -m_discard_rate default +static const CAmount DEFAULT_DISCARD_FEE = 10000; //! -mintxfee default static const CAmount DEFAULT_TRANSACTION_MINFEE = 1000; //! minimum recommended increment for BIP 125 replacement txs @@ -969,6 +971,7 @@ public: static CFeeRate minTxFee; static CFeeRate fallbackFee; + static CFeeRate m_discard_rate; /** * Estimate the minimum fee considering user set parameters * and the required fee |