Bulwark Re-Stake

src/kernel.cpp

@@ -278,18 +278,33 @@ bool stakeTargetHit(uint256 hashProofOfStake, int64_t nValueIn, uint256 bnTarget
 
 //instead of looping outside and reinitializing variables many times, we will give a nTimeTx and also search interval so that we can do all the hashing here
 bool CheckStakeKernelHash(unsigned int nBits, const CBlock blockFrom, const CTransaction txPrev, const COutPoint prevout, unsigned int& nTimeTx, unsigned int nHashDrift, bool fCheck, uint256& hashProofOfStake, bool fPrintProofOfStake) {
-    //assign new variables to make it easier to read
+    //Get stake input amount (output amount of a previous tx)
     int64_t nValueIn = txPrev.vout[prevout.n].nValue;
-    unsigned int nTimeBlockFrom = blockFrom.GetBlockTime();
+    unsigned int nTimeBlockFrom = blockFrom.GetBlockTime(); // When was the block of the tx we've staked created?
 
+    // Ensure we can't stake a tx on same block or any blocks before that
     if (nTimeTx < nTimeBlockFrom) // Transaction timestamp violation
         return error("CheckStakeKernelHash() : nTime violation");
 
-    // Consensus implementation of protocol change.
+    // Default requirement for stake is nStakeMinAge (1 * 60 * 60 for BWK)
     unsigned int nMinStakeAge = nStakeMinAge;
+
+    // IF spork is enabled (check "spork active") the requiremnt will be changed (12 * 60 * 60 for BWK)
     if (IsSporkActive(SPORK_23_STAKING_REQUIREMENTS) && nTimeBlockFrom >= GetSporkValue(SPORK_23_STAKING_REQUIREMENTS)) {
         nMinStakeAge = nStakeMinAgeConsensus;
     }
+
+    // Bulwark's "Re-Stake". Because Bulwark stores metadata identifying stake in tx we know that previously this was a POS reward
+    // If you have not previously staked on this input then you will have to wait longer for your stake to mature.
+    // This penalizes "Stake Grinding" and gives reason to leave stakes alone reducing traffic on the network.
+    if (IsSporkActive(SPORK_25_BWK_RESTAKE) && nTimeBlockFrom >= GetSporkValue(SPORK_25_BWK_RESTAKE)) {
+        // Make sure this was a basic stake with no splitthreshold (vout[0]=0 nonstandard,vout[1/2]=pos/mn)
+        if (!txPrev.IsCoinStake() || txPrev.vout.size() != 3) {
+            nMinStakeAge *= 2;
+        }
+    }
+
+    // Ensure at least nMinStakeAge passed between tx and tx with stake
     if (nTimeBlockFrom + nMinStakeAge > nTimeTx) // Min age requirement
         return error("CheckStakeKernelHash() : min age violation - nTimeBlockFrom=%d nStakeMinAge=%d nTimeTx=%d", nTimeBlockFrom, nMinStakeAge, nTimeTx);
 

src/main.cpp

@@ -907,6 +907,7 @@ int GetIXConfirmations(uint256 nTXHash) {
     return 0;
 }
 
+//@todo This function doesn't seem to be used anywhere, remove?
 // ppcoin: total coin age spent in transaction, in the unit of coin-days.
 // Only those coins meeting minimum age requirement counts. As those
 // transactions not in main chain are not currently indexed so we
@@ -915,6 +916,7 @@ int GetIXConfirmations(uint256 nTXHash) {
 // introduced to help nodes establish a consistent view of the coin
 // age (trust score) of competing branches.
 bool GetCoinAge(const CTransaction& tx, const unsigned int nTxTime, uint64_t& nCoinAge) {
+
     uint256 bnCentSecond = 0; // coin age in the unit of cent-seconds
     nCoinAge = 0;
 
@@ -4225,41 +4227,62 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bo
 
     if (block.IsProofOfStake()) {
         // Coinbase output should be empty if proof-of-stake block
+        // The way POS txs are structured is that the first output of first tx is empty with 0 value
         if (block.vtx[0].vout.size() != 1 || !block.vtx[0].vout[0].IsEmpty())
             return state.DoS(100, error("CheckBlock() : coinbase output not empty for proof-of-stake block"));
 
-        // Second transaction must be coinstake, the rest must not be
+        // Ensure there is only one stake in block and it's 1st tx:
         if (block.vtx.empty() || !block.vtx[1].IsCoinStake())
             return state.DoS(100, error("CheckBlock() : second tx is not coinstake"));
+
+        // Ensure there are no other stakes in tx
         for (unsigned int i = 2; i < block.vtx.size(); i++)
             if (block.vtx[i].IsCoinStake())
                 return state.DoS(100, error("CheckBlock() : more than one coinstake"));
 
-        // If consensus level checks are in place.
+        // After spork is enabled we'll perform additional POS checks
+        // If the spork is not enabled these conditions are NOT checked
         if (IsSporkActive(SPORK_23_STAKING_REQUIREMENTS) && block.GetBlockTime() >= GetSporkValue(SPORK_23_STAKING_REQUIREMENTS)) {
-            // Check for minimum value.
-            if (block.vtx[1].vout[1].nValue < Params().Stake_MinAmount())
-                return state.DoS(100, error("CheckBlock() : stake under min. stake value"));
+            CAmount minStakeAmount = Params().Stake_MinAmount();
+            unsigned int minStakeAge = nStakeMinAgeConsensus;
+            int minStakeConfirmations = Params().Stake_MinConfirmations();
 
-            // Check for coin age.
-            // First try finding the previous transaction in database.
+
+            // Get transaction of the staked input
             CTransaction txPrev;
             uint256 hashBlockPrev;
             if (!GetTransaction(block.vtx[1].vin[0].prevout.hash, txPrev, hashBlockPrev, true))
                 return state.DoS(100, error("CheckBlock() : stake failed to find vin transaction"));
-            // Find block in map.
+
+            // Bulwark's "Re-Stake". Because Bulwark stores metadata identifying stake in tx we know that previously this was a POS reward
+            // If you have not previously staked on this input then you will have to wait longer for your stake to mature.
+            // This penalizes "Stake Grinding" and gives reason to leave stakes alone reducing traffic on the network.
+            if (IsSporkActive(SPORK_25_BWK_RESTAKE) && block.GetBlockTime() >= GetSporkValue(SPORK_25_BWK_RESTAKE)) {
+                // Time is doubled if it's not a basic steak (without split)
+                if (!txPrev.IsCoinStake() || txPrev.vout.size() != 3) {
+                    minStakeAge *= 2;
+                    minStakeConfirmations *= 2;
+                }
+            }
+            // Ensure the output of the stake is above min amount (100 for BWK)
+            if (block.vtx[1].vout[1].nValue < minStakeAmount)
+                return state.DoS(100, error("CheckBlock() : stake under min. stake value"));
+
+            // Get block of this transaction (the transaction of staked input)
             CBlockIndex* pindex = NULL;
             BlockMap::iterator it = mapBlockIndex.find(hashBlockPrev);
             if (it != mapBlockIndex.end())
                 pindex = it->second;
             else
                 return state.DoS(100, error("CheckBlock() :  stake failed to find block index"));
-            // Check block time vs stake age requirement.
-            if (pindex->GetBlockHeader().nTime + nStakeMinAgeConsensus > GetAdjustedTime())
+
+            // Ensure the block age of the staked input block is at least nStakeMinAgeConsensus (12 * 60 * 60 for BWK)
+            //@todo this should probably look at chainActive.Tip()->GetBlockTime() not local computer GetAdjustedTime()
+            if (pindex->GetBlockHeader().nTime + minStakeAge > GetAdjustedTime())
                 return state.DoS(100, error("CheckBlock() : stake under min. stake age"));
-            
-            // Check that the prev. stake block has required confirmations by height.
-            if (chainActive.Tip()->nHeight - pindex->nHeight < Params().Stake_MinConfirmations())
+
+            // Ensure that the difference between latest block and staked block meets min confirmations requirement (475 for BWK)
+            if (chainActive.Tip()->nHeight - pindex->nHeight < minStakeConfirmations)
                 return state.DoS(100, error("CheckBlock() : stake under min. required confirmations"));
         }
     }

src/spork.cpp

@@ -134,6 +134,8 @@ int64_t GetSporkValue(int nSporkID) {
         if (nSporkID == SPORK_21_ENABLE_ZEROCOIN) r = SPORK_21_ENABLE_ZEROCOIN_DEFAULT;
         if (nSporkID == SPORK_22_ZEROCOIN_MAINTENANCE_MODE) r = SPORK_22_ZEROCOIN_MAINTENANCE_MODE_DEFAULT;
         if (nSporkID == SPORK_23_STAKING_REQUIREMENTS) r = SPORK_23_STAKING_REQUIREMENTS_DEFAULT;
+        if (nSporkID == SPORK_24_QUERY_NODES) r = SPORK_24_QUERY_NODES_DEFAULT;
+        if (nSporkID == SPORK_25_BWK_RESTAKE) r = SPORK_25_BWK_RESTAKE_DEFAULT;
 
         if (r == -1) LogPrintf("GetSpork::Unknown Spork %d\n", nSporkID);
     }
@@ -286,6 +288,8 @@ int CSporkManager::GetSporkIDByName(std::string strName) {
     if (strName == "SPORK_21_ENABLE_ZEROCOIN") return SPORK_21_ENABLE_ZEROCOIN;
     if (strName == "SPORK_22_ZEROCOIN_MAINTENANCE_MODE") return SPORK_22_ZEROCOIN_MAINTENANCE_MODE;
     if (strName == "SPORK_23_STAKING_REQUIREMENTS") return SPORK_23_STAKING_REQUIREMENTS;
+    if (strName == "SPORK_24_QUERY_NODES") return SPORK_24_QUERY_NODES;
+    if (strName == "SPORK_25_BWK_RESTAKE") return SPORK_25_BWK_RESTAKE;
 
     return -1;
 }
@@ -311,6 +315,8 @@ std::string CSporkManager::GetSporkNameByID(int id) {
     if (id == SPORK_21_ENABLE_ZEROCOIN) return "SPORK_21_ENABLE_ZEROCOIN";
     if (id == SPORK_22_ZEROCOIN_MAINTENANCE_MODE) return "SPORK_22_ZEROCOIN_MAINTENANCE_MODE";
     if (id == SPORK_23_STAKING_REQUIREMENTS) return "SPORK_23_STAKING_REQUIREMENTS";
+    if (id == SPORK_24_QUERY_NODES) return "SPORK_24_QUERY_NODES";
+    if (id == SPORK_25_BWK_RESTAKE) return "SPORK_25_BWK_RESTAKE";
 
     return "Unknown";
 }

src/spork.h

@@ -47,6 +47,8 @@ using namespace boost;
 #define SPORK_21_ENABLE_ZEROCOIN 10020
 #define SPORK_22_ZEROCOIN_MAINTENANCE_MODE 10021
 #define SPORK_23_STAKING_REQUIREMENTS 10022
+#define SPORK_24_QUERY_NODES 10023
+#define SPORK_25_BWK_RESTAKE 10024
 
 #define SPORK_2_SWIFTTX_DEFAULT 978307200                         //2001-1-1
 #define SPORK_3_SWIFTTX_BLOCK_FILTERING_DEFAULT 1424217600        //2015-2-18
@@ -73,6 +75,8 @@ using namespace boost;
 #define SPORK_21_ENABLE_ZEROCOIN_DEFAULT 4070908800               //OFF
 #define SPORK_22_ZEROCOIN_MAINTENANCE_MODE_DEFAULT 4070908800     //OFF
 #define SPORK_23_STAKING_REQUIREMENTS_DEFAULT 4070908800          //OFF
+#define SPORK_24_QUERY_NODES_DEFAULT 4070908800                   //OFF
+#define SPORK_25_BWK_RESTAKE_DEFAULT 4070908800                   //OFF
 
 class CSporkMessage;
 class CSporkManager;

src/test/main_tests.cpp

@@ -17,9 +17,9 @@ BOOST_AUTO_TEST_CASE(subsidy_limit_test) {
     for (int nHeight = 0; nHeight < 14000000; nHeight += 1000) {
         /* @TODO fix subsidity, add nBits */
         CAmount nSubsidy = GetBlockValue(nHeight);
-        BOOST_CHECK(nSubsidy <= 50 * COIN);
+        BOOST_CHECK_MESSAGE(nSubsidy <= 50 * COIN,"nSubsidy is " << nSubsidy << ". Expected 50 * COIN.");
         nSum += nSubsidy * 1000;
-        BOOST_CHECK(MoneyRange(nSum));
+        BOOST_CHECK_MESSAGE(MoneyRange(nSum),"nSum is " << nSum << ". MaxMoneyOut: " << Params().MaxMoneyOut());
     }
     BOOST_CHECK(nSum == 2099999997690000ULL);
 }

src/wallet.cpp

@@ -1696,6 +1696,9 @@ bool CWallet::SelectStakeCoins(std::set<std::pair<const CWalletTx*, unsigned int
     }
 
     BOOST_FOREACH(const COutput& out, vCoins) {
+        unsigned int minStakeAge = nMinStakeAge;
+        int minStakeDepth = nStakeDepth;
+
         //make sure not to outrun target amount
         if (nAmountSelected + out.tx->vout[out.i].nValue > nTargetAmount)
             continue;
@@ -1704,8 +1707,17 @@ bool CWallet::SelectStakeCoins(std::set<std::pair<const CWalletTx*, unsigned int
         if (out.tx->vout[out.i].nValue < nStakeAmount)
             continue;
 
+        //For Bulwark Re-staking since we know if a tx is previous stake it'll be considered re-stake resulting in various advantages
+        if (IsSporkActive(SPORK_25_BWK_RESTAKE)) {
+            // Basic restakes will receive rewards 2x faster. (These must not be split)
+            if (!out.tx->IsCoinStake() || out.tx->vout.size()!=3) {
+                minStakeAge *= 2;
+                minStakeDepth *= 2;
+            }
+        }
+
         //check that it is matured
-        if (out.nDepth < (out.tx->IsCoinStake() ? nStakeDepth : 10))
+        if (out.nDepth < (out.tx->IsCoinStake() ? minStakeDepth : 10))
             continue;
 
         //if zerocoinspend, then use the block time
@@ -1717,7 +1729,7 @@ bool CWallet::SelectStakeCoins(std::set<std::pair<const CWalletTx*, unsigned int
         }
 
         //check for min age
-        if (GetAdjustedTime() - nTxTime < nMinStakeAge)
+        if (GetAdjustedTime() - nTxTime < minStakeAge)
             continue;
 
         //add to our stake set