Merge pull request #82 from UdjinM6/110_select_nondenom_first

when Darksend is unchecked select nondenom inputs first - for v0.11.0.x

src/wallet.cpp

@@ -1249,6 +1249,23 @@ static void ApproximateBestSubset(vector<pair<int64_t, pair<const CWalletTx*,uns
 }
 
 
+// TODO: find appropriate place for this sort function
+// move denoms down
+bool less_then_denom (const COutput& out1, const COutput& out2)
+{
+    const CWalletTx *pcoin1 = out1.tx;
+    const CWalletTx *pcoin2 = out2.tx;
+
+    bool found1 = false;
+    bool found2 = false;
+    BOOST_FOREACH(int64_t d, darkSendDenominations) // loop through predefined denoms
+    {
+        if(pcoin1->vout[out1.i].nValue == d) found1 = true;
+        if(pcoin2->vout[out2.i].nValue == d) found2 = true;
+    }
+    return (!found1 && found2);
+}
+
 bool CWallet::SelectCoinsMinConf(int64_t nTargetValue, int nConfMine, int nConfTheirs, vector<COutput> vCoins,
                                  set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64_t& nValueRet) const
 {
@@ -1264,16 +1281,37 @@ bool CWallet::SelectCoinsMinConf(int64_t nTargetValue, int nConfMine, int nConfT
 
     random_shuffle(vCoins.begin(), vCoins.end(), GetRandInt);
 
+    // move denoms down on the list
+    sort(vCoins.begin(), vCoins.end(), less_then_denom);
+
+    // try to find nondenom first to prevent unneeded spending of mixed coins
+    for (unsigned int tryDenom = 0; tryDenom < 2; tryDenom++)
+    {
+        if (fDebug) LogPrint("selectcoins", "tryDenom: %d\n", tryDenom);
+        setCoinsRet.clear();
+        nValueRet = 0;
+        nTotalLower = 0;
+
         BOOST_FOREACH(COutput output, vCoins)
         {
             const CWalletTx *pcoin = output.tx;
 
+//            if (fDebug) LogPrint("selectcoins", "value %s confirms %d\n", FormatMoney(pcoin->vout[output.i].nValue), output.nDepth);
             if (output.nDepth < (pcoin->IsFromMe() ? nConfMine : nConfTheirs))
                 continue;
 
             int i = output.i;
             int64_t n = pcoin->vout[i].nValue;
 
+            if (tryDenom == 0) // first run?
+            {
+                bool found = false;
+                BOOST_FOREACH(int64_t d, darkSendDenominations) // loop through predefined denoms
+                    if(n == d)
+                        found = true;
+                if (found) continue; // we don't want denom values on first run
+            }
+
             pair<int64_t,pair<const CWalletTx*,unsigned int> > coin = make_pair(n,make_pair(pcoin, i));
 
             if (n == nTargetValue)
@@ -1305,13 +1343,25 @@ bool CWallet::SelectCoinsMinConf(int64_t nTargetValue, int nConfMine, int nConfT
 
         if (nTotalLower < nTargetValue)
         {
-        if (coinLowestLarger.second.first == NULL)
+            if (coinLowestLarger.second.first == NULL) // there is no input larger than nTargetValue
+            {
+                if (tryDenom == 0)
+                    // we didn't look at denom yet, let's do it
+                    continue;
+                else
+                    // we looked at everything possible and didn't find anything, no luck
                     return false;
+            }
             setCoinsRet.insert(coinLowestLarger.second);
             nValueRet += coinLowestLarger.first;
             return true;
         }
 
+        // nTotalLower > nTargetValue
+        break;
+
+    }
+
     // Solve subset sum by stochastic approximation
     sort(vValue.rbegin(), vValue.rend(), CompareValueOnly());
     vector<char> vfBest;