mempool: Replace maxFeeRate of 10000*minRelayTxFee with maxTxFee

src/init.cpp

@@ -406,8 +406,6 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-sendfreetransactions", strprintf(_("Send transactions as zero-fee transactions if possible (default: %u)"), DEFAULT_SEND_FREE_TRANSACTIONS));
     strUsage += HelpMessageOpt("-spendzeroconfchange", strprintf(_("Spend unconfirmed change when sending transactions (default: %u)"), DEFAULT_SPEND_ZEROCONF_CHANGE));
     strUsage += HelpMessageOpt("-txconfirmtarget=<n>", strprintf(_("If paytxfee is not set, include enough fee so transactions begin confirmation on average within n blocks (default: %u)"), DEFAULT_TX_CONFIRM_TARGET));
-    strUsage += HelpMessageOpt("-maxtxfee=<amt>", strprintf(_("Maximum total fees (in %s) to use in a single wallet transaction; setting this too low may abort large transactions (default: %s)"),
-        CURRENCY_UNIT, FormatMoney(DEFAULT_TRANSACTION_MAXFEE)));
     strUsage += HelpMessageOpt("-upgradewallet", _("Upgrade wallet to latest format on startup"));
     strUsage += HelpMessageOpt("-wallet=<file>", _("Specify wallet file (within data directory)") + " " + strprintf(_("(default: %s)"), "wallet.dat"));
     strUsage += HelpMessageOpt("-walletbroadcast", _("Make the wallet broadcast transactions") + " " + strprintf(_("(default: %u)"), DEFAULT_WALLETBROADCAST));
@@ -470,6 +468,8 @@ std::string HelpMessage(HelpMessageMode mode)
     }
     strUsage += HelpMessageOpt("-minrelaytxfee=<amt>", strprintf(_("Fees (in %s/kB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: %s)"),
         CURRENCY_UNIT, FormatMoney(DEFAULT_MIN_RELAY_TX_FEE)));
+    strUsage += HelpMessageOpt("-maxtxfee=<amt>", strprintf(_("Maximum total fees (in %s) to use in a single wallet transaction or raw transaction; setting this too low may abort large transactions (default: %s)"),
+        CURRENCY_UNIT, FormatMoney(DEFAULT_TRANSACTION_MAXFEE)));
     strUsage += HelpMessageOpt("-printtoconsole", _("Send trace/debug info to console instead of debug.log file"));
     if (showDebug)
     {
@@ -978,7 +978,7 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         CAmount nFeePerK = 0;
         if (!ParseMoney(mapArgs["-fallbackfee"], nFeePerK))
             return InitError(strprintf(_("Invalid amount for -fallbackfee=<amount>: '%s'"), mapArgs["-fallbackfee"]));
-        if (nFeePerK > nHighTransactionFeeWarning)
+        if (nFeePerK > HIGH_TX_FEE_PER_KB)
             InitWarning(_("-fallbackfee is set very high! This is the transaction fee you may pay when fee estimates are not available."));
         CWallet::fallbackFee = CFeeRate(nFeePerK);
     }
@@ -987,7 +987,7 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         CAmount nFeePerK = 0;
         if (!ParseMoney(mapArgs["-paytxfee"], nFeePerK))
             return InitError(AmountErrMsg("paytxfee", mapArgs["-paytxfee"]));
-        if (nFeePerK > nHighTransactionFeeWarning)
+        if (nFeePerK > HIGH_TX_FEE_PER_KB)
             InitWarning(_("-paytxfee is set very high! This is the transaction fee you will pay if you send a transaction."));
         payTxFee = CFeeRate(nFeePerK, 1000);
         if (payTxFee < ::minRelayTxFee)
@@ -1001,7 +1001,7 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         CAmount nMaxFee = 0;
         if (!ParseMoney(mapArgs["-maxtxfee"], nMaxFee))
             return InitError(AmountErrMsg("maxtxfee", mapArgs["-maxtxfee"]));
-        if (nMaxFee > nHighTransactionMaxFeeWarning)
+        if (nMaxFee > HIGH_MAX_TX_FEE)
             InitWarning(_("-maxtxfee is set very high! Fees this large could be paid on a single transaction."));
         maxTxFee = nMaxFee;
         if (CFeeRate(maxTxFee, 1000) < ::minRelayTxFee)

src/main.cpp

@@ -75,13 +75,11 @@ bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
 size_t nCoinCacheUsage = 5000 * 300;
 uint64_t nPruneTarget = 0;
 bool fAlerts = DEFAULT_ALERTS;
-/* If the tip is older than this (in seconds), the node is considered to be in initial block download.
- */
 int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
 bool fPermitReplacement = DEFAULT_PERMIT_REPLACEMENT;
 
-/** Fees smaller than this (in satoshi) are considered zero fee (for relaying, mining and transaction creation) */
 CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
+CAmount maxTxFee = DEFAULT_TRANSACTION_MAXFEE;
 
 CTxMemPool mempool(::minRelayTxFee);
 
@@ -1004,10 +1002,10 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState &state, const C
             dFreeCount += nSize;
         }
 
-        if (fRejectAbsurdFee && nFees > ::minRelayTxFee.GetFee(nSize) * 10000)
+        if (fRejectAbsurdFee && nFees > maxTxFee)
             return state.Invalid(false,
                 REJECT_HIGHFEE, "absurdly-high-fee",
-                strprintf("%d > %d", nFees, ::minRelayTxFee.GetFee(nSize) * 10000));
+                strprintf("%d > %d", nFees, maxTxFee));
 
         // Calculate in-mempool ancestors, up to a limit.
         CTxMemPool::setEntries setAncestors;

src/main.h

@@ -46,6 +46,12 @@ static const bool DEFAULT_ALERTS = true;
 static const bool DEFAULT_WHITELISTALWAYSRELAY = true;
 /** Default for -minrelaytxfee, minimum relay fee for transactions */
 static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000;
+//! -maxtxfee default
+static const CAmount DEFAULT_TRANSACTION_MAXFEE = 0.1 * COIN;
+//! Discourage users to set fees higher than this amount (in satoshis) per kB
+static const CAmount HIGH_TX_FEE_PER_KB = 0.01 * COIN;
+//! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
+static const CAmount HIGH_MAX_TX_FEE = 100 * HIGH_TX_FEE_PER_KB;
 /** Default for -maxorphantx, maximum number of orphan transactions kept in memory */
 static const unsigned int DEFAULT_MAX_ORPHAN_TRANSACTIONS = 100;
 /** Default for -limitancestorcount, max number of in-mempool ancestors */
@@ -138,8 +144,12 @@ extern unsigned int nBytesPerSigOp;
 extern bool fCheckBlockIndex;
 extern bool fCheckpointsEnabled;
 extern size_t nCoinCacheUsage;
+/** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */
 extern CFeeRate minRelayTxFee;
+/** Absolute maximum transaction fee (in satoshis) used by wallet and mempool (rejects high fee in sendrawtransaction) */
+extern CAmount maxTxFee;
 extern bool fAlerts;
+/* If the tip is older than this (in seconds), the node is considered to be in initial block download. */
 extern int64_t nMaxTipAge;
 extern bool fPermitReplacement;
 

src/wallet/wallet.cpp

@@ -37,7 +37,6 @@ using namespace std;
  * Settings
  */
 CFeeRate payTxFee(DEFAULT_TRANSACTION_FEE);
-CAmount maxTxFee = DEFAULT_TRANSACTION_MAXFEE;
 unsigned int nTxConfirmTarget = DEFAULT_TX_CONFIRM_TARGET;
 bool bSpendZeroConfChange = DEFAULT_SPEND_ZEROCONF_CHANGE;
 bool fSendFreeTransactions = DEFAULT_SEND_FREE_TRANSACTIONS;

src/wallet/wallet.h

@@ -32,7 +32,6 @@
  * Settings
  */
 extern CFeeRate payTxFee;
-extern CAmount maxTxFee;
 extern unsigned int nTxConfirmTarget;
 extern bool bSpendZeroConfChange;
 extern bool fSendFreeTransactions;
@@ -40,14 +39,10 @@ extern bool fSendFreeTransactions;
 static const unsigned int DEFAULT_KEYPOOL_SIZE = 100;
 //! -paytxfee default
 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
-static const CAmount DEFAULT_TRANSACTION_MAXFEE = 0.1 * COIN;
 //! minimum change amount
 static const CAmount MIN_CHANGE = CENT;
 //! Default for -spendzeroconfchange
@@ -56,8 +51,6 @@ static const bool DEFAULT_SPEND_ZEROCONF_CHANGE = true;
 static const bool DEFAULT_SEND_FREE_TRANSACTIONS = false;
 //! -txconfirmtarget default
 static const unsigned int DEFAULT_TX_CONFIRM_TARGET = 2;
-//! -maxtxfee will warn if called with a higher fee than this amount (in satoshis)
-static const CAmount nHighTransactionMaxFeeWarning = 100 * nHighTransactionFeeWarning;
 //! Largest (in bytes) free transaction we're willing to create
 static const unsigned int MAX_FREE_TRANSACTION_CREATE_SIZE = 1000;
 static const bool DEFAULT_WALLETBROADCAST = true;
@@ -211,6 +204,7 @@ public:
     int GetDepthInMainChain() const { const CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet); }
     bool IsInMainChain() const { const CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet) > 0; }
     int GetBlocksToMaturity() const;
+    /** Pass this transaction to the mempool. Fails if absolute fee exceeds maxTxFee. */
     bool AcceptToMemoryPool(bool fLimitFree=true, bool fRejectAbsurdFee=true);
     bool hashUnset() const { return (hashBlock.IsNull() || hashBlock == ABANDON_HASH); }
     bool isAbandoned() const { return (hashBlock == ABANDON_HASH); }