[RPC] add feerate option to fundrawtransaction

Author: jonasschnelli

qa/rpc-tests/fundrawtransaction.py

@@ -677,6 +677,14 @@ def run_test(self):
         assert(signedtx["complete"])
         self.nodes[0].sendrawtransaction(signedtx["hex"])
 
+        inputs = []
+        outputs = {self.nodes[2].getnewaddress() : 1}
+        rawtx = self.nodes[3].createrawtransaction(inputs, outputs)
+        result = self.nodes[3].fundrawtransaction(rawtx, )
+        result2 = self.nodes[3].fundrawtransaction(rawtx, {"feeRate": 2000})
+        result3 = self.nodes[3].fundrawtransaction(rawtx, {"feeRate": 10000})
+        assert_equal(result['fee']*2, result2['fee'])
+        assert_equal(result['fee']*10, result3['fee'])
 
 if __name__ == '__main__':
     RawTransactionsTest().main()

src/coincontrol.h

@@ -18,6 +18,8 @@ class CCoinControl
     bool fAllowWatchOnly;
     //! Minimum absolute fee (not per kilobyte)
     CAmount nMinimumTotalFee;
+    //! Feerate to use (0 = estimate fee with payTxFee fallback)
+    CFeeRate nFeeRate;
 
     CCoinControl()
     {
@@ -31,6 +33,7 @@ class CCoinControl
         fAllowWatchOnly = false;
         setSelected.clear();
         nMinimumTotalFee = 0;
+        nFeeRate = CFeeRate(0);
     }
 
     bool HasSelected() const

src/wallet/rpcwallet.cpp

@@ -2458,6 +2458,7 @@ UniValue fundrawtransaction(const UniValue& params, bool fHelp)
                             "     \"changePosition\"    (numeric, optional, default random) The index of the change output\n"
                             "     \"includeWatching\"   (boolean, optional, default false) Also select inputs which are watch only\n"
                             "     \"lockUnspents\"      (boolean, optional, default false) Lock selected unspent outputs\n"
+                            "     \"feeRate\"           (numeric, optional, default 0=estimate) Set a specific feerate (fee per KB)\n"
                             "   }\n"
                             "                         for backward compatibility: passing in a true instead of an object will result in {\"includeWatching\":true}\n"
                             "\nResult:\n"
@@ -2484,6 +2485,7 @@ UniValue fundrawtransaction(const UniValue& params, bool fHelp)
     int changePosition = -1;
     bool includeWatching = false;
     bool lockUnspents = false;
+    CFeeRate feeRate = CFeeRate(0);
 
     if (params.size() > 1) {
       if (params[1].type() == UniValue::VBOOL) {
@@ -2495,7 +2497,7 @@ UniValue fundrawtransaction(const UniValue& params, bool fHelp)
 
         UniValue options = params[1];
 
-        RPCTypeCheckObj(options, boost::assign::map_list_of("changeAddress", UniValue::VSTR)("changePosition", UniValue::VNUM)("includeWatching", UniValue::VBOOL)("lockUnspents", UniValue::VBOOL), true, true);
+        RPCTypeCheckObj(options, boost::assign::map_list_of("changeAddress", UniValue::VSTR)("changePosition", UniValue::VNUM)("includeWatching", UniValue::VBOOL)("lockUnspents", UniValue::VBOOL)("feeRate", UniValue::VNUM), true, true);
 
         if (options.exists("changeAddress")) {
             CBitcoinAddress address(options["changeAddress"].get_str());
@@ -2514,6 +2516,9 @@ UniValue fundrawtransaction(const UniValue& params, bool fHelp)
 
         if (options.exists("lockUnspents"))
             lockUnspents = options["lockUnspents"].get_bool();
+
+        if (options.exists("feeRate"))
+            feeRate = CFeeRate(options["feeRate"].get_real());
       }
     }
 
@@ -2529,16 +2534,16 @@ UniValue fundrawtransaction(const UniValue& params, bool fHelp)
         throw JSONRPCError(RPC_INVALID_PARAMETER, "changePosition out of bounds");
 
     CMutableTransaction tx(origTx);
-    CAmount nFee;
+    CAmount nFeeOut;
     string strFailReason;
 
-    if(!pwalletMain->FundTransaction(tx, nFee, changePosition, strFailReason, includeWatching, lockUnspents, changeAddress))
+    if(!pwalletMain->FundTransaction(tx, nFeeOut, feeRate, changePosition, strFailReason, includeWatching, lockUnspents, changeAddress))
         throw JSONRPCError(RPC_INTERNAL_ERROR, strFailReason);
 
     UniValue result(UniValue::VOBJ);
     result.push_back(Pair("hex", EncodeHexTx(tx)));
     result.push_back(Pair("changepos", changePosition));
-    result.push_back(Pair("fee", ValueFromAmount(nFee)));
+    result.push_back(Pair("fee", ValueFromAmount(nFeeOut)));
 
     return result;
 }

src/wallet/wallet.cpp

@@ -1918,7 +1918,7 @@ bool CWallet::SelectCoins(const vector<COutput>& vAvailableCoins, const CAmount&
     return res;
 }
 
-bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, bool includeWatching, bool lockUnspents, const CTxDestination& destChange)
+bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, const CFeeRate& specificFeeRate, int& nChangePosInOut, std::string& strFailReason, bool includeWatching, bool lockUnspents, const CTxDestination& destChange)
 {
     vector<CRecipient> vecSend;
 
@@ -1933,6 +1933,8 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC
     coinControl.destChange = destChange;
     coinControl.fAllowOtherInputs = true;
     coinControl.fAllowWatchOnly = includeWatching;
+    coinControl.nFeeRate = specificFeeRate;
+
     BOOST_FOREACH(const CTxIn& txin, tx.vin)
         coinControl.Select(txin.prevout);
 
@@ -2242,6 +2244,8 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
                 if (coinControl && nFeeNeeded > 0 && coinControl->nMinimumTotalFee > nFeeNeeded) {
                     nFeeNeeded = coinControl->nMinimumTotalFee;
                 }
+                if (coinControl && coinControl->nFeeRate > CFeeRate(0))
+                    nFeeNeeded = coinControl->nFeeRate.GetFee(nBytes);
 
                 // If we made it here and we aren't even able to meet the relay fee on the next pass, give up
                 // because we must be at the maximum allowed fee.

src/wallet/wallet.h

@@ -740,7 +740,7 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
      * Insert additional inputs into the transaction by
      * calling CreateTransaction();
      */
-    bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, bool includeWatching, bool lockUnspents, const CTxDestination& destChange = CNoDestination());
+    bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, const CFeeRate& specificFeeRate, int& nChangePosInOut, std::string& strFailReason, bool includeWatching, bool lockUnspents, const CTxDestination& destChange = CNoDestination());
 
     /**
      * Create a new transaction paying the recipients with a set of coins