src/checkpoints.h

   1 // Copyright (c) 2011 The Bitcoin developers
   2 // Copyright (c) 2011-2012 The PPCoin developers
   3 // Distributed under the MIT/X11 software license, see the accompanying
   4 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
   5 #ifndef BITCOIN_CHECKPOINT_H
   6 #define  BITCOIN_CHECKPOINT_H
   7
   8 #include <map>
   9 #include "util.h"
  10
  11 #define STAKE_MIN_AGE (60 * 60 * 24)      // minimum age for coin age
  12 #define CHECKPOINT_MIN_SPAN (60 * 60 * 4) // 4 hours checkpoint
  13
  14 class uint256;
  15 class CBlockIndex;
  16 class CSyncCheckpoint;
  17
  18 //
  19 // Block-chain checkpoints are compiled-in sanity checks.
  20 // They are updated every release or three.
  21 //
  22 namespace Checkpoints
  23 {
  24     // Returns true if block passes checkpoint checks
  25     bool CheckHardened(int nHeight, const uint256& hash);
  26
  27     // Return conservative estimate of total number of blocks, 0 if unknown
  28     int GetTotalBlocksEstimate();
  29
  30     // Returns last CBlockIndex* in mapBlockIndex that is a checkpoint
  31     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex);
  32
  33     extern uint256 hashSyncCheckpoint;
  34     extern CSyncCheckpoint checkpointMessage;
  35     extern uint256 hashInvalidCheckpoint;
  36     extern CCriticalSection cs_hashSyncCheckpoint;
  37
  38     CBlockIndex* GetLastSyncCheckpoint();
  39     bool WriteSyncCheckpoint(const uint256& hashCheckpoint);
  40     bool AcceptPendingSyncCheckpoint();
  41     uint256 AutoSelectSyncCheckpoint();
  42     bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev);
  43     bool WantedByPendingSyncCheckpoint(uint256 hashBlock);
  44     bool ResetSyncCheckpoint();
  45     void AskForPendingSyncCheckpoint(CNode* pfrom);
  46 }
  47
  48 // ppcoin: synchronized checkpoint
  49 class CUnsignedSyncCheckpoint
  50 {
  51 public:
  52     int nVersion;
  53     uint256 hashCheckpoint;      // checkpoint block
  54
  55     IMPLEMENT_SERIALIZE
  56     (
  57         READWRITE(this->nVersion);
  58         nVersion = this->nVersion;
  59         READWRITE(hashCheckpoint);
  60     )
  61
  62     void SetNull()
  63     {
  64         nVersion = 1;
  65         hashCheckpoint = 0;
  66     }
  67
  68     std::string ToString() const
  69     {
  70         return strprintf(
  71                 "CSyncCheckpoint(\n"
  72                 "    nVersion       = %d\n"
  73                 "    hashCheckpoint = %s\n"
  74                 ")\n",
  75             nVersion,
  76             hashCheckpoint.ToString().c_str());
  77     }
  78
  79     void print() const
  80     {
  81         printf("%s", ToString().c_str());
  82     }
  83 };
  84
  85 class CSyncCheckpoint : public CUnsignedSyncCheckpoint
  86 {
  87 public:
  88     static const std::string strMasterPubKey;
  89
  90     std::vector<unsigned char> vchMsg;
  91     std::vector<unsigned char> vchSig;
  92
  93     CSyncCheckpoint()
  94     {
  95         SetNull();
  96     }
  97
  98     IMPLEMENT_SERIALIZE
  99     (
 100         READWRITE(vchMsg);
 101         READWRITE(vchSig);
 102     )
 103
 104     void SetNull()
 105     {
 106         CUnsignedSyncCheckpoint::SetNull();
 107         vchMsg.clear();
 108         vchSig.clear();
 109     }
 110
 111     bool IsNull() const
 112     {
 113         return (hashCheckpoint == 0);
 114     }
 115
 116     uint256 GetHash() const
 117     {
 118         return SerializeHash(*this);
 119     }
 120
 121     bool RelayTo(CNode* pnode) const
 122     {
 123         // returns true if wasn't already sent
 124         if (pnode->hashCheckpointKnown != hashCheckpoint)
 125         {
 126             pnode->hashCheckpointKnown = hashCheckpoint;
 127             pnode->PushMessage("checkpoint", *this);
 128             return true;
 129         }
 130         return false;
 131     }
 132
 133     bool CheckSignature();
 134     bool ProcessSyncCheckpoint(CNode* pfrom);
 135 };
 136
 137 #endif