text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2012 The Bitcoin developers
  // Copyright (c) 2011-2015 The coinking developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "alert.h"
  #include "checkpoints.h"
  #include "db.h"
  #include "txdb.h"
  #include "net.h"
  #include "init.h"
  #include "ui_interface.h"
  #include "kernel.h"
  #include "checkqueue.h"
  #include "checkpointsync.h"
  #include <boost/algorithm/string/replace.hpp>
  #include <boost/filesystem.hpp>
  #include <boost/filesystem/fstream.hpp>
  
  using namespace std;
  using namespace boost;
  
  //
  // Global state
  //
  
  CCriticalSection cs_setpwalletRegistered;
  set<CWallet*> setpwalletRegistered;
  
  CCriticalSection cs_main;
  
  CTxMemPool mempool;
  unsigned int nTransactionsUpdated = 0;
  
  map<uint256, CBlockIndex*> mapBlockIndex;
  set<pair<COutPoint, unsigned int> > setStakeSeen;
  uint256 hashGenesisBlock = hashGenesisBlockOfficial;
  static CBigNum bnProofOfWorkLimit(~uint256(0) >> 32);
  static CBigNum bnInitialHashTarget(~uint256(0) >> 40);
  unsigned int nStakeMinAge = STAKE_MIN_AGE;
  int nCoinbaseMaturity = COINBASE_MATURITY_tkc;
  CBlockIndex* pindexGenesisBlock = NULL;
  int nBestHeight = -1;
  uint256 nBestChainTrust = 0;
  uint256 nBestInvalidTrust = 0;
  uint256 hashBestChain = 0;
  CBlockIndex* pindexBest = NULL;
  set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexValid; // may contain all CBlockIndex*'s that have validness >=BLOCK_VALID_TRANSACTIONS, and must contain those who aren't failed
  int64 nTimeBestReceived = 0;
  int nScriptCheckThreads = 0;
  bool fImporting = false;
  bool fReindex = false;
  bool fBenchmark = false;
  bool fTxIndex = false;
  unsigned int nCoinCacheSize = 5000;
  
  /** Fees smaller than this (in satoshi) are considered zero fee (for transaction creation) */
  int64 CTransaction::nMinTxFee = MIN_TX_FEE;  // Override with -mintxfee
  /** Fees smaller than this (in satoshi) are considered zero fee (for relaying) */
  int64 CTransaction::nMinRelayTxFee = MIN_RELAY_TX_FEE;
  
  CMedianFilter<int> cPeerBlockCounts(8, 0); // Amount of blocks that other nodes claim to have
  
  map<uint256, CBlock*> mapOrphanBlocks;
  map<uint256, CBlock*> mapDuplicateStakeBlocks;
  multimap<uint256, CBlock*> mapOrphanBlocksByPrev;
  set<pair<COutPoint, unsigned int> > setStakeSeenOrphan;
  map<uint256, uint256> mapProofOfStake;
  
  map<uint256, CTransaction> mapOrphanTransactions;
  map<uint256, set<uint256> > mapOrphanTransactionsByPrev;
  
  // Constant stuff for coinbase transactions we create:
  CScript COINBASE_FLAGS;
  
  const string strMessageMagic = "coinking Signed Message:\n";
  
  double dHashesPerSec = 0.0;
  int64 nHPSTimerStart = 0;
  
  #ifdef TESTING
  uint256 hashSingleStakeBlock;
  int nBlocksToIgnore = 0;
  #endif
  
  // Settings
  int64 nTransactionFee = MIN_TX_FEE;
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // dispatching functions
  //
  
  // These functions dispatch to one or all registered wallets
  
  
  void RegisterWallet(CWallet* pwalletIn)
  {
      {
          LOCK(cs_setpwalletRegistered);
          setpwalletRegistered.insert(pwalletIn);
      }
  }
  
  void UnregisterWallet(CWallet* pwalletIn)
  {
      {
          LOCK(cs_setpwalletRegistered);
          setpwalletRegistered.erase(pwalletIn);
      }
  }
  
  // get the wallet transaction with the given hash (if it exists)
  bool static GetTransaction(const uint256& hashTx, CWalletTx& wtx)
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          if (pwallet->GetTransaction(hashTx,wtx))
              return true;
      return false;
  }
  
  // erases transaction with the given hash from all wallets
  void static EraseFromWallets(uint256 hash)
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->EraseFromWallet(hash);
  }
  
  // make sure all wallets know about the given transaction, in the given block
  void SyncWithWallets(const uint256 &hash, const CTransaction& tx, const CBlock* pblock, bool fUpdate, bool fConnect)
  {
      if (!fConnect)
      {
          // tkcoin: wallets need to refund inputs when disconnecting coinstake
          if (tx.IsCoinStake())
          {
              BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
                  if (pwallet->IsFromMe(tx))
                      pwallet->DisableTransaction(tx);
          }
          return;
      }
  
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->AddToWalletIfInvolvingMe(hash, tx, pblock, fUpdate);
  }
  
  // notify wallets about a new best chain
  void static SetBestChain(const CBlockLocator& loc)
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->SetBestChain(loc);
  }
  
  // notify wallets about an updated transaction
  void static UpdatedTransaction(const uint256& hashTx)
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->UpdatedTransaction(hashTx);
  }
  
  // dump all wallets
  void static PrintWallets(const CBlock& block)
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->PrintWallet(block);
  }
  
  // notify wallets about an incoming inventory (for request counts)
  void static Inventory(const uint256& hash)
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->Inventory(hash);
  }
  
  // ask wallets to resend their transactions
  void static ResendWalletTransactions()
  {
      BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
          pwallet->ResendWalletTransactions();
  }
  
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CCoinsView implementations
  //
  
  bool CCoinsView::GetCoins(const uint256 &txid, CCoins &coins) { return false; }
  bool CCoinsView::SetCoins(const uint256 &txid, const CCoins &coins) { return false; }
  bool CCoinsView::HaveCoins(const uint256 &txid) { return false; }
  CBlockIndex *CCoinsView::GetBestBlock() { return NULL; }
  bool CCoinsView::SetBestBlock(CBlockIndex *pindex) { return false; }
  bool CCoinsView::BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockIndex *pindex) { return false; }
  bool CCoinsView::GetStats(CCoinsStats &stats) { return false; }
  
  
  CCoinsViewBacked::CCoinsViewBacked(CCoinsView &viewIn) : base(&viewIn) { }
  bool CCoinsViewBacked::GetCoins(const uint256 &txid, CCoins &coins) { return base->GetCoins(txid, coins); }
  bool CCoinsViewBacked::SetCoins(const uint256 &txid, const CCoins &coins) { return base->SetCoins(txid, coins); }
  bool CCoinsViewBacked::HaveCoins(const uint256 &txid) { return base->HaveCoins(txid); }
  CBlockIndex *CCoinsViewBacked::GetBestBlock() { return base->GetBestBlock(); }
  bool CCoinsViewBacked::SetBestBlock(CBlockIndex *pindex) { return base->SetBestBlock(pindex); }
  void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
  bool CCoinsViewBacked::BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockIndex *pindex) { return base->BatchWrite(mapCoins, pindex); }
  bool CCoinsViewBacked::GetStats(CCoinsStats &stats) { return base->GetStats(stats); }
  
  CCoinsViewCache::CCoinsViewCache(CCoinsView &baseIn, bool fDummy) : CCoinsViewBacked(baseIn), pindexTip(NULL) { }
  
  bool CCoinsViewCache::GetCoins(const uint256 &txid, CCoins &coins) {
      if (cacheCoins.count(txid)) {
          coins = cacheCoins[txid];
          return true;
      }
      if (base->GetCoins(txid, coins)) {
          cacheCoins[txid] = coins;
          return true;
      }
      return false;
  }
  
  std::map<uint256,CCoins>::iterator CCoinsViewCache::FetchCoins(const uint256 &txid) {
      std::map<uint256,CCoins>::iterator it = cacheCoins.lower_bound(txid);
      if (it != cacheCoins.end() && it->first == txid)
          return it;
      CCoins tmp;
      if (!base->GetCoins(txid,tmp))
          return cacheCoins.end();
      std::map<uint256,CCoins>::iterator ret = cacheCoins.insert(it, std::make_pair(txid, CCoins()));
      tmp.swap(ret->second);
      return ret;
  }
  
  CCoins &CCoinsViewCache::GetCoins(const uint256 &txid) {
      std::map<uint256,CCoins>::iterator it = FetchCoins(txid);
      assert(it != cacheCoins.end());
      return it->second;
  }
  
  bool CCoinsViewCache::SetCoins(const uint256 &txid, const CCoins &coins) {
      cacheCoins[txid] = coins;
      return true;
  }
  
  bool CCoinsViewCache::HaveCoins(const uint256 &txid) {
      return FetchCoins(txid) != cacheCoins.end();
  }
  
  CBlockIndex *CCoinsViewCache::GetBestBlock() {
      if (pindexTip == NULL)
          pindexTip = base->GetBestBlock();
      return pindexTip;
  }
  
  bool CCoinsViewCache::SetBestBlock(CBlockIndex *pindex) {
      pindexTip = pindex;
      return true;
  }
  
  bool CCoinsViewCache::BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockIndex *pindex) {
      for (std::map<uint256, CCoins>::const_iterator it = mapCoins.begin(); it != mapCoins.end(); it++)
          cacheCoins[it->first] = it->second;
      pindexTip = pindex;
      return true;
  }
  
  bool CCoinsViewCache::Flush() {
      bool fOk = base->BatchWrite(cacheCoins, pindexTip);
      if (fOk)
          cacheCoins.clear();
      return fOk;
  }
  
  unsigned int CCoinsViewCache::GetCacheSize() {
      return cacheCoins.size();
  }
  
  /** CCoinsView that brings transactions from a memorypool into view.
      It does not check for spendings by memory pool transactions. */
  CCoinsViewMemPool::CCoinsViewMemPool(CCoinsView &baseIn, CTxMemPool &mempoolIn) : CCoinsViewBacked(baseIn), mempool(mempoolIn) { }
  
  bool CCoinsViewMemPool::GetCoins(const uint256 &txid, CCoins &coins) {
      if (base->GetCoins(txid, coins))
          return true;
      if (mempool.exists(txid)) {
          const CTransaction &tx = mempool.lookup(txid);
          coins = CCoins(tx, MEMPOOL_HEIGHT);
          return true;
      }
      return false;
  }
  
  bool CCoinsViewMemPool::HaveCoins(const uint256 &txid) {
      return mempool.exists(txid) || base->HaveCoins(txid);
  }
  
  CCoinsViewCache *pcoinsTip = NULL;
  CBlockTreeDB *pblocktree = NULL;
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // mapOrphanTransactions
  //
  
  bool AddOrphanTx(const CTransaction& tx)
  {
      uint256 hash = tx.GetHash();
      if (mapOrphanTransactions.count(hash))
          return false;
  
      // Ignore big transactions, to avoid a
      // send-big-orphans memory exhaustion attack. If a peer has a legitimate
      // large transaction with a missing parent then we assume
      // it will rebroadcast it later, after the parent transaction(s)
      // have been mined or received.
      // 10,000 orphans, each of which is at most 5,000 bytes big is
      // at most 500 megabytes of orphans:
      unsigned int sz = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION);
      if (sz > 5000)
      {
          printf("ignoring large orphan tx (size: %u, hash: %s)\n", sz, hash.ToString().c_str());
          return false;
      }
  
      mapOrphanTransactions[hash] = tx;
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
          mapOrphanTransactionsByPrev[txin.prevout.hash].insert(hash);
  
      printf("stored orphan tx %s (mapsz %" PRIszu")\n", hash.ToString().c_str(),
          mapOrphanTransactions.size());
      return true;
  }
  
  void static EraseOrphanTx(uint256 hash)
  {
      if (!mapOrphanTransactions.count(hash))
          return;
      const CTransaction& tx = mapOrphanTransactions[hash];
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
      {
          mapOrphanTransactionsByPrev[txin.prevout.hash].erase(hash);
          if (mapOrphanTransactionsByPrev[txin.prevout.hash].empty())
              mapOrphanTransactionsByPrev.erase(txin.prevout.hash);
      }
      mapOrphanTransactions.erase(hash);
  }
  
  unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
  {
      unsigned int nEvicted = 0;
      while (mapOrphanTransactions.size() > nMaxOrphans)
      {
          // Evict a random orphan:
          uint256 randomhash = GetRandHash();
          map<uint256, CTransaction>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
          if (it == mapOrphanTransactions.end())
              it = mapOrphanTransactions.begin();
          EraseOrphanTx(it->first);
          ++nEvicted;
      }
      return nEvicted;
  }
  
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CTransaction / CTxOut
  //
  
  bool CTxOut::IsDust() const
  {
      // "Dust" is defined in terms of CTransaction::nMinRelayTxFee,
      // which has units satoshis-per-kilobyte.
      // If you'd pay more than 1/3 in fees
      // to spend something, then we consider it dust.
      // A typical txout is 34 bytes big, and will
      // need a CTxIn of at least 148 bytes to spend,
      // so dust is a txout less than 54 uBTC
      // (5460 satoshis) with default nMinRelayTxFee
      return ((nValue*1000)/(3*((int)GetSerializeSize(SER_DISK,0)+148)) < CTransaction::nMinRelayTxFee);
  }
  
  bool CTransaction::IsStandard(string& strReason) const
  {
      if (nVersion > CTransaction::CURRENT_VERSION || nVersion < 1) {
          strReason = "version";
          return false;
      }
  
      if (!IsFinal()) {
          strReason = "not-final";
          return false;
      }
  
      // Extremely large transactions with lots of inputs can cost the network
      // almost as much to process as they cost the sender in fees, because
      // computing signature hashes is O(ninputs*txsize). Limiting transactions
      // to MAX_STANDARD_TX_SIZE mitigates CPU exhaustion attacks.
      unsigned int sz = this->GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION);
      if (sz >= MAX_STANDARD_TX_SIZE) {
          strReason = "tx-size";
          return false;
      }
  
      BOOST_FOREACH(const CTxIn& txin, vin)
      {
          // Biggest 'standard' txin is a 3-signature 3-of-3 CHECKMULTISIG
          // pay-to-script-hash, which is 3 ~80-byte signatures, 3
          // ~65-byte public keys, plus a few script ops.
          if (txin.scriptSig.size() > 500) {
              strReason = "scriptsig-size";
              return false;
          }
          if (!txin.scriptSig.IsPushOnly()) {
              strReason = "scriptsig-not-pushonly";
              return false;
          }
      }
  
      unsigned int nDataOut = 0;
      txnouttype whichType;
      BOOST_FOREACH(const CTxOut& txout, vout) {
          if (!::IsStandard(txout.scriptPubKey, whichType)) {
              strReason = "scriptpubkey";
              return false;
          }
          if (whichType == TX_NULL_DATA)
              nDataOut++;
          else if (txout.IsDust()) {
              strReason = "dust";
              return false;
          }
      }
  
      // only one OP_RETURN txout is permitted
      if (nDataOut > 1) {
          strReason = "mucho-data";
          return false;
      }
  
      return true;
  }
  
  //
  // Check transaction inputs, and make sure any
  // pay-to-script-hash transactions are evaluating IsStandard scripts
  //
  // Why bother? To avoid denial-of-service attacks; an attacker
  // can submit a standard HASH... OP_EQUAL transaction,
  // which will get accepted into blocks. The redemption
  // script can be anything; an attacker could use a very
  // expensive-to-check-upon-redemption script like:
  //   DUP CHECKSIG DROP ... repeated 100 times... OP_1
  //
  bool CTransaction::AreInputsStandard(CCoinsViewCache& mapInputs) const
  {
      if (IsCoinBase())
          return true; // Coinbases don't use vin normally
  
      for (unsigned int i = 0; i < vin.size(); i++)
      {
          const CTxOut& prev = GetOutputFor(vin[i], mapInputs);
  
          vector<vector<unsigned char> > vSolutions;
          txnouttype whichType;
          // get the scriptPubKey corresponding to this input:
          const CScript& prevScript = prev.scriptPubKey;
          if (!Solver(prevScript, whichType, vSolutions))
              return false;
          int nArgsExpected = ScriptSigArgsExpected(whichType, vSolutions);
          if (nArgsExpected < 0)
              return false;
  
          // Transactions with extra stuff in their scriptSigs are
          // non-standard. Note that this EvalScript() call will
          // be quick, because if there are any operations
          // beside "push data" in the scriptSig the
          // IsStandard() call returns false
          vector<vector<unsigned char> > stack;
          if (!EvalScript(stack, vin[i].scriptSig, *this, i, false, 0))
              return false;
  
          if (whichType == TX_SCRIPTHASH)
          {
              if (stack.empty())
                  return false;
              CScript subscript(stack.back().begin(), stack.back().end());
              vector<vector<unsigned char> > vSolutions2;
              txnouttype whichType2;
              if (!Solver(subscript, whichType2, vSolutions2))
                  return false;
              if (whichType2 == TX_SCRIPTHASH)
                  return false;
  
              int tmpExpected;
              tmpExpected = ScriptSigArgsExpected(whichType2, vSolutions2);
              if (tmpExpected < 0)
                  return false;
              nArgsExpected += tmpExpected;
          }
  
          if (stack.size() != (unsigned int)nArgsExpected)
              return false;
      }
  
      return true;
  }
  
  unsigned int CTransaction::GetLegacySigOpCount() const
  {
      unsigned int nSigOps = 0;
      BOOST_FOREACH(const CTxIn& txin, vin)
      {
          nSigOps += txin.scriptSig.GetSigOpCount(false);
      }
      BOOST_FOREACH(const CTxOut& txout, vout)
      {
          nSigOps += txout.scriptPubKey.GetSigOpCount(false);
      }
      return nSigOps;
  }
  
  
  int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
  {
      CBlock blockTmp;
  
      if (pblock == NULL) {
          CCoins coins;
          if (pcoinsTip->GetCoins(GetHash(), coins)) {
              CBlockIndex *pindex = FindBlockByHeight(coins.nHeight);
              if (pindex) {
                  if (!blockTmp.ReadFromDisk(pindex))
                      return 0;
                  pblock = &blockTmp;
              }
          }
      }
  
      if (pblock) {
          // Update the tx's hashBlock
          hashBlock = pblock->GetHash();
  
          // Locate the transaction
          for (nIndex = 0; nIndex < (int)pblock->vtx.size(); nIndex++)
              if (pblock->vtx[nIndex] == *(CTransaction*)this)
                  break;
          if (nIndex == (int)pblock->vtx.size())
          {
              vMerkleBranch.clear();
              nIndex = -1;
              printf("ERROR: SetMerkleBranch() : couldn't find tx in block\n");
              return 0;
          }
  
          // Fill in merkle branch
          vMerkleBranch = pblock->GetMerkleBranch(nIndex);
      }
  
      // Is the tx in a block that's in the main chain
      map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hashBlock);
      if (mi == mapBlockIndex.end())
          return 0;
      CBlockIndex* pindex = (*mi).second;
      if (!pindex || !pindex->IsInMainChain())
          return 0;
  
      return pindexBest->nHeight - pindex->nHeight + 1;
  }
  
  
  
  
  
  
  
  bool CTransaction::CheckTransaction(CValidationState &state) const
  {
      // Basic checks that don't depend on any context
      if (vin.empty())
          return state.DoS(10, error("CTransaction::CheckTransaction() : vin empty"));
      if (vout.empty())
          return state.DoS(10, error("CTransaction::CheckTransaction() : vout empty"));
      // Time (prevent mempool memory exhaustion attack)
      if (nTime > GetAdjustedTime() + nMaxClockDrift)
          return state.DoS(10, error("CTransaction::CheckTransaction() : timestamp is too far into the future"));
      // Size limits
      if (::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
          return state.DoS(100, error("CTransaction::CheckTransaction() : size limits failed"));
  
      // Check for negative or overflow output values
      int64 nValueOut = 0;
      BOOST_FOREACH(const CTxOut& txout, vout)
      {
          if (txout.IsEmpty() && (!IsCoinBase()) && (!IsCoinStake()))
              return state.DoS(100, error("CTransaction::CheckTransaction() : txout empty for user transaction"));
          // tkcoin: enforce minimum output amount
          // v0.5 protocol: zero amount allowed
          if ((!txout.IsEmpty()) && txout.nValue < MIN_TXOUT_AMOUNT &&
              !(IsProtocolV05(nTime) && (txout.nValue == 0)))
              return state.DoS(100, error("CTransaction::CheckTransaction() : txout.nValue below minimum"));
          if (txout.nValue > MAX_MONEY)
              return state.DoS(100, error("CTransaction::CheckTransaction() : txout.nValue too high"));
          nValueOut += txout.nValue;
          if (!MoneyRange(nValueOut))
              return state.DoS(100, error("CTransaction::CheckTransaction() : txout total out of range"));
      }
  
      // Check for duplicate inputs
      set<COutPoint> vInOutPoints;
      BOOST_FOREACH(const CTxIn& txin, vin)
      {
          if (vInOutPoints.count(txin.prevout))
              return state.DoS(100, error("CTransaction::CheckTransaction() : duplicate inputs"));
          vInOutPoints.insert(txin.prevout);
      }
  
      if (IsCoinBase())
      {
          if (vin[0].scriptSig.size() < 2 || vin[0].scriptSig.size() > 100)
              return state.DoS(100, error("CTransaction::CheckTransaction() : coinbase script size"));
      }
      else
      {
          BOOST_FOREACH(const CTxIn& txin, vin)
              if (txin.prevout.IsNull())
                  return state.DoS(10, error("CTransaction::CheckTransaction() : prevout is null"));
      }
  
      return true;
  }
  
  int64 CTransaction::GetMinFee(unsigned int nBlockSize, bool fAllowFree,
                                enum GetMinFee_mode mode) const
  {
      // Base fee is either nMinTxFee or nMinRelayTxFee
      int64 nBaseFee = (mode == GMF_RELAY) ? nMinRelayTxFee : nMinTxFee;
  
      unsigned int nBytes = ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION);
      unsigned int nNewBlockSize = nBlockSize + nBytes;
      int64 nMinFee = (1 + (int64)nBytes / 1000) * nBaseFee;
  
      if (fAllowFree)
      {
          // There is a free transaction area in blocks created by most miners,
          // * If we are relaying we allow transactions up to DEFAULT_BLOCK_PRIORITY_SIZE - 1000
          //   to be considered to fall into this category. We don't want to encourage sending
          //   multiple transactions instead of one big transaction to avoid fees.
          // * If we are creating a transaction we allow transactions up to 1,000 bytes
          //   to be considered safe and assume they can likely make it into this section.
          if (nBytes < (mode == GMF_SEND ? 1000 : (DEFAULT_BLOCK_PRIORITY_SIZE - 1000)))
              nMinFee = 0;
      }
  
      // This code can be removed after enough miners have upgraded to version 0.9.
      // Until then, be safe when sending and require a fee if any output
      // is less than CENT:
      if (nMinFee < nBaseFee && mode == GMF_SEND)
      {
          BOOST_FOREACH(const CTxOut& txout, vout)
              if (txout.nValue < CENT)
                  nMinFee = nBaseFee;
      }
  
      // Raise the price as the block approaches full
      if (nBlockSize != 1 && nNewBlockSize >= MAX_BLOCK_SIZE_GEN/2)
      {
          if (nNewBlockSize >= MAX_BLOCK_SIZE_GEN)
              return MAX_MONEY;
          nMinFee *= MAX_BLOCK_SIZE_GEN / (MAX_BLOCK_SIZE_GEN - nNewBlockSize);
      }
  
      if (!MoneyRange(nMinFee))
          nMinFee = MAX_MONEY;
      return nMinFee;
  }
  
  void CTxMemPool::pruneSpent(const uint256 &hashTx, CCoins &coins)
  {
      LOCK(cs);
  
      std::map<COutPoint, CInPoint>::iterator it = mapNextTx.lower_bound(COutPoint(hashTx, 0));
  
      // iterate over all COutPoints in mapNextTx whose hash equals the provided hashTx
      while (it != mapNextTx.end() && it->first.hash == hashTx) {
          coins.Spend(it->first.n); // and remove those outputs from coins
          it++;
      }
  }
  
  bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fCheckInputs, bool fLimitFree,
                          bool* pfMissingInputs)
  {
      if (pfMissingInputs)
          *pfMissingInputs = false;
  
      if (!tx.CheckTransaction(state))
          return error("CTxMemPool::accept() : CheckTransaction failed");
  
      // Coinbase is only valid in a block, not as a loose transaction
      if (tx.IsCoinBase())
          return state.DoS(100, error("CTxMemPool::accept() : coinbase as individual tx"));
      // tkcoin: coinstake is also only valid in a block, not as a loose transaction
      if (tx.IsCoinStake())
          return state.DoS(100, error("CTxMemPool::accept() : coinstake as individual tx"));
  
      // To help v0.1.5 clients who would see it as a negative number
      if ((int64)tx.nLockTime > std::numeric_limits<int>::max())
          return error("CTxMemPool::accept() : not accepting nLockTime beyond 2038 yet");
  
      // Rather not work on nonstandard transactions (unless -testnet)
      string strNonStd;
      if (!fTestNet && !tx.IsStandard(strNonStd))
          return error("CTxMemPool::accept() : nonstandard transaction (%s)",
                       strNonStd.c_str());
  
      // is it already in the memory pool?
      uint256 hash = tx.GetHash();
      {
          LOCK(cs);
          if (mapTx.count(hash))
              return false;
      }
  
      // Check for conflicts with in-memory transactions
      CTransaction* ptxOld = NULL;
      for (unsigned int i = 0; i < tx.vin.size(); i++)
      {
          COutPoint outpoint = tx.vin[i].prevout;
          if (mapNextTx.count(outpoint))
          {
              // Disable replacement feature for now
              return false;
  
              // Allow replacing with a newer version of the same transaction
              if (i != 0)
                  return false;
              ptxOld = mapNextTx[outpoint].ptx;
              if (ptxOld->IsFinal())
                  return false;
              if (!tx.IsNewerThan(*ptxOld))
                  return false;
              for (unsigned int i = 0; i < tx.vin.size(); i++)
              {
                  COutPoint outpoint = tx.vin[i].prevout;
                  if (!mapNextTx.count(outpoint) || mapNextTx[outpoint].ptx != ptxOld)
                      return false;
              }
              break;
          }
      }
  
      if (fCheckInputs)
      {
          CCoinsView dummy;
          CCoinsViewCache view(dummy);
  
          {
          LOCK(cs);
          CCoinsViewMemPool viewMemPool(*pcoinsTip, *this);
          view.SetBackend(viewMemPool);
  
          // do we already have it?
          if (view.HaveCoins(hash))
              return false;
  
          // do all inputs exist?
          // Note that this does not check for the presence of actual outputs (see the next check for that),
          // only helps filling in pfMissingInputs (to determine missing vs spent).
          BOOST_FOREACH(const CTxIn txin, tx.vin) {
              if (!view.HaveCoins(txin.prevout.hash)) {
                  if (pfMissingInputs)
                      *pfMissingInputs = true;
                  return false;
              }
          }
  
          // are the actual inputs available?
          if (!tx.HaveInputs(view))
              return state.Invalid(error("CTxMemPool::accept() : inputs already spent"));
  
          // Bring the best block into scope
          view.GetBestBlock();
  
          // we have all inputs cached now, so switch back to dummy, so we don't need to keep lock on mempool
          view.SetBackend(dummy);
          }
  
          // Check for non-standard pay-to-script-hash in inputs
          if (!tx.AreInputsStandard(view) && !fTestNet)
              return error("CTxMemPool::accept() : nonstandard transaction input");
  
          // Note: if you modify this code to accept non-standard transactions, then
          // you should add code here to check that the transaction does a
          // reasonable number of ECDSA signature verifications.
  
          int64 nFees = tx.GetValueIn(view)-tx.GetValueOut();
          unsigned int nSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
  
          // Don't accept it if it can't get into a block
          int64 txMinFee = tx.GetMinFee(1000, false, GMF_RELAY);
          if (nFees < txMinFee)
              return error("CTxMemPool::accept() : not enough fees %s, %" PRI64d" < %" PRI64d,
                           hash.ToString().c_str(),
                           nFees, txMinFee);
  
          // Continuously rate-limit free transactions
          // This mitigates 'penny-flooding' -- sending thousands of free transactions just to
          // be annoying or make others' transactions take longer to confirm.
          if (fLimitFree && nFees < CTransaction::nMinRelayTxFee)
          {
              static double dFreeCount;
              static int64 nLastTime;
              int64 nNow = GetTime();
  
              LOCK(cs);
  
              // Use an exponentially decaying ~10-minute window:
              dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime));
              nLastTime = nNow;
              // -limitfreerelay unit is thousand-bytes-per-minute
              // At default rate it would take over a month to fill 1GB
              if (dFreeCount >= GetArg("-limitfreerelay", 15)*10*1000)
                  return error("CTxMemPool::accept() : free transaction rejected by rate limiter");
              if (fDebug)
                  printf("Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
              dFreeCount += nSize;
          }
  
          // Check against previous transactions
          // This is done last to help prevent CPU exhaustion denial-of-service attacks.
          if (!tx.CheckInputs(state, view, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC))
          {
              return error("CTxMemPool::accept() : ConnectInputs failed %s", hash.ToString().c_str());
          }
      }
  
      // Store transaction in memory
      {
          LOCK(cs);
          if (ptxOld)
          {
              printf("CTxMemPool::accept() : replacing tx %s with new version\n", ptxOld->GetHash().ToString().c_str());
              remove(*ptxOld);
          }
          addUnchecked(hash, tx);
      }
  
      ///// are we sure this is ok when loading transactions or restoring block txes
      // If updated, erase old tx from wallet
      if (ptxOld)
          EraseFromWallets(ptxOld->GetHash());
      SyncWithWallets(hash, tx, NULL, true);
  
      return true;
  }
  
  bool CTransaction::AcceptToMemoryPool(CValidationState &state, bool fCheckInputs, bool fLimitFree, bool* pfMissingInputs)
  {
      try {
          return mempool.accept(state, *this, fCheckInputs, fLimitFree, pfMissingInputs);
      } catch(std::runtime_error &e) {
          return state.Abort(_("System error: ") + e.what());
      }
  }
  
  bool CTxMemPool::addUnchecked(const uint256& hash, const CTransaction &tx)
  {
      // Add to memory pool without checking anything.  Don't call this directly,
      // call CTxMemPool::accept to properly check the transaction first.
      {
          mapTx[hash] = tx;
          for (unsigned int i = 0; i < tx.vin.size(); i++)
              mapNextTx[tx.vin[i].prevout] = CInPoint(&mapTx[hash], i);
          nTransactionsUpdated++;
      }
      return true;
  }
  
  
  bool CTxMemPool::remove(const CTransaction &tx, bool fRecursive)
  {
      // Remove transaction from memory pool
      {
          LOCK(cs);
          uint256 hash = tx.GetHash();
          if (fRecursive) {
              for (unsigned int i = 0; i < tx.vout.size(); i++) {
                  std::map<COutPoint, CInPoint>::iterator it = mapNextTx.find(COutPoint(hash, i));
                  if (it != mapNextTx.end())
                      remove(*it->second.ptx, true);
              }
          }
          if (mapTx.count(hash))
          {
              BOOST_FOREACH(const CTxIn& txin, tx.vin)
                  mapNextTx.erase(txin.prevout);
              mapTx.erase(hash);
              nTransactionsUpdated++;
          }
      }
      return true;
  }
  
  bool CTxMemPool::removeConflicts(const CTransaction &tx)
  {
      // Remove transactions which depend on inputs of tx, recursively
      LOCK(cs);
      BOOST_FOREACH(const CTxIn &txin, tx.vin) {
          std::map<COutPoint, CInPoint>::iterator it = mapNextTx.find(txin.prevout);
          if (it != mapNextTx.end()) {
              const CTransaction &txConflict = *it->second.ptx;
              if (txConflict != tx)
                  remove(txConflict, true);
          }
      }
      return true;
  }
  
  void CTxMemPool::clear()
  {
      LOCK(cs);
      mapTx.clear();
      mapNextTx.clear();
      ++nTransactionsUpdated;
  }
  
  void CTxMemPool::queryHashes(std::vector<uint256>& vtxid)
  {
      vtxid.clear();
  
      LOCK(cs);
      vtxid.reserve(mapTx.size());
      for (map<uint256, CTransaction>::iterator mi = mapTx.begin(); mi != mapTx.end(); ++mi)
          vtxid.push_back((*mi).first);
  }
  
  
  
  
  int CMerkleTx::GetDepthInMainChain(CBlockIndex* &pindexRet) const
  {
      if (hashBlock == 0 || nIndex == -1)
          return 0;
  
      // Find the block it claims to be in
      map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hashBlock);
      if (mi == mapBlockIndex.end())
          return 0;
      CBlockIndex* pindex = (*mi).second;
      if (!pindex || !pindex->IsInMainChain())
          return 0;
  
      // Make sure the merkle branch connects to this block
      if (!fMerkleVerified)
      {
          if (CBlock::CheckMerkleBranch(GetHash(), vMerkleBranch, nIndex) != pindex->hashMerkleRoot)
              return 0;
          fMerkleVerified = true;
      }
  
      pindexRet = pindex;
      return pindexBest->nHeight - pindex->nHeight + 1;
  }
  
  
  int CMerkleTx::GetBlocksToMaturity() const
  {
      if (!(IsCoinBase() || IsCoinStake()))
          return 0;
      return max(0, (nCoinbaseMaturity+20) - GetDepthInMainChain());
  }
  
  
  bool CMerkleTx::AcceptToMemoryPool(bool fCheckInputs, bool fLimitFree)
  {
      CValidationState state;
      return CTransaction::AcceptToMemoryPool(state, fCheckInputs, fLimitFree);
  }
  
  
  
  bool CWalletTx::AcceptWalletTransaction(bool fCheckInputs)
  {
      {
          LOCK(mempool.cs);
          // Add previous supporting transactions first
          BOOST_FOREACH(CMerkleTx& tx, vtxPrev)
          {
              if (!(tx.IsCoinBase() || tx.IsCoinStake()))
              {
                  uint256 hash = tx.GetHash();
                  if (!mempool.exists(hash) && pcoinsTip->HaveCoins(hash))
                      tx.AcceptToMemoryPool(fCheckInputs, false);
              }
          }
          return AcceptToMemoryPool(fCheckInputs, false);
      }
      return false;
  }
  
  
  // Return transaction in tx, and if it was found inside a block, its hash is placed in hashBlock
  bool GetTransaction(const uint256 &hash, CTransaction &txOut, uint256 &hashBlock, bool fAllowSlow)
  {
      CBlockIndex *pindexSlow = NULL;
      {
          LOCK(cs_main);
          {
              LOCK(mempool.cs);
              if (mempool.exists(hash))
              {
                  txOut = mempool.lookup(hash);
                  return true;
              }
          }
  
          if (fTxIndex) {
              CDiskTxPos postx;
              if (pblocktree->ReadTxIndex(hash, postx)) {
                  CAutoFile file(OpenBlockFile(postx, true), SER_DISK, CLIENT_VERSION);
                  CBlockHeader header;
                  try {
                      file >> header;
                      fseek(file, postx.nTxOffset, SEEK_CUR);
                      file >> txOut;
                  } catch (std::exception &e) {
                      return error("%s() : deserialize or I/O error", __PRETTY_FUNCTION__);
                  }
                  hashBlock = header.GetHash();
                  if (txOut.GetHash() != hash)
                      return error("%s() : txid mismatch", __PRETTY_FUNCTION__);
                  return true;
              }
          }
  
          if (fAllowSlow) { // use coin database to locate block that contains transaction, and scan it
              int nHeight = -1;
              {
                  CCoinsViewCache &view = *pcoinsTip;
                  CCoins coins;
                  if (view.GetCoins(hash, coins))
                      nHeight = coins.nHeight;
              }
              if (nHeight > 0)
                  pindexSlow = FindBlockByHeight(nHeight);
          }
      }
  
      if (pindexSlow) {
          CBlock block;
          if (block.ReadFromDisk(pindexSlow)) {
              BOOST_FOREACH(const CTransaction &tx, block.vtx) {
                  if (tx.GetHash() == hash) {
                      txOut = tx;
                      hashBlock = pindexSlow->GetBlockHash();
                      return true;
                  }
              }
          }
      }
  
      return false;
  }
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CBlock and CBlockIndex
  //
  
  static CBlockIndex* pblockindexFBBHLast;
  CBlockIndex* FindBlockByHeight(int nHeight)
  {
      CBlockIndex *pblockindex;
      if (nHeight < nBestHeight / 2)
          pblockindex = pindexGenesisBlock;
      else
          pblockindex = pindexBest;
      if (pblockindexFBBHLast && abs(nHeight - pblockindex->nHeight) > abs(nHeight - pblockindexFBBHLast->nHeight))
          pblockindex = pblockindexFBBHLast;
      while (pblockindex->nHeight > nHeight)
          pblockindex = pblockindex->pprev;
      while (pblockindex->nHeight < nHeight)
          pblockindex = pblockindex->pnext;
      pblockindexFBBHLast = pblockindex;
      return pblockindex;
  }
  
  bool CBlock::ReadFromDisk(const CBlockIndex* pindex)
  {
      if (!ReadFromDisk(pindex->GetBlockPos()))
          return false;
      if (GetHash() != pindex->GetBlockHash())
          return error("CBlock::ReadFromDisk() : GetHash() doesn't match index");
      return true;
  }
  
  uint256 static GetOrphanRoot(const CBlockHeader* pblock)
  {
      // Work back to the first block in the orphan chain
      while (mapOrphanBlocks.count(pblock->hashPrevBlock))
          pblock = mapOrphanBlocks[pblock->hashPrevBlock];
      return pblock->GetHash();
  }
  
  int64 GetProofOfWorkReward(unsigned int nBits)
  {
      CBigNum bnSubsidyLimit = MAX_MINT_PROOF_OF_WORK;
      CBigNum bnTarget;
      bnTarget.SetCompact(nBits);
      CBigNum bnTargetLimit = bnProofOfWorkLimit;
      bnTargetLimit.SetCompact(bnTargetLimit.GetCompact());
  
      // tkcoin: subsidy is cut in half every 16x multiply of difficulty
      // A reasonably continuous curve is used to avoid shock to market
      // (nSubsidyLimit / nSubsidy) ** 4 == bnProofOfWorkLimit / bnTarget
      CBigNum bnLowerBound = CENT;
      CBigNum bnUpperBound = bnSubsidyLimit;
      while (bnLowerBound + CENT <= bnUpperBound)
      {
          CBigNum bnMidValue = (bnLowerBound + bnUpperBound) / 2;
          if (fDebug && GetBoolArg("-printcreation"))
              printf("GetProofOfWorkReward() : lower=%" PRI64d" upper=%" PRI64d" mid=%" PRI64d"\n", bnLowerBound.getuint64(), bnUpperBound.getuint64(), bnMidValue.getuint64());
          if (bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnTargetLimit > bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnTarget)
              bnUpperBound = bnMidValue;
          else
              bnLowerBound = bnMidValue;
      }
  
      int64 nSubsidy = bnUpperBound.getuint64();
      nSubsidy = (nSubsidy / CENT) * CENT;
      if (fDebug && GetBoolArg("-printcreation"))
          printf("GetProofOfWorkReward() : create=%s nBits=0x%08x nSubsidy=%" PRI64d"\n", FormatMoney(nSubsidy).c_str(), nBits, nSubsidy);
  
      if(nBestHeight < 1){
          return 2.65 * COIN;
      }
      // You get 1 or 2 utkc or less
      return min(nSubsidy, MAX_MINT_PROOF_OF_WORK);
  }
  
  // tkcoin: miner's coin stake is rewarded based on coin age spent (coin-days)
  int64 GetProofOfStakeReward(int64 nCoinAge)
  {
      //Assuming 2.65 coins at start we want a total circulation of 25 after ~12 months
      //Per coin one cent will be created with coinking so the amount of coins will increase by a factor of 1.10x
      //Giving 10% profit from staking per year. We need 943.3% profit, so that would make it 943 * COIN nRewardCoinYear
      static int64 nRewardCoinYear = 943 * COIN;  // creation amount per coin-year
      int64 nSubsidy = nCoinAge * 33 / (365 * 33 + 8) * nRewardCoinYear;
      if (fDebug && GetBoolArg("-printcreation"))
          printf("GetProofOfStakeReward(): create=%s nCoinAge=%" PRI64d"\n", FormatMoney(nSubsidy).c_str(), nCoinAge);
      return nSubsidy;
  }
  
  // Remove a random orphan block (which does not have any dependent orphans).
  void static PruneOrphanBlocks()
  {
      if (mapOrphanBlocksByPrev.size() <= (size_t)std::max((int64)0, GetArg("-maxorphanblocks", DEFAULT_MAX_ORPHAN_BLOCKS)))
          return;
  
      // Pick a random orphan block.
      int pos = insecure_rand() % mapOrphanBlocksByPrev.size();
      std::multimap<uint256, CBlock*>::iterator it = mapOrphanBlocksByPrev.begin();
      while (pos--) it++;
  
      // As long as this block has other orphans depending on it, move to one of those successors.
      do {
          std::multimap<uint256, CBlock*>::iterator it2 = mapOrphanBlocksByPrev.find(it->second->GetHash());
          if (it2 == mapOrphanBlocksByPrev.end())
              break;
          it = it2;
      } while(1);
  
      uint256 hash = it->second->GetHash();
      delete it->second;
      mapOrphanBlocksByPrev.erase(it);
      mapOrphanBlocks.erase(hash);
  }
  
  
  static const int64 nTargetTimespan = 7 * 24 * 60 * 60;  // one week
  static const int64 nTargetSpacingWorkMax = 12 * STAKE_TARGET_SPACING; // 2-hour
  
  //
  // minimum amount of work that could possibly be required nTime after
  // minimum work required was nBase
  //
  unsigned int ComputeMinWork(unsigned int nBase, int64 nTime)
  {
      CBigNum bnResult;
      bnResult.SetCompact(nBase);
      bnResult *= 2;
      while (nTime > 0 && bnResult < bnProofOfWorkLimit)
      {
          // Maximum 200% adjustment per day...
          bnResult *= 2;
          nTime -= 24 * 60 * 60;
      }
      if (bnResult > bnProofOfWorkLimit)
          bnResult = bnProofOfWorkLimit;
      return bnResult.GetCompact();
  }
  
  // tkcoin: find last block index up to pindex
  const CBlockIndex* GetLastBlockIndex(const CBlockIndex* pindex, bool fProofOfStake)
  {
      while (pindex && pindex->pprev && (pindex->IsProofOfStake() != fProofOfStake))
          pindex = pindex->pprev;
      return pindex;
  }
  
  #ifdef TESTING
  unsigned int GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake)
  #else
  unsigned int static GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake)
  #endif
  {
      if (pindexLast == NULL)
          return bnProofOfWorkLimit.GetCompact(); // genesis block
  
      const CBlockIndex* pindexPrev = GetLastBlockIndex(pindexLast, fProofOfStake);
      if (pindexPrev->pprev == NULL)
          return bnInitialHashTarget.GetCompact(); // first block
      const CBlockIndex* pindexPrevPrev = GetLastBlockIndex(pindexPrev->pprev, fProofOfStake);
      if (pindexPrevPrev->pprev == NULL)
          return bnInitialHashTarget.GetCompact(); // second block
  
      int64 nActualSpacing = pindexPrev->GetBlockTime() - pindexPrevPrev->GetBlockTime();
  
      // tkcoin: target change every block
      // tkcoin: retarget with exponential moving toward target spacing
      CBigNum bnNew;
      bnNew.SetCompact(pindexPrev->nBits);
      int64 nTargetSpacing = fProofOfStake? STAKE_TARGET_SPACING : min(nTargetSpacingWorkMax, (int64) STAKE_TARGET_SPACING * (1 + pindexLast->nHeight - pindexPrev->nHeight));
      int64 nInterval = nTargetTimespan / nTargetSpacing;
      bnNew *= ((nInterval - 1) * nTargetSpacing + nActualSpacing + nActualSpacing);
      bnNew /= ((nInterval + 1) * nTargetSpacing);
  
      if (bnNew > bnProofOfWorkLimit)
          bnNew = bnProofOfWorkLimit;
  
      return bnNew.GetCompact();
  }
  
  bool CheckProofOfWork(uint256 hash, unsigned int nBits)
  {
      CBigNum bnTarget;
      bnTarget.SetCompact(nBits);
  
      // Check range
      if (bnTarget <= 0 || bnTarget > bnProofOfWorkLimit)
          return error("CheckProofOfWork() : nBits below minimum work");
  
      // Check proof of work matches claimed amount
      if (hash > bnTarget.getuint256())
          return error("CheckProofOfWork() : hash doesn't match nBits");
  
      return true;
  }
  
  // Return maximum amount of blocks that other nodes claim to have
  int GetNumBlocksOfPeers()
  {
      return std::max(cPeerBlockCounts.median(), Checkpoints::GetTotalBlocksEstimate());
  }
  
  bool IsInitialBlockDownload()
  {
      #ifdef TESTING
      return false;
      #endif
  
      if (pindexBest == NULL || fImporting || fReindex || nBestHeight < Checkpoints::GetTotalBlocksEstimate())
          return true;
      static int64 nLastUpdate;
      static CBlockIndex* pindexLastBest;
      if (pindexBest != pindexLastBest)
      {
          pindexLastBest = pindexBest;
          nLastUpdate = GetTime();
      }
      return (GetTime() - nLastUpdate < 10 &&
              pindexBest->GetBlockTime() < GetTime() - 24 * 60 * 60);
  }
  
  void static InvalidChainFound(CBlockIndex* pindexNew)
  {
      if (pindexNew->nChainTrust > nBestInvalidTrust)
      {
          nBestInvalidTrust = pindexNew->nChainTrust;
          pblocktree->WriteBestInvalidTrust(CBigNum(nBestInvalidTrust));
          uiInterface.NotifyBlocksChanged();
      }
      printf("InvalidChainFound: invalid block=%s  height=%d  log2_trust=%.8g  date=%s\n",
        pindexNew->GetBlockHash().ToString().c_str(), pindexNew->nHeight,
        log(pindexNew->nChainTrust.getdouble())/log(2.0), DateTimeStrFormat("%Y-%m-%d %H:%M:%S",
        pindexNew->GetBlockTime()).c_str());
      printf("InvalidChainFound:  current best=%s  height=%d  log2_trust=%.8g  date=%s\n",
        hashBestChain.ToString().c_str(), nBestHeight, log(nBestChainTrust.getdouble())/log(2.0),
        DateTimeStrFormat("%Y-%m-%d %H:%M:%S", pindexBest->GetBlockTime()).c_str());
      if (pindexBest && nBestInvalidTrust > nBestChainTrust + (pindexBest->GetBlockTrust() * 6).getuint256())
          printf("InvalidChainFound: Warning: Displayed transactions may not be correct! You may need to upgrade, or other nodes may need to upgrade.\n");
      // tkcoin: should not enter safe mode for longer invalid chain
  }
  
  void static InvalidBlockFound(CBlockIndex *pindex) {
      pindex->nStatus |= BLOCK_FAILED_VALID;
      pblocktree->WriteBlockIndex(CDiskBlockIndex(pindex));
      setBlockIndexValid.erase(pindex);
      InvalidChainFound(pindex);
      if (pindex->pnext) {
          CValidationState stateDummy;
          ConnectBestBlock(stateDummy); // reorganise away from the failed block
      }
  }
  
  bool ConnectBestBlock(CValidationState &state) {
      do {
          CBlockIndex *pindexNewBest;
  
          {
              std::set<CBlockIndex*,CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexValid.rbegin();
              if (it == setBlockIndexValid.rend())
                  return true;
              pindexNewBest = *it;
          }
  
          if (pindexNewBest == pindexBest || (pindexBest && pindexNewBest->nChainTrust == pindexBest->nChainTrust))
              return true; // nothing to do
  
          // check ancestry
          CBlockIndex *pindexTest = pindexNewBest;
          std::vector<CBlockIndex*> vAttach;
          do {
              if (pindexTest->nStatus & BLOCK_FAILED_MASK) {
                  // mark descendants failed
                  CBlockIndex *pindexFailed = pindexNewBest;
                  while (pindexTest != pindexFailed) {
                      pindexFailed->nStatus |= BLOCK_FAILED_CHILD;
                      setBlockIndexValid.erase(pindexFailed);
                      pblocktree->WriteBlockIndex(CDiskBlockIndex(pindexFailed));
                      pindexFailed = pindexFailed->pprev;
                  }
                  InvalidChainFound(pindexNewBest);
                  break;
              }
  
              if (pindexBest == NULL || pindexTest->nChainTrust > pindexBest->nChainTrust)
                  vAttach.push_back(pindexTest);
  
              if (pindexTest->pprev == NULL || pindexTest->pnext != NULL) {
                  reverse(vAttach.begin(), vAttach.end());
                  BOOST_FOREACH(CBlockIndex *pindexSwitch, vAttach) {
                      boost::this_thread::interruption_point();
                      try {
                          if (!SetBestChain(state, pindexSwitch))
                              return false;
                      } catch(std::runtime_error &e) {
                          return state.Abort(_("System error: ") + e.what());
                      }
                  }
                  return true;
              }
              pindexTest = pindexTest->pprev;
          } while(true);
      } while(true);
  }
  
  void CBlockHeader::UpdateTime(const CBlockIndex* pindexPrev)
  {
      nTime = max(GetBlockTime(), GetAdjustedTime());
  }
  
  
  
  
  
  
  
  
  
  
  
  const CTxOut &CTransaction::GetOutputFor(const CTxIn& input, CCoinsViewCache& view)
  {
      const CCoins &coins = view.GetCoins(input.prevout.hash);
      assert(coins.IsAvailable(input.prevout.n));
      return coins.vout[input.prevout.n];
  }
  
  int64 CTransaction::GetValueIn(CCoinsViewCache& inputs) const
  {
      if (IsCoinBase())
          return 0;
  
      int64 nResult = 0;
      for (unsigned int i = 0; i < vin.size(); i++)
          nResult += GetOutputFor(vin[i], inputs).nValue;
  
      return nResult;
  }
  
  unsigned int CTransaction::GetP2SHSigOpCount(CCoinsViewCache& inputs) const
  {
      if (IsCoinBase())
          return 0;
  
      unsigned int nSigOps = 0;
      for (unsigned int i = 0; i < vin.size(); i++)
      {
          const CTxOut &prevout = GetOutputFor(vin[i], inputs);
          if (prevout.scriptPubKey.IsPayToScriptHash())
              nSigOps += prevout.scriptPubKey.GetSigOpCount(vin[i].scriptSig);
      }
      return nSigOps;
  }
  
  void CTransaction::UpdateCoins(CValidationState &state, CCoinsViewCache &inputs, CTxUndo &txundo, int nHeight, const uint256 &txhash) const
  {
      // mark inputs spent
      if (!IsCoinBase()) {
          BOOST_FOREACH(const CTxIn &txin, vin) {
              CCoins &coins = inputs.GetCoins(txin.prevout.hash);
              CTxInUndo undo;
              assert(coins.Spend(txin.prevout, undo));
              txundo.vprevout.push_back(undo);
          }
      }
  
      // add outputs
      assert(inputs.SetCoins(txhash, CCoins(*this, nHeight)));
  }
  
  bool CTransaction::HaveInputs(CCoinsViewCache &inputs) const
  {
      if (!IsCoinBase()) {
          // first check whether information about the prevout hash is available
          for (unsigned int i = 0; i < vin.size(); i++) {
              const COutPoint &prevout = vin[i].prevout;
              if (!inputs.HaveCoins(prevout.hash))
                  return false;
          }
  
          // then check whether the actual outputs are available
          for (unsigned int i = 0; i < vin.size(); i++) {
              const COutPoint &prevout = vin[i].prevout;
              const CCoins &coins = inputs.GetCoins(prevout.hash);
              if (!coins.IsAvailable(prevout.n))
                  return false;
          }
      }
      return true;
  }
  
  bool CScriptCheck::operator()() const {
      const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
      if (!VerifyScript(scriptSig, scriptPubKey, *ptxTo, nIn, nFlags, nHashType))
          return error("CScriptCheck() : %s VerifySignature failed", ptxTo->GetHash().ToString().c_str());
      return true;
  }
  
  bool VerifySignature(const CCoins& txFrom, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType)
  {
      assert(nIn < txTo.vin.size());
      if (txTo.vin[nIn].prevout.n >= txFrom.vout.size())
          return false;
  
      return CScriptCheck(txFrom, txTo, nIn, flags, nHashType)();
  }
  
  bool CTransaction::CheckInputs(CValidationState &state, CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, std::vector<CScriptCheck> *pvChecks) const
  {
      if (!IsCoinBase())
      {
          if (pvChecks)
              pvChecks->reserve(vin.size());
  
          // This doesn't trigger the DoS code on purpose; if it did, it would make it easier
          // for an attacker to attempt to split the network.
          if (!HaveInputs(inputs))
              return state.Invalid(error("CheckInputs() : %s inputs unavailable", GetHash().ToString().c_str()));
  
          // While checking, GetBestBlock() refers to the parent block.
          // This is also true for mempool checks.
          int nSpendHeight = inputs.GetBestBlock()->nHeight + 1;
          int64 nValueIn = 0;
          int64 nFees = 0;
          for (unsigned int i = 0; i < vin.size(); i++)
          {
              const COutPoint &prevout = vin[i].prevout;
              const CCoins &coins = inputs.GetCoins(prevout.hash);
  
              // If prev is coinbase, check that it's matured
              if (coins.IsCoinBase() || coins.IsCoinStake()) {
                  if (nSpendHeight - coins.nHeight < nCoinbaseMaturity)
                      return state.Invalid(error("CheckInputs() : tried to spend coinbase at depth %d", nSpendHeight - coins.nHeight));
              }
  
              // tkcoin: check transaction timestamp
              if (coins.nTime > nTime)
                  return state.DoS(100, error("CheckInputs() : transaction timestamp earlier than input transaction"));
  
              // Check for negative or overflow input values
              nValueIn += coins.vout[prevout.n].nValue;
              if (!MoneyRange(coins.vout[prevout.n].nValue) || !MoneyRange(nValueIn))
                  return state.DoS(100, error("CheckInputs() : txin values out of range"));
  
          }
  
          if (IsCoinStake())
          {
              // tkcoin: coin stake tx earns reward instead of paying fee
              uint64 nCoinAge;
              if (!GetCoinAge(state, inputs, nCoinAge))
                  return error("CheckInputs() : %s unable to get coin age for coinstake", GetHash().ToString().c_str());
              int64 nStakeReward = GetValueOut() - nValueIn;
              if (nStakeReward > GetProofOfStakeReward(nCoinAge) - GetMinFee() + MIN_TX_FEE)
                  return state.DoS(100, error("CheckInputs() : %s stake reward exceeded", GetHash().ToString().c_str()));
          }
          else
          {
              if (nValueIn < GetValueOut())
                  return state.DoS(100, error("CheckInputs() : %s value in < value out", GetHash().ToString().c_str()));
      
              // Tally transaction fees
              int64 nTxFee = nValueIn - GetValueOut();
              if (nTxFee < 0)
                  return state.DoS(100, error("CheckInputs() : %s nTxFee < 0", GetHash().ToString().c_str()));
              // tkcoin: enforce transaction fees for every block
              if (nTxFee < GetMinFee())
                  return state.DoS(100, error("CheckInputs() : %s not paying required fee=%s, paid=%s", GetHash().ToString().c_str(), FormatMoney(GetMinFee()).c_str(), FormatMoney(nTxFee).c_str()));
              nFees += nTxFee;
              if (!MoneyRange(nFees))
                  return state.DoS(100, error("CheckInputs() : nFees out of range"));
          }
  
          // The first loop above does all the inexpensive checks.
          // Only if ALL inputs pass do we perform expensive ECDSA signature checks.
          // Helps prevent CPU exhaustion attacks.
  
          // Skip ECDSA signature verification when connecting blocks
          // before the last block chain checkpoint. This is safe because block merkle hashes are
          // still computed and checked, and any change will be caught at the next checkpoint.
          if (fScriptChecks) {
              for (unsigned int i = 0; i < vin.size(); i++) {
                  const COutPoint &prevout = vin[i].prevout;
                  const CCoins &coins = inputs.GetCoins(prevout.hash);
  
                  // Verify signature
                  CScriptCheck check(coins, *this, i, flags, 0);
                  if (pvChecks) {
                      pvChecks->push_back(CScriptCheck());
                      check.swap(pvChecks->back());
                  } else if (!check()) {
                      if (flags & SCRIPT_VERIFY_STRICTENC) {
                          // For now, check whether the failure was caused by non-canonical
                          // encodings or not; if so, don't trigger DoS protection.
                          CScriptCheck check(coins, *this, i, flags & (~SCRIPT_VERIFY_STRICTENC), 0);
                          if (check())
                              return state.Invalid();
                      }
                      return state.DoS(100,false);
                  }
              }
          }
      }
  
      return true;
  }
  
  
  
  
  bool CBlock::DisconnectBlock(CValidationState &state, CBlockIndex *pindex, CCoinsViewCache &view, bool *pfClean)
  {
      assert(pindex == view.GetBestBlock());
  
      if (pfClean)
          *pfClean = false;
  
      bool fClean = true;
  
      CBlockUndo blockUndo;
      CDiskBlockPos pos = pindex->GetUndoPos();
      if (pos.IsNull())
          return error("DisconnectBlock() : no undo data available");
      if (!blockUndo.ReadFromDisk(pos, pindex->pprev->GetBlockHash()))
          return error("DisconnectBlock() : failure reading undo data");
  
      if (blockUndo.vtxundo.size() + 1 != vtx.size())
          return error("DisconnectBlock() : block and undo data inconsistent");
  
      // undo transactions in reverse order
      for (int i = vtx.size() - 1; i >= 0; i--) {
          const CTransaction &tx = vtx[i];
          uint256 hash = tx.GetHash();
  
          // check that all outputs are available
          if (!view.HaveCoins(hash)) {
              fClean = fClean && error("DisconnectBlock() : outputs still spent? database corrupted");
              view.SetCoins(hash, CCoins());
          }
          CCoins &outs = view.GetCoins(hash);
  
          CCoins outsBlock = CCoins(tx, pindex->nHeight);
          // The CCoins serialization does not serialize negative numbers.
          // No network rules currently depend on the version here, so an inconsistency is harmless
          // but it must be corrected before txout nversion ever influences a network rule.
          if (outsBlock.nVersion < 0)
              outs.nVersion = outsBlock.nVersion;
          if (outs != outsBlock)
              fClean = fClean && error("DisconnectBlock() : added transaction mismatch? database corrupted");
  
          // remove outputs
          outs = CCoins();
  
          // restore inputs
          if (i > 0) { // not coinbases
              const CTxUndo &txundo = blockUndo.vtxundo[i-1];
              if (txundo.vprevout.size() != tx.vin.size())
                  return error("DisconnectBlock() : transaction and undo data inconsistent");
              for (unsigned int j = tx.vin.size(); j-- > 0;) {
                  const COutPoint &out = tx.vin[j].prevout;
                  const CTxInUndo &undo = txundo.vprevout[j];
                  CCoins coins;
                  view.GetCoins(out.hash, coins); // this can fail if the prevout was already entirely spent
                  if (undo.nHeight != 0) {
                      // undo data contains height: this is the last output of the prevout tx being spent
                      if (!coins.IsPruned())
                          fClean = fClean && error("DisconnectBlock() : undo data overwriting existing transaction");
                      coins = CCoins();
                      coins.fCoinBase = undo.fCoinBase;
                      coins.nHeight = undo.nHeight;
                      coins.nVersion = undo.nVersion;
                      coins.fCoinStake = undo.fCoinStake; // tkcoin
                      coins.nTime = undo.nTime;           // tkcoin
                  } else {
                      if (coins.IsPruned())
                          fClean = fClean && error("DisconnectBlock() : undo data adding output to missing transaction");
                  }
                  if (coins.IsAvailable(out.n))
                      fClean = fClean && error("DisconnectBlock() : undo data overwriting existing output");
                  if (coins.vout.size() < out.n+1)
                      coins.vout.resize(out.n+1);
                  coins.vout[out.n] = undo.txout;
                  if (!view.SetCoins(out.hash, coins))
                      return error("DisconnectBlock() : cannot restore coin inputs");
              }
          }
      }
  
      // move best block pointer to prevout block
      view.SetBestBlock(pindex->pprev);
  
      // tkcoin: clean up wallet after disconnecting coinstake
      BOOST_FOREACH(CTransaction& tx, vtx)
          SyncWithWallets(tx.GetHash(), tx, this, false, false);
  
      if (pfClean) {
          *pfClean = fClean;
          return true;
      } else {
          return fClean;
      }
  }
  
  void static FlushBlockFile(bool fFinalize = false)
  {
      LOCK(cs_LastBlockFile);
  
      CDiskBlockPos posOld(nLastBlockFile, 0);
  
      FILE *fileOld = OpenBlockFile(posOld);
      if (fileOld) {
          if (fFinalize)
              TruncateFile(fileOld, infoLastBlockFile.nSize);
          FileCommit(fileOld);
          fclose(fileOld);
      }
  
      fileOld = OpenUndoFile(posOld);
      if (fileOld) {
          if (fFinalize)
              TruncateFile(fileOld, infoLastBlockFile.nUndoSize);
          FileCommit(fileOld);
          fclose(fileOld);
      }
  }
  
  bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize);
  
  static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
  
  void ThreadScriptCheck() {
      RenameThread("bitcoin-scriptch");
      scriptcheckqueue.Thread();
  }
  
  bool CBlock::ConnectBlock(CValidationState &state, CBlockIndex* pindex, CCoinsViewCache &view, bool fJustCheck)
  {
      // Check it again in case a previous version let a bad block in
      if (!CheckBlock(state, !fJustCheck, !fJustCheck))
          return false;
  
      // verify that the view's current state corresponds to the previous block
      assert(pindex->pprev == view.GetBestBlock());
  
      // Special case for the genesis block, skipping connection of its transactions
      // (its coinbase is unspendable)
      if (GetHash() == hashGenesisBlock) {
          view.SetBestBlock(pindex);
          pindexGenesisBlock = pindex;
          return true;
      }
  
      bool fScriptChecks = pindex->nHeight >= Checkpoints::GetTotalBlocksEstimate();
  
      // Do not allow blocks that contain transactions which 'overwrite' older transactions,
      // unless those are already completely spent.
      // If such overwrites are allowed, coinbases and transactions depending upon those
      // can be duplicated to remove the ability to spend the first instance -- even after
      // being sent to another address.
      // See BIP30 and http://r6.ca/blog/20120206T005236Z.html for more information.
      // This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
      // already refuses previously-known transaction ids entirely.
      // This rule was originally applied all blocks whose timestamp was after March 15, 2012, 0:00 UTC.
      // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the
      // two in the chain that violate it. This prevents exploiting the issue against nodes in their
      // initial block download.
      bool fEnforceBIP30 = (!pindex->phashBlock) || // Enforce on CreateNewBlock invocations which don't have a hash.
                            !((pindex->nHeight==91842 && pindex->GetBlockHash() == uint256("0x00000000000a4d0a398161ffc163c503763b1f4360639393e0e4c8e300e0caec")) ||
                             (pindex->nHeight==91880 && pindex->GetBlockHash() == uint256("0x00000000000743f190a18c5577a3c2d2a1f610ae9601ac046a38084ccb7cd721")));
      if (fEnforceBIP30) {
          for (unsigned int i=0; i<vtx.size(); i++) {
              uint256 hash = GetTxHash(i);
              if (view.HaveCoins(hash) && !view.GetCoins(hash).IsPruned())
                  return state.DoS(100, error("ConnectBlock() : tried to overwrite transaction"));
          }
      }
  
      // BIP16 didn't become active until Apr 1 2012
      int64 nBIP16SwitchTime = 1333238400;
      bool fStrictPayToScriptHash = (pindex->nTime >= nBIP16SwitchTime);
  
      unsigned int flags = SCRIPT_VERIFY_NOCACHE |
                           (fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE);
  
      // Start enforcing CHECKLOCKTIMEVERIFY, (BIP65) for ProtocolV06 blocks.
      if (IsProtocolV06(pindex->pprev)) {
          flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
      }
  
      CBlockUndo blockundo;
  
      CCheckQueueControl<CScriptCheck> control(fScriptChecks && nScriptCheckThreads ? &scriptcheckqueue : NULL);
  
      int64 nStart = GetTimeMicros();
      int64 nFees = 0;
      int64 nValueIn = 0;
      int64 nValueOut = 0;
      int nInputs = 0;
      unsigned int nSigOps = 0;
      CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(vtx.size()));
      std::vector<std::pair<uint256, CDiskTxPos> > vPos;
      vPos.reserve(vtx.size());
      for (unsigned int i=0; i<vtx.size(); i++)
      {
          const CTransaction &tx = vtx[i];
  
          nInputs += tx.vin.size();
          nSigOps += tx.GetLegacySigOpCount();
          if (nSigOps > MAX_BLOCK_SIGOPS)
              return state.DoS(100, error("ConnectBlock() : too many sigops"));
  
          if (tx.IsCoinBase())
              nValueOut += tx.GetValueOut();
          else
          {
              if (!tx.HaveInputs(view))
                  return state.DoS(100, error("ConnectBlock() : inputs missing/spent"));
  
              if (fStrictPayToScriptHash)
              {
                  // Add in sigops done by pay-to-script-hash inputs;
                  // this is to prevent a "rogue miner" from creating
                  // an incredibly-expensive-to-validate block.
                  nSigOps += tx.GetP2SHSigOpCount(view);
                  if (nSigOps > MAX_BLOCK_SIGOPS)
                       return state.DoS(100, error("ConnectBlock() : too many sigops"));
              }
  
              int64 nTxValueIn = tx.GetValueIn(view);
              int64 nTxValueOut = tx.GetValueOut();
              nValueIn += nTxValueIn;
              nValueOut += nTxValueOut;
              if (!tx.IsCoinStake())
                  nFees += nTxValueIn - nTxValueOut;
  
              std::vector<CScriptCheck> vChecks;
              if (!tx.CheckInputs(state, view, fScriptChecks, flags, nScriptCheckThreads ? &vChecks : NULL))
                  return false;
              control.Add(vChecks);
          }
  
          CTxUndo txundo;
          tx.UpdateCoins(state, view, txundo, pindex->nHeight, GetTxHash(i));
          if (!tx.IsCoinBase())
              blockundo.vtxundo.push_back(txundo);
  
          vPos.push_back(std::make_pair(GetTxHash(i), pos));
          pos.nTxOffset += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
      }
      int64 nTime = GetTimeMicros() - nStart;
      if (fBenchmark)
          printf("- Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin)\n", (unsigned)vtx.size(), 0.001 * nTime, 0.001 * nTime / vtx.size(), nInputs <= 1 ? 0 : 0.001 * nTime / (nInputs-1));
  
      // tkcoin: coinbase reward check relocated to CheckBlock()
  
      if (!control.Wait())
          return state.DoS(100, false);
      int64 nTime2 = GetTimeMicros() - nStart;
      if (fBenchmark)
          printf("- Verify %u txins: %.2fms (%.3fms/txin)\n", nInputs - 1, 0.001 * nTime2, nInputs <= 1 ? 0 : 0.001 * nTime2 / (nInputs-1));
  
      if (fJustCheck)
          return true;
  
      // tkcoin: track money supply and mint amount info
      pindex->nMint = nValueOut - nValueIn + nFees;
      pindex->nMoneySupply = (pindex->pprev? pindex->pprev->nMoneySupply : 0) + nValueOut - nValueIn;
  
      // tkcoin: fees are not collected by miners as in bitcoin
      // tkcoin: fees are destroyed to compensate the entire network
      if (fDebug && GetBoolArg("-printcreation"))
          printf("ConnectBlock() : destroy=%s nFees=%" PRI64d"\n", FormatMoney(nFees).c_str(), nFees);
  
      // Write undo information to disk
      if (pindex->GetUndoPos().IsNull() || (pindex->nStatus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS)
      {
          if (pindex->GetUndoPos().IsNull()) {
              CDiskBlockPos pos;
              if (!FindUndoPos(state, pindex->nFile, pos, ::GetSerializeSize(blockundo, SER_DISK, CLIENT_VERSION) + 40))
                  return error("ConnectBlock() : FindUndoPos failed");
              if (!blockundo.WriteToDisk(pos, pindex->pprev->GetBlockHash()))
                  return state.Abort(_("Failed to write undo data"));
  
              // update nUndoPos in block index
              pindex->nUndoPos = pos.nPos;
              pindex->nStatus |= BLOCK_HAVE_UNDO;
          }
  
          pindex->nStatus = (pindex->nStatus & ~BLOCK_VALID_MASK) | BLOCK_VALID_SCRIPTS;
  
          CDiskBlockIndex blockindex(pindex);
          if (!pblocktree->WriteBlockIndex(blockindex))
              return state.Abort(_("Failed to write block index"));
      }
  
      if (fTxIndex)
          if (!pblocktree->WriteTxIndex(vPos))
              return state.Abort(_("Failed to write transaction index"));
  
      // add this block to the view's block chain
      assert(view.SetBestBlock(pindex));
  
      // Watch for transactions paying to me
      for (unsigned int i=0; i<vtx.size(); i++)
          SyncWithWallets(GetTxHash(i), vtx[i], this, true);
  
      return true;
  }
  
  bool SetBestChain(CValidationState &state, CBlockIndex* pindexNew)
  {
      // All modifications to the coin state will be done in this cache.
      // Only when all have succeeded, we push it to pcoinsTip.
      CCoinsViewCache view(*pcoinsTip, true);
  
      // Find the fork (typically, there is none)
      CBlockIndex* pfork = view.GetBestBlock();
      CBlockIndex* plonger = pindexNew;
      while (pfork && pfork != plonger)
      {
          while (plonger->nHeight > pfork->nHeight) {
              plonger = plonger->pprev;
              assert(plonger != NULL);
          }
          if (pfork == plonger)
              break;
          pfork = pfork->pprev;
          assert(pfork != NULL);
      }
  
      // List of what to disconnect (typically nothing)
      vector<CBlockIndex*> vDisconnect;
      for (CBlockIndex* pindex = view.GetBestBlock(); pindex != pfork; pindex = pindex->pprev)
          vDisconnect.push_back(pindex);
  
      // List of what to connect (typically only pindexNew)
      vector<CBlockIndex*> vConnect;
      for (CBlockIndex* pindex = pindexNew; pindex != pfork; pindex = pindex->pprev)
          vConnect.push_back(pindex);
      reverse(vConnect.begin(), vConnect.end());
  
      if (vDisconnect.size() > 0) {
          printf("REORGANIZE: Disconnect %" PRIszu" blocks; %s..\n", vDisconnect.size(), pfork->GetBlockHash().ToString().c_str());
          printf("REORGANIZE: Connect %" PRIszu" blocks; ..%s\n", vConnect.size(), pindexNew->GetBlockHash().ToString().c_str());
      }
  
      // Disconnect shorter branch
      list<CTransaction> vResurrect;
      BOOST_FOREACH(CBlockIndex* pindex, vDisconnect) {
          CBlock block;
          if (!block.ReadFromDisk(pindex))
              return state.Abort(_("Failed to read block"));
          int64 nStart = GetTimeMicros();
          if (!block.DisconnectBlock(state, pindex, view))
              return error("SetBestBlock() : DisconnectBlock %s failed", pindex->GetBlockHash().ToString().c_str());
          if (fBenchmark)
              printf("- Disconnect: %.2fms\n", (GetTimeMicros() - nStart) * 0.001);
  
          // Queue memory transactions to resurrect.
          // We only do this for blocks after the last checkpoint (reorganisation before that
          // point should only happen with -reindex/-loadblock, or a misbehaving peer.
          BOOST_REVERSE_FOREACH(const CTransaction& tx, block.vtx)
              if (!(tx.IsCoinBase() || tx.IsCoinStake()) && pindex->nHeight > Checkpoints::GetTotalBlocksEstimate())
                  vResurrect.push_front(tx);
      }
  
      // Connect longer branch
      vector<CTransaction> vDelete;
      BOOST_FOREACH(CBlockIndex *pindex, vConnect) {
          CBlock block;
          if (!block.ReadFromDisk(pindex))
              return state.Abort(_("Failed to read block"));
          int64 nStart = GetTimeMicros();
          if (!block.ConnectBlock(state, pindex, view)) {
              if (state.IsInvalid()) {
                  InvalidChainFound(pindexNew);
                  InvalidBlockFound(pindex);
              }
              return error("SetBestBlock() : ConnectBlock %s failed", pindex->GetBlockHash().ToString().c_str());
          }
          if (fBenchmark)
              printf("- Connect: %.2fms\n", (GetTimeMicros() - nStart) * 0.001);
  
          // Queue memory transactions to delete
          BOOST_FOREACH(const CTransaction& tx, block.vtx)
              vDelete.push_back(tx);
      }
  
      // Flush changes to global coin state
      int64 nStart = GetTimeMicros();
      int nModified = view.GetCacheSize();
      assert(view.Flush());
      int64 nTime = GetTimeMicros() - nStart;
      if (fBenchmark)
          printf("- Flush %i transactions: %.2fms (%.4fms/tx)\n", nModified, 0.001 * nTime, 0.001 * nTime / nModified);
  
      // Make sure it's successfully written to disk before changing memory structure
      bool fIsInitialDownload = IsInitialBlockDownload();
      if (!fIsInitialDownload || pcoinsTip->GetCacheSize() > nCoinCacheSize) {
          // Typical CCoins structures on disk are around 100 bytes in size.
          // Pushing a new one to the database can cause it to be written
          // twice (once in the log, and once in the tables). This is already
          // an overestimation, as most will delete an existing entry or
          // overwrite one. Still, use a conservative safety factor of 2.
          if (!CheckDiskSpace(100 * 2 * 2 * pcoinsTip->GetCacheSize()))
              return state.Error();
          FlushBlockFile();
          pblocktree->Sync();
          if (!pcoinsTip->Flush())
              return state.Abort(_("Failed to write to coin database"));
      }
  
      // At this point, all changes have been done to the database.
      // Proceed by updating the memory structures.
  
      // Disconnect shorter branch
      BOOST_FOREACH(CBlockIndex* pindex, vDisconnect)
          if (pindex->pprev)
              pindex->pprev->pnext = NULL;
  
      // Connect longer branch
      BOOST_FOREACH(CBlockIndex* pindex, vConnect)
          if (pindex->pprev)
              pindex->pprev->pnext = pindex;
  
      // Resurrect memory transactions that were in the disconnected branch
      BOOST_FOREACH(CTransaction& tx, vResurrect) {
          // ignore validation errors in resurrected transactions
          CValidationState stateDummy;
          if (!tx.AcceptToMemoryPool(stateDummy, true, false))
              mempool.remove(tx, true);
      }
  
      // Delete redundant memory transactions that are in the connected branch
      BOOST_FOREACH(CTransaction& tx, vDelete) {
          mempool.remove(tx);
          mempool.removeConflicts(tx);
      }
  
      // Update best block in wallet (so we can detect restored wallets)
      if ((pindexNew->nHeight % 20160) == 0 || (!fIsInitialDownload && (pindexNew->nHeight % 144) == 0))
      {
          const CBlockLocator locator(pindexNew);
          ::SetBestChain(locator);
      }
  
      // New best block
      hashBestChain = pindexNew->GetBlockHash();
      pindexBest = pindexNew;
      pblockindexFBBHLast = NULL;
      nBestHeight = pindexBest->nHeight;
      nBestChainTrust = pindexNew->nChainTrust;
      nTimeBestReceived = GetTime();
      nTransactionsUpdated++;
      printf("SetBestChain: new best=%s  height=%d  log2_trust=%.8g  moneysupply=%s  tx=%lu  date=%s progress=%f\n",
        hashBestChain.ToString().c_str(), nBestHeight, log(nBestChainTrust.getdouble())/log(2.0), FormatMoney(pindexBest->nMoneySupply).c_str(),
        (unsigned long)pindexNew->nChainTx,
        DateTimeStrFormat("%Y-%m-%d %H:%M:%S", pindexBest->GetBlockTime()).c_str(),
        Checkpoints::GuessVerificationProgress(pindexBest));
  
      // Check the version of the last 100 blocks to see if we need to upgrade:
      if (!fIsInitialDownload)
      {
          int nUpgraded = 0;
          const CBlockIndex* pindex = pindexBest;
          for (int i = 0; i < 100 && pindex != NULL; i++)
          {
              if (pindex->nVersion > CBlock::CURRENT_VERSION)
                  ++nUpgraded;
              pindex = pindex->pprev;
          }
          if (nUpgraded > 0)
              printf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, CBlock::CURRENT_VERSION);
          if (nUpgraded > 100/2)
              // strMiscWarning is read by GetWarnings(), called by Qt and the JSON-RPC code to warn the user:
              strMiscWarning = _("Warning: This version is obsolete, upgrade required!");
      }
  
      if (!IsSyncCheckpointEnforced()) // checkpoint advisory mode
      {
          if (pindexBest->pprev && !CheckSyncCheckpoint(pindexBest->GetBlockHash(), pindexBest->pprev))
              strCheckpointWarning = _("Warning: checkpoint on different blockchain fork, contact developers to resolve the issue");
          else
              strCheckpointWarning = "";
      }
  
      std::string strCmd = GetArg("-blocknotify", "");
  
      if (!fIsInitialDownload && !strCmd.empty())
      {
          boost::replace_all(strCmd, "%s", hashBestChain.GetHex());
          boost::thread t(runCommand, strCmd); // thread runs free
      }
  
      return true;
  }
  
  
  // tkcoin: 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
  // might not find out about their coin age. Older transactions are 
  // guaranteed to be in main chain by sync-checkpoint. This rule is
  // introduced to help nodes establish a consistent view of the coin
  // age (trust score) of competing branches.
  bool CTransaction::GetCoinAge(CValidationState &state, CCoinsViewCache &view, uint64& nCoinAge) const
  {
      CBigNum bnCentSecond = 0;  // coin age in the unit of cent-seconds
      nCoinAge = 0;
  
      if (IsCoinBase())
          return true;
  
      BOOST_FOREACH(const CTxIn& txin, vin)
      {
          // First try finding the previous transaction in database
          const COutPoint &prevout = txin.prevout;
          CCoins coins;
  
          if (!view.GetCoins(prevout.hash, coins))
              continue;  // previous transaction not in main chain
          if (nTime < coins.nTime)
              return false;  // Transaction timestamp violation
  
          // Transaction index is required to get to block header
          if (!fTxIndex)
              return false;  // Transaction index not available
  
          CDiskTxPos postx;
          CTransaction txPrev;
          if (pblocktree->ReadTxIndex(prevout.hash, postx))
          {
              CAutoFile file(OpenBlockFile(postx, true), SER_DISK, CLIENT_VERSION);
              CBlockHeader header;
              try {
                  file >> header;
                  fseek(file, postx.nTxOffset, SEEK_CUR);
                  file >> txPrev;
              } catch (std::exception &e) {
                  return error("%s() : deserialize or I/O error in GetCoinAge()", __PRETTY_FUNCTION__);
              }
              if (txPrev.GetHash() != prevout.hash)
                  return error("%s() : txid mismatch in GetCoinAge()", __PRETTY_FUNCTION__);
  
              if (header.GetBlockTime() + nStakeMinAge > nTime)
                  continue; // only count coins meeting min age requirement
  
              int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
              bnCentSecond += CBigNum(nValueIn) * (nTime-txPrev.nTime) / CENT;
  
              if (fDebug && GetBoolArg("-printcoinage"))
                  printf("coin age nValueIn=%-12" PRI64d" nTimeDiff=%d bnCentSecond=%s\n", nValueIn, nTime - txPrev.nTime, bnCentSecond.ToString().c_str());
          }
          else
              return error("%s() : tx missing in tx index in GetCoinAge()", __PRETTY_FUNCTION__);
      }
  
      CBigNum bnCoinDay = bnCentSecond * CENT / COIN / (24 * 60 * 60);
      if (fDebug && GetBoolArg("-printcoinage"))
          printf("coin age bnCoinDay=%s\n", bnCoinDay.ToString().c_str());
      nCoinAge = bnCoinDay.getuint64();
      return true;
  }
  
  // tkcoin: total coin age spent in block, in the unit of coin-days.
  bool CBlock::GetCoinAge(uint64& nCoinAge) const
  {
      nCoinAge = 0;
  
      CCoinsViewCache view(*pcoinsTip, true);
      BOOST_FOREACH(const CTransaction& tx, vtx)
      {
          uint64 nTxCoinAge;
          CValidationState state;
          if (tx.GetCoinAge(state, view, nTxCoinAge))
              nCoinAge += nTxCoinAge;
          else
              return false;
      }
  
      if (nCoinAge == 0) // block coin age minimum 1 coin-day
          nCoinAge = 1;
      if (fDebug && GetBoolArg("-printcoinage"))
          printf("block coin age total nCoinDays=%" PRI64d"\n", nCoinAge);
      return true;
  }
  
  
  bool CBlock::AddToBlockIndex(CValidationState &state, const CDiskBlockPos &pos)
  {
      // Check for duplicate
      uint256 hash = GetHash();
      if (mapBlockIndex.count(hash))
          return state.Invalid(error("AddToBlockIndex() : %s already exists", hash.ToString().c_str()));
  
      // Construct new block index object
      CBlockIndex* pindexNew = new CBlockIndex(*this);
      assert(pindexNew);
      map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
      pindexNew->phashBlock = &((*mi).first);
      map<uint256, CBlockIndex*>::iterator miPrev = mapBlockIndex.find(hashPrevBlock);
      if (miPrev != mapBlockIndex.end())
      {
          pindexNew->pprev = (*miPrev).second;
          pindexNew->nHeight = pindexNew->pprev->nHeight + 1;
      }
      pindexNew->nTx = vtx.size();
      pindexNew->nChainTrust = (pindexNew->pprev ? pindexNew->pprev->nChainTrust : 0) + pindexNew->GetBlockTrust().getuint256();
      pindexNew->nChainTx = (pindexNew->pprev ? pindexNew->pprev->nChainTx : 0) + pindexNew->nTx;
      pindexNew->nFile = pos.nFile;
      pindexNew->nDataPos = pos.nPos;
      pindexNew->nUndoPos = 0;
      pindexNew->nStatus = BLOCK_VALID_TRANSACTIONS | BLOCK_HAVE_DATA;
  
      // tkcoin: compute stake entropy bit for stake modifier
      if (!pindexNew->SetStakeEntropyBit(GetStakeEntropyBit()))
          return error("AddToBlockIndex() : SetStakeEntropyBit() failed");
  
      // tkcoin: record proof-of-stake hash value
      if (pindexNew->IsProofOfStake())
      {
          if (!mapProofOfStake.count(hash))
              return error("AddToBlockIndex() : hashProofOfStake not found in map");
          pindexNew->hashProofOfStake = mapProofOfStake[hash];
      }
  
      // tkcoin: compute stake modifier
      uint64 nStakeModifier = 0;
      bool fGeneratedStakeModifier = false;
      if (!ComputeNextStakeModifier(pindexNew, nStakeModifier, fGeneratedStakeModifier))
          return error("AddToBlockIndex() : ComputeNextStakeModifier() failed");
      pindexNew->SetStakeModifier(nStakeModifier, fGeneratedStakeModifier);
      pindexNew->nStakeModifierChecksum = GetStakeModifierChecksum(pindexNew);
      if (!CheckStakeModifierCheckpoints(pindexNew->nHeight, pindexNew->nStakeModifierChecksum))
          return error("AddToBlockIndex() : Rejected by stake modifier checkpoint height=%d, modifier=0x%016" PRI64x, pindexNew->nHeight, nStakeModifier);
  
      // tkcoin: remember stake
      if (pindexNew->IsProofOfStake())
          setStakeSeen.insert(make_pair(pindexNew->prevoutStake, pindexNew->nStakeTime));
  
      setBlockIndexValid.insert(pindexNew);
  
      if (!pblocktree->WriteBlockIndex(CDiskBlockIndex(pindexNew)))
          return state.Abort(_("Failed to write block index"));
  
      // New best?
      if (!ConnectBestBlock(state))
          return false;
  
      if (pindexNew == pindexBest)
      {
          // Notify UI to display prev block's coinbase if it was ours
          static uint256 hashPrevBestCoinBase;
          UpdatedTransaction(hashPrevBestCoinBase);
          hashPrevBestCoinBase = GetTxHash(0);
      }
  
      if (!pblocktree->Flush())
          return state.Abort(_("Failed to sync block index"));
  
      uiInterface.NotifyBlocksChanged();
      return true;
  }
  
  
  bool FindBlockPos(CValidationState &state, CDiskBlockPos &pos, unsigned int nAddSize, unsigned int nHeight, uint64 nTime, bool fKnown = false)
  {
      bool fUpdatedLast = false;
  
      LOCK(cs_LastBlockFile);
  
      if (fKnown) {
          if (nLastBlockFile != pos.nFile) {
              nLastBlockFile = pos.nFile;
              infoLastBlockFile.SetNull();
              pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile);
              fUpdatedLast = true;
          }
      } else {
          while (infoLastBlockFile.nSize + nAddSize >= MAX_BLOCKFILE_SIZE) {
              printf("Leaving block file %i: %s\n", nLastBlockFile, infoLastBlockFile.ToString().c_str());
              FlushBlockFile(true);
              nLastBlockFile++;
              infoLastBlockFile.SetNull();
              pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile); // check whether data for the new file somehow already exist; can fail just fine
              fUpdatedLast = true;
          }
          pos.nFile = nLastBlockFile;
          pos.nPos = infoLastBlockFile.nSize;
      }
  
      infoLastBlockFile.nSize += nAddSize;
      infoLastBlockFile.AddBlock(nHeight, nTime);
  
      if (!fKnown) {
          unsigned int nOldChunks = (pos.nPos + BLOCKFILE_CHUNK_SIZE - 1) / BLOCKFILE_CHUNK_SIZE;
          unsigned int nNewChunks = (infoLastBlockFile.nSize + BLOCKFILE_CHUNK_SIZE - 1) / BLOCKFILE_CHUNK_SIZE;
          if (nNewChunks > nOldChunks) {
              if (CheckDiskSpace(nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos)) {
                  FILE *file = OpenBlockFile(pos);
                  if (file) {
                      printf("Pre-allocating up to position 0x%x in blk%05u.dat\n", nNewChunks * BLOCKFILE_CHUNK_SIZE, pos.nFile);
                      AllocateFileRange(file, pos.nPos, nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos);
                      fclose(file);
                  }
              }
              else
                  return state.Error();
          }
      }
  
      if (!pblocktree->WriteBlockFileInfo(nLastBlockFile, infoLastBlockFile))
          return state.Abort(_("Failed to write file info"));
      if (fUpdatedLast)
          pblocktree->WriteLastBlockFile(nLastBlockFile);
  
      return true;
  }
  
  bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize)
  {
      pos.nFile = nFile;
  
      LOCK(cs_LastBlockFile);
  
      unsigned int nNewSize;
      if (nFile == nLastBlockFile) {
          pos.nPos = infoLastBlockFile.nUndoSize;
          nNewSize = (infoLastBlockFile.nUndoSize += nAddSize);
          if (!pblocktree->WriteBlockFileInfo(nLastBlockFile, infoLastBlockFile))
              return state.Abort(_("Failed to write block info"));
      } else {
          CBlockFileInfo info;
          if (!pblocktree->ReadBlockFileInfo(nFile, info))
              return state.Abort(_("Failed to read block info"));
          pos.nPos = info.nUndoSize;
          nNewSize = (info.nUndoSize += nAddSize);
          if (!pblocktree->WriteBlockFileInfo(nFile, info))
              return state.Abort(_("Failed to write block info"));
      }
  
      unsigned int nOldChunks = (pos.nPos + UNDOFILE_CHUNK_SIZE - 1) / UNDOFILE_CHUNK_SIZE;
      unsigned int nNewChunks = (nNewSize + UNDOFILE_CHUNK_SIZE - 1) / UNDOFILE_CHUNK_SIZE;
      if (nNewChunks > nOldChunks) {
          if (CheckDiskSpace(nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos)) {
              FILE *file = OpenUndoFile(pos);
              if (file) {
                  printf("Pre-allocating up to position 0x%x in rev%05u.dat\n", nNewChunks * UNDOFILE_CHUNK_SIZE, pos.nFile);
                  AllocateFileRange(file, pos.nPos, nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos);
                  fclose(file);
              }
          }
          else
              return state.Error();
      }
  
      return true;
  }
  
  
  bool CBlock::CheckBlock(CValidationState &state, bool fCheckPOW, bool fCheckMerkleRoot) const
  {
      // These are checks that are independent of context
      // that can be verified before saving an orphan block.
  
      // Size limits
      if (vtx.empty() || vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
          return state.DoS(100, error("CheckBlock() : size limits failed"));
  
      // Special short-term limits to avoid 10,000 BDB lock limit:
      if (GetBlockTime() >= 1363867200 && // start enforcing 21 March 2013, noon GMT
          GetBlockTime() < 1368576000)  // stop enforcing 15 May 2013 00:00:00
      {
          // Rule is: #unique txids referenced <= 4,500
          // ... to prevent 10,000 BDB lock exhaustion on old clients
          set<uint256> setTxIn;
          for (size_t i = 0; i < vtx.size(); i++)
          {
              setTxIn.insert(vtx[i].GetHash());
              if (i == 0) continue; // skip coinbase txin
              BOOST_FOREACH(const CTxIn& txin, vtx[i].vin)
                  setTxIn.insert(txin.prevout.hash);
          }
          size_t nTxids = setTxIn.size();
          if (nTxids > 4500)
              return error("CheckBlock() : 15 May maxlocks violation");
      }
  
      // Check proof of work matches claimed amount
      if (fCheckPOW && IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits))
          return state.DoS(50, error("CheckBlock() : proof of work failed"));
  
      // Check timestamp
      if (GetBlockTime() > GetAdjustedTime() + nMaxClockDrift)
          return state.Invalid(error("CheckBlock() : block timestamp too far in the future"));
  
      // First transaction must be coinbase, the rest must not be
      if (vtx.empty() || !vtx[0].IsCoinBase())
          return state.DoS(100, error("CheckBlock() : first tx is not coinbase"));
      for (unsigned int i = 1; i < vtx.size(); i++)
          if (vtx[i].IsCoinBase())
              return state.DoS(100, error("CheckBlock() : more than one coinbase"));
  
      // tkcoin: only the second transaction can be the optional coinstake
      for (unsigned int i = 2; i < vtx.size(); i++)
          if (vtx[i].IsCoinStake())
              return state.DoS(100, error("CheckBlock() : coinstake in wrong position"));
  
      // tkcoin: coinbase output should be empty if proof-of-stake block
      if (IsProofOfStake() && (vtx[0].vout.size() != 1 || !vtx[0].vout[0].IsEmpty()))
          return error("CheckBlock() : coinbase output not empty for proof-of-stake block");
  
      // Check coinbase timestamp
      if (GetBlockTime() > (int64)vtx[0].nTime + nMaxClockDrift)
          return state.DoS(50, error("CheckBlock() : coinbase timestamp is too early"));
  
      // Check coinstake timestamp
      if (IsProofOfStake() && !CheckCoinStakeTimestamp(GetBlockTime(), (int64)vtx[1].nTime))
          return state.DoS(50, error("CheckBlock() : coinstake timestamp violation nTimeBlock=%" PRI64u" nTimeTx=%u", GetBlockTime(), vtx[1].nTime));
  
      // Check coinbase reward
      if (vtx[0].GetValueOut() > (IsProofOfWork()? (GetProofOfWorkReward(nBits) - vtx[0].GetMinFee() + MIN_TX_FEE) : 0))
          return state.DoS(50, error("CheckBlock() : coinbase reward exceeded %s > %s", 
                     FormatMoney(vtx[0].GetValueOut()).c_str(),
                     FormatMoney(IsProofOfWork()? GetProofOfWorkReward(nBits) : 0).c_str()));
  
      // Check transactions
      BOOST_FOREACH(const CTransaction& tx, vtx)
      {
          if (!tx.CheckTransaction(state))
              return error("CheckBlock() : CheckTransaction failed");
          // tkcoin: check transaction timestamp
          if (GetBlockTime() < (int64)tx.nTime)
              return state.DoS(50, error("CheckBlock() : block timestamp earlier than transaction timestamp"));
      }
  
      // Build the merkle tree already. We need it anyway later, and it makes the
      // block cache the transaction hashes, which means they don't need to be
      // recalculated many times during this block's validation.
      BuildMerkleTree();
  
      // Check for duplicate txids. This is caught by ConnectInputs(),
      // but catching it earlier avoids a potential DoS attack:
      set<uint256> uniqueTx;
      for (unsigned int i=0; i<vtx.size(); i++) {
          uniqueTx.insert(GetTxHash(i));
      }
      if (uniqueTx.size() != vtx.size())
          return state.DoS(100, error("CheckBlock() : duplicate transaction"), true);
  
      unsigned int nSigOps = 0;
      BOOST_FOREACH(const CTransaction& tx, vtx)
      {
          nSigOps += tx.GetLegacySigOpCount();
      }
      if (nSigOps > MAX_BLOCK_SIGOPS)
          return state.DoS(100, error("CheckBlock() : out-of-bounds SigOpCount"));
  
      // Check merkle root
      if (fCheckMerkleRoot && hashMerkleRoot != BuildMerkleTree())
          return state.DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"));
  
      // tkcoin: check block signature
      // Only check block signature if check merkle root, c.f. commit 3cd01fdf
      if (fCheckMerkleRoot && !CheckBlockSignature())
          return state.DoS(100, error("CheckBlock() : bad block signature"));
  
      return true;
  }
  
  bool CBlock::AcceptBlock(CValidationState &state, CDiskBlockPos *dbp)
  {
      // Check for duplicate
      uint256 hash = GetHash();
      if (mapBlockIndex.count(hash))
          return state.Invalid(error("AcceptBlock() : block already in mapBlockIndex"));
  
      // Get prev block index
      CBlockIndex* pindexPrev = NULL;
      int nHeight = 0;
      if (hash != hashGenesisBlock) {
          map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hashPrevBlock);
          if (mi == mapBlockIndex.end())
              return state.DoS(10, error("AcceptBlock() : prev block not found"));
          pindexPrev = (*mi).second;
          nHeight = pindexPrev->nHeight+1;
  
          // Check proof-of-work or proof-of-stake
          if (nBits != GetNextTargetRequired(pindexPrev, IsProofOfStake()))
              return state.DoS(100, error("AcceptBlock() : incorrect proof-of-work/proof-of-stake"));
  
          // Check timestamp against prev
          if (GetBlockTime() <= pindexPrev->GetMedianTimePast() || GetBlockTime() + nMaxClockDrift < pindexPrev->GetBlockTime())
              return state.Invalid(error("AcceptBlock() : block's timestamp is too early"));
  
          // Check that all transactions are finalized
          BOOST_FOREACH(const CTransaction& tx, vtx)
              if (!tx.IsFinal(nHeight, GetBlockTime()))
                  return state.DoS(10, error("AcceptBlock() : contains a non-final transaction"));
  
          // Check that the block chain matches the known block chain up to a hardened checkpoint
          if (!Checkpoints::CheckHardened(nHeight, hash))
              return state.DoS(100, error("AcceptBlock() : rejected by hardened checkpoint lock-in at %d", nHeight));
  
          // tkcoin: check that the block satisfies synchronized checkpoint
          if (IsSyncCheckpointEnforced() // checkpoint enforce mode
              && !CheckSyncCheckpoint(hash, pindexPrev))
              return state.Invalid(error("AcceptBlock() : rejected by synchronized checkpoint"));
  
          if (IsProtocolV06(pindexPrev))
          {
              // Reject block.nVersion=1 blocks when protocol v06 got activated.
              if (nVersion < 2)
              {
                  return state.Invalid(error("AcceptBlock() : rejected nVersion=1 block"));
              }
              // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
              else
              {
                  CScript expect = CScript() << nHeight;
                  if (vtx[0].vin[0].scriptSig.size() < expect.size() ||
                      !std::equal(expect.begin(), expect.end(), vtx[0].vin[0].scriptSig.begin()))
                      return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"));
              }
          }
      }
  
      // Write block to history file
      try {
          unsigned int nBlockSize = ::GetSerializeSize(*this, SER_DISK, CLIENT_VERSION);
          CDiskBlockPos blockPos;
          if (dbp != NULL)
              blockPos = *dbp;
          if (!FindBlockPos(state, blockPos, nBlockSize+8, nHeight, nTime, dbp != NULL))
              return error("AcceptBlock() : FindBlockPos failed");
          if (dbp == NULL)
              if (!WriteToDisk(blockPos))
                  return state.Abort(_("Failed to write block"));
          if (!AddToBlockIndex(state, blockPos))
              return error("AcceptBlock() : AddToBlockIndex failed");
      } catch(std::runtime_error &e) {
          return state.Abort(_("System error: ") + e.what());
      }
  
      // Relay inventory, but don't relay old inventory during initial block download
      int nBlockEstimate = Checkpoints::GetTotalBlocksEstimate();
      if (hashBestChain == hash)
      {
          LOCK(cs_vNodes);
          BOOST_FOREACH(CNode* pnode, vNodes)
              if (nBestHeight > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : nBlockEstimate))
                  pnode->PushInventory(CInv(MSG_BLOCK, hash));
      }
  
      // tkcoin: check pending sync-checkpoint
      AcceptPendingSyncCheckpoint();
  
      return true;
  }
  
  bool CBlockIndex::IsSuperMajority(int minVersion, const CBlockIndex* pstart, unsigned int nRequired, unsigned int nToCheck)
  {
      unsigned int nFound = 0;
      for (unsigned int i = 0; i < nToCheck && nFound < nRequired && pstart != NULL; pstart = pstart->pprev )
      {
          if (!pstart->IsProofOfStake())
              continue;
  
          if (pstart->nVersion >= minVersion)
              ++nFound;
  
          i++;
      }
      return (nFound >= nRequired);
  }
  
  void CleanUpOldDuplicateStakeBlocks()
  {
      uint64 maxAge = 24 * 60 * 60;
      uint64 minTime = GetAdjustedTime() - maxAge;
  
      BOOST_FOREACH(PAIRTYPE(const uint256, CBlock*)& item, mapDuplicateStakeBlocks)
      {
          const uint256& hash = item.first;
          CBlock* block = item.second;
          if (block->GetBlockTime() < minTime)
          {
              mapDuplicateStakeBlocks.erase(hash);
              delete block;
          }
      }
  }
  
  bool ProcessBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDiskBlockPos *dbp)
  {
  #ifdef TESTING
      static set<uint256> setIgnoredBlockHashes;
      if (nBlocksToIgnore)
      {
          nBlocksToIgnore--;
          setIgnoredBlockHashes.insert(pblock->GetHash());
          return error("ProcessBlock() : block ignored");
      }
      if (setIgnoredBlockHashes.count(pblock->GetHash()))
          return error("ProcessBlock() : block ignored");
  #endif
      // Check for duplicate
      uint256 hash = pblock->GetHash();
      if (mapBlockIndex.count(hash))
          return state.Invalid(error("ProcessBlock() : already have block %d %s", mapBlockIndex[hash]->nHeight, hash.ToString().c_str()));
      if (mapOrphanBlocks.count(hash))
          return state.Invalid(error("ProcessBlock() : already have block (orphan) %s", hash.ToString().c_str()));
  
      // tkcoin: check proof-of-stake
      bool fDuplicateStakeOfBestBlock = false;
      if (pblock->IsProofOfStake())
      {
          std::pair<COutPoint, unsigned int> proofOfStake = pblock->GetProofOfStake();
  
          if (pindexBest->IsProofOfStake() && proofOfStake.first == pindexBest->prevoutStake)
              // If the best block's stake is reused, we cancel the best block after the block checks
              fDuplicateStakeOfBestBlock = true;
          else
          {
              // Limited duplicity on stake: prevents block flood attack
              // Duplicate stake allowed only when there is orphan child block
              if (pblock->IsProofOfStake() && setStakeSeen.count(proofOfStake) && !mapOrphanBlocksByPrev.count(hash) && !WantedByPendingSyncCheckpoint(hash))
                  return error("ProcessBlock() : duplicate proof-of-stake (%s, %d) for block %s", proofOfStake.first.ToString().c_str(), proofOfStake.second, hash.ToString().c_str());
          }
      }
  
      // Preliminary checks
      if (!pblock->CheckBlock(state))
          return error("ProcessBlock() : CheckBlock FAILED");
  
      // tkcoin: verify hash target and signature of coinstake tx
      if (pblock->IsProofOfStake())
      {
          uint256 hashProofOfStake = 0;
          if (!CheckProofOfStake(state, pblock->vtx[1], pblock->nBits, hashProofOfStake))
          {
              printf("WARNING: ProcessBlock(): check proof-of-stake failed for block %s\n", hash.ToString().c_str());
              return false; // do not error here as we expect this during initial block download
          }
          if (!mapProofOfStake.count(hash)) // add to mapProofOfStake
              mapProofOfStake.insert(make_pair(hash, hashProofOfStake));
      }
  
      CBlockIndex* pcheckpoint = GetLastSyncCheckpoint();
      if (pcheckpoint && pblock->hashPrevBlock != hashBestChain && !WantedByPendingSyncCheckpoint(hash))
      {
          // Extra checks to prevent "fill up memory by spamming with bogus blocks"
          int64 deltaTime = pblock->GetBlockTime() - pcheckpoint->nTime;
          CBigNum bnNewBlock;
          bnNewBlock.SetCompact(pblock->nBits);
          CBigNum bnRequired;
          bnRequired.SetCompact(ComputeMinWork(GetLastBlockIndex(pcheckpoint, pblock->IsProofOfStake())->nBits, deltaTime));
  
          if (bnNewBlock > bnRequired)
          {
              return state.DoS(100, error("ProcessBlock() : block with too little %s", pblock->IsProofOfStake()? "proof-of-stake" : "proof-of-work"));
          }
      }
  
      // tkcoin: ask for pending sync-checkpoint if any
      if (!IsInitialBlockDownload())
          AskForPendingSyncCheckpoint(pfrom);
  
      if (fDuplicateStakeOfBestBlock)
      {
          printf("ProcessBlock() : block uses the same stake as the best block. Canceling the best block\n");
  
          // Save the block to be able to accept it if a new chain is built from it despite the rejection
          mapDuplicateStakeBlocks[pblock->GetHash()] = new CBlock(*pblock);
  
          // Relay the duplicate block so that other nodes are aware of the duplication
          RelayBlock(*pblock, hash);
  
          // Cancel the best block
          setBlockIndexValid.erase(pindexBest); // Remove from the list of immediate candidates for the best chain
          InvalidChainFound(pindexBest);
          CValidationState stateDummy;
          if (!SetBestChain(stateDummy, pindexBest->pprev))
              return error("ProcessBlock(): SetBestChain on previous best block failed");
  
          return false;
      }
  
      if (!mapBlockIndex.count(pblock->hashPrevBlock) && mapDuplicateStakeBlocks.count(pblock->hashPrevBlock))
      {
          printf("ProcessBlock() : parent block was previously rejected because of stake duplication. Reaccepting parent\n");
          CBlock* pprevBlock = mapDuplicateStakeBlocks[pblock->hashPrevBlock];
          // Block was already checked when it was first received, so we can just accept it here
          if (!pprevBlock->AcceptBlock(state, dbp))
              return error("ProcessBlock() : AcceptBlock of previously duplicate block FAILED");
          mapDuplicateStakeBlocks.erase(pblock->hashPrevBlock);
          delete pprevBlock;
      }
  
      if (mapDuplicateStakeBlocks.size())
          CleanUpOldDuplicateStakeBlocks();
  
      // If we don't already have its previous block, shunt it off to holding area until we get it
      if (pblock->hashPrevBlock != 0 && !mapBlockIndex.count(pblock->hashPrevBlock))
      {
          printf("ProcessBlock: ORPHAN BLOCK, prev=%s\n", pblock->hashPrevBlock.ToString().c_str());
  
          // Accept orphans as long as there is a node to request its parents from
          if (pfrom) {
              PruneOrphanBlocks();
              CBlock* pblock2 = new CBlock(*pblock);
              // tkcoin: check proof-of-stake
              if (pblock2->IsProofOfStake())
              {
                  // Limited duplicity on stake: prevents block flood attack
                  // Duplicate stake allowed only when there is orphan child block
                  if (setStakeSeenOrphan.count(pblock2->GetProofOfStake()) && !mapOrphanBlocksByPrev.count(hash) && !WantedByPendingSyncCheckpoint(hash))
                      return error("ProcessBlock() : duplicate proof-of-stake (%s, %d) for orphan block %s", pblock2->GetProofOfStake().first.ToString().c_str(), pblock2->GetProofOfStake().second, hash.ToString().c_str());
                  else
                      setStakeSeenOrphan.insert(pblock2->GetProofOfStake());
              }
              mapOrphanBlocks.insert(make_pair(hash, pblock2));
              mapOrphanBlocksByPrev.insert(make_pair(pblock2->hashPrevBlock, pblock2));
  
              // Ask this guy to fill in what we're missing
              pfrom->PushGetBlocks(pindexBest, GetOrphanRoot(pblock2));
              // tkcoin: getblocks may not obtain the ancestor block rejected
              // earlier by duplicate-stake check so we ask for it again directly
              if (!IsInitialBlockDownload())
                  pfrom->AskFor(CInv(MSG_BLOCK, WantedByOrphan(pblock2)));
          }
          return true;
      }
  
      // Store to disk
      if (!pblock->AcceptBlock(state, dbp))
          return error("ProcessBlock() : AcceptBlock FAILED");
  
      // Recursively process any orphan blocks that depended on this one
      vector<uint256> vWorkQueue;
      vWorkQueue.push_back(hash);
      for (unsigned int i = 0; i < vWorkQueue.size(); i++)
      {
          uint256 hashPrev = vWorkQueue[i];
          for (multimap<uint256, CBlock*>::iterator mi = mapOrphanBlocksByPrev.lower_bound(hashPrev);
               mi != mapOrphanBlocksByPrev.upper_bound(hashPrev);
               ++mi)
          {
              CBlock* pblockOrphan = (*mi).second;
              // Use a dummy CValidationState so someone can't setup nodes to counter-DoS based on orphan resolution (that is, feeding people an invalid block based on LegitBlockX in order to get anyone relaying LegitBlockX banned)
              CValidationState stateDummy;
              if (pblockOrphan->AcceptBlock(stateDummy))
                  vWorkQueue.push_back(pblockOrphan->GetHash());
              mapOrphanBlocks.erase(pblockOrphan->GetHash());
              setStakeSeenOrphan.erase(pblockOrphan->GetProofOfStake());
              delete pblockOrphan;
          }
          mapOrphanBlocksByPrev.erase(hashPrev);
      }
  
      printf("ProcessBlock: ACCEPTED\n");
  
      // tkcoin: if responsible for sync-checkpoint send it
      if (pfrom && !CSyncCheckpoint::strMasterPrivKey.empty() &&
          (int)GetArg("-checkpointdepth", -1) >= 0)
          SendSyncCheckpoint(AutoSelectSyncCheckpoint());
  
      return true;
  }
  
  // tkcoin: sign block
  bool CBlock::SignBlock(const CKeyStore& keystore)
  {
      vector<valtype> vSolutions;
      txnouttype whichType;
      const CTxOut& txout = IsProofOfStake()? vtx[1].vout[1] : vtx[0].vout[0];
  
      if (!Solver(txout.scriptPubKey, whichType, vSolutions))
          return false;
      if (whichType == TX_PUBKEY)
      {
          // Sign
          const valtype& vchPubKey = vSolutions[0];
          CKey key;
          if (!keystore.GetKey(Hash160(vchPubKey), key))
              return false;
          if (key.GetPubKey() != vchPubKey)
              return false;
          return key.Sign(GetHash(), vchBlockSig);
      }
      return false;
  }
  
  // tkcoin: check block signature
  bool CBlock::CheckBlockSignature() const
  {
      if (GetHash() == hashGenesisBlock)
          return vchBlockSig.empty();
  
      vector<valtype> vSolutions;
      txnouttype whichType;
      const CTxOut& txout = IsProofOfStake()? vtx[1].vout[1] : vtx[0].vout[0];
  
      if (!Solver(txout.scriptPubKey, whichType, vSolutions))
          return false;
      if (whichType == TX_PUBKEY)
      {
          const valtype& vchPubKey = vSolutions[0];
          CKey key;
          if (!key.SetPubKey(vchPubKey))
              return false;
          if (vchBlockSig.empty())
              return false;
          return key.Verify(GetHash(), vchBlockSig);
      }
      return false;
  }
  
  // tkcoin: entropy bit for stake modifier if chosen by modifier
  unsigned int CBlock::GetStakeEntropyBit() const
  {
      unsigned int nEntropyBit = 0;
      if (IsProtocolV04(nTime))
      {
          nEntropyBit = ((GetHash().Get64()) & 1llu);// last bit of block hash
          if (fDebug && GetBoolArg("-printstakemodifier"))
              printf("GetStakeEntropyBit(v0.4+): nTime=%u hashBlock=%s entropybit=%d\n", nTime, GetHash().ToString().c_str(), nEntropyBit);
      }
      else
      {
          // old protocol for entropy bit pre v0.4
          uint160 hashSig = Hash160(vchBlockSig);
          if (fDebug && GetBoolArg("-printstakemodifier"))
              printf("GetStakeEntropyBit(v0.3): nTime=%u hashSig=%s", nTime, hashSig.ToString().c_str());
          hashSig >>= 159; // take the first bit of the hash
          nEntropyBit = hashSig.Get64();
          if (fDebug && GetBoolArg("-printstakemodifier"))
              printf(" entropybit=%d\n", nEntropyBit);
      }
      return nEntropyBit;
  }
  
  
  
  
  
  CMerkleBlock::CMerkleBlock(const CBlock& block, CBloomFilter& filter)
  {
      header = block.GetBlockHeader();
  
      vector<bool> vMatch;
      vector<uint256> vHashes;
  
      vMatch.reserve(block.vtx.size());
      vHashes.reserve(block.vtx.size());
  
      for (unsigned int i = 0; i < block.vtx.size(); i++)
      {
          uint256 hash = block.vtx[i].GetHash();
          if (filter.IsRelevantAndUpdate(block.vtx[i], hash))
          {
              vMatch.push_back(true);
              vMatchedTxn.push_back(make_pair(i, hash));
          }
          else
              vMatch.push_back(false);
          vHashes.push_back(hash);
      }
  
      txn = CPartialMerkleTree(vHashes, vMatch);
  }
  
  
  
  
  
  
  
  
  uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::vector<uint256> &vTxid) {
      if (height == 0) {
          // hash at height 0 is the txids themself
          return vTxid[pos];
      } else {
          // calculate left hash
          uint256 left = CalcHash(height-1, pos*2, vTxid), right;
          // calculate right hash if not beyong the end of the array - copy left hash otherwise1
          if (pos*2+1 < CalcTreeWidth(height-1))
              right = CalcHash(height-1, pos*2+1, vTxid);
          else
              right = left;
          // combine subhashes
          return Hash(BEGIN(left), END(left), BEGIN(right), END(right));
      }
  }
  
  void CPartialMerkleTree::TraverseAndBuild(int height, unsigned int pos, const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) {
      // determine whether this node is the parent of at least one matched txid
      bool fParentOfMatch = false;
      for (unsigned int p = pos << height; p < (pos+1) << height && p < nTransactions; p++)
          fParentOfMatch |= vMatch[p];
      // store as flag bit
      vBits.push_back(fParentOfMatch);
      if (height==0 || !fParentOfMatch) {
          // if at height 0, or nothing interesting below, store hash and stop
          vHash.push_back(CalcHash(height, pos, vTxid));
      } else {
          // otherwise, don't store any hash, but descend into the subtrees
          TraverseAndBuild(height-1, pos*2, vTxid, vMatch);
          if (pos*2+1 < CalcTreeWidth(height-1))
              TraverseAndBuild(height-1, pos*2+1, vTxid, vMatch);
      }
  }
  
  uint256 CPartialMerkleTree::TraverseAndExtract(int height, unsigned int pos, unsigned int &nBitsUsed, unsigned int &nHashUsed, std::vector<uint256> &vMatch) {
      if (nBitsUsed >= vBits.size()) {
          // overflowed the bits array - failure
          fBad = true;
          return 0;
      }
      bool fParentOfMatch = vBits[nBitsUsed++];
      if (height==0 || !fParentOfMatch) {
          // if at height 0, or nothing interesting below, use stored hash and do not descend
          if (nHashUsed >= vHash.size()) {
              // overflowed the hash array - failure
              fBad = true;
              return 0;
          }
          const uint256 &hash = vHash[nHashUsed++];
          if (height==0 && fParentOfMatch) // in case of height 0, we have a matched txid
              vMatch.push_back(hash);
          return hash;
      } else {
          // otherwise, descend into the subtrees to extract matched txids and hashes
          uint256 left = TraverseAndExtract(height-1, pos*2, nBitsUsed, nHashUsed, vMatch), right;
          if (pos*2+1 < CalcTreeWidth(height-1))
              right = TraverseAndExtract(height-1, pos*2+1, nBitsUsed, nHashUsed, vMatch);
          else
              right = left;
          // and combine them before returning
          return Hash(BEGIN(left), END(left), BEGIN(right), END(right));
      }
  }
  
  CPartialMerkleTree::CPartialMerkleTree(const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) : nTransactions(vTxid.size()), fBad(false) {
      // reset state
      vBits.clear();
      vHash.clear();
  
      // calculate height of tree
      int nHeight = 0;
      while (CalcTreeWidth(nHeight) > 1)
          nHeight++;
  
      // traverse the partial tree
      TraverseAndBuild(nHeight, 0, vTxid, vMatch);
  }
  
  CPartialMerkleTree::CPartialMerkleTree() : nTransactions(0), fBad(true) {}
  
  uint256 CPartialMerkleTree::ExtractMatches(std::vector<uint256> &vMatch) {
      vMatch.clear();
      // An empty set will not work
      if (nTransactions == 0)
          return 0;
      // check for excessively high numbers of transactions
      if (nTransactions > MAX_BLOCK_SIZE / 60) // 60 is the lower bound for the size of a serialized CTransaction
          return 0;
      // there can never be more hashes provided than one for every txid
      if (vHash.size() > nTransactions)
          return 0;
      // there must be at least one bit per node in the partial tree, and at least one node per hash
      if (vBits.size() < vHash.size())
          return 0;
      // calculate height of tree
      int nHeight = 0;
      while (CalcTreeWidth(nHeight) > 1)
          nHeight++;
      // traverse the partial tree
      unsigned int nBitsUsed = 0, nHashUsed = 0;
      uint256 hashMerkleRoot = TraverseAndExtract(nHeight, 0, nBitsUsed, nHashUsed, vMatch);
      // verify that no problems occured during the tree traversal
      if (fBad)
          return 0;
      // verify that all bits were consumed (except for the padding caused by serializing it as a byte sequence)
      if ((nBitsUsed+7)/8 != (vBits.size()+7)/8)
          return 0;
      // verify that all hashes were consumed
      if (nHashUsed != vHash.size())
          return 0;
      return hashMerkleRoot;
  }
  
  
  
  
  
  
  
  bool AbortNode(const std::string &strMessage) {
      strMiscWarning = strMessage;
      printf("*** %s\n", strMessage.c_str());
      uiInterface.ThreadSafeMessageBox(strMessage, "", CClientUIInterface::MSG_ERROR);
      StartShutdown();
      return false;
  }
  
  bool CheckDiskSpace(uint64 nAdditionalBytes)
  {
      uint64 nFreeBytesAvailable = filesystem::space(GetDataDir()).available;
  
      // Check for nMinDiskSpace bytes (currently 50MB)
      if (nFreeBytesAvailable < nMinDiskSpace + nAdditionalBytes)
          return AbortNode(_("Error: Disk space is low!"));
  
      return true;
  }
  
  CCriticalSection cs_LastBlockFile;
  CBlockFileInfo infoLastBlockFile;
  int nLastBlockFile = 0;
  
  FILE* OpenDiskFile(const CDiskBlockPos &pos, const char *prefix, bool fReadOnly)
  {
      if (pos.IsNull())
          return NULL;
      boost::filesystem::path path = GetDataDir() / "blocks" / strprintf("%s%05u.dat", prefix, pos.nFile);
      boost::filesystem::create_directories(path.parent_path());
      FILE* file = fopen(path.string().c_str(), "rb+");
      if (!file && !fReadOnly)
          file = fopen(path.string().c_str(), "wb+");
      if (!file) {
          printf("Unable to open file %s\n", path.string().c_str());
          return NULL;
      }
      if (pos.nPos) {
          if (fseek(file, pos.nPos, SEEK_SET)) {
              printf("Unable to seek to position %u of %s\n", pos.nPos, path.string().c_str());
              fclose(file);
              return NULL;
          }
      }
      return file;
  }
  
  FILE* OpenBlockFile(const CDiskBlockPos &pos, bool fReadOnly) {
      return OpenDiskFile(pos, "blk", fReadOnly);
  }
  
  FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly) {
      return OpenDiskFile(pos, "rev", fReadOnly);
  }
  
  CBlockIndex * InsertBlockIndex(uint256 hash)
  {
      if (hash == 0)
          return NULL;
  
      // Return existing
      map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
      if (mi != mapBlockIndex.end())
          return (*mi).second;
  
      // Create new
      CBlockIndex* pindexNew = new CBlockIndex();
      if (!pindexNew)
          throw runtime_error("LoadBlockIndex() : new CBlockIndex failed");
      mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
      pindexNew->phashBlock = &((*mi).first);
  
      return pindexNew;
  }
  
  bool static LoadBlockIndexDB()
  {
      if (!pblocktree->LoadBlockIndexGuts())
          return false;
  
      boost::this_thread::interruption_point();
  
      // Calculate nChainTrust
      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->nChainTrust = (pindex->pprev ? pindex->pprev->nChainTrust : 0) + pindex->GetBlockTrust().getuint256();
          // tkcoin: calculate stake modifier checksum
          pindex->nStakeModifierChecksum = GetStakeModifierChecksum(pindex);
          if (!CheckStakeModifierCheckpoints(pindex->nHeight, pindex->nStakeModifierChecksum))
              return error("LoadBlockIndexDB() : Failed stake modifier checkpoint height=%d, modifier=0x%016" PRI64x, pindex->nHeight, pindex->nStakeModifier);
  
          pindex->nChainTx = (pindex->pprev ? pindex->pprev->nChainTx : 0) + pindex->nTx;
          if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS && !(pindex->nStatus & BLOCK_FAILED_MASK))
              setBlockIndexValid.insert(pindex);
      }
  
      // Load block file info
      pblocktree->ReadLastBlockFile(nLastBlockFile);
      printf("LoadBlockIndexDB(): last block file = %i\n", nLastBlockFile);
      if (pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile))
          printf("LoadBlockIndexDB(): last block file info: %s\n", infoLastBlockFile.ToString().c_str());
  
      // tkcoin: load hashSyncCheckpoint
      if (!pblocktree->ReadSyncCheckpoint(hashSyncCheckpoint))
      {
          printf("LoadBlockIndexDB(): synchronized checkpoint not read\n");
          hashSyncCheckpoint = hashGenesisBlock;
      }
      printf("LoadBlockIndexDB(): synchronized checkpoint %s\n", hashSyncCheckpoint.ToString().c_str());
  
      // Load nBestInvalidTrust, OK if it doesn't exist
      CBigNum bnBestInvalidTrust;
      pblocktree->ReadBestInvalidTrust(bnBestInvalidTrust);
      nBestInvalidTrust = bnBestInvalidTrust.getuint256();
  
      // Check whether we need to continue reindexing
      bool fReindexing = false;
      pblocktree->ReadReindexing(fReindexing);
      fReindex |= fReindexing;
  
      // Check whether we have a transaction index
      pblocktree->ReadFlag("txindex", fTxIndex);
      printf("LoadBlockIndexDB(): transaction index %s\n", fTxIndex ? "enabled" : "disabled");
  
      // Load hashBestChain pointer to end of best chain
      pindexBest = pcoinsTip->GetBestBlock();
      if (pindexBest == NULL)
          return true;
      hashBestChain = pindexBest->GetBlockHash();
      nBestHeight = pindexBest->nHeight;
      nBestChainTrust = pindexBest->nChainTrust;
  
      // set 'next' pointers in best chain
      CBlockIndex *pindex = pindexBest;
      while(pindex != NULL && pindex->pprev != NULL) {
           CBlockIndex *pindexPrev = pindex->pprev;
           pindexPrev->pnext = pindex;
           pindex = pindexPrev;
      }
      printf("LoadBlockIndexDB(): hashBestChain=%s  height=%d date=%s\n",
          hashBestChain.ToString().c_str(), nBestHeight,
          DateTimeStrFormat("%Y-%m-%d %H:%M:%S", pindexBest->GetBlockTime()).c_str());
  
      return true;
  }
  
  bool VerifyDB() {
      if (pindexBest == NULL || pindexBest->pprev == NULL)
          return true;
  
      // Verify blocks in the best chain
      int nCheckLevel = GetArg("-checklevel", 3);
      int nCheckDepth = GetArg( "-checkblocks", 288);
      if (nCheckDepth == 0)
          nCheckDepth = 1000000000; // suffices until the year 19000
      if (nCheckDepth > nBestHeight)
          nCheckDepth = nBestHeight;
      nCheckLevel = std::max(0, std::min(4, nCheckLevel));
      printf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
      CCoinsViewCache coins(*pcoinsTip, true);
      CBlockIndex* pindexState = pindexBest;
      CBlockIndex* pindexFailure = NULL;
      int nGoodTransactions = 0;
      CValidationState state;
      for (CBlockIndex* pindex = pindexBest; pindex && pindex->pprev; pindex = pindex->pprev)
      {
          boost::this_thread::interruption_point();
          if (pindex->nHeight < nBestHeight-nCheckDepth)
              break;
          CBlock block;
          // check level 0: read from disk
          if (!block.ReadFromDisk(pindex))
              return error("VerifyDB() : *** block.ReadFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
          // check level 1: verify block validity
          if (nCheckLevel >= 1 && !block.CheckBlock(state))
              return error("VerifyDB() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
          // check level 2: verify undo validity
          if (nCheckLevel >= 2 && pindex) {
              CBlockUndo undo;
              CDiskBlockPos pos = pindex->GetUndoPos();
              if (!pos.IsNull()) {
                  if (!undo.ReadFromDisk(pos, pindex->pprev->GetBlockHash()))
                      return error("VerifyDB() : *** found bad undo data at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
              }
          }
          // check level 3: check for inconsistencies during memory-only disconnect of tip blocks
          if (nCheckLevel >= 3 && pindex == pindexState && (coins.GetCacheSize() + pcoinsTip->GetCacheSize()) <= 2*nCoinCacheSize + 32000) {
              bool fClean = true;
              if (!block.DisconnectBlock(state, pindex, coins, &fClean))
                  return error("VerifyDB() : *** irrecoverable inconsistency in block data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
              pindexState = pindex->pprev;
              if (!fClean) {
                  nGoodTransactions = 0;
                  pindexFailure = pindex;
              } else
                  nGoodTransactions += block.vtx.size();
          }
      }
      if (pindexFailure)
          return error("VerifyDB() : *** coin database inconsistencies found (last %i blocks, %i good transactions before that)\n", pindexBest->nHeight - pindexFailure->nHeight + 1, nGoodTransactions);
  
      // check level 4: try reconnecting blocks
      if (nCheckLevel >= 4) {
          CBlockIndex *pindex = pindexState;
          while (pindex != pindexBest) {
              boost::this_thread::interruption_point();
              pindex = pindex->pnext;
              CBlock block;
              if (!block.ReadFromDisk(pindex))
                  return error("VerifyDB() : *** block.ReadFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
              if (!block.ConnectBlock(state, pindex, coins))
                  return error("VerifyDB() : *** found unconnectable block at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
          }
      }
  
      printf("No coin database inconsistencies in last %i blocks (%i transactions)\n", pindexBest->nHeight - pindexState->nHeight, nGoodTransactions);
  
      return true;
  }
  
  void UnloadBlockIndex()
  {
      mapBlockIndex.clear();
      setBlockIndexValid.clear();
      pindexGenesisBlock = NULL;
      nBestHeight = 0;
      nBestChainTrust = 0;
      nBestInvalidTrust = 0;
      hashBestChain = 0;
      pindexBest = NULL;
  }
  
  bool LoadBlockIndex()
  {
      GetMessageStart(pchMessageStart);
  
      if (fTestNet)
      {
  #ifdef TESTING
          hashGenesisBlock = uint256("00008d0d88095d31f6dbdbcf80f6e51f71adf2be15740301f5e05cc0f3b2d2c0");
          bnProofOfWorkLimit = CBigNum(~uint256(0) >> 15);
          nStakeMinAge = 60 * 60 * 24; // test net min age is 1 day
          nCoinbaseMaturity = 60;
          bnInitialHashTarget = CBigNum(~uint256(0) >> 15);
          nModifierInterval = 60 * 20; // test net modifier interval is 20 minutes
  #else
          hashGenesisBlock = hashGenesisBlockTestNet;
          bnProofOfWorkLimit = CBigNum(~uint256(0) >> 28);
          nStakeMinAge = 60 * 60 * 24; // test net min age is 1 day
          nCoinbaseMaturity = 60;
          bnInitialHashTarget = CBigNum(~uint256(0) >> 29);
          nModifierInterval = 60 * 20; // test net modifier interval is 20 minutes
  #endif
      }
  
      printf("%s Network: genesis=0x%s nBitsLimit=0x%08x nBitsInitial=0x%08x nStakeMinAge=%d nCoinbaseMaturity=%d nModifierInterval=%d\n",
             fTestNet? "Test" : "coinking", hashGenesisBlock.ToString().substr(0, 20).c_str(), bnProofOfWorkLimit.GetCompact(), bnInitialHashTarget.GetCompact(), nStakeMinAge, nCoinbaseMaturity, nModifierInterval);
  
      //
      // Load block index from databases
      //
      if (!fReindex && !LoadBlockIndexDB())
          return false;
  
      return true;
  }
  
  
  bool InitBlockIndex() {
      // Check whether we're already initialized
      if (pindexGenesisBlock != NULL)
          return true;
  
      // Use the provided setting for -txindex in the new database
      fTxIndex = true; // tkcoin: txindex is always enabled
      pblocktree->WriteFlag("txindex", fTxIndex);
      printf("Initializing databases...\n");
  
      // Only add the genesis block if not reindexing (in which case we reuse the one already on disk)
      if (!fReindex) {
          // Genesis Block:
          // CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
          //   CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
          //     CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
          //     CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
          //   vMerkleTree: 4a5e1e
  
          // Genesis block
          const char* pszTimestamp = "16 jan 2018";
          CTransaction txNew;
          txNew.nTime = 1515175990;
          txNew.vin.resize(1);
          txNew.vout.resize(1);
          txNew.vin[0].scriptSig = CScript() << 486604799 << CBigNum(9999) << vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
          txNew.vout[0].SetEmpty();
          CBlock block;
          block.vtx.push_back(txNew);
          block.hashPrevBlock = 0;
          block.hashMerkleRoot = block.BuildMerkleTree();
          block.nVersion = 1;
          block.nTime    = 1515177990;
          block.nBits    = bnProofOfWorkLimit.GetCompact();
          block.nNonce   = 684121426;
  
          if (fTestNet)
          {
              block.nTime    = 1515177979;
              block.nNonce   = 122894938;
          }
  
  #ifdef TESTING
          CBigNum bnTarget;
          bnTarget.SetCompact(block.nBits);
          while (block.GetHash() > bnTarget.getuint256())
          {
              if (block.nNonce % 1048576 == 0)
                  printf("n=%dM hash=%s\n", block.nNonce / 1048576,
                         block.GetHash().ToString().c_str());
              block.nNonce++;
          }
          printf("n=%dM hash=%s\n", block.nNonce, block.GetHash().ToString().c_str());
  #endif
  
          //// debug print
          uint256 hash = block.GetHash();
          printf("%s\n", hash.ToString().c_str());
          printf("%s\n", hashGenesisBlock.ToString().c_str());
          printf("%s\n", block.hashMerkleRoot.ToString().c_str());
          assert(block.hashMerkleRoot == uint256("0x185eb24d298b140c0441dbfd8abf3a715ceafabd70cad1d50822d42d995700bf"));
          block.print();
          assert(hash == hashGenesisBlock);
          // tkcoin: check genesis block
          {
              CValidationState state;
              assert(block.CheckBlock(state));
          }
  
          // Start new block file
          try {
              unsigned int nBlockSize = ::GetSerializeSize(block, SER_DISK, CLIENT_VERSION);
              CDiskBlockPos blockPos;
              CValidationState state;
              if (!FindBlockPos(state, blockPos, nBlockSize+8, 0, block.nTime))
                  return error("LoadBlockIndex() : FindBlockPos failed");
              if (!block.WriteToDisk(blockPos))
                  return error("LoadBlockIndex() : writing genesis block to disk failed");
              if (!block.AddToBlockIndex(state, blockPos))
                  return error("LoadBlockIndex() : genesis block not accepted");
          } catch(std::runtime_error &e) {
              return error("LoadBlockIndex() : failed to initialize block database: %s", e.what());
          }
  
          // tkcoin: initialize synchronized checkpoint
          if (!WriteSyncCheckpoint(hashGenesisBlock))
              return error("LoadBlockIndex() : failed to init sync checkpoint");
      }
  
      // tkcoin: if checkpoint master key changed must reset sync-checkpoint
      if (!CheckCheckpointPubKey())
          return error("LoadBlockIndex() : failed to reset checkpoint master pubkey");
  
      return true;
  }
  
  
  
  void PrintBlockTree()
  {
      // pre-compute tree structure
      map<CBlockIndex*, vector<CBlockIndex*> > mapNext;
      for (map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.begin(); mi != mapBlockIndex.end(); ++mi)
      {
          CBlockIndex* pindex = (*mi).second;
          mapNext[pindex->pprev].push_back(pindex);
          // test
          //while (rand() % 3 == 0)
          //    mapNext[pindex->pprev].push_back(pindex);
      }
  
      vector<pair<int, CBlockIndex*> > vStack;
      vStack.push_back(make_pair(0, pindexGenesisBlock));
  
      int nPrevCol = 0;
      while (!vStack.empty())
      {
          int nCol = vStack.back().first;
          CBlockIndex* pindex = vStack.back().second;
          vStack.pop_back();
  
          // print split or gap
          if (nCol > nPrevCol)
          {
              for (int i = 0; i < nCol-1; i++)
                  printf("| ");
              printf("|\\\n");
          }
          else if (nCol < nPrevCol)
          {
              for (int i = 0; i < nCol; i++)
                  printf("| ");
              printf("|\n");
         }
          nPrevCol = nCol;
  
          // print columns
          for (int i = 0; i < nCol; i++)
              printf("| ");
  
          // print item
          CBlock block;
          block.ReadFromDisk(pindex);
          printf("%d (blk%05u.dat:0x%x)  %s  %08x  %s  mint %7s  tx %" PRIszu"",
              pindex->nHeight,
              pindex->GetBlockPos().nFile, pindex->GetBlockPos().nPos,
              block.GetHash().ToString().c_str(),
              block.nBits,
              DateTimeStrFormat("%Y-%m-%d %H:%M:%S", block.GetBlockTime()).c_str(),
              FormatMoney(pindex->nMint).c_str(),
              block.vtx.size());
  
          PrintWallets(block);
  
          // put the main time-chain first
          vector<CBlockIndex*>& vNext = mapNext[pindex];
          for (unsigned int i = 0; i < vNext.size(); i++)
          {
              if (vNext[i]->pnext)
              {
                  swap(vNext[0], vNext[i]);
                  break;
              }
          }
  
          // iterate children
          for (unsigned int i = 0; i < vNext.size(); i++)
              vStack.push_back(make_pair(nCol+i, vNext[i]));
      }
  }
  
  bool LoadExternalBlockFile(FILE* fileIn, CDiskBlockPos *dbp)
  {
      int64 nStart = GetTimeMillis();
  
      int nLoaded = 0;
      try {
          CBufferedFile blkdat(fileIn, 2*MAX_BLOCK_SIZE, MAX_BLOCK_SIZE+8, SER_DISK, CLIENT_VERSION);
          uint64 nStartByte = 0;
          if (dbp) {
              // (try to) skip already indexed part
              CBlockFileInfo info;
              if (pblocktree->ReadBlockFileInfo(dbp->nFile, info)) {
                  nStartByte = info.nSize;
                  blkdat.Seek(info.nSize);
              }
          }
          uint64 nRewind = blkdat.GetPos();
          while (blkdat.good() && !blkdat.eof()) {
              boost::this_thread::interruption_point();
  
              blkdat.SetPos(nRewind);
              nRewind++; // start one byte further next time, in case of failure
              blkdat.SetLimit(); // remove former limit
              unsigned int nSize = 0;
              try {
                  // locate a header
                  unsigned char buf[4];
                  blkdat.FindByte(pchMessageStart[0]);
                  nRewind = blkdat.GetPos()+1;
                  blkdat >> FLATDATA(buf);
                  if (memcmp(buf, pchMessageStart, 4))
                      continue;
                  // read size
                  blkdat >> nSize;
                  if (nSize < 80 || nSize > MAX_BLOCK_SIZE)
                      continue;
              } catch (std::exception &e) {
                  // no valid block header found; don't complain
                  break;
              }
              try {
                  // read block
                  uint64 nBlockPos = blkdat.GetPos();
                  blkdat.SetLimit(nBlockPos + nSize);
                  CBlock block;
                  blkdat >> block;
                  nRewind = blkdat.GetPos();
  
                  // process block
                  if (nBlockPos >= nStartByte) {
                      LOCK(cs_main);
                      if (dbp)
                          dbp->nPos = nBlockPos;
                      CValidationState state;
                      if (ProcessBlock(state, NULL, &block, dbp))
                          nLoaded++;
                      if (state.IsError())
                          break;
                  }
              } catch (std::exception &e) {
                  printf("%s() : Deserialize or I/O error caught during load\n", __PRETTY_FUNCTION__);
              }
          }
          fclose(fileIn);
      } catch(std::runtime_error &e) {
          AbortNode(_("Error: system error: ") + e.what());
      }
      if (nLoaded > 0)
          printf("Loaded %i blocks from external file in %" PRI64d"ms\n", nLoaded, GetTimeMillis() - nStart);
      return nLoaded > 0;
  }
  
  
  
  
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CAlert
  //
  
  extern map<uint256, CAlert> mapAlerts;
  extern CCriticalSection cs_mapAlerts;
  
  static string strMintWarning;
  
  string GetWarnings(string strFor)
  {
      int nPriority = 0;
      string strStatusBar;
      string strRPC;
  
      if (GetBoolArg("-testsafemode"))
          strRPC = "test";
  
      if (!CLIENT_VERSION_IS_RELEASE)
          strStatusBar = _("This is a pre-release test build - use at your own risk - do not use for mining or merchant applications");
  
      // tkcoin: wallet lock warning for minting
      if (strMintWarning != "")
      {
          nPriority = 0;
          strStatusBar = strMintWarning;
      }
  
      // tkcoin: checkpoint warning
      // should not enter safe mode for longer invalid chain
      if (strCheckpointWarning != "")
      {
          nPriority = 900;
          strStatusBar = strCheckpointWarning;
      }
  
      // Misc warnings like out of disk space and clock is wrong
      if (strMiscWarning != "")
      {
          nPriority = 1000;
          strStatusBar = strMiscWarning;
      }
  
      // tkcoin: if detected invalid checkpoint enter safe mode
      if (hashInvalidCheckpoint != 0)
      {
          nPriority = 3000;
          strStatusBar = strRPC = "WARNING: Inconsistent checkpoint found! Stop enforcing checkpoints and notify developers to resolve the issue.";
      }
  
      // Alerts
      {
          LOCK(cs_mapAlerts);
          BOOST_FOREACH(PAIRTYPE(const uint256, CAlert)& item, mapAlerts)
          {
              const CAlert& alert = item.second;
              if (alert.AppliesToMe() && alert.nPriority > nPriority)
              {
                  nPriority = alert.nPriority;
                  strStatusBar = alert.strStatusBar;
                  if (nPriority > 1000)
                      strRPC = strStatusBar;  // tkcoin: safe mode for high alert
              }
          }
      }
  
      if (strFor == "statusbar")
          return strStatusBar;
      else if (strFor == "rpc")
          return strRPC;
      assert(!"GetWarnings() : invalid parameter");
      return "error";
  }
  
  
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // Messages
  //
  
  
  bool static AlreadyHave(const CInv& inv)
  {
      switch (inv.type)
      {
      case MSG_TX:
          {
              bool txInMap = false;
              {
                  LOCK(mempool.cs);
                  txInMap = mempool.exists(inv.hash);
              }
              return txInMap || mapOrphanTransactions.count(inv.hash) ||
                  pcoinsTip->HaveCoins(inv.hash);
          }
      case MSG_BLOCK:
          return mapBlockIndex.count(inv.hash) ||
                 mapOrphanBlocks.count(inv.hash);
      }
      // Don't know what it is, just say we already got one
      return true;
  }
  
  
  
  
  void static ProcessGetData(CNode* pfrom)
  {
      std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
  
      vector<CInv> vNotFound;
  
      while (it != pfrom->vRecvGetData.end()) {
          // Don't bother if send buffer is too full to respond anyway
          if (pfrom->nSendSize >= SendBufferSize())
              break;
  
          const CInv &inv = *it;
          {
              boost::this_thread::interruption_point();
              it++;
  
              // tkcoin: relay memory may contain blocks too
              bool found = false;
  
              if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK)
              {
                  // Send block from disk
                  map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(inv.hash);
                  if (mi != mapBlockIndex.end())
                  {
                      found = true;
                      CBlock block;
                      block.ReadFromDisk((*mi).second);
                      if (inv.type == MSG_BLOCK)
                          pfrom->PushMessage("block", block);
                      else // MSG_FILTERED_BLOCK)
                      {
                          LOCK(pfrom->cs_filter);
                          if (pfrom->pfilter)
                          {
                              CMerkleBlock merkleBlock(block, *pfrom->pfilter);
                              pfrom->PushMessage("merkleblock", merkleBlock);
                              // CMerkleBlock just contains hashes, so also push any transactions in the block the client did not see
                              // This avoids hurting performance by pointlessly requiring a round-trip
                              // Note that there is currently no way for a node to request any single transactions we didnt send here -
                              // they must either disconnect and retry or request the full block.
                              // Thus, the protocol spec specified allows for us to provide duplicate txn here,
                              // however we MUST always provide at least what the remote peer needs
                              typedef std::pair<unsigned int, uint256> PairType;
                              BOOST_FOREACH(PairType& pair, merkleBlock.vMatchedTxn)
                                  if (!pfrom->setInventoryKnown.count(CInv(MSG_TX, pair.second)))
                                      pfrom->PushMessage("tx", block.vtx[pair.first]);
                          }
                          // else
                              // no response
                      }
  
                      // Trigger them to send a getblocks request for the next batch of inventory
                      if (inv.hash == pfrom->hashContinue)
                      {
                          // Bypass PushInventory, this must send even if redundant,
                          // and we want it right after the last block so they don't
                          // wait for other stuff first.
                          // tkcoin: send latest proof-of-work block to allow the
                          // download node to accept as orphan (proof-of-stake 
                          // block might be rejected by stake connection check)
                          vector<CInv> vInv;
                          vInv.push_back(CInv(MSG_BLOCK, GetLastBlockIndex(pindexBest, false)->GetBlockHash()));
                          pfrom->PushMessage("inv", vInv);
                          pfrom->hashContinue = 0;
                      }
                  }
              }
  
              if (!found && inv.IsKnownType())
              {
                  // Send stream from relay memory
                  bool pushed = false;
                  {
                      LOCK(cs_mapRelay);
                      map<CInv, CDataStream>::iterator mi = mapRelay.find(inv);
                      if (mi != mapRelay.end()) {
                          pfrom->PushMessage(inv.GetCommand(), (*mi).second);
                          pushed = true;
                      }
                  }
                  if (!pushed && inv.type == MSG_TX) {
                      LOCK(mempool.cs);
                      if (mempool.exists(inv.hash)) {
                          CTransaction tx = mempool.lookup(inv.hash);
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss << tx;
                          pfrom->PushMessage("tx", ss);
                          pushed = true;
                      }
                  }
                  if (!pushed) {
                      vNotFound.push_back(inv);
                  }
              }
  
              // Track requests for our stuff.
              Inventory(inv.hash);
  
              if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK)
                  break;
          }
      }
  
      pfrom->vRecvGetData.erase(pfrom->vRecvGetData.begin(), it);
  
      if (!vNotFound.empty()) {
          // Let the peer know that we didn't find what it asked for, so it doesn't
          // have to wait around forever. Currently only SPV clients actually care
          // about this message: it's needed when they are recursively walking the
          // dependencies of relevant unconfirmed transactions. SPV clients want to
          // do that because they want to know about (and store and rebroadcast and
          // risk analyze) the dependencies of transactions relevant to them, without
          // having to download the entire memory pool.
          pfrom->PushMessage("notfound", vNotFound);
      }
  }
  
  bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
  {
      RandAddSeedPerfmon();
      if (fDebug) {
          printf("%s ", DateTimeStrFormat(GetTime()).c_str());
          printf("received: %s (%" PRIszu" bytes)\n", strCommand.c_str(), vRecv.size());
      }
      if (mapArgs.count("-dropmessagestest") && GetRand(atoi(mapArgs["-dropmessagestest"])) == 0)
      {
          printf("dropmessagestest DROPPING RECV MESSAGE\n");
          return true;
      }
  
  
  
  
  
      if (strCommand == "version")
      {
          // Each connection can only send one version message
          if (pfrom->nVersion != 0)
          {
              pfrom->Misbehaving(1);
              return false;
          }
  
          int64 nTime;
          CAddress addrMe;
          CAddress addrFrom;
          uint64 nNonce = 1;
          vRecv >> pfrom->nVersion >> pfrom->nServices >> nTime >> addrMe;
          if (pfrom->nVersion < MIN_PROTO_VERSION)
          {
              // Since February 20, 2012, the protocol is initiated at version 209,
              // and earlier versions are no longer supported
              printf("partner %s using obsolete version %i; disconnecting\n", pfrom->addr.ToString().c_str(), pfrom->nVersion);
              pfrom->fDisconnect = true;
              return false;
          }
  
          if (pfrom->nVersion == 10300)
              pfrom->nVersion = 300;
          if (!vRecv.empty())
              vRecv >> addrFrom >> nNonce;
          if (!vRecv.empty()) {
              vRecv >> pfrom->strSubVer;
              pfrom->cleanSubVer = SanitizeString(pfrom->strSubVer);
          }
          if (!vRecv.empty())
              vRecv >> pfrom->nStartingHeight;
          if (!vRecv.empty())
              vRecv >> pfrom->fRelayTxes; // set to true after we get the first filter* message
          else
              pfrom->fRelayTxes = true;
  
          if (pfrom->fInbound && addrMe.IsRoutable())
          {
              pfrom->addrLocal = addrMe;
              SeenLocal(addrMe);
          }
  
          // Disconnect if we connected to ourself
          if (nNonce == nLocalHostNonce && nNonce > 1)
          {
              printf("connected to self at %s, disconnecting\n", pfrom->addr.ToString().c_str());
              pfrom->fDisconnect = true;
              return true;
          }
  
          // tkcoin: record my external IP reported by peer
          if (addrFrom.IsRoutable() && addrMe.IsRoutable())
              addrSeenByPeer = addrMe;
  
          // Be shy and don't send version until we hear
          if (pfrom->fInbound)
              pfrom->PushVersion();
  
          pfrom->fClient = !(pfrom->nServices & NODE_NETWORK);
  
          AddTimeData(pfrom->addr, nTime);
  
          // Change version
          pfrom->PushMessage("verack");
          pfrom->ssSend.SetVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
  
          if (!pfrom->fInbound)
          {
              // Advertise our address
              if (!fNoListen && !IsInitialBlockDownload())
              {
                  CAddress addr = GetLocalAddress(&pfrom->addr);
                  if (addr.IsRoutable())
                      pfrom->PushAddress(addr);
              }
  
              // Get recent addresses
              if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION || addrman.size() < 1000)
              {
                  pfrom->PushMessage("getaddr");
                  pfrom->fGetAddr = true;
              }
              addrman.Good(pfrom->addr);
          } else {
              if (((CNetAddr)pfrom->addr) == (CNetAddr)addrFrom)
              {
                  addrman.Add(addrFrom, addrFrom);
                  addrman.Good(addrFrom);
              }
          }
  
          // Relay alerts
          {
              LOCK(cs_mapAlerts);
              BOOST_FOREACH(PAIRTYPE(const uint256, CAlert)& item, mapAlerts)
                  item.second.RelayTo(pfrom);
          }
  
          // tkcoin: relay sync-checkpoint
          {
              LOCK(cs_hashSyncCheckpoint);
              if (!checkpointMessage.IsNull())
                  checkpointMessage.RelayTo(pfrom);
          }
  
          pfrom->fSuccessfullyConnected = true;
  
          printf("receive version message: %s: version %d, blocks=%d, us=%s, them=%s, peer=%s\n", pfrom->cleanSubVer.c_str(), pfrom->nVersion, pfrom->nStartingHeight, addrMe.ToString().c_str(), addrFrom.ToString().c_str(), pfrom->addr.ToString().c_str());
  
          cPeerBlockCounts.input(pfrom->nStartingHeight);
  
          // tkcoin: ask for pending sync-checkpoint if any
          if (!IsInitialBlockDownload())
              AskForPendingSyncCheckpoint(pfrom);
      }
  
  
      else if (pfrom->nVersion == 0)
      {
          // Must have a version message before anything else
          pfrom->Misbehaving(1);
          return false;
      }
  
  
      else if (strCommand == "verack")
      {
          pfrom->SetRecvVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
      }
  
  
      else if (strCommand == "addr")
      {
          vector<CAddress> vAddr;
          vRecv >> vAddr;
  
          // Don't want addr from older versions unless seeding
          if (pfrom->nVersion < CADDR_TIME_VERSION && addrman.size() > 1000)
              return true;
          if (vAddr.size() > 1000)
          {
              pfrom->Misbehaving(20);
              return error("message addr size() = %" PRIszu"", vAddr.size());
          }
  
          // Store the new addresses
          vector<CAddress> vAddrOk;
          int64 nNow = GetAdjustedTime();
          int64 nSince = nNow - 10 * 60;
          BOOST_FOREACH(CAddress& addr, vAddr)
          {
              boost::this_thread::interruption_point();
  
              if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60)
                  addr.nTime = nNow - 5 * 24 * 60 * 60;
              pfrom->AddAddressKnown(addr);
              bool fReachable = IsReachable(addr);
              if (addr.nTime > nSince && !pfrom->fGetAddr && vAddr.size() <= 10 && addr.IsRoutable())
              {
                  // Relay to a limited number of other nodes
                  {
                      LOCK(cs_vNodes);
                      // Use deterministic randomness to send to the same nodes for 24 hours
                      // at a time so the setAddrKnowns of the chosen nodes prevent repeats
                      static uint256 hashSalt;
                      if (hashSalt == 0)
                          hashSalt = GetRandHash();
                      uint64 hashAddr = addr.GetHash();
                      uint256 hashRand = hashSalt ^ (hashAddr<<32) ^ ((GetTime()+hashAddr)/(24*60*60));
                      hashRand = Hash(BEGIN(hashRand), END(hashRand));
                      multimap<uint256, CNode*> mapMix;
                      BOOST_FOREACH(CNode* pnode, vNodes)
                      {
                          if (pnode->nVersion < CADDR_TIME_VERSION)
                              continue;
                          unsigned int nPointer;
                          memcpy(&nPointer, &pnode, sizeof(nPointer));
                          uint256 hashKey = hashRand ^ nPointer;
                          hashKey = Hash(BEGIN(hashKey), END(hashKey));
                          mapMix.insert(make_pair(hashKey, pnode));
                      }
                      int nRelayNodes = fReachable ? 2 : 1; // limited relaying of addresses outside our network(s)
                      for (multimap<uint256, CNode*>::iterator mi = mapMix.begin(); mi != mapMix.end() && nRelayNodes-- > 0; ++mi)
                          ((*mi).second)->PushAddress(addr);
                  }
              }
              // Do not store addresses outside our network
              if (fReachable)
                  vAddrOk.push_back(addr);
          }
          addrman.Add(vAddrOk, pfrom->addr, 2 * 60 * 60);
          if (vAddr.size() < 1000)
              pfrom->fGetAddr = false;
          if (pfrom->fOneShot)
              pfrom->fDisconnect = true;
      }
  
  
      else if (strCommand == "inv")
      {
          vector<CInv> vInv;
          vRecv >> vInv;
          if (vInv.size() > MAX_INV_SZ)
          {
              pfrom->Misbehaving(20);
              return error("message inv size() = %" PRIszu"", vInv.size());
          }
  
          // find last block in inv vector
          unsigned int nLastBlock = (unsigned int)(-1);
          for (unsigned int nInv = 0; nInv < vInv.size(); nInv++) {
              if (vInv[vInv.size() - 1 - nInv].type == MSG_BLOCK) {
                  nLastBlock = vInv.size() - 1 - nInv;
                  break;
              }
          }
          for (unsigned int nInv = 0; nInv < vInv.size(); nInv++)
          {
              const CInv &inv = vInv[nInv];
  
              boost::this_thread::interruption_point();
              pfrom->AddInventoryKnown(inv);
  
              bool fAlreadyHave = AlreadyHave(inv);
              if (fDebug)
                  printf("  got inventory: %s  %s\n", inv.ToString().c_str(), fAlreadyHave ? "have" : "new");
  
              if (!fAlreadyHave) {
                  if (!fImporting && !fReindex)
                      pfrom->AskFor(inv);
              } else if (inv.type == MSG_BLOCK && mapOrphanBlocks.count(inv.hash)) {
                  pfrom->PushGetBlocks(pindexBest, GetOrphanRoot(mapOrphanBlocks[inv.hash]));
              } else if (nInv == nLastBlock) {
                  // In case we are on a very long side-chain, it is possible that we already have
                  // the last block in an inv bundle sent in response to getblocks. Try to detect
                  // this situation and push another getblocks to continue.
                  pfrom->PushGetBlocks(mapBlockIndex[inv.hash], uint256(0));
                  if (fDebug)
                      printf("force request: %s\n", inv.ToString().c_str());
              }
  
              // Track requests for our stuff
              Inventory(inv.hash);
          }
      }
  
  
      else if (strCommand == "getdata")
      {
          vector<CInv> vInv;
          vRecv >> vInv;
          if (vInv.size() > MAX_INV_SZ)
          {
              pfrom->Misbehaving(20);
              return error("message getdata size() = %" PRIszu"", vInv.size());
          }
  
          if (fDebugNet || (vInv.size() != 1))
              printf("received getdata (%" PRIszu" invsz)\n", vInv.size());
  
          if ((fDebugNet && vInv.size() > 0) || (vInv.size() == 1))
              printf("received getdata for: %s\n", vInv[0].ToString().c_str());
  
          pfrom->vRecvGetData.insert(pfrom->vRecvGetData.end(), vInv.begin(), vInv.end());
          ProcessGetData(pfrom);
      }
  
  
      else if (strCommand == "getblocks")
      {
          CBlockLocator locator;
          uint256 hashStop;
          vRecv >> locator >> hashStop;
  
          // Find the last block the caller has in the main chain
          CBlockIndex* pindex = locator.GetBlockIndex();
  
          // Send the rest of the chain
          if (pindex)
              pindex = pindex->pnext;
          int nLimit = 500;
          printf("getblocks %d to %s limit %d\n", (pindex ? pindex->nHeight : -1), hashStop.ToString().c_str(), nLimit);
          for (; pindex; pindex = pindex->pnext)
          {
              if (pindex->GetBlockHash() == hashStop)
              {
                  printf("  getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
                  // tkcoin: tell downloading node about the latest block if it's
                  // without risk being rejected due to stake connection check
                  if (hashStop != hashBestChain && pindex->GetBlockTime() + nStakeMinAge > pindexBest->GetBlockTime())
                      pfrom->PushInventory(CInv(MSG_BLOCK, hashBestChain));
                  break;
              }
              pfrom->PushInventory(CInv(MSG_BLOCK, pindex->GetBlockHash()));
              if (--nLimit <= 0)
              {
                  // When this block is requested, we'll send an inv that'll make them
                  // getblocks the next batch of inventory.
                  printf("  getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString().c_str());
                  pfrom->hashContinue = pindex->GetBlockHash();
                  break;
              }
          }
      }
  
  
      else if (strCommand == "getheaders")
      {
          CBlockLocator locator;
          uint256 hashStop;
          vRecv >> locator >> hashStop;
  
          CBlockIndex* pindex = NULL;
          if (locator.IsNull())
          {
              // If locator is null, return the hashStop block
              map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hashStop);
              if (mi == mapBlockIndex.end())
                  return true;
              pindex = (*mi).second;
          }
          else
          {
              // Find the last block the caller has in the main chain
              pindex = locator.GetBlockIndex();
              if (pindex)
                  pindex = pindex->pnext;
          }
  
          // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end
          vector<CBlock> vHeaders;
          int nLimit = 2000;
          printf("getheaders %d to %s\n", (pindex ? pindex->nHeight : -1), hashStop.ToString().c_str());
          for (; pindex; pindex = pindex->pnext)
          {
              vHeaders.push_back(pindex->GetBlockHeader());
              if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop)
                  break;
          }
          pfrom->PushMessage("headers", vHeaders);
      }
  
  
      else if (strCommand == "tx")
      {
          vector<uint256> vWorkQueue;
          vector<uint256> vEraseQueue;
          CDataStream vMsg(vRecv);
          CTransaction tx;
          vRecv >> tx;
  
          CInv inv(MSG_TX, tx.GetHash());
          pfrom->AddInventoryKnown(inv);
  
          bool fMissingInputs = false;
          CValidationState state;
          if (tx.AcceptToMemoryPool(state, true, true, &fMissingInputs))
          {
              RelayTransaction(tx, inv.hash);
              mapAlreadyAskedFor.erase(inv);
              vWorkQueue.push_back(inv.hash);
              vEraseQueue.push_back(inv.hash);
  
              printf("AcceptToMemoryPool: %s %s : accepted %s (poolsz %" PRIszu")\n",
                  pfrom->addr.ToString().c_str(), pfrom->cleanSubVer.c_str(),
                  tx.GetHash().ToString().c_str(),
                  mempool.mapTx.size());
  
              // Recursively process any orphan transactions that depended on this one
              for (unsigned int i = 0; i < vWorkQueue.size(); i++)
              {
                  uint256 hashPrev = vWorkQueue[i];
                  for (set<uint256>::iterator mi = mapOrphanTransactionsByPrev[hashPrev].begin();
                       mi != mapOrphanTransactionsByPrev[hashPrev].end();
                       ++mi)
                  {
                      const uint256& orphanHash = *mi;
                      const CTransaction& orphanTx = mapOrphanTransactions[orphanHash];
                      bool fMissingInputs2 = false;
                      // Use a dummy CValidationState so someone can't setup nodes to counter-DoS based on orphan
                      // resolution (that is, feeding people an invalid transaction based on LegitTxX in order to get
                      // anyone relaying LegitTxX banned)
                      CValidationState stateDummy;
  
                      if (tx.AcceptToMemoryPool(stateDummy, true, true, &fMissingInputs2))
                      {
                          printf("   accepted orphan tx %s\n", orphanHash.ToString().c_str());
                          RelayTransaction(orphanTx, orphanHash);
                          mapAlreadyAskedFor.erase(CInv(MSG_TX, orphanHash));
                          vWorkQueue.push_back(orphanHash);
                          vEraseQueue.push_back(orphanHash);
                      }
                      else if (!fMissingInputs2)
                      {
                          // invalid or too-little-fee orphan
                          vEraseQueue.push_back(orphanHash);
                          printf("   removed orphan tx %s\n", orphanHash.ToString().c_str());
                      }
                  }
              }
  
              BOOST_FOREACH(uint256 hash, vEraseQueue)
                  EraseOrphanTx(hash);
          }
          else if (fMissingInputs)
          {
              AddOrphanTx(tx);
  
              // DoS prevention: do not allow mapOrphanTransactions to grow unbounded
              unsigned int nMaxOrphanTx = (unsigned int)std::max((int64)0, GetArg("-maxorphantx", DEFAULT_MAX_ORPHAN_TRANSACTIONS));
              unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx);
              if (nEvicted > 0)
                  printf("mapOrphan overflow, removed %u tx\n", nEvicted);
          }
          int nDoS = 0;
          if (state.IsInvalid(nDoS))
          {
              printf("%s from %s %s was not accepted into the memory pool\n", tx.GetHash().ToString().c_str(),
                  pfrom->addr.ToString().c_str(), pfrom->cleanSubVer.c_str());
              if (nDoS > 0)
                  pfrom->Misbehaving(nDoS);
          }
      }
  
  
      else if (strCommand == "block" && !fImporting && !fReindex) // Ignore blocks received while importing
      {
          CBlock block;
          vRecv >> block;
  
          printf("received block %s\n", block.GetHash().ToString().c_str());
          // block.print();
  
          CInv inv(MSG_BLOCK, block.GetHash());
          pfrom->AddInventoryKnown(inv);
  
          CValidationState state;
          if (ProcessBlock(state, pfrom, &block) || state.CorruptionPossible())
              mapAlreadyAskedFor.erase(inv);
          int nDoS = 0;
          if (state.IsInvalid(nDoS))
              if (nDoS > 0)
                  pfrom->Misbehaving(nDoS);
      }
  
  
      else if (strCommand == "getaddr")
      {
          pfrom->vAddrToSend.clear();
          vector<CAddress> vAddr = addrman.GetAddr();
          BOOST_FOREACH(const CAddress &addr, vAddr)
              pfrom->PushAddress(addr);
      }
  
  
      else if (strCommand == "mempool")
      {
          std::vector<uint256> vtxid;
          LOCK2(mempool.cs, pfrom->cs_filter);
          mempool.queryHashes(vtxid);
          vector<CInv> vInv;
          BOOST_FOREACH(uint256& hash, vtxid) {
              CInv inv(MSG_TX, hash);
              if ((pfrom->pfilter && pfrom->pfilter->IsRelevantAndUpdate(mempool.lookup(hash), hash)) ||
                 (!pfrom->pfilter))
                  vInv.push_back(inv);
              if (vInv.size() == MAX_INV_SZ)
                  break;
          }
          if (vInv.size() > 0)
              pfrom->PushMessage("inv", vInv);
      }
  
  
      else if (strCommand == "ping")
      {
          if (pfrom->nVersion > BIP0031_VERSION)
          {
              uint64 nonce = 0;
              vRecv >> nonce;
              // Echo the message back with the nonce. This allows for two useful features:
              //
              // 1) A remote node can quickly check if the connection is operational
              // 2) Remote nodes can measure the latency of the network thread. If this node
              //    is overloaded it won't respond to pings quickly and the remote node can
              //    avoid sending us more work, like chain download requests.
              //
              // The nonce stops the remote getting confused between different pings: without
              // it, if the remote node sends a ping once per second and this node takes 5
              // seconds to respond to each, the 5th ping the remote sends would appear to
              // return very quickly.
              pfrom->PushMessage("pong", nonce);
          }
      }
  
  
      else if (strCommand == "alert")
      {
          CAlert alert;
          vRecv >> alert;
  
          uint256 alertHash = alert.GetHash();
          if (pfrom->setKnown.count(alertHash) == 0)
          {
              if (alert.ProcessAlert())
              {
                  // Relay
                  pfrom->setKnown.insert(alertHash);
                  {
                      LOCK(cs_vNodes);
                      BOOST_FOREACH(CNode* pnode, vNodes)
                          alert.RelayTo(pnode);
                  }
              }
              else {
                  // Small DoS penalty so peers that send us lots of
                  // duplicate/expired/invalid-signature/whatever alerts
                  // eventually get banned.
                  // This isn't a Misbehaving(100) (immediate ban) because the
                  // peer might be an older or different implementation with
                  // a different signature key, etc.
                  pfrom->Misbehaving(10);
              }
          }
      }
  
      else if (strCommand == "checkpoint")
      {
          CSyncCheckpoint checkpoint;
          vRecv >> checkpoint;
  
          if (checkpoint.ProcessSyncCheckpoint(pfrom))
          {
              // Relay
              pfrom->hashCheckpointKnown = checkpoint.hashCheckpoint;
              LOCK(cs_vNodes);
              BOOST_FOREACH(CNode* pnode, vNodes)
                  checkpoint.RelayTo(pnode);
          }
      }
  
      else if (strCommand == "filterload")
      {
          CBloomFilter filter;
          vRecv >> filter;
  
          if (!filter.IsWithinSizeConstraints())
              // There is no excuse for sending a too-large filter
              pfrom->Misbehaving(100);
          else
          {
              LOCK(pfrom->cs_filter);
              delete pfrom->pfilter;
              pfrom->pfilter = new CBloomFilter(filter);
              pfrom->pfilter->UpdateEmptyFull();
          }
          pfrom->fRelayTxes = true;
      }
  
  
      else if (strCommand == "filteradd")
      {
          vector<unsigned char> vData;
          vRecv >> vData;
  
          // Nodes must NEVER send a data item > 520 bytes (the max size for a script data object,
          // and thus, the maximum size any matched object can have) in a filteradd message
          if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE)
          {
              pfrom->Misbehaving(100);
          } else {
              LOCK(pfrom->cs_filter);
              if (pfrom->pfilter)
                  pfrom->pfilter->insert(vData);
              else
                  pfrom->Misbehaving(100);
          }
      }
  
  
      else if (strCommand == "filterclear")
      {
          LOCK(pfrom->cs_filter);
          delete pfrom->pfilter;
          pfrom->pfilter = new CBloomFilter();
          pfrom->fRelayTxes = true;
      }
  
  
      else
      {
          // Ignore unknown commands for extensibility
      }
  
  
      // Update the last seen time for this node's address
      if (pfrom->fNetworkNode)
          if (strCommand == "version" || strCommand == "addr" || strCommand == "inv" || strCommand == "getdata" || strCommand == "ping")
              AddressCurrentlyConnected(pfrom->addr);
  
  
      return true;
  }
  
  // requires LOCK(cs_vRecvMsg)
  bool ProcessMessages(CNode* pfrom)
  {
      //if (fDebug)
      //    printf("ProcessMessages(%zu messages)\n", pfrom->vRecvMsg.size());
  
      //
      // Message format
      //  (4) message start
      //  (12) command
      //  (4) size
      //  (4) checksum
      //  (x) data
      //
  
      static int64 nTimeLastPrintMessageStart = 0;
      if (fDebug && GetBoolArg("-printmessagestart") && nTimeLastPrintMessageStart + 30 < GetAdjustedTime())
      {
          string strMessageStart((const char *)pchMessageStart, sizeof(pchMessageStart));
          vector<unsigned char> vchMessageStart(strMessageStart.begin(), strMessageStart.end());
          printf("ProcessMessages : AdjustedTime=%" PRI64d" MessageStart=%s\n", GetAdjustedTime(), HexStr(vchMessageStart).c_str());
          nTimeLastPrintMessageStart = GetAdjustedTime();
      }
  
      bool fOk = true;
  
      if (!pfrom->vRecvGetData.empty())
          ProcessGetData(pfrom);
  
      // this maintains the order of responses
      if (!pfrom->vRecvGetData.empty()) return fOk;
  
      std::deque<CNetMessage>::iterator it = pfrom->vRecvMsg.begin();
      while (!pfrom->fDisconnect && it != pfrom->vRecvMsg.end()) {
          // Don't bother if send buffer is too full to respond anyway
          if (pfrom->nSendSize >= SendBufferSize())
              break;
  
          // get next message
          CNetMessage& msg = *it;
  
          //if (fDebug)
          //    printf("ProcessMessages(message %u msgsz, %zu bytes, complete:%s)\n",
          //            msg.hdr.nMessageSize, msg.vRecv.size(),
          //            msg.complete() ? "Y" : "N");
  
          // end, if an incomplete message is found
          if (!msg.complete())
              break;
  
          // at this point, any failure means we can delete the current message
          it++;
  
          // Scan for message start
          if (memcmp(msg.hdr.pchMessageStart, pchMessageStart, sizeof(pchMessageStart)) != 0) {
              printf("\n\nPROCESSMESSAGE: INVALID MESSAGESTART\n\n");
              fOk = false;
              break;
          }
  
          // Read header
          CMessageHeader& hdr = msg.hdr;
          if (!hdr.IsValid())
          {
              printf("\n\nPROCESSMESSAGE: ERRORS IN HEADER %s\n\n\n", hdr.GetCommand().c_str());
              continue;
          }
          string strCommand = hdr.GetCommand();
  
          // Message size
          unsigned int nMessageSize = hdr.nMessageSize;
  
          // Checksum
          CDataStream& vRecv = msg.vRecv;
          uint256 hash = Hash(vRecv.begin(), vRecv.begin() + nMessageSize);
          unsigned int nChecksum = 0;
          memcpy(&nChecksum, &hash, sizeof(nChecksum));
          if (nChecksum != hdr.nChecksum)
          {
              printf("ProcessMessages(%s, %u bytes) : CHECKSUM ERROR nChecksum=%08x hdr.nChecksum=%08x\n",
                 strCommand.c_str(), nMessageSize, nChecksum, hdr.nChecksum);
              continue;
          }
  
          // Process message
          bool fRet = false;
          try
          {
              {
                  LOCK(cs_main);
                  fRet = ProcessMessage(pfrom, strCommand, vRecv);
              }
              boost::this_thread::interruption_point();
          }
          catch (std::ios_base::failure& e)
          {
              if (strstr(e.what(), "end of data"))
              {
                  // Allow exceptions from under-length message on vRecv
                  printf("ProcessMessages(%s, %u bytes) : Exception '%s' caught, normally caused by a message being shorter than its stated length\n", strCommand.c_str(), nMessageSize, e.what());
              }
              else if (strstr(e.what(), "size too large"))
              {
                  // Allow exceptions from over-long size
                  printf("ProcessMessages(%s, %u bytes) : Exception '%s' caught\n", strCommand.c_str(), nMessageSize, e.what());
              }
              else
              {
                  PrintExceptionContinue(&e, "ProcessMessages()");
              }
          }
          catch (boost::thread_interrupted) {
              throw;
          }
          catch (std::exception& e) {
              PrintExceptionContinue(&e, "ProcessMessages()");
          } catch (...) {
              PrintExceptionContinue(NULL, "ProcessMessages()");
          }
  
          if (!fRet)
              printf("ProcessMessage(%s, %u bytes) FAILED\n", strCommand.c_str(), nMessageSize);
  
          break;
      }
  
      // In case the connection got shut down, its receive buffer was wiped
      if (!pfrom->fDisconnect)
          pfrom->vRecvMsg.erase(pfrom->vRecvMsg.begin(), it);
  
      return fOk;
  }
  
  
  bool SendMessages(CNode* pto, bool fSendTrickle)
  {
      TRY_LOCK(cs_main, lockMain);
      if (lockMain) {
          // Don't send anything until we get their version message
          if (pto->nVersion == 0)
              return true;
  
          // Keep-alive ping. We send a nonce of zero because we don't use it anywhere
          // right now.
          if (pto->nLastSend && GetTime() - pto->nLastSend > 30 * 60 && pto->vSendMsg.empty()) {
              uint64 nonce = 0;
              if (pto->nVersion > BIP0031_VERSION)
                  pto->PushMessage("ping", nonce);
              else
                  pto->PushMessage("ping");
          }
  
          // Start block sync
          if (pto->fStartSync && !fImporting && !fReindex) {
              pto->fStartSync = false;
              pto->PushGetBlocks(pindexBest, uint256(0));
          }
  
          // Resend wallet transactions that haven't gotten in a block yet
          // Except during reindex, importing and IBD, when old wallet
          // transactions become unconfirmed and spams other nodes.
          if (!fReindex && !fImporting && !IsInitialBlockDownload())
          {
              ResendWalletTransactions();
          }
  
          // Address refresh broadcast
          static int64 nLastRebroadcast;
          if (!IsInitialBlockDownload() && (GetTime() - nLastRebroadcast > 24 * 60 * 60))
          {
              {
                  LOCK(cs_vNodes);
                  BOOST_FOREACH(CNode* pnode, vNodes)
                  {
                      // Periodically clear setAddrKnown to allow refresh broadcasts
                      if (nLastRebroadcast)
                          pnode->setAddrKnown.clear();
  
                      // Rebroadcast our address
                      if (!fNoListen)
                      {
                          CAddress addr = GetLocalAddress(&pnode->addr);
                          if (addr.IsRoutable())
                              pnode->PushAddress(addr);
                      }
                  }
              }
              nLastRebroadcast = GetTime();
          }
  
          //
          // Message: addr
          //
          if (fSendTrickle)
          {
              vector<CAddress> vAddr;
              vAddr.reserve(pto->vAddrToSend.size());
              BOOST_FOREACH(const CAddress& addr, pto->vAddrToSend)
              {
                  // returns true if wasn't already contained in the set
                  if (pto->setAddrKnown.insert(addr).second)
                  {
                      vAddr.push_back(addr);
                      // receiver rejects addr messages larger than 1000
                      if (vAddr.size() >= 1000)
                      {
                          pto->PushMessage("addr", vAddr);
                          vAddr.clear();
                      }
                  }
              }
              pto->vAddrToSend.clear();
              if (!vAddr.empty())
                  pto->PushMessage("addr", vAddr);
          }
  
  
          //
          // Message: inventory
          //
          vector<CInv> vInv;
          vector<CInv> vInvWait;
          {
              LOCK(pto->cs_inventory);
              vInv.reserve(pto->vInventoryToSend.size());
              vInvWait.reserve(pto->vInventoryToSend.size());
              BOOST_FOREACH(const CInv& inv, pto->vInventoryToSend)
              {
                  if (pto->setInventoryKnown.count(inv))
                      continue;
  
                  // trickle out tx inv to protect privacy
                  if (inv.type == MSG_TX && !fSendTrickle)
                  {
                      // 1/4 of tx invs blast to all immediately
                      static uint256 hashSalt;
                      if (hashSalt == 0)
                          hashSalt = GetRandHash();
                      uint256 hashRand = inv.hash ^ hashSalt;
                      hashRand = Hash(BEGIN(hashRand), END(hashRand));
                      bool fTrickleWait = ((hashRand & 3) != 0);
  
                      // always trickle our own transactions
                      if (!fTrickleWait)
                      {
                          CWalletTx wtx;
                          if (GetTransaction(inv.hash, wtx))
                              if (wtx.fFromMe)
                                  fTrickleWait = true;
                      }
  
                      if (fTrickleWait)
                      {
                          vInvWait.push_back(inv);
                          continue;
                      }
                  }
  
                  // returns true if wasn't already contained in the set
                  if (pto->setInventoryKnown.insert(inv).second)
                  {
                      vInv.push_back(inv);
                      if (vInv.size() >= 1000)
                      {
                          pto->PushMessage("inv", vInv);
                          vInv.clear();
                      }
                  }
              }
              pto->vInventoryToSend = vInvWait;
          }
          if (!vInv.empty())
              pto->PushMessage("inv", vInv);
  
  
          //
          // Message: getdata
          //
          vector<CInv> vGetData;
          int64 nNow = GetTime() * 1000000;
          while (!pto->mapAskFor.empty() && (*pto->mapAskFor.begin()).first <= nNow)
          {
              const CInv& inv = (*pto->mapAskFor.begin()).second;
              if (!AlreadyHave(inv))
              {
                  if (fDebugNet)
                      printf("sending getdata: %s\n", inv.ToString().c_str());
                  vGetData.push_back(inv);
                  if (vGetData.size() >= 1000)
                  {
                      pto->PushMessage("getdata", vGetData);
                      vGetData.clear();
                  }
              }
              pto->mapAskFor.erase(pto->mapAskFor.begin());
          }
          if (!vGetData.empty())
              pto->PushMessage("getdata", vGetData);
  
      }
      return true;
  }
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // BitcoinMiner
  //
  
  int static FormatHashBlocks(void* pbuffer, unsigned int len)
  {
      unsigned char* pdata = (unsigned char*)pbuffer;
      unsigned int blocks = 1 + ((len + 8) / 64);
      unsigned char* pend = pdata + 64 * blocks;
      memset(pdata + len, 0, 64 * blocks - len);
      pdata[len] = 0x80;
      unsigned int bits = len * 8;
      pend[-1] = (bits >> 0) & 0xff;
      pend[-2] = (bits >> 8) & 0xff;
      pend[-3] = (bits >> 16) & 0xff;
      pend[-4] = (bits >> 24) & 0xff;
      return blocks;
  }
  
  static const unsigned int pSHA256InitState[8] =
  {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
  
  void SHA256Transform(void* pstate, void* pinput, const void* pinit)
  {
      SHA256_CTX ctx;
      unsigned char data[64];
  
      SHA256_Init(&ctx);
  
      for (int i = 0; i < 16; i++)
          ((uint32_t*)data)[i] = ByteReverse(((uint32_t*)pinput)[i]);
  
      for (int i = 0; i < 8; i++)
          ctx.h[i] = ((uint32_t*)pinit)[i];
  
      SHA256_Update(&ctx, data, sizeof(data));
      for (int i = 0; i < 8; i++)
          ((uint32_t*)pstate)[i] = ctx.h[i];
  }
  
  //
  // ScanHash scans nonces looking for a hash with at least some zero bits.
  // It operates on big endian data.  Caller does the byte reversing.
  // All input buffers are 16-byte aligned.  nNonce is usually preserved
  // between calls, but periodically or if nNonce is 0xffff0000 or above,
  // the block is rebuilt and nNonce starts over at zero.
  //
  unsigned int static ScanHash_CryptoPP(char* pmidstate, char* pdata, char* phash1, char* phash, unsigned int& nHashesDone)
  {
      unsigned int& nNonce = *(unsigned int*)(pdata + 12);
      for (;;)
      {
          // Crypto++ SHA256
          // Hash pdata using pmidstate as the starting state into
          // pre-formatted buffer phash1, then hash phash1 into phash
          nNonce++;
          SHA256Transform(phash1, pdata, pmidstate);
          SHA256Transform(phash, phash1, pSHA256InitState);
  
          // Return the nonce if the hash has at least some zero bits,
          // caller will check if it has enough to reach the target
          if (((unsigned short*)phash)[14] == 0)
              return nNonce;
  
          // If nothing found after trying for a while, return -1
          if ((nNonce & 0xffff) == 0)
          {
              nHashesDone = 0xffff+1;
              return (unsigned int) -1;
          }
          if ((nNonce & 0xfff) == 0)
              boost::this_thread::interruption_point();
      }
  }
  
  // Some explaining would be appreciated
  class COrphan
  {
  public:
      CTransaction* ptx;
      set<uint256> setDependsOn;
      double dPriority;
      double dFeePerKb;
  
      COrphan(CTransaction* ptxIn)
      {
          ptx = ptxIn;
          dPriority = dFeePerKb = 0;
      }
  
      void print() const
      {
          printf("COrphan(hash=%s, dPriority=%.1f, dFeePerKb=%.1f)\n",
                 ptx->GetHash().ToString().c_str(), dPriority, dFeePerKb);
          BOOST_FOREACH(uint256 hash, setDependsOn)
              printf("   setDependsOn %s\n", hash.ToString().c_str());
      }
  };
  
  
  uint64 nLastBlockTx = 0;
  uint64 nLastBlockSize = 0;
  int64 nLastCoinStakeSearchInterval = 0;
  
  // We want to sort transactions by priority and fee, so:
  typedef boost::tuple<double, double, CTransaction*> TxPriority;
  class TxPriorityCompare
  {
      bool byFee;
  public:
      TxPriorityCompare(bool _byFee) : byFee(_byFee) { }
      bool operator()(const TxPriority& a, const TxPriority& b)
      {
          if (byFee)
          {
              if (a.get<1>() == b.get<1>())
                  return a.get<0>() < b.get<0>();
              return a.get<1>() < b.get<1>();
          }
          else
          {
              if (a.get<0>() == b.get<0>())
                  return a.get<1>() < b.get<1>();
              return a.get<0>() < b.get<0>();
          }
      }
  };
  
  // CreateNewBlock:
  //   fProofOfStake: try (best effort) to make a proof-of-stake block
  CBlockTemplate* CreateNewBlock(CReserveKey& reservekey, CWallet* pwallet, bool fProofOfStake)
  {
      // Create new block
      auto_ptr<CBlockTemplate> pblocktemplate(new CBlockTemplate());
      if(!pblocktemplate.get())
          return NULL;
      CBlock *pblock = &pblocktemplate->block; // pointer for convenience
  
      // Create coinbase tx
      CTransaction txNew;
      txNew.vin.resize(1);
      txNew.vin[0].prevout.SetNull();
      txNew.vout.resize(1);
      CPubKey pubkey;
      if (!reservekey.GetReservedKey(pubkey))
          return NULL;
      txNew.vout[0].scriptPubKey << pubkey << OP_CHECKSIG;
  
      // Add our coinbase tx as first transaction
      pblock->vtx.push_back(txNew);
      pblocktemplate->vTxFees.push_back(-1); // updated at end
      pblocktemplate->vTxSigOps.push_back(-1); // updated at end
  
      // Largest block you're willing to create:
      unsigned int nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE);
      // Limit to betweeen 1K and MAX_BLOCK_SIZE-1K for sanity:
      nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
  
      // Special compatibility rule before 15 May: limit size to 500,000 bytes:
      if (GetAdjustedTime() < 1368576000)
          nBlockMaxSize = std::min(nBlockMaxSize, (unsigned int)(MAX_BLOCK_SIZE_GEN));
  
      // How much of the block should be dedicated to high-priority transactions,
      // included regardless of the fees they pay
      unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE);
      nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
  
      // Minimum block size you want to create; block will be filled with free transactions
      // until there are no more or the block reaches this size:
      unsigned int nBlockMinSize = GetArg("-blockminsize", 0);
      nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
  
      // tkcoin: if coinstake available add coinstake tx
      static int64 nLastCoinStakeSearchTime = GetAdjustedTime();  // only initialized at startup
      CBlockIndex* pindexPrev = pindexBest;
  
      if (fProofOfStake)  // attemp to find a coinstake
      {
          pblock->nBits = GetNextTargetRequired(pindexPrev, true);
          CTransaction txCoinStake;
          int64 nSearchTime = txCoinStake.nTime; // search to current time
          if (nSearchTime > nLastCoinStakeSearchTime)
          {
              if (pwallet->CreateCoinStake(*pwallet, pblock->nBits, nSearchTime-nLastCoinStakeSearchTime, txCoinStake))
              {
                  if (txCoinStake.nTime >= max(pindexPrev->GetMedianTimePast()+1, pindexPrev->GetBlockTime() - nMaxClockDrift))
                  {   // make sure coinstake would meet timestamp protocol
                      // as it would be the same as the block timestamp
                      pblock->vtx[0].vout[0].SetEmpty();
                      pblock->vtx[0].nTime = txCoinStake.nTime;
                      pblock->vtx.push_back(txCoinStake);
                  }
              }
              nLastCoinStakeSearchInterval = nSearchTime - nLastCoinStakeSearchTime;
              nLastCoinStakeSearchTime = nSearchTime;
          }
      }
  
      pblock->nBits = GetNextTargetRequired(pindexPrev, pblock->IsProofOfStake());
  
      // Collect memory pool transactions into the block
      int64 nFees = 0;
      {
          LOCK2(cs_main, mempool.cs);
          CBlockIndex* pindexPrev = pindexBest;
          CCoinsViewCache view(*pcoinsTip, true);
  
          // Priority order to process transactions
          list<COrphan> vOrphan; // list memory doesn't move
          map<uint256, vector<COrphan*> > mapDependers;
          bool fPrintPriority = GetBoolArg("-printpriority");
  
          // This vector will be sorted into a priority queue:
          vector<TxPriority> vecPriority;
          vecPriority.reserve(mempool.mapTx.size());
          for (map<uint256, CTransaction>::iterator mi = mempool.mapTx.begin(); mi != mempool.mapTx.end(); ++mi)
          {
              CTransaction& tx = (*mi).second;
              if (tx.IsCoinBase() || tx.IsCoinStake() || !tx.IsFinal())
                  continue;
  
              COrphan* porphan = NULL;
              double dPriority = 0;
              int64 nTotalIn = 0;
              bool fMissingInputs = false;
              BOOST_FOREACH(const CTxIn& txin, tx.vin)
              {
                  // Read prev transaction
                  if (!view.HaveCoins(txin.prevout.hash))
                  {
                      // This should never happen; all transactions in the memory
                      // pool should connect to either transactions in the chain
                      // or other transactions in the memory pool.
                      if (!mempool.mapTx.count(txin.prevout.hash))
                      {
                          printf("ERROR: mempool transaction missing input\n");
                          if (fDebug) assert("mempool transaction missing input" == 0);
                          fMissingInputs = true;
                          if (porphan)
                              vOrphan.pop_back();
                          break;
                      }
  
                      // Has to wait for dependencies
                      if (!porphan)
                      {
                          // Use list for automatic deletion
                          vOrphan.push_back(COrphan(&tx));
                          porphan = &vOrphan.back();
                      }
                      mapDependers[txin.prevout.hash].push_back(porphan);
                      porphan->setDependsOn.insert(txin.prevout.hash);
                      nTotalIn += mempool.mapTx[txin.prevout.hash].vout[txin.prevout.n].nValue;
                      continue;
                  }
                  const CCoins &coins = view.GetCoins(txin.prevout.hash);
  
                  int64 nValueIn = coins.vout[txin.prevout.n].nValue;
                  nTotalIn += nValueIn;
  
                  int nConf = pindexPrev->nHeight - coins.nHeight + 1;
  
                  dPriority += (double)nValueIn * nConf;
              }
              if (fMissingInputs) continue;
  
              // Priority is sum(valuein * age) / txsize
              unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
              dPriority /= nTxSize;
  
              // This is a more accurate fee-per-kilobyte than is used by the client code, because the
              // client code rounds up the size to the nearest 1K. That's good, because it gives an
              // incentive to create smaller transactions.
              double dFeePerKb =  double(nTotalIn-tx.GetValueOut()) / (double(nTxSize)/1000.0);
  
              if (porphan)
              {
                  porphan->dPriority = dPriority;
                  porphan->dFeePerKb = dFeePerKb;
              }
              else
                  vecPriority.push_back(TxPriority(dPriority, dFeePerKb, &(*mi).second));
          }
  
          // Collect transactions into block
          uint64 nBlockSize = 1000;
          uint64 nBlockTx = 0;
          int nBlockSigOps = 100;
          bool fSortedByFee = (nBlockPrioritySize <= 0);
  
          TxPriorityCompare comparer(fSortedByFee);
          std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
  
          while (!vecPriority.empty())
          {
              // Take highest priority transaction off the priority queue:
              double dPriority = vecPriority.front().get<0>();
              double dFeePerKb = vecPriority.front().get<1>();
              CTransaction& tx = *(vecPriority.front().get<2>());
  
              std::pop_heap(vecPriority.begin(), vecPriority.end(), comparer);
              vecPriority.pop_back();
  
              // Size limits
              unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
              if (nBlockSize + nTxSize >= nBlockMaxSize)
                  continue;
  
              // Legacy limits on sigOps:
              unsigned int nTxSigOps = tx.GetLegacySigOpCount();
              if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
                  continue;
  
              // tkcoin: timestamp limit
              if (tx.nTime > GetAdjustedTime() || (pblock->IsProofOfStake() && tx.nTime > pblock->vtx[1].nTime))
                  continue;
  
              // Skip free transactions if we're past the minimum block size:
              if (fSortedByFee && (dFeePerKb < CTransaction::nMinTxFee) && (nBlockSize + nTxSize >= nBlockMinSize))
                  continue;
  
              // Prioritize by fee once past the priority size or we run out of high-priority
              // transactions:
              if (!fSortedByFee &&
                  ((nBlockSize + nTxSize >= nBlockPrioritySize) || (dPriority < COIN * 144 / 250)))
              {
                  fSortedByFee = true;
                  comparer = TxPriorityCompare(fSortedByFee);
                  std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
              }
  
              if (!tx.HaveInputs(view))
                  continue;
  
              int64 nTxFees = tx.GetValueIn(view)-tx.GetValueOut();
              // tkcoin: simplify transaction fee - allow free = false
              int64 nMinFee = tx.GetMinFee(nBlockSize, false, GMF_BLOCK);
              if (nTxFees < nMinFee)
                  continue;
  
              nTxSigOps += tx.GetP2SHSigOpCount(view);
              if (nBlockSigOps + nTxSigOps >= MAX_BLOCK_SIGOPS)
                  continue;
  
              CValidationState state;
              if (!tx.CheckInputs(state, view, true, SCRIPT_VERIFY_P2SH))
                  continue;
  
              CTxUndo txundo;
              uint256 hash = tx.GetHash();
              tx.UpdateCoins(state, view, txundo, pindexPrev->nHeight+1, hash);
  
              // Added
              pblock->vtx.push_back(tx);
              pblocktemplate->vTxFees.push_back(nTxFees);
              pblocktemplate->vTxSigOps.push_back(nTxSigOps);
              nBlockSize += nTxSize;
              ++nBlockTx;
              nBlockSigOps += nTxSigOps;
              nFees += nTxFees;
  
              if (fPrintPriority)
              {
                  printf("priority %.1f feeperkb %.1f txid %s\n",
                         dPriority, dFeePerKb, tx.GetHash().ToString().c_str());
              }
  
              // Add transactions that depend on this one to the priority queue
              if (mapDependers.count(hash))
              {
                  BOOST_FOREACH(COrphan* porphan, mapDependers[hash])
                  {
                      if (!porphan->setDependsOn.empty())
                      {
                          porphan->setDependsOn.erase(hash);
                          if (porphan->setDependsOn.empty())
                          {
                              vecPriority.push_back(TxPriority(porphan->dPriority, porphan->dFeePerKb, porphan->ptx));
                              std::push_heap(vecPriority.begin(), vecPriority.end(), comparer);
                          }
                      }
                  }
              }
          }
  
          nLastBlockTx = nBlockTx;
          nLastBlockSize = nBlockSize;
          if (fDebug && GetBoolArg("-printpriority"))
              printf("CreateNewBlock(): total size %" PRI64u"\n", nBlockSize);
  
          if (pblock->IsProofOfWork())
              pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
          pblocktemplate->vTxFees[0] = -nFees;
  
          // Fill in header
          pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
          if (pblock->IsProofOfStake())
              pblock->nTime      = pblock->vtx[1].nTime; //same as coinstake timestamp
          pblock->nTime          = max(pindexPrev->GetMedianTimePast()+1, pblock->GetMaxTransactionTime());
          pblock->nTime          = max(pblock->GetBlockTime(), pindexPrev->GetBlockTime() - nMaxClockDrift);
          if (pblock->IsProofOfWork())
              pblock->UpdateTime(pindexPrev);
          pblock->nNonce         = 0;
          pblock->vtx[0].vin[0].scriptSig = CScript() << OP_0 << OP_0;
          pblocktemplate->vTxSigOps[0] = pblock->vtx[0].GetLegacySigOpCount();
  
          CBlockIndex indexDummy(*pblock);
          indexDummy.pprev = pindexPrev;
          indexDummy.nHeight = pindexPrev->nHeight + 1;
          CCoinsViewCache viewNew(*pcoinsTip, true);
          CValidationState state;
          if (!pblock->ConnectBlock(state, &indexDummy, viewNew, true))
              throw std::runtime_error("CreateNewBlock() : ConnectBlock failed");
      }
  
      return pblocktemplate.release();
  }
  
  
  void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce)
  {
      // Update nExtraNonce
      static uint256 hashPrevBlock;
      if (hashPrevBlock != pblock->hashPrevBlock)
      {
          nExtraNonce = 0;
          hashPrevBlock = pblock->hashPrevBlock;
      }
      ++nExtraNonce;
      unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
      pblock->vtx[0].vin[0].scriptSig = (CScript() << nHeight << CBigNum(nExtraNonce)) + COINBASE_FLAGS;
      assert(pblock->vtx[0].vin[0].scriptSig.size() <= 100);
  
      pblock->hashMerkleRoot = pblock->BuildMerkleTree();
  }
  
  
  void FormatHashBuffers(CBlock* pblock, char* pmidstate, char* pdata, char* phash1)
  {
      //
      // Pre-build hash buffers
      //
      struct
      {
          struct unnamed2
          {
              int nVersion;
              uint256 hashPrevBlock;
              uint256 hashMerkleRoot;
              unsigned int nTime;
              unsigned int nBits;
              unsigned int nNonce;
          }
          block;
          unsigned char pchPadding0[64];
          uint256 hash1;
          unsigned char pchPadding1[64];
      }
      tmp;
      memset(&tmp, 0, sizeof(tmp));
  
      tmp.block.nVersion       = pblock->nVersion;
      tmp.block.hashPrevBlock  = pblock->hashPrevBlock;
      tmp.block.hashMerkleRoot = pblock->hashMerkleRoot;
      tmp.block.nTime          = pblock->nTime;
      tmp.block.nBits          = pblock->nBits;
      tmp.block.nNonce         = pblock->nNonce;
  
      FormatHashBlocks(&tmp.block, sizeof(tmp.block));
      FormatHashBlocks(&tmp.hash1, sizeof(tmp.hash1));
  
      // Byte swap all the input buffer
      for (unsigned int i = 0; i < sizeof(tmp)/4; i++)
          ((unsigned int*)&tmp)[i] = ByteReverse(((unsigned int*)&tmp)[i]);
  
      // Precalc the first half of the first hash, which stays constant
      SHA256Transform(pmidstate, &tmp.block, pSHA256InitState);
  
      memcpy(pdata, &tmp.block, 128);
      memcpy(phash1, &tmp.hash1, 64);
  }
  
  
  bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
  {
      uint256 hash = pblock->GetHash();
      uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
  
      if (hash > hashTarget && pblock->IsProofOfWork())
          return error("coinkingMiner : proof-of-work not meeting target");
  
      //// debug print
      printf("coinkingMiner:\n");
      printf("new block found  \n  hash: %s  \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
      pblock->print();
      printf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue).c_str());
  
      // Found a solution
      {
          LOCK(cs_main);
          if (pblock->hashPrevBlock != hashBestChain)
              return error("coinkingMiner : generated block is stale");
  
          // Remove key from key pool
          reservekey.KeepKey();
  
          // Track how many getdata requests this block gets
          {
              LOCK(wallet.cs_wallet);
              wallet.mapRequestCount[pblock->GetHash()] = 0;
          }
  
          // Process this block the same as if we had received it from another node
          CValidationState state;
          if (!ProcessBlock(state, NULL, pblock))
              return error("coinkingMiner : ProcessBlock, block not accepted");
      }
  
      return true;
  }
  
  #ifdef TESTING
  void BitcoinMiner(CWallet *pwallet, bool fProofOfStake, bool fGenerateSingleBlock)
  #else
  void BitcoinMiner(CWallet *pwallet, bool fProofOfStake)
  #endif
  {
      printf("CPUMiner started for proof-of-%s\n", fProofOfStake? "stake" : "work");
      SetThreadPriority(THREAD_PRIORITY_LOWEST);
      RenameThread(fProofOfStake? "tkcoin-stake-minter" : "tkcoin-miner");
  
      // Each thread has its own key and counter
      CReserveKey reservekey(pwallet);
      unsigned int nExtraNonce = 0;
  
      string strMintMessage = _("Info: Minting suspended due to locked wallet.");
      string strMintDisabledMessage = _("Info: Minting disabled by 'nominting' option.");
  
      try { loop {
          if (GetBoolArg("-nominting"))
          {
              strMintWarning = strMintDisabledMessage;
              return;
          }
  
          while (vNodes.empty())
              MilliSleep(1000);
  
          while (pwallet->IsLocked())
          {
              strMintWarning = strMintMessage;
              MilliSleep(1000);
          }
          strMintWarning = "";
  
          //
          // Create new block
          //
          unsigned int nTransactionsUpdatedLast = nTransactionsUpdated;
          CBlockIndex* pindexPrev = pindexBest;
  
          auto_ptr<CBlockTemplate> pblocktemplate(CreateNewBlock(reservekey, pwallet, fProofOfStake));
          if (!pblocktemplate.get())
              return;
          CBlock *pblock = &pblocktemplate->block;
          IncrementExtraNonce(pblock, pindexPrev, nExtraNonce);
  
          if (fProofOfStake)
          {
              // tkcoin: if proof-of-stake block found then process block
              if (pblock->IsProofOfStake())
              {
                  if (!pblock->SignBlock(*pwalletMain))
                  {
                      strMintWarning = strMintMessage;
                      continue;
                  }
                  strMintWarning = "";
                  printf("CPUMiner : proof-of-stake block found %s\n", pblock->GetHash().ToString().c_str()); 
  #ifdef TESTING
                  SetThreadPriority(THREAD_PRIORITY_NORMAL);
                  bool fSuccess = CheckWork(pblock, *pwalletMain, reservekey);
                  SetThreadPriority(THREAD_PRIORITY_LOWEST);
                  if (fSuccess && fGenerateSingleBlock)
                  {
                      hashSingleStakeBlock = pblock->GetHash();
                      return;
                  }
  #else
                  SetThreadPriority(THREAD_PRIORITY_NORMAL);
                  CheckWork(pblock, *pwalletMain, reservekey);
                  SetThreadPriority(THREAD_PRIORITY_LOWEST);
  #endif
              }
              MilliSleep(500);
              continue;
          }
  
          printf("Running coinkingMiner with %" PRIszu" transactions in block (%u bytes)\n", pblock->vtx.size(),
                 ::GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION));
  
          //
          // Pre-build hash buffers
          //
          char pmidstatebuf[32+16]; char* pmidstate = alignup<16>(pmidstatebuf);
          char pdatabuf[128+16];    char* pdata     = alignup<16>(pdatabuf);
          char phash1buf[64+16];    char* phash1    = alignup<16>(phash1buf);
  
          FormatHashBuffers(pblock, pmidstate, pdata, phash1);
  
          unsigned int& nBlockTime = *(unsigned int*)(pdata + 64 + 4);
          unsigned int& nBlockNonce = *(unsigned int*)(pdata + 64 + 12);
  
  
          //
          // Search
          //
          int64 nStart = GetTime();
          uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
          uint256 hashbuf[2];
          uint256& hash = *alignup<16>(hashbuf);
          loop
          {
              unsigned int nHashesDone = 0;
              unsigned int nNonceFound;
  
              // Crypto++ SHA256
              nNonceFound = ScanHash_CryptoPP(pmidstate, pdata + 64, phash1,
                                              (char*)&hash, nHashesDone);
  
              // Check if something found
              if (nNonceFound != (unsigned int) -1)
              {
                  for (unsigned int i = 0; i < sizeof(hash)/4; i++)
                      ((unsigned int*)&hash)[i] = ByteReverse(((unsigned int*)&hash)[i]);
  
                  if (hash <= hashTarget)
                  {
                      // Found a solution
                      pblock->nNonce = ByteReverse(nNonceFound);
                      assert(hash == pblock->GetHash());
                      if (!pblock->SignBlock(*pwalletMain))
                      {
                          strMintWarning = strMintMessage;
                          break;
                      }
                      strMintWarning = "";
                      SetThreadPriority(THREAD_PRIORITY_NORMAL);
                      CheckWork(pblock, *pwalletMain, reservekey);
                      SetThreadPriority(THREAD_PRIORITY_LOWEST);
                      break;
                  }
              }
  
              // Meter hashes/sec
              static int64 nHashCounter;
              if (nHPSTimerStart == 0)
              {
                  nHPSTimerStart = GetTimeMillis();
                  nHashCounter = 0;
              }
              else
                  nHashCounter += nHashesDone;
              if (GetTimeMillis() - nHPSTimerStart > 4000)
              {
                  static CCriticalSection cs;
                  {
                      LOCK(cs);
                      if (GetTimeMillis() - nHPSTimerStart > 4000)
                      {
                          dHashesPerSec = 1000.0 * nHashCounter / (GetTimeMillis() - nHPSTimerStart);
                          nHPSTimerStart = GetTimeMillis();
                          nHashCounter = 0;
                          static int64 nLogTime;
                          if (GetTime() - nLogTime > 30 * 60)
                          {
                              nLogTime = GetTime();
                              printf("hashmeter %6.0f khash/s\n", dHashesPerSec/1000.0);
                          }
                      }
                  }
              }
  
              // Check for stop or if block needs to be rebuilt
              boost::this_thread::interruption_point();
              if (vNodes.empty())
                  break;
              if (nBlockNonce >= 0xffff0000)
                  break;
              if (nTransactionsUpdated != nTransactionsUpdatedLast && GetTime() - nStart > 60)
                  break;
              if (pindexPrev != pindexBest)
                  break;
  
              // Update nTime every few seconds
              pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, pblock->GetMaxTransactionTime());
              pblock->nTime = max(pblock->GetBlockTime(), pindexPrev->GetBlockTime() - nMaxClockDrift);
              pblock->UpdateTime(pindexPrev);
              nBlockTime = ByteReverse(pblock->nTime);
              if (pblock->GetBlockTime() >= (int64)pblock->vtx[0].nTime + nMaxClockDrift)
                  break;  // need to update coinbase timestamp
          }
      } }
      catch (boost::thread_interrupted)
      {
          if(!fProofOfStake) printf("coinkingMiner terminated\n");
          throw;
      }
  }
  
  void GenerateBitcoins(bool fGenerate, CWallet* pwallet)
  {
      static boost::thread_group* minerThreads = NULL;
  
      int nThreads = GetArg("-genproclimit", -1);
      if (nThreads < 0)
          nThreads = boost::thread::hardware_concurrency();
  
      if (minerThreads != NULL)
      {
          minerThreads->interrupt_all();
          delete minerThreads;
          minerThreads = NULL;
      }
  
      if (nThreads == 0 || !fGenerate)
          return;
  
      minerThreads = new boost::thread_group();
      for (int i = 0; i < nThreads; i++)
  #ifdef TESTING
          minerThreads->create_thread(boost::bind(&BitcoinMiner, pwallet, false, false));
  #else
          minerThreads->create_thread(boost::bind(&BitcoinMiner, pwallet, false));
  #endif
  }
  
  // tkcoin: stake minter thread
  void static ThreadStakeMinter(void* parg)
  {
      printf("ThreadStakeMinter started\n");
      CWallet* pwallet = (CWallet*)parg;
      try
      {
          BitcoinMiner(pwallet, true);
      }
      catch (boost::thread_interrupted) {
          printf("stakeminter thread interrupt\n");
      } catch (std::exception& e) {
          PrintException(&e, "ThreadStakeMinter()");
      } catch (...) {
          PrintException(NULL, "ThreadStakeMinter()");
      }
      printf("ThreadStakeMinter exiting\n");
  }
  
  // tkcoin: stake minter
  void MintStake(boost::thread_group& threadGroup, CWallet* pwallet)
  {
      // tkcoin: mint proof-of-stake blocks in the background
      threadGroup.create_thread(boost::bind(&ThreadStakeMinter, pwallet));
  }
  
  // Amount compression:
  // * If the amount is 0, output 0
  // * first, divide the amount (in base units) by the largest power of 10 possible; call the exponent e (e is max 9)
  // * if e<9, the last digit of the resulting number cannot be 0; store it as d, and drop it (divide by 10)
  //   * call the result n
  //   * output 1 + 10*(9*n + d - 1) + e
  // * if e==9, we only know the resulting number is not zero, so output 1 + 10*(n - 1) + 9
  // (this is decodable, as d is in [1-9] and e is in [0-9])
  
  uint64 CTxOutCompressor::CompressAmount(uint64 n)
  {
      if (n == 0)
          return 0;
      int e = 0;
      while (((n % 10) == 0) && e < 9) {
          n /= 10;
          e++;
      }
      if (e < 9) {
          int d = (n % 10);
          assert(d >= 1 && d <= 9);
          n /= 10;
          return 1 + (n*9 + d - 1)*10 + e;
      } else {
          return 1 + (n - 1)*10 + 9;
      }
  }
  
  uint64 CTxOutCompressor::DecompressAmount(uint64 x)
  {
      // x = 0  OR  x = 1+10*(9*n + d - 1) + e  OR  x = 1+10*(n - 1) + 9
      if (x == 0)
          return 0;
      x--;
      // x = 10*(9*n + d - 1) + e
      int e = x % 10;
      x /= 10;
      uint64 n = 0;
      if (e < 9) {
          // x = 9*n + d - 1
          int d = (x % 9) + 1;
          x /= 9;
          // x = n
          n = x*10 + d;
      } else {
          n = x+1;
      }
      while (e) {
          n *= 10;
          e--;
      }
      return n;
  }
  
  
  class CMainCleanup
  {
  public:
      CMainCleanup() {}
      ~CMainCleanup() {
          // block headers
          std::map<uint256, CBlockIndex*>::iterator it1 = mapBlockIndex.begin();
          for (; it1 != mapBlockIndex.end(); it1++)
              delete (*it1).second;
          mapBlockIndex.clear();
  
          // orphan blocks
          std::map<uint256, CBlock*>::iterator it2 = mapOrphanBlocks.begin();
          for (; it2 != mapOrphanBlocks.end(); it2++)
              delete (*it2).second;
          mapOrphanBlocks.clear();
  
          // orphan transactions
          mapOrphanTransactions.clear();
      }
  } instance_of_cmaincleanup;
  