Switch to CCoins & CCoinsView approach
[novacoin.git] / src / wallet.cpp
index 7ddd67f..20bedc5 100644 (file)
@@ -3,12 +3,14 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "db.h"
 #include "wallet.h"
 #include "walletdb.h"
 #include "crypter.h"
 #include "ui_interface.h"
 #include "base58.h"
 #include "kernel.h"
+#include "coincontrol.h"
 #include <boost/algorithm/string/replace.hpp>
 
 using namespace std;
@@ -247,7 +249,7 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
     vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
     RAND_bytes(&vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
 
-    CMasterKey kMasterKey;
+    CMasterKey kMasterKey(nDerivationMethodIndex);
 
     RandAddSeedPerfmon();
     kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
@@ -737,7 +739,7 @@ void CWalletTx::GetAccountAmounts(const string& strAccount, int64& nGenerated, i
     }
 }
 
-void CWalletTx::AddSupportingTransactions(CTxDB& txdb)
+void CWalletTx::AddSupportingTransactions()
 {
     vtxPrev.clear();
 
@@ -748,7 +750,6 @@ void CWalletTx::AddSupportingTransactions(CTxDB& txdb)
         BOOST_FOREACH(const CTxIn& txin, vin)
             vWorkQueue.push_back(txin.prevout.hash);
 
-        // This critsect is OK because txdb is already open
         {
             LOCK(pwallet->cs_wallet);
             map<uint256, const CMerkleTx*> mapWalletPrev;
@@ -772,15 +773,6 @@ void CWalletTx::AddSupportingTransactions(CTxDB& txdb)
                 {
                     tx = *mapWalletPrev[hash];
                 }
-                else if (!fClient && txdb.ReadDiskTx(hash, tx))
-                {
-                    ;
-                }
-                else
-                {
-                    printf("ERROR: AddSupportingTransactions() : unsupported transaction\n");
-                    continue;
-                }
 
                 int nDepth = tx.SetMerkleBranch();
                 vtxPrev.push_back(tx);
@@ -827,54 +819,41 @@ int CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
     return ret;
 }
 
-int CWallet::ScanForWalletTransaction(const uint256& hashTx)
-{
-    CTransaction tx;
-    tx.ReadFromDisk(COutPoint(hashTx, 0));
-    if (AddToWalletIfInvolvingMe(tx, NULL, true, true))
-        return 1;
-    return 0;
-}
-
 void CWallet::ReacceptWalletTransactions()
 {
-    CTxDB txdb("r");
+    CCoinsDB coinsdb("r");
     bool fRepeat = true;
     while (fRepeat)
     {
         LOCK(cs_wallet);
         fRepeat = false;
-        vector<CDiskTxPos> vMissingTx;
+        bool fMissing = false;
         BOOST_FOREACH(PAIRTYPE(const uint256, CWalletTx)& item, mapWallet)
         {
             CWalletTx& wtx = item.second;
-            if ((wtx.IsCoinBase() && wtx.IsSpent(0)) || (wtx.IsCoinStake() && wtx.IsSpent(1)))
+            if (wtx.IsCoinBase() && wtx.IsSpent(0))
                 continue;
 
-            CTxIndex txindex;
+            CCoins coins;
             bool fUpdated = false;
-            if (txdb.ReadTxIndex(wtx.GetHash(), txindex))
+            bool fNotFound = coinsdb.ReadCoins(wtx.GetHash(), coins);
+            if (!fNotFound || wtx.GetDepthInMainChain() > 0)
             {
                 // Update fSpent if a tx got spent somewhere else by a copy of wallet.dat
-                if (txindex.vSpent.size() != wtx.vout.size())
-                {
-                    printf("ERROR: ReacceptWalletTransactions() : txindex.vSpent.size() %"PRIszu" != wtx.vout.size() %"PRIszu"\n", txindex.vSpent.size(), wtx.vout.size());
-                    continue;
-                }
-                for (unsigned int i = 0; i < txindex.vSpent.size(); i++)
+                for (unsigned int i = 0; i < wtx.vout.size(); i++)
                 {
                     if (wtx.IsSpent(i))
                         continue;
-                    if (!txindex.vSpent[i].IsNull() && IsMine(wtx.vout[i]))
+                    if ((i >= coins.vout.size() || coins.vout[i].IsNull()) && IsMine(wtx.vout[i]))
                     {
                         wtx.MarkSpent(i);
                         fUpdated = true;
-                        vMissingTx.push_back(txindex.vSpent[i]);
+                        fMissing = true;
                     }
                 }
                 if (fUpdated)
                 {
-                    printf("ReacceptWalletTransactions found spent coin %snvc %s\n", FormatMoney(wtx.GetCredit()).c_str(), wtx.GetHash().ToString().c_str());
+                    printf("ReacceptWalletTransactions found spent coin %sbc %s\n", FormatMoney(wtx.GetCredit()).c_str(), wtx.GetHash().ToString().c_str());
                     wtx.MarkDirty();
                     wtx.WriteToDisk();
                 }
@@ -882,11 +861,11 @@ void CWallet::ReacceptWalletTransactions()
             else
             {
                 // Re-accept any txes of ours that aren't already in a block
-                if (!(wtx.IsCoinBase() || wtx.IsCoinStake()))
-                    wtx.AcceptWalletTransaction(txdb, false);
+                if (!wtx.IsCoinBase())
+                    wtx.AcceptWalletTransaction(coinsdb, false);
             }
         }
-        if (!vMissingTx.empty())
+        if (fMissing)
         {
             // TODO: optimize this to scan just part of the block chain?
             if (ScanForWalletTransactions(pindexGenesisBlock))
@@ -895,32 +874,32 @@ void CWallet::ReacceptWalletTransactions()
     }
 }
 
-void CWalletTx::RelayWalletTransaction(CTxDB& txdb)
+void CWalletTx::RelayWalletTransaction(CCoinsDB& coinsdb)
 {
     BOOST_FOREACH(const CMerkleTx& tx, vtxPrev)
     {
-        if (!(tx.IsCoinBase() || tx.IsCoinStake()))
+        if (!tx.IsCoinBase())
         {
             uint256 hash = tx.GetHash();
-            if (!txdb.ContainsTx(hash))
-                RelayMessage(CInv(MSG_TX, hash), (CTransaction)tx);
+            if (!coinsdb.HaveCoins(hash))
+                RelayTransaction((CTransaction)tx, hash);
         }
     }
-    if (!(IsCoinBase() || IsCoinStake()))
+    if (!IsCoinBase())
     {
         uint256 hash = GetHash();
-        if (!txdb.ContainsTx(hash))
+        if (!coinsdb.HaveCoins(hash))
         {
             printf("Relaying wtx %s\n", hash.ToString().substr(0,10).c_str());
-            RelayMessage(CInv(MSG_TX, hash), (CTransaction)*this);
+            RelayTransaction((CTransaction)*this, hash);
         }
     }
 }
 
 void CWalletTx::RelayWalletTransaction()
 {
-   CTxDB txdb("r");
-   RelayWalletTransaction(txdb);
+   CCoinsDB coinsdb("r");
+   RelayWalletTransaction(coinsdb);
 }
 
 void CWallet::ResendWalletTransactions()
@@ -943,7 +922,7 @@ void CWallet::ResendWalletTransactions()
 
     // Rebroadcast any of our txes that aren't in a block yet
     printf("ResendWalletTransactions()\n");
-    CTxDB txdb("r");
+    CCoinsDB coinsdb("r");
     {
         LOCK(cs_wallet);
         // Sort them in chronological order
@@ -959,10 +938,7 @@ void CWallet::ResendWalletTransactions()
         BOOST_FOREACH(PAIRTYPE(const unsigned int, CWalletTx*)& item, mapSorted)
         {
             CWalletTx& wtx = *item.second;
-            if (wtx.CheckTransaction())
-                wtx.RelayWalletTransaction(txdb);
-            else
-                printf("ResendWalletTransactions() : CheckTransaction failed for transaction %s\n", wtx.GetHash().ToString().c_str());
+            wtx.RelayWalletTransaction(coinsdb);
         }
     }
 }
@@ -1025,7 +1001,7 @@ int64 CWallet::GetImmatureBalance() const
 }
 
 // populate vCoins with vector of spendable COutputs
-void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed) const
+void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed, const CCoinControl *coinControl) const
 {
     vCoins.clear();
 
@@ -1048,7 +1024,32 @@ void CWallet::AvailableCoins(vector<COutput>& vCoins, bool fOnlyConfirmed) const
                 continue;
 
             for (unsigned int i = 0; i < pcoin->vout.size(); i++)
-                if (!(pcoin->IsSpent(i)) && IsMine(pcoin->vout[i]) && pcoin->vout[i].nValue > 0)
+                if (!(pcoin->IsSpent(i)) && IsMine(pcoin->vout[i]) && pcoin->vout[i].nValue >= nMinimumInputValue &&
+                (!coinControl || !coinControl->HasSelected() || coinControl->IsSelected((*it).first, i)))
+                    vCoins.push_back(COutput(pcoin, i, pcoin->GetDepthInMainChain()));
+
+        }
+    }
+}
+
+void CWallet::AvailableCoinsMinConf(vector<COutput>& vCoins, int nConf) const
+{
+    vCoins.clear();
+
+    {
+        LOCK(cs_wallet);
+        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        {
+            const CWalletTx* pcoin = &(*it).second;
+
+            if (!pcoin->IsFinal())
+                continue;
+
+            if(pcoin->GetDepthInMainChain() < nConf)
+                continue;
+
+            for (unsigned int i = 0; i < pcoin->vout.size(); i++)
+                if (!(pcoin->IsSpent(i)) && IsMine(pcoin->vout[i]) && pcoin->vout[i].nValue >= nMinimumInputValue)
                     vCoins.push_back(COutput(pcoin, i, pcoin->GetDepthInMainChain()));
         }
     }
@@ -1142,8 +1143,9 @@ bool CWallet::SelectCoinsMinConf(int64 nTargetValue, unsigned int nSpendTime, in
 
         int i = output.i;
 
+        // Follow the timestamp rules
         if (pcoin->nTime > nSpendTime)
-            continue;  // ppcoin: timestamp must not exceed spend time
+            continue;
 
         int64 n = pcoin->vout[i].nValue;
 
@@ -1224,20 +1226,72 @@ bool CWallet::SelectCoinsMinConf(int64 nTargetValue, unsigned int nSpendTime, in
     return true;
 }
 
-bool CWallet::SelectCoins(int64 nTargetValue, unsigned int nSpendTime, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64& nValueRet) const
+bool CWallet::SelectCoins(int64 nTargetValue, unsigned int nSpendTime, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64& nValueRet, const CCoinControl* coinControl) const
 {
     vector<COutput> vCoins;
-    AvailableCoins(vCoins);
+    AvailableCoins(vCoins, true, coinControl);
+
+    // coin control -> return all selected outputs (we want all selected to go into the transaction for sure)
+    if (coinControl && coinControl->HasSelected())
+    {
+        BOOST_FOREACH(const COutput& out, vCoins)
+        {
+            nValueRet += out.tx->vout[out.i].nValue;
+            setCoinsRet.insert(make_pair(out.tx, out.i));
+        }
+        return (nValueRet >= nTargetValue);
+    }
 
     return (SelectCoinsMinConf(nTargetValue, nSpendTime, 1, 6, vCoins, setCoinsRet, nValueRet) ||
             SelectCoinsMinConf(nTargetValue, nSpendTime, 1, 1, vCoins, setCoinsRet, nValueRet) ||
             SelectCoinsMinConf(nTargetValue, nSpendTime, 0, 1, vCoins, setCoinsRet, nValueRet));
 }
 
+// Select some coins without random shuffle or best subset approximation
+bool CWallet::SelectCoinsSimple(int64 nTargetValue, unsigned int nSpendTime, int nMinConf, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, int64& nValueRet) const
+{
+    vector<COutput> vCoins;
+    AvailableCoinsMinConf(vCoins, nMinConf);
+
+    setCoinsRet.clear();
+    nValueRet = 0;
+
+    BOOST_FOREACH(COutput output, vCoins)
+    {
+        const CWalletTx *pcoin = output.tx;
+        int i = output.i;
+
+        // Stop if we've chosen enough inputs
+        if (nValueRet >= nTargetValue)
+            break;
+
+        // Follow the timestamp rules
+        if (pcoin->nTime > nSpendTime)
+            continue;
+
+        int64 n = pcoin->vout[i].nValue;
+
+        pair<int64,pair<const CWalletTx*,unsigned int> > coin = make_pair(n,make_pair(pcoin, i));
 
+        if (n >= nTargetValue)
+        {
+            // If input value is greater or equal to target then simply insert
+            //    it into the current subset and exit
+            setCoinsRet.insert(coin.second);
+            nValueRet += coin.first;
+            break;
+        }
+        else if (n < nTargetValue + CENT)
+        {
+            setCoinsRet.insert(coin.second);
+            nValueRet += coin.first;
+        }
+    }
 
+    return true;
+}
 
-bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet)
+bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet, const CCoinControl* coinControl)
 {
     int64 nValue = 0;
     BOOST_FOREACH (const PAIRTYPE(CScript, int64)& s, vecSend)
@@ -1253,11 +1307,9 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
 
     {
         LOCK2(cs_main, cs_wallet);
-        // txdb must be opened before the mapWallet lock
-        CTxDB txdb("r");
         {
             nFeeRet = nTransactionFee;
-            loop
+            while (true)
             {
                 wtxNew.vin.clear();
                 wtxNew.vout.clear();
@@ -1272,7 +1324,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
                 // Choose coins to use
                 set<pair<const CWalletTx*,unsigned int> > setCoins;
                 int64 nValueIn = 0;
-                if (!SelectCoins(nTotalValue, wtxNew.nTime, setCoins, nValueIn))
+                if (!SelectCoins(nTotalValue, wtxNew.nTime, setCoins, nValueIn, coinControl))
                     return false;
                 BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
                 {
@@ -1291,7 +1343,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
                     nFeeRet += nMoveToFee;
                 }
 
-                // ppcoin: sub-cent change is moved to fee
+                // sub-cent change is moved to fee
                 if (nChange > 0 && nChange < MIN_TXOUT_AMOUNT)
                 {
                     nFeeRet += nChange;
@@ -1300,22 +1352,30 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
 
                 if (nChange > 0)
                 {
-                    // Note: We use a new key here to keep it from being obvious which side is the change.
-                    //  The drawback is that by not reusing a previous key, the change may be lost if a
-                    //  backup is restored, if the backup doesn't have the new private key for the change.
-                    //  If we reused the old key, it would be possible to add code to look for and
-                    //  rediscover unknown transactions that were written with keys of ours to recover
-                    //  post-backup change.
-
-                    // Reserve a new key pair from key pool
-                    CPubKey vchPubKey = reservekey.GetReservedKey();
-                    // assert(mapKeys.count(vchPubKey));
-
                     // Fill a vout to ourself
                     // TODO: pass in scriptChange instead of reservekey so
                     // change transaction isn't always pay-to-bitcoin-address
                     CScript scriptChange;
-                    scriptChange.SetDestination(vchPubKey.GetID());
+
+                    // coin control: send change to custom address
+                    if (coinControl && !boost::get<CNoDestination>(&coinControl->destChange))
+                        scriptChange.SetDestination(coinControl->destChange);
+
+                    // no coin control: send change to newly generated address
+                    else
+                    {
+                        // Note: We use a new key here to keep it from being obvious which side is the change.
+                        //  The drawback is that by not reusing a previous key, the change may be lost if a
+                        //  backup is restored, if the backup doesn't have the new private key for the change.
+                        //  If we reused the old key, it would be possible to add code to look for and
+                        //  rediscover unknown transactions that were written with keys of ours to recover
+                        //  post-backup change.
+
+                        // Reserve a new key pair from key pool
+                        CPubKey vchPubKey = reservekey.GetReservedKey();
+
+                        scriptChange.SetDestination(vchPubKey.GetID());
+                    }
 
                     // Insert change txn at random position:
                     vector<CTxOut>::iterator position = wtxNew.vout.begin()+GetRandInt(wtxNew.vout.size());
@@ -1342,8 +1402,8 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
 
                 // Check that enough fee is included
                 int64 nPayFee = nTransactionFee * (1 + (int64)nBytes / 1000);
-                int64 nMinFee = wtxNew.GetMinFee(1, false, GMF_SEND);
-
+                bool fAllowFree = CTransaction::AllowFree(dPriority);
+                int64 nMinFee = wtxNew.GetMinFee(1, fAllowFree, GMF_SEND);
                 if (nFeeRet < max(nPayFee, nMinFee))
                 {
                     nFeeRet = max(nPayFee, nMinFee);
@@ -1351,7 +1411,7 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
                 }
 
                 // Fill vtxPrev by copying from previous transactions vtxPrev
-                wtxNew.AddSupportingTransactions(txdb);
+                wtxNew.AddSupportingTransactions();
                 wtxNew.fTimeReceivedIsTxTime = true;
 
                 break;
@@ -1361,143 +1421,201 @@ bool CWallet::CreateTransaction(const vector<pair<CScript, int64> >& vecSend, CW
     return true;
 }
 
-bool CWallet::CreateTransaction(CScript scriptPubKey, int64 nValue, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet)
+bool CWallet::CreateTransaction(CScript scriptPubKey, int64 nValue, CWalletTx& wtxNew, CReserveKey& reservekey, int64& nFeeRet, const CCoinControl* coinControl)
 {
     vector< pair<CScript, int64> > vecSend;
     vecSend.push_back(make_pair(scriptPubKey, nValue));
-    return CreateTransaction(vecSend, wtxNew, reservekey, nFeeRet);
+    return CreateTransaction(vecSend, wtxNew, reservekey, nFeeRet, coinControl);
 }
 
-// NovaCoin: get current stake generation power
-uint64 CWallet::GetStakeMintPower(const CKeyStore& keystore, enum StakeWeightMode mode)
+// NovaCoin: get current stake weight
+bool CWallet::GetStakeWeight(const CKeyStore& keystore, uint64& nMinWeight, uint64& nMaxWeight, uint64& nWeight)
 {
-    LOCK2(cs_main, cs_wallet);
-
     // Choose coins to use
     int64 nBalance = GetBalance();
     int64 nReserveBalance = 0;
-    uint64 nCoinAge = 0;
 
     if (mapArgs.count("-reservebalance") && !ParseMoney(mapArgs["-reservebalance"], nReserveBalance))
     {
-        error("CreateCoinStake : invalid reserve balance amount");
-        return 0;
+        error("GetStakeWeight : invalid reserve balance amount");
+        return false;
     }
 
     if (nBalance <= nReserveBalance)
-        return 0;
+        return false;
 
-    set<pair<const CWalletTx*,unsigned int> > setCoins;
     vector<const CWalletTx*> vwtxPrev;
+
+/*
+ * TODO: performance comparison
+
+    static set<pair<const CWalletTx*,unsigned int> > setCoins;
+    static uint256 hashPrevBlock;
+    static int64 nValueIn = 0;
+
+    // Cache outputs unless best block changed
+    if (hashPrevBlock != pindexBest->GetBlockHash())
+    {
+        if (!SelectCoinsSimple(nBalance - nReserveBalance, GetAdjustedTime(), nCoinbaseMaturity * 10, setCoins, nValueIn))
+            return false;
+
+        if (setCoins.empty())
+            return false;
+
+        hashPrevBlock == pindexBest->GetBlockHash();
+    }
+*/
+
+    set<pair<const CWalletTx*,unsigned int> > setCoins;
     int64 nValueIn = 0;
-    if (!SelectCoins(nBalance - nReserveBalance, GetTime(), setCoins, nValueIn))
-        return 0;
+
+    if (!SelectCoinsSimple(nBalance - nReserveBalance, GetTime(), nCoinbaseMaturity * 10, setCoins, nValueIn))
+        return false;
+
     if (setCoins.empty())
-        return 0;
+        return false;
 
+    CCoinsDB coinsdb("r");
+    CCoinsViewDB view(coinsdb);
     BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
     {
-        CTxDB txdb("r");
-        CTxIndex txindex;
-        if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex))
-            continue;
-
-        switch(mode)
+        CCoins coins;
         {
-            case STAKE_NORMAL:
-                // Do not count input that is still less than 30 days old
-                if (pcoin.first->nTime + nStakeMinAge > GetTime())
-                    continue;
-            break;
-            case STAKE_MAXWEIGHT:
-                // Do not count input that is still less than 90 days old
-                if (pcoin.first->nTime + nStakeMaxAge > GetTime())
-                    continue;
-            break;
-            case STAKE_MINWEIGHT:
-                // Count only inputs with suitable age (from 30 to 90 days old)
-                if (pcoin.first->nTime + nStakeMaxAge < GetTime())
-                    continue;
-                if (pcoin.first->nTime + nStakeMinAge > GetTime())
-                    continue;
-            break;
-            case STAKE_BELOWMIN:
-                // Count only inputs with suitable age (less than 30 days old)
-                if (pcoin.first->nTime + nStakeMinAge < GetTime())
-                    continue;
-            break;
+            LOCK2(cs_main, cs_wallet);
+            if (!view.GetCoins(pcoin.first->GetHash(), coins))
+                continue;
         }
 
-        CBigNum bnCentSecond = CBigNum(pcoin.first->vout[pcoin.second].nValue) * (GetTime()-pcoin.first->nTime) / CENT;
-        CBigNum bnCoinDay = bnCentSecond * CENT / COIN / (24 * 60 * 60);
+        int64 nTimeWeight = GetWeight((int64)pcoin.first->nTime, (int64)GetTime());
+        CBigNum bnCoinDayWeight = CBigNum(pcoin.first->vout[pcoin.second].nValue) * nTimeWeight / COIN / (24 * 60 * 60);
 
+        // Weight is greater than zero
+        if (nTimeWeight > 0)
+        {
+            nWeight += bnCoinDayWeight.getuint64();
+        }
 
-        nCoinAge += bnCoinDay.getuint64();
-    }
+        // Weight is greater than zero, but the maximum value isn't reached yet
+        if (nTimeWeight > 0 && nTimeWeight < nStakeMaxAge)
+        {
+            nMinWeight += bnCoinDayWeight.getuint64();
+        }
 
-    if (fDebug && GetBoolArg("-printcoinage"))
-        printf("StakePower bnCoinDay=%"PRI64d"\n", nCoinAge);
+        // Maximum weight was reached
+        if (nTimeWeight == nStakeMaxAge)
+        {
+            nMaxWeight += bnCoinDayWeight.getuint64();
+        }
+    }
 
-    return nCoinAge;
+    return true;
 }
 
-// ppcoin: create coin stake transaction
-bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int64 nSearchInterval, CTransaction& txNew)
+bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int64 nSearchInterval, CTransaction& txNew, CKey& key)
 {
-    // The following split & combine thresholds are important to security
+    // The following combine threshold is important to security
     // Should not be adjusted if you don't understand the consequences
-    static unsigned int nStakeSplitAge = (60 * 60 * 24 * 90);
     int64 nCombineThreshold = GetProofOfWorkReward(GetLastBlockIndex(pindexBest, false)->nBits) / 3;
 
     CBigNum bnTargetPerCoinDay;
     bnTargetPerCoinDay.SetCompact(nBits);
 
-    LOCK2(cs_main, cs_wallet);
     txNew.vin.clear();
     txNew.vout.clear();
+
     // Mark coin stake transaction
     CScript scriptEmpty;
     scriptEmpty.clear();
     txNew.vout.push_back(CTxOut(0, scriptEmpty));
+
     // Choose coins to use
     int64 nBalance = GetBalance();
     int64 nReserveBalance = 0;
+
     if (mapArgs.count("-reservebalance") && !ParseMoney(mapArgs["-reservebalance"], nReserveBalance))
         return error("CreateCoinStake : invalid reserve balance amount");
+
     if (nBalance <= nReserveBalance)
         return false;
-    set<pair<const CWalletTx*,unsigned int> > setCoins;
+
     vector<const CWalletTx*> vwtxPrev;
+
+/*
+ * TODO: performance comparison
+
+    static set<pair<const CWalletTx*,unsigned int> > setCoins;
+    static uint256 hashPrevBlock;
+    static int64 nValueIn = 0;
+
+    // Cache outputs unless best block changed
+    if (hashPrevBlock != pindexBest->GetBlockHash())
+    {
+        if (!SelectCoinsSimple(nBalance - nReserveBalance, txNew.nTime, nCoinbaseMaturity * 10, setCoins, nValueIn))
+            return false;
+
+        if (setCoins.empty())
+            return false;
+
+        hashPrevBlock == pindexBest->GetBlockHash();
+    }
+*/
+
+    set<pair<const CWalletTx*,unsigned int> > setCoins;
     int64 nValueIn = 0;
-    if (!SelectCoins(nBalance - nReserveBalance, txNew.nTime, setCoins, nValueIn))
+
+    // Select coins with suitable depth
+    if (!SelectCoinsSimple(nBalance - nReserveBalance, txNew.nTime, nCoinbaseMaturity * 10, setCoins, nValueIn))
         return false;
+
     if (setCoins.empty())
         return false;
+
     int64 nCredit = 0;
     CScript scriptPubKeyKernel;
+
+    CCoinsDB coinsdb("r");
+    CCoinsViewDB view(coinsdb);
     BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
     {
-        CTxDB txdb("r");
-        CTxIndex txindex;
-        if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex))
-            continue;
+        CCoins coins;
+        {
+            LOCK2(cs_main, cs_wallet);
+            if (!view.GetCoins(pcoin.first->GetHash(), coins))
+                continue;
+        }
 
-        // Read block header
-        CBlock block;
-        if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
-            continue;
         static int nMaxStakeSearchInterval = 60;
-        if (block.GetBlockTime() + nStakeMinAge > txNew.nTime - nMaxStakeSearchInterval)
+        if (coins.nBlockTime + nStakeMinAge > txNew.nTime - nMaxStakeSearchInterval)
             continue; // only count coins meeting min age requirement
 
+        // Read block header
+        CBlock block;
+        unsigned int nTxPos = 0;
+        {
+            LOCK2(cs_main, cs_wallet);
+            CBlockIndex *pindex = FindBlockByHeight(coins.nHeight);
+
+            if (!block.ReadFromDisk(pindex))
+                continue;
+
+            BOOST_FOREACH(const CTransaction &tx, block.vtx) {
+                if (tx.GetHash() == pcoin.first->GetHash()) {
+                    break;
+                }
+                nTxPos += tx.GetSerializeSize(SER_DISK, CLIENT_VERSION);
+            }
+            nTxPos += GetSerializeSize(CBlock(), SER_DISK, CLIENT_VERSION) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(block.vtx.size());
+        }
+
+
         bool fKernelFound = false;
         for (unsigned int n=0; n<min(nSearchInterval,(int64)nMaxStakeSearchInterval) && !fKernelFound && !fShutdown; n++)
         {
             // Search backward in time from the given txNew timestamp 
             // Search nSearchInterval seconds back up to nMaxStakeSearchInterval
-            uint256 hashProofOfStake = 0;
+            uint256 hashProofOfStake = 0, targetProofOfStake = 0;
             COutPoint prevoutStake = COutPoint(pcoin.first->GetHash(), pcoin.second);
-            if (CheckStakeKernelHash(nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, *pcoin.first, prevoutStake, txNew.nTime - n, hashProofOfStake))
+            if (CheckStakeKernelHash(nBits, block, nTxPos, *pcoin.first, prevoutStake, txNew.nTime - n, hashProofOfStake, targetProofOfStake))
             {
                 // Found a kernel
                 if (fDebug && GetBoolArg("-printcoinstake"))
@@ -1523,7 +1641,6 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
                 if (whichType == TX_PUBKEYHASH) // pay to address type
                 {
                     // convert to pay to public key type
-                    CKey key;
                     if (!keystore.GetKey(uint160(vSolutions[0]), key))
                     {
                         if (fDebug && GetBoolArg("-printcoinstake"))
@@ -1532,15 +1649,33 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
                     }
                     scriptPubKeyOut << key.GetPubKey() << OP_CHECKSIG;
                 }
-                else
+                if (whichType == TX_PUBKEY)
+                {
+                    valtype& vchPubKey = vSolutions[0];
+                    if (!keystore.GetKey(Hash160(vchPubKey), key))
+                    {
+                        if (fDebug && GetBoolArg("-printcoinstake"))
+                            printf("CreateCoinStake : failed to get key for kernel type=%d\n", whichType);
+                        break;  // unable to find corresponding public key
+                    }
+
+                if (key.GetPubKey() != vchPubKey)
+                {
+                    if (fDebug && GetBoolArg("-printcoinstake"))
+                        printf("CreateCoinStake : invalid key for kernel type=%d\n", whichType);
+                        break; // keys mismatch
+                    }
+
                     scriptPubKeyOut = scriptPubKeyKernel;
+                }
 
-                txNew.nTime -= n; 
+                txNew.nTime -= n;
                 txNew.vin.push_back(CTxIn(pcoin.first->GetHash(), pcoin.second));
                 nCredit += pcoin.first->vout[pcoin.second].nValue;
                 vwtxPrev.push_back(pcoin.first);
                 txNew.vout.push_back(CTxOut(0, scriptPubKeyOut));
-                if (block.GetBlockTime() + nStakeSplitAge > txNew.nTime)
+
+                if (GetWeight(block.GetBlockTime(), (int64)txNew.nTime) < nStakeMaxAge)
                     txNew.vout.push_back(CTxOut(0, scriptPubKeyOut)); //split stake
                 if (fDebug && GetBoolArg("-printcoinstake"))
                     printf("CreateCoinStake : added kernel type=%d\n", whichType);
@@ -1548,11 +1683,14 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
                 break;
             }
         }
+
         if (fKernelFound || fShutdown)
             break; // if kernel is found stop searching
     }
+
     if (nCredit == 0 || nCredit > nBalance - nReserveBalance)
         return false;
+
     BOOST_FOREACH(PAIRTYPE(const CWalletTx*, unsigned int) pcoin, setCoins)
     {
         // Attempt to add more inputs
@@ -1560,6 +1698,8 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
         if (txNew.vout.size() == 2 && ((pcoin.first->vout[pcoin.second].scriptPubKey == scriptPubKeyKernel || pcoin.first->vout[pcoin.second].scriptPubKey == txNew.vout[1].scriptPubKey))
             && pcoin.first->GetHash() != txNew.vin[0].prevout.hash)
         {
+            int64 nTimeWeight = GetWeight((int64)pcoin.first->nTime, (int64)txNew.nTime);
+
             // Stop adding more inputs if already too many inputs
             if (txNew.vin.size() >= 100)
                 break;
@@ -1573,24 +1713,29 @@ bool CWallet::CreateCoinStake(const CKeyStore& keystore, unsigned int nBits, int
             if (pcoin.first->vout[pcoin.second].nValue > nCombineThreshold)
                 continue;
             // Do not add input that is still too young
-            if (pcoin.first->nTime + nStakeMaxAge > txNew.nTime)
+            if (nTimeWeight < nStakeMaxAge)
                 continue;
+
             txNew.vin.push_back(CTxIn(pcoin.first->GetHash(), pcoin.second));
             nCredit += pcoin.first->vout[pcoin.second].nValue;
             vwtxPrev.push_back(pcoin.first);
         }
     }
+
     // Calculate coin age reward
     {
         uint64 nCoinAge;
-        CTxDB txdb("r");
-        if (!txNew.GetCoinAge(txdb, nCoinAge))
+
+        CCoinsDB coindb("r");
+        CCoinsViewDB view(coindb);
+
+        if (!txNew.GetCoinAge(view, nCoinAge))
             return error("CreateCoinStake : failed to calculate coin age");
         nCredit += GetProofOfStakeReward(nCoinAge, nBits, txNew.nTime);
     }
 
     int64 nMinFee = 0;
-    loop
+    while (true)
     {
         // Set output amount
         if (txNew.vout.size() == 3)
@@ -1868,7 +2013,7 @@ bool CWallet::NewKeyPool()
     return true;
 }
 
-bool CWallet::TopUpKeyPool()
+bool CWallet::TopUpKeyPool(unsigned int nSize)
 {
     {
         LOCK(cs_wallet);
@@ -1879,7 +2024,12 @@ bool CWallet::TopUpKeyPool()
         CWalletDB walletdb(strWalletFile);
 
         // Top up key pool
-        unsigned int nTargetSize = max(GetArg("-keypool", 100), 0LL);
+        unsigned int nTargetSize;
+        if (nSize > 0)
+            nTargetSize = nSize;
+        else
+            nTargetSize = max(GetArg("-keypool", 100), 0LL);
+
         while (setKeyPool.size() < (nTargetSize + 1))
         {
             int64 nEnd = 1;
@@ -2131,16 +2281,17 @@ void CWallet::FixSpentCoins(int& nMismatchFound, int64& nBalanceInQuestion, bool
     for (map<uint256, CWalletTx>::iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
         vCoins.push_back(&(*it).second);
 
-    CTxDB txdb("r");
+    CCoinsDB coinsdb("r");
     BOOST_FOREACH(CWalletTx* pcoin, vCoins)
     {
         // Find the corresponding transaction index
-        CTxIndex txindex;
-        if (!txdb.ReadTxIndex(pcoin->GetHash(), txindex))
-            continue;
+        CCoins coins;
+
+        bool fNotFound = coinsdb.ReadCoins(pcoin->GetHash(), coins);
+
         for (unsigned int n=0; n < pcoin->vout.size(); n++)
         {
-            if (IsMine(pcoin->vout[n]) && pcoin->IsSpent(n) && (txindex.vSpent.size() <= n || txindex.vSpent[n].IsNull()))
+            if (!fNotFound && IsMine(pcoin->vout[n]) && pcoin->IsSpent(n) && coins.IsAvailable(n))
             {
                 printf("FixSpentCoins found lost coin %sppc %s[%d], %s\n",
                     FormatMoney(pcoin->vout[n].nValue).c_str(), pcoin->GetHash().ToString().c_str(), n, fCheckOnly? "repair not attempted" : "repairing");
@@ -2152,7 +2303,7 @@ void CWallet::FixSpentCoins(int& nMismatchFound, int64& nBalanceInQuestion, bool
                     pcoin->WriteToDisk();
                 }
             }
-            else if (IsMine(pcoin->vout[n]) && !pcoin->IsSpent(n) && (txindex.vSpent.size() > n && !txindex.vSpent[n].IsNull()))
+            else if (!fNotFound && IsMine(pcoin->vout[n]) && !pcoin->IsSpent(n) && coins.IsAvailable(n))
             {
                 printf("FixSpentCoins found spent coin %sppc %s[%d], %s\n",
                     FormatMoney(pcoin->vout[n].nValue).c_str(), pcoin->GetHash().ToString().c_str(), n, fCheckOnly? "repair not attempted" : "repairing");