PPCoin: Define synchronized checkpoint

[novacoin.git] / src / checkpoints.cpp

diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp
index 69024e2..89e53ca 100644 (file)
--- a/src/checkpoints.cpp
+++ b/src/checkpoints.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2011 The Bitcoin developers
-// Copyright (c) 2011 The PPCoin developers
+// Copyright (c) 2011-2012 The PPCoin developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
 
@@ -25,9 +25,6 @@ namespace Checkpoints
         ( 0, hashGenesisBlock )
         ; // ppcoin: no checkpoint yet; to be created in future releases
 
-    // ppcoin: automatic checkpoint (represented by height of checkpoint)
-    int nAutoCheckpoint = 0;
-
     bool CheckHardened(int nHeight, const uint256& hash)
     {
         if (fTestNet) return true; // Testnet has no checkpoints
@@ -37,6 +34,39 @@ namespace Checkpoints
         return hash == i->second;
     }
 
+    int GetTotalBlocksEstimate()
+    {
+        if (fTestNet) return 0;
+
+        return mapCheckpoints.rbegin()->first;
+    }
+
+    CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
+    {
+        if (fTestNet) return NULL;
+
+        int64 nResult;
+        BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
+        {
+            const uint256& hash = i.second;
+            std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
+            if (t != mapBlockIndex.end())
+                return t->second;
+        }
+        return NULL;
+    }
+
+    // ppcoin: synchronized checkpoint (centrally broadcasted)
+    uint256 hashSyncCheckpoint;
+
+    bool AcceptNewSyncCheckpoint(uint256 hashCheckpoint)
+    {
+    }
+
+    // ppcoin: automatic checkpoint (represented by height of checkpoint)
+    int nAutoCheckpoint = 0;
+    int nBranchPoint = 0;    // branch point to alternative branch
+
     // ppcoin: check automatic checkpoint
     // To pass the check:
     //   - All ancestors (including the block itself) have block index already
@@ -51,7 +81,10 @@ namespace Checkpoints
                 if (pindex->nHeight >= nAutoCheckpoint)
                     return true;
                 else
+                {
+                    nBranchPoint = pindex->nHeight;
                     return error("Checkpoints: new block on alternative branch at height=%d before auto checkpoint at height=%d", pindex->nHeight, nAutoCheckpoint);
+                }
             }
             else
                 pindex = pindex->pprev;
@@ -121,25 +154,29 @@ namespace Checkpoints
         printf("Checkpoints: auto checkpoint now at height=%d\n", nAutoCheckpoint);
     }
 
-    int GetTotalBlocksEstimate()
+    // ppcoin: reset auto checkpoint
+    bool ResetAutoCheckpoint(int nCheckpoint)
     {
-        if (fTestNet) return 0;
-
-        return mapCheckpoints.rbegin()->first;
-    }
-
-    CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
-    {
-        if (fTestNet) return NULL;
-
-        int64 nResult;
-        BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
+        if (nCheckpoint <= 0 || nCheckpoint > nBestHeight)
+            return error("ResetAutoCheckpoint() : new checkpoint invalid");
+        if (nCheckpoint >= nAutoCheckpoint)
+            return error("ResetAutoCheckpoint() : new checkpoint not earlier than current auto checkpoint");
+        CTxDB txdb;
+        txdb.TxnBegin();
+        if (!txdb.WriteAutoCheckpoint(nCheckpoint, true))
+            return error("ResetAutoCheckpoint() : database write failed");
+        if (!txdb.TxnCommit())
+            return error("ResetAutoCheckpoint() : database commit failed");
+        nAutoCheckpoint = nCheckpoint;
+        nBranchPoint = 0;  // clear branch point
+
+        // clear ban list to accept alternative branches
+        CRITICAL_BLOCK(cs_vNodes)
         {
-            const uint256& hash = i.second;
-            std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
-            if (t != mapBlockIndex.end())
-                return t->second;
+            BOOST_FOREACH(CNode* pnode, vNodes)
+                pnode->ClearBanned();
         }
-        return NULL;
+
+        return true;
     }
 }