Make sure that new stake modifier meets fixed generation interval.

diff --git a/src/kernel.cpp b/src/kernel.cpp
index 1c1ca44..c937232 100644 (file)
--- a/src/kernel.cpp
+++ b/src/kernel.cpp
@@ -12,6 +12,15 @@ using namespace std;
 extern int nStakeMaxAge;
 extern int nStakeTargetSpacing;
 
+// Protocol switch time for fixed kernel modifier interval
+unsigned int nModifierSwitchTime  = 1402531200;    // Thu, 12 Jun 2014 00:00:00 GMT
+unsigned int nModifierTestSwitchTime = 1397520000; // Tue, 15 Apr 2014 00:00:00 GMT
+//
+// Note: user must upgrade before the protocol switch deadline, otherwise it's required to
+//   re-download the blockchain. The timestamp of upgrade is recorded in the blockchain 
+//   database.
+unsigned int nModifierUpgradeTime = 0;
+
 typedef std::map<int, unsigned int> MapModifierCheckpoints;
 
 // Hard checkpoints of stake modifiers to ensure they are deterministic
@@ -39,6 +48,12 @@ int64 GetWeight(int64 nIntervalBeginning, int64 nIntervalEnd)
     return min(nIntervalEnd - nIntervalBeginning - nStakeMinAge, (int64)nStakeMaxAge);
 }
 
+// Whether the given block is subject to new modifier protocol
+bool IsFixedModifierInterval(unsigned int nTimeBlock)
+{
+    return (nTimeBlock >= (fTestNet? nModifierTestSwitchTime : nModifierSwitchTime));
+}
+
 // Get the last stake modifier and its generation time from a given block
 static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64& nStakeModifier, int64& nModifierTime)
 {
@@ -128,15 +143,17 @@ static bool SelectBlockFromCandidates(vector<pair<int64, uint256> >& vSortedByTi
 // block. This is to make it difficult for an attacker to gain control of
 // additional bits in the stake modifier, even after generating a chain of
 // blocks.
-bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModifier, bool& fGeneratedStakeModifier)
+bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64& nStakeModifier, bool& fGeneratedStakeModifier)
 {
     nStakeModifier = 0;
     fGeneratedStakeModifier = false;
+    const CBlockIndex* pindexPrev = pindexCurrent->pprev;
     if (!pindexPrev)
     {
         fGeneratedStakeModifier = true;
         return true;  // genesis block's modifier is 0
     }
+
     // First find current stake modifier and its generation block time
     // if it's not old enough, return the same stake modifier
     int64 nModifierTime = 0;
@@ -144,10 +161,35 @@ bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModif
         return error("ComputeNextStakeModifier: unable to get last modifier");
     if (fDebug)
     {
-        printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str());
+        printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s epoch=%u\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str(), (unsigned int)nModifierTime);
     }
     if (nModifierTime / nModifierInterval >= pindexPrev->GetBlockTime() / nModifierInterval)
+    {
+        if (fDebug)
+        {
+            printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexPrev nHeight=%d nTime=%u\n", pindexPrev->nHeight, (unsigned int)pindexPrev->GetBlockTime());
+        }
         return true;
+    }
+    if (nModifierTime / nModifierInterval >= pindexCurrent->GetBlockTime() / nModifierInterval)
+    {
+        // fixed interval protocol requires current block timestamp also be in a different modifier interval
+        if (IsFixedModifierInterval(pindexCurrent->nTime))
+        {
+            if (fDebug)
+            {
+                printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime());
+            }
+            return true;
+        }
+        else
+        {
+            if (fDebug)
+            {
+                printf("ComputeNextStakeModifier: old modifier at block %s not meeting fixed modifier interval: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->GetBlockHash().ToString().c_str(), pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime());
+            }
+        }
+    }
 
     // Sort candidate blocks by timestamp
     vector<pair<int64, uint256> > vSortedByTimestamp;

diff --git a/src/kernel.h b/src/kernel.h
index 6b9cd6b..63e03c6 100644 (file)
--- a/src/kernel.h
+++ b/src/kernel.h
@@ -6,6 +6,12 @@
 
 #include "main.h"
 
+// ChainDB upgrade time
+extern unsigned int nModifierUpgradeTime;
+
+// Whether a given block is subject to new modifier protocol
+bool IsFixedModifierInterval(unsigned int nTimeBlock);
+
 // MODIFIER_INTERVAL: time to elapse before new modifier is computed
 extern unsigned int nModifierInterval;
 
@@ -14,7 +20,7 @@ extern unsigned int nModifierInterval;
 static const int MODIFIER_INTERVAL_RATIO = 3;
 
 // Compute the hash modifier for proof-of-stake
-bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModifier, bool& fGeneratedStakeModifier);
+bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64& nStakeModifier, bool& fGeneratedStakeModifier);
 
 // Check whether stake kernel meets hash target
 // Sets hashProofOfStake and targetProofOfStake on success return

diff --git a/src/main.cpp b/src/main.cpp
index 1e68aef..e7bb584 100644 (file)
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2122,7 +2122,7 @@ bool CBlock::AddToBlockIndex(const CDiskBlockPos &pos)
     // Compute stake modifier
     uint64 nStakeModifier = 0;
     bool fGeneratedStakeModifier = false;
-    if (!ComputeNextStakeModifier(pindexNew->pprev, nStakeModifier, fGeneratedStakeModifier))
+    if (!ComputeNextStakeModifier(pindexNew, nStakeModifier, fGeneratedStakeModifier))
         return error("AddToBlockIndex() : ComputeNextStakeModifier() failed");
     pindexNew->SetStakeModifier(nStakeModifier, fGeneratedStakeModifier);
     pindexNew->nStakeModifierChecksum = GetStakeModifierChecksum(pindexNew);
@@ -3072,6 +3072,11 @@ bool LoadBlockIndex(bool fAllowNew)
         // initialize synchronized checkpoint
         if (!Checkpoints::WriteSyncCheckpoint((!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet)))
             return error("LoadBlockIndex() : failed to init sync checkpoint");
+
+        // upgrade time set to zero if txdb initialized
+        if (!pblocktree->WriteModifierUpgradeTime(0))
+            return error("LoadBlockIndex() : failed to init upgrade info");
+        printf(" Upgrade Info: blocktreedb initialization\n");
     }
 
     string strPubKey = "";
@@ -3089,6 +3094,22 @@ bool LoadBlockIndex(bool fAllowNew)
             return error("LoadBlockIndex() : failed to reset sync-checkpoint");
     }
 
+    // upgrade time set to zero if blocktreedb initialized
+    if (pblocktree->ReadModifierUpgradeTime(nModifierUpgradeTime))
+    {
+        if (nModifierUpgradeTime)
+            printf(" Upgrade Info: blocktreedb upgrade detected at timestamp %d\n", nModifierUpgradeTime);
+        else
+            printf(" Upgrade Info: no blocktreedb upgrade detected.\n");
+    }
+    else
+    {
+        nModifierUpgradeTime = GetTime();
+        printf(" Upgrade Info: upgrading blocktreedb at timestamp %u\n", nModifierUpgradeTime);
+        if (!pblocktree->WriteModifierUpgradeTime(nModifierUpgradeTime))
+            return error("LoadBlockIndex() : failed to write upgrade info");
+    }
+
     return true;
 }
 
@@ -3266,6 +3287,14 @@ string GetWarnings(string strFor)
         strStatusBar = _("WARNING: Checkpoint is too old. Wait for block chain to download, or notify developers.");
     }
 
+    // if detected unmet upgrade requirement enter safe mode
+    // Note: Modifier upgrade requires blockchain redownload if past protocol switch
+    if (IsFixedModifierInterval(nModifierUpgradeTime + 60*60*24)) // 1 day margin
+    {
+        nPriority = 5000;
+        strStatusBar = strRPC = "WARNING: Blockchain redownload required approaching or past v.0.4.4.7b6 upgrade deadline.";
+    }
+
     // ppcoin: if detected invalid checkpoint enter safe mode
     if (Checkpoints::hashInvalidCheckpoint != 0)
     {

diff --git a/src/txdb.cpp b/src/txdb.cpp
index e6b7409..10ffd15 100644 (file)
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -98,6 +98,16 @@ bool CBlockTreeDB::WriteCheckpointPubKey(const string& strPubKey)
     return Write('K', strPubKey);
 }
 
+bool CBlockTreeDB::ReadModifierUpgradeTime(unsigned int& nUpgradeTime)
+{
+    return Read('M', nUpgradeTime);
+}
+
+bool CBlockTreeDB::WriteModifierUpgradeTime(const unsigned int& nUpgradeTime)
+{
+    return Write('M', nUpgradeTime);
+}
+
 bool CBlockTreeDB::WriteBlockFileInfo(int nFile, const CBlockFileInfo &info) {
     return Write(make_pair('f', nFile), info);
 }

diff --git a/src/txdb.h b/src/txdb.h
index 3f07f0e..cc85d21 100644 (file)
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -45,6 +45,8 @@ public:
     bool WriteSyncCheckpoint(uint256 hashCheckpoint);
     bool ReadCheckpointPubKey(std::string& strPubKey);
     bool WriteCheckpointPubKey(const std::string& strPubKey);
+    bool ReadModifierUpgradeTime(unsigned int& nUpgradeTime);
+    bool WriteModifierUpgradeTime(const unsigned int& nUpgradeTime);
     bool LoadBlockIndexGuts();
 };