PPCoin: Switch main chain protocol to score with proof-of-stake difficulty

        Upgrade requirement: backup wallet and redownload block chain

diff --git a/src/db.cpp b/src/db.cpp
index 04f400e..bc9c216 100644 (file)
--- a/src/db.cpp
+++ b/src/db.cpp
@@ -488,14 +488,14 @@ bool CTxDB::WriteHashBestChain(uint256 hashBestChain)
     return Write(string("hashBestChain"), hashBestChain);
 }
 
-bool CTxDB::ReadBestInvalidTrust(uint64& nBestInvalidTrust)
+bool CTxDB::ReadBestInvalidTrust(CBigNum& bnBestInvalidTrust)
 {
-    return Read(string("nBestInvalidTrust"), nBestInvalidTrust);
+    return Read(string("bnBestInvalidTrust"), bnBestInvalidTrust);
 }
 
-bool CTxDB::WriteBestInvalidTrust(uint64 nBestInvalidTrust)
+bool CTxDB::WriteBestInvalidTrust(CBigNum bnBestInvalidTrust)
 {
-    return Write(string("nBestInvalidTrust"), nBestInvalidTrust);
+    return Write(string("bnBestInvalidTrust"), bnBestInvalidTrust);
 }
 
 bool CTxDB::ReadSyncCheckpoint(uint256& hashCheckpoint)
@@ -577,7 +577,6 @@ bool CTxDB::LoadBlockIndex()
             pindexNew->pnext          = InsertBlockIndex(diskindex.hashNext);
             pindexNew->nFile          = diskindex.nFile;
             pindexNew->nBlockPos      = diskindex.nBlockPos;
-            pindexNew->nChainTrust    = diskindex.nChainTrust;
             pindexNew->nHeight        = diskindex.nHeight;
             pindexNew->fProofOfStake  = diskindex.fProofOfStake;
             pindexNew->prevoutStake   = diskindex.prevoutStake;
@@ -612,6 +611,21 @@ bool CTxDB::LoadBlockIndex()
     if (fRequestShutdown)
         return true;
 
+    // Calculate bnChainTrust
+    vector<pair<int, CBlockIndex*> > vSortedByHeight;
+    vSortedByHeight.reserve(mapBlockIndex.size());
+    BOOST_FOREACH(const PAIRTYPE(uint256, CBlockIndex*)& item, mapBlockIndex)
+    {
+        CBlockIndex* pindex = item.second;
+        vSortedByHeight.push_back(make_pair(pindex->nHeight, pindex));
+    }
+    sort(vSortedByHeight.begin(), vSortedByHeight.end());
+    BOOST_FOREACH(const PAIRTYPE(int, CBlockIndex*)& item, vSortedByHeight)
+    {
+        CBlockIndex* pindex = item.second;
+        pindex->bnChainTrust = (pindex->pprev ? pindex->pprev->bnChainTrust : 0) + pindex->GetBlockTrust();
+    }
+
     // Load hashBestChain pointer to end of best chain
     if (!ReadHashBestChain(hashBestChain))
     {
@@ -623,16 +637,16 @@ bool CTxDB::LoadBlockIndex()
         return error("CTxDB::LoadBlockIndex() : hashBestChain not found in the block index");
     pindexBest = mapBlockIndex[hashBestChain];
     nBestHeight = pindexBest->nHeight;
-    nBestChainTrust = pindexBest->nChainTrust;
-    printf("LoadBlockIndex(): hashBestChain=%s  height=%d  trust=%d\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, nBestChainTrust);
+    bnBestChainTrust = pindexBest->bnChainTrust;
+    printf("LoadBlockIndex(): hashBestChain=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, bnBestChainTrust.ToString().c_str());
 
     // ppcoin: load hashSyncCheckpoint
     if (!ReadSyncCheckpoint(Checkpoints::hashSyncCheckpoint))
         return error("CTxDB::LoadBlockIndex() : hashSyncCheckpoint not loaded");
     printf("LoadBlockIndex(): synchronized checkpoint %s\n", Checkpoints::hashSyncCheckpoint.ToString().c_str());
 
-    // Load nBestInvalidTrust, OK if it doesn't exist
-    ReadBestInvalidTrust(nBestInvalidTrust);
+    // Load bnBestInvalidTrust, OK if it doesn't exist
+    ReadBestInvalidTrust(bnBestInvalidTrust);
 
     // Verify blocks in the best chain
     int nCheckLevel = GetArg("-checklevel", 1);

diff --git a/src/db.h b/src/db.h
index 792d5ca..db9fb8a 100644 (file)
--- a/src/db.h
+++ b/src/db.h
@@ -294,8 +294,8 @@ public:
     bool EraseBlockIndex(uint256 hash);
     bool ReadHashBestChain(uint256& hashBestChain);
     bool WriteHashBestChain(uint256 hashBestChain);
-    bool ReadBestInvalidTrust(uint64& nBestInvalidTrust);
-    bool WriteBestInvalidTrust(uint64 nBestInvalidTrust);
+    bool ReadBestInvalidTrust(CBigNum& bnBestInvalidTrust);
+    bool WriteBestInvalidTrust(CBigNum bnBestInvalidTrust);
     bool ReadSyncCheckpoint(uint256& hashCheckpoint);
     bool WriteSyncCheckpoint(uint256 hashCheckpoint);
     bool ReadCheckpointPubKey(std::string& strPubKey);

diff --git a/src/main.cpp b/src/main.cpp
index 2a633f6..7b11741 100644 (file)
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -35,8 +35,8 @@ static CBigNum bnProofOfWorkLimit(~uint256(0) >> 32);
 static CBigNum bnInitialHashTarget(~uint256(0) >> 40);
 CBlockIndex* pindexGenesisBlock = NULL;
 int nBestHeight = -1;
-uint64 nBestChainTrust = 0;
-uint64 nBestInvalidTrust = 0;
+CBigNum bnBestChainTrust = 0;
+CBigNum bnBestInvalidTrust = 0;
 uint256 hashBestChain = 0;
 CBlockIndex* pindexBest = NULL;
 int64 nTimeBestReceived = 0;
@@ -965,14 +965,14 @@ bool IsInitialBlockDownload()
 
 void static InvalidChainFound(CBlockIndex* pindexNew)
 {
-    if (pindexNew->nChainTrust > nBestInvalidTrust)
+    if (pindexNew->bnChainTrust > bnBestInvalidTrust)
     {
-        nBestInvalidTrust = pindexNew->nChainTrust;
-        CTxDB().WriteBestInvalidTrust(nBestInvalidTrust);
+        bnBestInvalidTrust = pindexNew->bnChainTrust;
+        CTxDB().WriteBestInvalidTrust(bnBestInvalidTrust);
         MainFrameRepaint();
     }
-    printf("InvalidChainFound: invalid block=%s  height=%d  trust=%s\n", pindexNew->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->nHeight, CBigNum(pindexNew->nChainTrust).ToString().c_str());
-    printf("InvalidChainFound:  current best=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, CBigNum(nBestChainTrust).ToString().c_str());
+    printf("InvalidChainFound: invalid block=%s  height=%d  trust=%s\n", pindexNew->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->nHeight, CBigNum(pindexNew->bnChainTrust).ToString().c_str());
+    printf("InvalidChainFound:  current best=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, CBigNum(bnBestChainTrust).ToString().c_str());
     // ppcoin: should not enter safe mode for longer invalid chain
 }
 
@@ -1597,7 +1597,7 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
 
         // Reorganize is costly in terms of db load, as it works in a single db transaction.
         // Try to limit how much needs to be done inside
-        while (pindexIntermediate->pprev && pindexIntermediate->pprev->nChainTrust > pindexBest->nChainTrust)
+        while (pindexIntermediate->pprev && pindexIntermediate->pprev->bnChainTrust > pindexBest->bnChainTrust)
         {
             vpindexSecondary.push_back(pindexIntermediate);
             pindexIntermediate = pindexIntermediate->pprev;
@@ -1645,10 +1645,10 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
     hashBestChain = hash;
     pindexBest = pindexNew;
     nBestHeight = pindexBest->nHeight;
-    nBestChainTrust = pindexNew->nChainTrust;
+    bnBestChainTrust = pindexNew->bnChainTrust;
     nTimeBestReceived = GetTime();
     nTransactionsUpdated++;
-    printf("SetBestChain: new best=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, CBigNum(nBestChainTrust).ToString().c_str());
+    printf("SetBestChain: new best=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, bnBestChainTrust.ToString().c_str());
 
     std::string strCmd = GetArg("-blocknotify", "");
 
@@ -1818,10 +1818,7 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
     }
 
     // ppcoin: compute chain trust score
-    uint64 nCoinAge;
-    if (!GetCoinAge(nCoinAge))
-        return error("AddToBlockIndex() : invalid transaction in block");
-    pindexNew->nChainTrust = (pindexNew->pprev ? pindexNew->pprev->nChainTrust : 0) + nCoinAge;
+    pindexNew->bnChainTrust = (pindexNew->pprev ? pindexNew->pprev->bnChainTrust : 0) + pindexNew->GetBlockTrust();
 
     CTxDB txdb;
     if (!txdb.TxnBegin())
@@ -1831,7 +1828,7 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
         return false;
 
     // New best
-    if (pindexNew->nChainTrust > nBestChainTrust)
+    if (pindexNew->bnChainTrust > bnBestChainTrust)
         if (!SetBestChain(txdb, pindexNew))
             return false;
 

diff --git a/src/main.h b/src/main.h
index 6ea3269..67bc8a7 100644 (file)
--- a/src/main.h
+++ b/src/main.h
@@ -63,8 +63,8 @@ extern std::set<std::pair<COutPoint, unsigned int> > setStakeSeen;
 extern uint256 hashGenesisBlock;
 extern CBlockIndex* pindexGenesisBlock;
 extern int nBestHeight;
-extern uint64 nBestChainTrust;
-extern uint64 nBestInvalidTrust;
+extern CBigNum bnBestChainTrust;
+extern CBigNum bnBestInvalidTrust;
 extern uint256 hashBestChain;
 extern CBlockIndex* pindexBest;
 extern unsigned int nTransactionsUpdated;
@@ -1126,7 +1126,7 @@ public:
     CBlockIndex* pnext;
     unsigned int nFile;
     unsigned int nBlockPos;
-    uint64 nChainTrust;// ppcoin: trust score of chain, in the unit of coin-days
+    CBigNum bnChainTrust; // ppcoin: trust score of block chain
     int nHeight;
     bool fProofOfStake; // ppcoin: is the block of proof-of-stake type
     COutPoint prevoutStake;
@@ -1148,7 +1148,7 @@ public:
         nFile = 0;
         nBlockPos = 0;
         nHeight = 0;
-        nChainTrust = 0;
+        bnChainTrust = 0;
         fProofOfStake = true;
         prevoutStake.SetNull();
         nStakeTime = 0;
@@ -1168,7 +1168,7 @@ public:
         nFile = nFileIn;
         nBlockPos = nBlockPosIn;
         nHeight = 0;
-        nChainTrust = 0;
+        bnChainTrust = 0;
         fProofOfStake = block.IsProofOfStake();
         if (fProofOfStake)
         {
@@ -1211,9 +1211,13 @@ public:
         return (int64)nTime;
     }
 
-    int64 GetBlockTrust() const
+    CBigNum GetBlockTrust() const
     {
-        return (nChainTrust - (pprev? pprev->nChainTrust : 0));
+        CBigNum bnTarget;
+        bnTarget.SetCompact(nBits);
+        if (bnTarget <= 0)
+            return 0;
+        return (fProofOfStake? (CBigNum(1)<<256) / (bnTarget+1) : 1);
     }
 
     bool IsInMainChain() const
@@ -1281,8 +1285,8 @@ public:
 
     std::string ToString() const
     {
-        return strprintf("CBlockIndex(nprev=%08x, pnext=%08x, nFile=%d, nBlockPos=%-6d nChainTrust=%"PRI64d" nHeight=%d, fProofOfStake=%d prevoutStake=(%s), nStakeTime=%d merkle=%s, hashBlock=%s)",
-            pprev, pnext, nFile, nBlockPos, nChainTrust, nHeight,
+        return strprintf("CBlockIndex(nprev=%08x, pnext=%08x, nFile=%d, nBlockPos=%-6d nHeight=%d, fProofOfStake=%d prevoutStake=(%s), nStakeTime=%d merkle=%s, hashBlock=%s)",
+            pprev, pnext, nFile, nBlockPos, nHeight,
             fProofOfStake, prevoutStake.ToString().c_str(), nStakeTime,
             hashMerkleRoot.ToString().substr(0,10).c_str(),
             GetBlockHash().ToString().substr(0,20).c_str());
@@ -1323,7 +1327,6 @@ public:
         READWRITE(hashNext);
         READWRITE(nFile);
         READWRITE(nBlockPos);
-        READWRITE(nChainTrust);
         READWRITE(nHeight);
         READWRITE(fProofOfStake);
         if (fProofOfStake)