text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2014-2015 The Dash developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "main.h"
  
  #include "addrman.h"
  #include "alert.h"
  #include "chainparams.h"
  #include "checkpoints.h"
  #include "checkqueue.h"
  #include "init.h"
  #include "instantx.h"
  #include "darksend.h"
  #include "masternodeman.h"
  #include "net.h"
  #include "txdb.h"
  #include "txmempool.h"
  #include "ui_interface.h"
  #include "util.h"
  #include "spork.h"
  
  #include <sstream>
  
  #include <boost/algorithm/string/replace.hpp>
  #include <boost/filesystem.hpp>
  #include <boost/filesystem/fstream.hpp>
  #include <boost/lexical_cast.hpp>
  
  using namespace std;
  using namespace boost;
  
  #if defined(NDEBUG)
  # error "Dash cannot be compiled without assertions."
  #endif
  
  //
  // Global state
  //
  
  CCriticalSection cs_main;
  
  CTxMemPool mempool;
  
  map<uint256, CBlockIndex*> mapBlockIndex;
  CChain chainActive;
  CChain chainMostWork;
  int64_t nTimeBestReceived = 0;
  int nScriptCheckThreads = 0;
  bool fImporting = false;
  bool fReindex = false;
  bool fBenchmark = false;
  bool fTxIndex = false;
  bool fLargeWorkForkFound = false;
  bool fLargeWorkInvalidChainFound = false;
  
  unsigned int nCoinCacheSize = 5000;
  
  /** Fees smaller than this (in satoshi) are considered zero fee (for transaction creation) */
  int64_t CTransaction::nMinTxFee = 10000;  // Override with -mintxfee
  /** Fees smaller than this (in satoshi) are considered zero fee (for relaying and mining) */
  int64_t CTransaction::nMinRelayTxFee = 1000;
  
  struct COrphanBlock {
      uint256 hashBlock;
      uint256 hashPrev;
      vector<unsigned char> vchBlock;
  };
  map<uint256, COrphanBlock*> mapOrphanBlocks;
  multimap<uint256, COrphanBlock*> mapOrphanBlocksByPrev;
  
  struct COrphanTx {
      CTransaction tx;
      NodeId fromPeer;
  };
  map<uint256, COrphanTx> mapOrphanTransactions;
  map<uint256, set<uint256> > mapOrphanTransactionsByPrev;
  void EraseOrphansFor(NodeId peer);
  
  // Constant stuff for coinbase transactions we create:
  CScript COINBASE_FLAGS;
  
  const string strMessageMagic = "DarkCoin Signed Message:\n";
  
  // Internal stuff
  namespace {
      struct CBlockIndexWorkComparator
      {
          bool operator()(CBlockIndex *pa, CBlockIndex *pb) {
              // First sort by most total work, ...
              if (pa->nChainWork > pb->nChainWork) return false;
              if (pa->nChainWork < pb->nChainWork) return true;
  
              // ... then by earliest time received, ...
              if (pa->nSequenceId < pb->nSequenceId) return false;
              if (pa->nSequenceId > pb->nSequenceId) return true;
  
              // Use pointer address as tie breaker (should only happen with blocks
              // loaded from disk, as those all have id 0).
              if (pa < pb) return false;
              if (pa > pb) return true;
  
              // Identical blocks.
              return false;
          }
      };
  
      CBlockIndex *pindexBestInvalid;
      // may contain all CBlockIndex*'s that have validness >=BLOCK_VALID_TRANSACTIONS, and must contain those who aren't failed
      set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexValid;
  
      CCriticalSection cs_LastBlockFile;
      CBlockFileInfo infoLastBlockFile;
      int nLastBlockFile = 0;
  
      // Every received block is assigned a unique and increasing identifier, so we
      // know which one to give priority in case of a fork.
      CCriticalSection cs_nBlockSequenceId;
      // Blocks loaded from disk are assigned id 0, so start the counter at 1.
      uint32_t nBlockSequenceId = 1;
  
      // Sources of received blocks, to be able to send them reject messages or ban
      // them, if processing happens afterwards. Protected by cs_main.
      map<uint256, NodeId> mapBlockSource;
  
      // Blocks that are in flight, and that are in the queue to be downloaded.
      // Protected by cs_main.
      struct QueuedBlock {
          uint256 hash;
          int64_t nTime;  // Time of "getdata" request in microseconds.
          int nQueuedBefore;  // Number of blocks in flight at the time of request.
      };
      map<uint256, pair<NodeId, list<QueuedBlock>::iterator> > mapBlocksInFlight;
      map<uint256, pair<NodeId, list<uint256>::iterator> > mapBlocksToDownload;
  }
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // dispatching functions
  //
  
  // These functions dispatch to one or all registered wallets
  
  namespace {
  struct CMainSignals {
      // Notifies listeners of updated transaction data (passing hash, transaction, and optionally the block it is found in.
      boost::signals2::signal<void (const uint256 &, const CTransaction &, const CBlock *)> SyncTransaction;
      // Notifies listeners of an erased transaction (currently disabled, requires transaction replacement).
      boost::signals2::signal<void (const uint256 &)> EraseTransaction;
      // Notifies listeners of an updated transaction without new data (for now: a coinbase potentially becoming visible).
      boost::signals2::signal<void (const uint256 &)> UpdatedTransaction;
      // Notifies listeners of a new active block chain.
      boost::signals2::signal<void (const CBlockLocator &)> SetBestChain;
      // Notifies listeners about an inventory item being seen on the network.
      boost::signals2::signal<void (const uint256 &)> Inventory;
      // Tells listeners to broadcast their data.
      boost::signals2::signal<void ()> Broadcast;
  } g_signals;
  }
  
  void RegisterWallet(CWalletInterface* pwalletIn) {
      g_signals.SyncTransaction.connect(boost::bind(&CWalletInterface::SyncTransaction, pwalletIn, _1, _2, _3));
      g_signals.EraseTransaction.connect(boost::bind(&CWalletInterface::EraseFromWallet, pwalletIn, _1));
      g_signals.UpdatedTransaction.connect(boost::bind(&CWalletInterface::UpdatedTransaction, pwalletIn, _1));
      g_signals.SetBestChain.connect(boost::bind(&CWalletInterface::SetBestChain, pwalletIn, _1));
      g_signals.Inventory.connect(boost::bind(&CWalletInterface::Inventory, pwalletIn, _1));
      g_signals.Broadcast.connect(boost::bind(&CWalletInterface::ResendWalletTransactions, pwalletIn));
  }
  
  void UnregisterWallet(CWalletInterface* pwalletIn) {
      g_signals.Broadcast.disconnect(boost::bind(&CWalletInterface::ResendWalletTransactions, pwalletIn));
      g_signals.Inventory.disconnect(boost::bind(&CWalletInterface::Inventory, pwalletIn, _1));
      g_signals.SetBestChain.disconnect(boost::bind(&CWalletInterface::SetBestChain, pwalletIn, _1));
      g_signals.UpdatedTransaction.disconnect(boost::bind(&CWalletInterface::UpdatedTransaction, pwalletIn, _1));
      g_signals.EraseTransaction.disconnect(boost::bind(&CWalletInterface::EraseFromWallet, pwalletIn, _1));
      g_signals.SyncTransaction.disconnect(boost::bind(&CWalletInterface::SyncTransaction, pwalletIn, _1, _2, _3));
  }
  
  void UnregisterAllWallets() {
      g_signals.Broadcast.disconnect_all_slots();
      g_signals.Inventory.disconnect_all_slots();
      g_signals.SetBestChain.disconnect_all_slots();
      g_signals.UpdatedTransaction.disconnect_all_slots();
      g_signals.EraseTransaction.disconnect_all_slots();
      g_signals.SyncTransaction.disconnect_all_slots();
  }
  
  void SyncWithWallets(const uint256 &hash, const CTransaction &tx, const CBlock *pblock) {
      g_signals.SyncTransaction(hash, tx, pblock);
  }
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // Registration of network node signals.
  //
  
  namespace {
  
  struct CBlockReject {
      unsigned char chRejectCode;
      string strRejectReason;
      uint256 hashBlock;
  };
  
  // Maintain validation-specific state about nodes, protected by cs_main, instead
  // by CNode's own locks. This simplifies asynchronous operation, where
  // processing of incoming data is done after the ProcessMessage call returns,
  // and we're no longer holding the node's locks.
  struct CNodeState {
      // Accumulated misbehaviour score for this peer.
      int nMisbehavior;
      // Whether this peer should be disconnected and banned.
      bool fShouldBan;
      // String name of this peer (debugging/logging purposes).
      std::string name;
      // List of asynchronously-determined block rejections to notify this peer about.
      std::vector<CBlockReject> rejects;
      list<QueuedBlock> vBlocksInFlight;
      int nBlocksInFlight;
      list<uint256> vBlocksToDownload;
      int nBlocksToDownload;
      int64_t nLastBlockReceive;
      int64_t nLastBlockProcess;
  
      CNodeState() {
          nMisbehavior = 0;
          fShouldBan = false;
          nBlocksToDownload = 0;
          nBlocksInFlight = 0;
          nLastBlockReceive = 0;
          nLastBlockProcess = 0;
      }
  };
  
  // Map maintaining per-node state. Requires cs_main.
  map<NodeId, CNodeState> mapNodeState;
  
  // Requires cs_main.
  CNodeState *State(NodeId pnode) {
      map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
      if (it == mapNodeState.end())
          return NULL;
      return &it->second;
  }
  
  int GetHeight()
  {
      LOCK(cs_main);
      return chainActive.Height();
  }
  
  void InitializeNode(NodeId nodeid, const CNode *pnode) {
      LOCK(cs_main);
      CNodeState &state = mapNodeState.insert(std::make_pair(nodeid, CNodeState())).first->second;
      state.name = pnode->addrName;
  }
  
  void FinalizeNode(NodeId nodeid) {
      LOCK(cs_main);
      CNodeState *state = State(nodeid);
  
      BOOST_FOREACH(const QueuedBlock& entry, state->vBlocksInFlight)
          mapBlocksInFlight.erase(entry.hash);
      BOOST_FOREACH(const uint256& hash, state->vBlocksToDownload)
          mapBlocksToDownload.erase(hash);
      EraseOrphansFor(nodeid);
  
      mapNodeState.erase(nodeid);
  }
  
  // Requires cs_main.
  void MarkBlockAsReceived(const uint256 &hash, NodeId nodeFrom = -1) {
      map<uint256, pair<NodeId, list<uint256>::iterator> >::iterator itToDownload = mapBlocksToDownload.find(hash);
      if (itToDownload != mapBlocksToDownload.end()) {
          CNodeState *state = State(itToDownload->second.first);
          state->vBlocksToDownload.erase(itToDownload->second.second);
          state->nBlocksToDownload--;
          mapBlocksToDownload.erase(itToDownload);
      }
  
      map<uint256, pair<NodeId, list<QueuedBlock>::iterator> >::iterator itInFlight = mapBlocksInFlight.find(hash);
      if (itInFlight != mapBlocksInFlight.end()) {
          CNodeState *state = State(itInFlight->second.first);
          state->vBlocksInFlight.erase(itInFlight->second.second);
          state->nBlocksInFlight--;
          if (itInFlight->second.first == nodeFrom)
              state->nLastBlockReceive = GetTimeMicros();
          mapBlocksInFlight.erase(itInFlight);
      }
  
  }
  
  // Requires cs_main.
  bool AddBlockToQueue(NodeId nodeid, const uint256 &hash) {
      if (mapBlocksToDownload.count(hash) || mapBlocksInFlight.count(hash))
          return false;
  
      CNodeState *state = State(nodeid);
      if (state == NULL)
          return false;
  
      list<uint256>::iterator it = state->vBlocksToDownload.insert(state->vBlocksToDownload.end(), hash);
      state->nBlocksToDownload++;
      if (state->nBlocksToDownload > 5000)
          Misbehaving(nodeid, 10);
      mapBlocksToDownload[hash] = std::make_pair(nodeid, it);
      return true;
  }
  
  // Requires cs_main.
  void MarkBlockAsInFlight(NodeId nodeid, const uint256 &hash) {
      CNodeState *state = State(nodeid);
      assert(state != NULL);
  
      // Make sure it's not listed somewhere already.
      MarkBlockAsReceived(hash);
  
      QueuedBlock newentry = {hash, GetTimeMicros(), state->nBlocksInFlight};
      if (state->nBlocksInFlight == 0)
          state->nLastBlockReceive = newentry.nTime; // Reset when a first request is sent.
      list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(), newentry);
      state->nBlocksInFlight++;
      mapBlocksInFlight[hash] = std::make_pair(nodeid, it);
  }
  
  }
  
  bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
      LOCK(cs_main);
      CNodeState *state = State(nodeid);
      if (state == NULL)
          return false;
      stats.nMisbehavior = state->nMisbehavior;
      return true;
  }
  
  void RegisterNodeSignals(CNodeSignals& nodeSignals)
  {
      nodeSignals.GetHeight.connect(&GetHeight);
      nodeSignals.ProcessMessages.connect(&ProcessMessages);
      nodeSignals.SendMessages.connect(&SendMessages);
      nodeSignals.InitializeNode.connect(&InitializeNode);
      nodeSignals.FinalizeNode.connect(&FinalizeNode);
  }
  
  void UnregisterNodeSignals(CNodeSignals& nodeSignals)
  {
      nodeSignals.GetHeight.disconnect(&GetHeight);
      nodeSignals.ProcessMessages.disconnect(&ProcessMessages);
      nodeSignals.SendMessages.disconnect(&SendMessages);
      nodeSignals.InitializeNode.disconnect(&InitializeNode);
      nodeSignals.FinalizeNode.disconnect(&FinalizeNode);
  }
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CChain implementation
  //
  
  CBlockIndex *CChain::SetTip(CBlockIndex *pindex) {
      if (pindex == NULL) {
          vChain.clear();
          return NULL;
      }
      vChain.resize(pindex->nHeight + 1);
      while (pindex && vChain[pindex->nHeight] != pindex) {
          vChain[pindex->nHeight] = pindex;
          pindex = pindex->pprev;
      }
      return pindex;
  }
  
  CBlockLocator CChain::GetLocator(const CBlockIndex *pindex) const {
      int nStep = 1;
      std::vector<uint256> vHave;
      vHave.reserve(32);
  
      if (!pindex)
          pindex = Tip();
      while (pindex) {
          vHave.push_back(pindex->GetBlockHash());
          // Stop when we have added the genesis block.
          if (pindex->nHeight == 0)
              break;
          // Exponentially larger steps back, plus the genesis block.
          int nHeight = std::max(pindex->nHeight - nStep, 0);
          // In case pindex is not in this chain, iterate pindex->pprev to find blocks.
          while (pindex->nHeight > nHeight && !Contains(pindex))
              pindex = pindex->pprev;
          // If pindex is in this chain, use direct height-based access.
          if (pindex->nHeight > nHeight)
              pindex = (*this)[nHeight];
          if (vHave.size() > 10)
              nStep *= 2;
      }
  
      return CBlockLocator(vHave);
  }
  
  CBlockIndex *CChain::FindFork(const CBlockLocator &locator) const {
      // Find the first block the caller has in the main chain
      BOOST_FOREACH(const uint256& hash, locator.vHave) {
          std::map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(hash);
          if (mi != mapBlockIndex.end())
          {
              CBlockIndex* pindex = (*mi).second;
              if (Contains(pindex))
                  return pindex;
          }
      }
      return Genesis();
  }
  
  CCoinsViewCache *pcoinsTip = NULL;
  CBlockTreeDB *pblocktree = NULL;
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // mapOrphanTransactions
  //
  
  bool AddOrphanTx(const CTransaction& tx, NodeId peer)
  {
      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)
      {
          LogPrint("mempool", "ignoring large orphan tx (size: %u, hash: %s)\n", sz, hash.ToString());
          return false;
      }
  
      mapOrphanTransactions[hash].tx = tx;
      mapOrphanTransactions[hash].fromPeer = peer;
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
          mapOrphanTransactionsByPrev[txin.prevout.hash].insert(hash);
  
      LogPrint("mempool", "stored orphan tx %s (mapsz %u prevsz %u)\n", hash.ToString(),
               mapOrphanTransactions.size(), mapOrphanTransactionsByPrev.size());
      return true;
  }
  
  void static EraseOrphanTx(uint256 hash)
  {
      map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.find(hash);
      if (it == mapOrphanTransactions.end())
          return;
      BOOST_FOREACH(const CTxIn& txin, it->second.tx.vin)
      {
          map<uint256, set<uint256> >::iterator itPrev = mapOrphanTransactionsByPrev.find(txin.prevout.hash);
          if (itPrev == mapOrphanTransactionsByPrev.end())
              continue;
          itPrev->second.erase(hash);
          if (itPrev->second.empty())
              mapOrphanTransactionsByPrev.erase(itPrev);
      }
      mapOrphanTransactions.erase(it);
  }
  
  void EraseOrphansFor(NodeId peer)
  {
      int nErased = 0;
      map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
      while (iter != mapOrphanTransactions.end())
      {
          map<uint256, COrphanTx>::iterator maybeErase = iter++; // increment to avoid iterator becoming invalid
          if (maybeErase->second.fromPeer == peer)
          {
              EraseOrphanTx(maybeErase->second.tx.GetHash());
              ++nErased;
          }
      }
      if (nErased > 0) LogPrint("mempool", "Erased %d orphan tx from peer %d\n", nErased, peer);
  }
  
  
  unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
  {
      unsigned int nEvicted = 0;
      while (mapOrphanTransactions.size() > nMaxOrphans)
      {
          // Evict a random orphan:
          uint256 randomhash = GetRandHash();
          map<uint256, COrphanTx>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
          if (it == mapOrphanTransactions.end())
              it = mapOrphanTransactions.begin();
          EraseOrphanTx(it->first);
          ++nEvicted;
      }
      return nEvicted;
  }
  
  
  
  
  
  
  
  bool IsStandardTx(const CTransaction& tx, string& reason)
  {
      AssertLockHeld(cs_main);
      if (tx.nVersion > CTransaction::CURRENT_VERSION || tx.nVersion < 1) {
          reason = "version";
          return false;
      }
  
      // Treat non-final transactions as non-standard to prevent a specific type
      // of double-spend attack, as well as DoS attacks. (if the transaction
      // can't be mined, the attacker isn't expending resources broadcasting it)
      // Basically we don't want to propagate transactions that can't included in
      // the next block.
      //
      // However, IsFinalTx() is confusing... Without arguments, it uses
      // chainActive.Height() to evaluate nLockTime; when a block is accepted, chainActive.Height()
      // is set to the value of nHeight in the block. However, when IsFinalTx()
      // is called within CBlock::AcceptBlock(), the height of the block *being*
      // evaluated is what is used. Thus if we want to know if a transaction can
      // be part of the *next* block, we need to call IsFinalTx() with one more
      // than chainActive.Height().
      //
      // Timestamps on the other hand don't get any special treatment, because we
      // can't know what timestamp the next block will have, and there aren't
      // timestamp applications where it matters.
      if (!IsFinalTx(tx, chainActive.Height() + 1)) {
          reason = "non-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 = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION);
      if (sz >= MAX_STANDARD_TX_SIZE) {
          reason = "tx-size";
          return false;
      }
  
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
      {
          // Biggest 'standard' txin is a 15-of-15 P2SH multisig with compressed
          // keys. (remember the 520 byte limit on redeemScript size) That works
          // out to a (15*(33+1))+3=513 byte redeemScript, 513+1+15*(73+1)=1624
          // bytes of scriptSig, which we round off to 1650 bytes for some minor
          // future-proofing. That's also enough to spend a 20-of-20
          // CHECKMULTISIG scriptPubKey, though such a scriptPubKey is not
          // considered standard)
          if (txin.scriptSig.size() > 1650) {
              reason = "scriptsig-size";
              return false;
          }
          if (!txin.scriptSig.IsPushOnly()) {
              reason = "scriptsig-not-pushonly";
              return false;
          }
          if (!txin.scriptSig.HasCanonicalPushes()) {
              reason = "scriptsig-non-canonical-push";
              return false;
          }
      }
  
      unsigned int nDataOut = 0;
      txnouttype whichType;
      BOOST_FOREACH(const CTxOut& txout, tx.vout) {
          if (!::IsStandard(txout.scriptPubKey, whichType)) {
              reason = "scriptpubkey";
              return false;
          }
          if (whichType == TX_NULL_DATA)
              nDataOut++;
          else if (txout.IsDust(CTransaction::nMinRelayTxFee)) {
              reason = "dust";
              return false;
          }
      }
  
      // only one OP_RETURN txout is permitted
      if (nDataOut > 1) {
          reason = "multi-op-return";
          return false;
      }
  
      return true;
  }
  
  bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
  {
      AssertLockHeld(cs_main);
      // Time based nLockTime implemented in 0.1.6
      if (tx.nLockTime == 0)
          return true;
      if (nBlockHeight == 0)
          nBlockHeight = chainActive.Height();
      if (nBlockTime == 0)
          nBlockTime = GetAdjustedTime();
      if ((int64_t)tx.nLockTime < ((int64_t)tx.nLockTime < LOCKTIME_THRESHOLD ? (int64_t)nBlockHeight : nBlockTime))
          return true;
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
          if (!txin.IsFinal())
              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 AreInputsStandard(const CTransaction& tx, CCoinsViewCache& mapInputs)
  {
      if (tx.IsCoinBase())
          return true; // Coinbases don't use vin normally
  
      for (unsigned int i = 0; i < tx.vin.size(); i++)
      {
          const CTxOut& prev = mapInputs.GetOutputFor(tx.vin[i]);
  
          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, tx.vin[i].scriptSig, tx, 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 GetLegacySigOpCount(const CTransaction& tx)
  {
      unsigned int nSigOps = 0;
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
      {
          nSigOps += txin.scriptSig.GetSigOpCount(false);
      }
      BOOST_FOREACH(const CTxOut& txout, tx.vout)
      {
          nSigOps += txout.scriptPubKey.GetSigOpCount(false);
      }
      return nSigOps;
  }
  
  unsigned int GetP2SHSigOpCount(const CTransaction& tx, CCoinsViewCache& inputs)
  {
      if (tx.IsCoinBase())
          return 0;
  
      unsigned int nSigOps = 0;
      for (unsigned int i = 0; i < tx.vin.size(); i++)
      {
          const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
          if (prevout.scriptPubKey.IsPayToScriptHash())
              nSigOps += prevout.scriptPubKey.GetSigOpCount(tx.vin[i].scriptSig);
      }
      return nSigOps;
  }
  
  int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
  {
      AssertLockHeld(cs_main);
      CBlock blockTmp;
  
      if (pblock == NULL) {
          CCoins coins;
          if (pcoinsTip->GetCoins(GetHash(), coins)) {
              CBlockIndex *pindex = chainActive[coins.nHeight];
              if (pindex) {
                  if (!ReadBlockFromDisk(blockTmp, 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;
              LogPrintf("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 || !chainActive.Contains(pindex))
          return 0;
  
      return chainActive.Height() - pindex->nHeight + 1;
  }
  
  int GetInputAge(CTxIn& vin)
  {
      // Fetch previous transactions (inputs):
      CCoinsView viewDummy;
      CCoinsViewCache view(viewDummy);
      {
          LOCK(mempool.cs);
          CCoinsViewCache &viewChain = *pcoinsTip;
          CCoinsViewMemPool viewMempool(viewChain, mempool);
          view.SetBackend(viewMempool); // temporarily switch cache backend to db+mempool view
  
          const uint256& prevHash = vin.prevout.hash;
          CCoins coins;
          view.GetCoins(prevHash, coins); // this is certainly allowed to fail
          view.SetBackend(viewDummy); // switch back to avoid locking mempool for too long
      }
  
      if(!view.HaveCoins(vin.prevout.hash)) return -1;
  
      const CCoins &coins = view.GetCoins(vin.prevout.hash);
  
      return (chainActive.Tip()->nHeight+1) - coins.nHeight;
  }
  
  
  bool CheckTransaction(const CTransaction& tx, CValidationState &state)
  {
      // Basic checks that don't depend on any context
      if (tx.vin.empty())
          return state.DoS(10, error("CheckTransaction() : vin empty"),
                           REJECT_INVALID, "bad-txns-vin-empty");
      if (tx.vout.empty())
          return state.DoS(10, error("CheckTransaction() : vout empty"),
                           REJECT_INVALID, "bad-txns-vout-empty");
      // Size limits
      if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
          return state.DoS(100, error("CheckTransaction() : size limits failed"),
                           REJECT_INVALID, "bad-txns-oversize");
  
      // Check for negative or overflow output values
      int64_t nValueOut = 0;
      BOOST_FOREACH(const CTxOut& txout, tx.vout)
      {
          if (txout.nValue < 0)
              return state.DoS(100, error("CheckTransaction() : txout.nValue negative"),
                               REJECT_INVALID, "bad-txns-vout-negative");
          if (txout.nValue > MAX_MONEY)
              return state.DoS(100, error("CheckTransaction() : txout.nValue too high"),
                               REJECT_INVALID, "bad-txns-vout-toolarge");
          nValueOut += txout.nValue;
          if (!MoneyRange(nValueOut))
              return state.DoS(100, error("CheckTransaction() : txout total out of range"),
                               REJECT_INVALID, "bad-txns-txouttotal-toolarge");
      }
  
      // Check for duplicate inputs
      set<COutPoint> vInOutPoints;
      BOOST_FOREACH(const CTxIn& txin, tx.vin)
      {
          if (vInOutPoints.count(txin.prevout))
              return state.DoS(100, error("CheckTransaction() : duplicate inputs"),
                               REJECT_INVALID, "bad-txns-inputs-duplicate");
          vInOutPoints.insert(txin.prevout);
      }
  
      if (tx.IsCoinBase())
      {
          if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
              return state.DoS(100, error("CheckTransaction() : coinbase script size"),
                               REJECT_INVALID, "bad-cb-length");
      }
      else
      {
          BOOST_FOREACH(const CTxIn& txin, tx.vin)
              if (txin.prevout.IsNull())
                  return state.DoS(10, error("CheckTransaction() : prevout is null"),
                                   REJECT_INVALID, "bad-txns-prevout-null");
      }
  
      return true;
  }
  
  int64_t GetMinFee(const CTransaction& tx, unsigned int nBytes, bool fAllowFree, enum GetMinFee_mode mode)
  {
      // Base fee is either nMinTxFee or nMinRelayTxFee
      int64_t nBaseFee = (mode == GMF_RELAY) ? tx.nMinRelayTxFee : tx.nMinTxFee;
  
      int64_t nMinFee = (1 + (int64_t)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, tx.vout)
              if (txout.nValue < CENT)
                  nMinFee = nBaseFee;
      }
  
      if (!MoneyRange(nMinFee))
          nMinFee = MAX_MONEY;
      return nMinFee;
  }
  
  
  bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree,
                          bool* pfMissingInputs, bool fRejectInsaneFee, bool ignoreFees)
  {
      AssertLockHeld(cs_main);
      if (pfMissingInputs)
          *pfMissingInputs = false;
  
      if (!CheckTransaction(tx, state))
          return error("AcceptToMemoryPool: : CheckTransaction failed");
  
      // Coinbase is only valid in a block, not as a loose transaction
      if (tx.IsCoinBase())
          return state.DoS(100, error("AcceptToMemoryPool: : coinbase as individual tx"),
                           REJECT_INVALID, "coinbase");
  
      // Rather not work on nonstandard transactions (unless -testnet/-regtest)
      string reason;
      if (Params().NetworkID() == CChainParams::MAIN && !IsStandardTx(tx, reason))
          return state.DoS(0,
                           error("AcceptToMemoryPool : nonstandard transaction: %s", reason),
                           REJECT_NONSTANDARD, reason);
  
      // is it already in the memory pool?
      uint256 hash = tx.GetHash();
      if (pool.exists(hash))
          return false;
  
      // ----------- instantX transaction scanning -----------
  
      BOOST_FOREACH(const CTxIn& in, tx.vin){
          if(mapLockedInputs.count(in.prevout)){
              if(mapLockedInputs[in.prevout] != tx.GetHash()){
                  return state.DoS(0,
                                   error("AcceptToMemoryPool : conflicts with existing transaction lock: %s", reason),
                                   REJECT_INVALID, "tx-lock-conflict");
              }
          }
      }
  
      // Check for conflicts with in-memory transactions
      {
      LOCK(pool.cs); // protect pool.mapNextTx
      for (unsigned int i = 0; i < tx.vin.size(); i++)
      {
          COutPoint outpoint = tx.vin[i].prevout;
          if (pool.mapNextTx.count(outpoint))
          {
              // Disable replacement feature for now
              return false;
          }
      }
      }
  
  
      {
          CCoinsView dummy;
          CCoinsViewCache view(dummy);
  
          {
          LOCK(pool.cs);
          CCoinsViewMemPool viewMemPool(*pcoinsTip, pool);
          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 (!view.HaveInputs(tx))
              return state.Invalid(error("AcceptToMemoryPool : inputs already spent"),
                                   REJECT_DUPLICATE, "bad-txns-inputs-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 (Params().NetworkID() == CChainParams::MAIN && !AreInputsStandard(tx, view))
              return error("AcceptToMemoryPool: : 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_t nValueIn = view.GetValueIn(tx);
          int64_t nValueOut = tx.GetValueOut();
          int64_t nFees = nValueIn-nValueOut;
          double dPriority = view.GetPriority(tx, chainActive.Height());
  
          CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height());
          unsigned int nSize = entry.GetTxSize();
  
          // Don't accept it if it can't get into a block
          if(!ignoreFees){
              int64_t txMinFee = GetMinFee(tx, nSize, true, GMF_RELAY);
              if (fLimitFree && nFees < txMinFee)
                  return state.DoS(0, error("AcceptToMemoryPool : not enough fees %s, %d < %d",
                                            hash.ToString(), nFees, txMinFee),
                                   REJECT_INSUFFICIENTFEE, "insufficient fee");
  
              // 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 CCriticalSection csFreeLimiter;
                  static double dFreeCount;
                  static int64_t nLastTime;
                  int64_t nNow = GetTime();
  
                  LOCK(csFreeLimiter);
  
                  // 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 state.DoS(0, error("AcceptToMemoryPool : free transaction rejected by rate limiter"),
                                       REJECT_INSUFFICIENTFEE, "insufficient priority");
                  LogPrint("mempool", "Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
                  dFreeCount += nSize;
              }
          }
  
          if (fRejectInsaneFee && nFees > CTransaction::nMinRelayTxFee * 10000)
              return error("AcceptToMemoryPool: : insane fees %s, %d > %d",
                           hash.ToString(),
                           nFees, CTransaction::nMinRelayTxFee * 10000);
  
          // Check against previous transactions
          // This is done last to help prevent CPU exhaustion denial-of-service attacks.
          if (!CheckInputs(tx, state, view, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC | SCRIPT_VERIFY_DERSIG))
          {
              return error("AcceptToMemoryPool: : ConnectInputs failed %s", hash.ToString());
          }
          // Store transaction in memory
          pool.addUnchecked(hash, entry);
      }
  
      g_signals.SyncTransaction(hash, tx, NULL);
  
      return true;
  }
  
  bool AcceptableInputs(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool ignoreFees)
  {
      AssertLockHeld(cs_main);
  
      if (!CheckTransaction(tx, state))
          return error("AcceptToMemoryPool: : CheckTransaction failed");
  
      // Coinbase is only valid in a block, not as a loose transaction
      if (tx.IsCoinBase())
          return state.DoS(100, error("AcceptToMemoryPool: : coinbase as individual tx"),
                           REJECT_INVALID, "coinbase");
  
      // is it already in the memory pool?
      uint256 hash = tx.GetHash();
      if (pool.exists(hash))
          return false;
  
      // Check for conflicts with in-memory transactions
      {
          LOCK(pool.cs); // protect pool.mapNextTx
          for (unsigned int i = 0; i < tx.vin.size(); i++)
          {
              COutPoint outpoint = tx.vin[i].prevout;
              if (pool.mapNextTx.count(outpoint))
              {
                  // Disable replacement feature for now
                  return false;
              }
          }
      }
  
      {
          CCoinsView dummy;
          CCoinsViewCache view(dummy);
  
          {
              LOCK(pool.cs);
              CCoinsViewMemPool viewMemPool(*pcoinsTip, pool);
              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)) {
                      return false;
                  }
              }
  
              // are the actual inputs available?
              if (!view.HaveInputs(tx))
                  return state.Invalid(error("AcceptToMemoryPool : inputs already spent"),
                                       REJECT_DUPLICATE, "bad-txns-inputs-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);
          }
  
          // Don't accept it if it can't get into a block
          if(!ignoreFees){
              int64_t nValueIn = view.GetValueIn(tx);
              int64_t nValueOut = tx.GetValueOut();
              int64_t nFees = nValueIn-nValueOut;
              double dPriority = view.GetPriority(tx, chainActive.Height());
  
              CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height());
              unsigned int nSize = entry.GetTxSize();
  
              int64_t txMinFee = GetMinFee(tx, nSize, true, GMF_RELAY);
              if (nFees < txMinFee)
                  return state.DoS(0, error("AcceptToMemoryPool : not enough fees %s, %d < %d",
                                            hash.ToString(), nFees, txMinFee),
                                   REJECT_INSUFFICIENTFEE, "insufficient fee");
  
              // 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 (nFees < CTransaction::nMinRelayTxFee)
              {
                  static CCriticalSection csFreeLimiter;
                  static double dFreeCount;
                  static int64_t nLastTime;
                  int64_t nNow = GetTime();
  
                  LOCK(csFreeLimiter);
  
                  // 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 state.DoS(0, error("AcceptToMemoryPool : free transaction rejected by rate limiter"),
                                       REJECT_INSUFFICIENTFEE, "insufficient priority");
                  LogPrint("mempool", "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 (!CheckInputs(tx, state, view, false, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC))
          {
              return error("AcceptToMemoryPool: : ConnectInputs failed %s", hash.ToString());
          }
      }
  
      return true;
  }
  
  
  int CMerkleTx::GetDepthInMainChainINTERNAL(CBlockIndex* &pindexRet) const
  {
      if (hashBlock == 0 || nIndex == -1)
          return 0;
      AssertLockHeld(cs_main);
  
      // 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 || !chainActive.Contains(pindex))
          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 chainActive.Height() - pindex->nHeight + 1;
  }
  
  int CMerkleTx::GetTransactionLockSignatures() const
  {
      if(fLargeWorkForkFound || fLargeWorkInvalidChainFound) return -2;
      if(!IsSporkActive(SPORK_2_INSTANTX)) return -3;
      if(nInstantXDepth == 0) return -1;
  
      //compile consessus vote
      std::map<uint256, CTransactionLock>::iterator i = mapTxLocks.find(GetHash());
      if (i != mapTxLocks.end()){
          return (*i).second.CountSignatures();
      }
  
      return -1;
  }
  
  bool CMerkleTx::IsTransactionLockTimedOut() const
  {
      if(nInstantXDepth == 0) return 0;
  
      //compile consessus vote
      std::map<uint256, CTransactionLock>::iterator i = mapTxLocks.find(GetHash());
      if (i != mapTxLocks.end()){
          return GetTime() > (*i).second.nTimeout;
      }
  
      return false;
  }
  
  int CMerkleTx::GetDepthInMainChain(CBlockIndex* &pindexRet, bool enableIX) const
  {
      AssertLockHeld(cs_main);
      int nResult = GetDepthInMainChainINTERNAL(pindexRet);
      if (nResult == 0 && !mempool.exists(GetHash()))
          return -1; // Not in chain, not in mempool
  
      if(enableIX){
          if (nResult < 6){
              int signatures = GetTransactionLockSignatures();
              if(signatures >= INSTANTX_SIGNATURES_REQUIRED){
                  return nInstantXDepth+nResult;
              }
          }
      }
  
      return nResult;
  }
  
  int CMerkleTx::GetBlocksToMaturity() const
  {
      if (!IsCoinBase())
          return 0;
      return max(0, COINBASE_MATURITY - GetDepthInMainChain());
  }
  
  
  bool CMerkleTx::AcceptToMemoryPool(bool fLimitFree)
  {
      CValidationState state;
      return ::AcceptToMemoryPool(mempool, state, *this, fLimitFree, NULL);
  }
  
  
  // 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);
          {
              if (mempool.lookup(hash, txOut))
              {
                  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 - %s", __func__, e.what());
                  }
                  hashBlock = header.GetHash();
                  if (txOut.GetHash() != hash)
                      return error("%s : txid mismatch", __func__);
                  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 = chainActive[nHeight];
          }
      }
  
      if (pindexSlow) {
          CBlock block;
          if (ReadBlockFromDisk(block, pindexSlow)) {
              BOOST_FOREACH(const CTransaction &tx, block.vtx) {
                  if (tx.GetHash() == hash) {
                      txOut = tx;
                      hashBlock = pindexSlow->GetBlockHash();
                      return true;
                  }
              }
          }
      }
  
      return false;
  }
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CBlock and CBlockIndex
  //
  
  bool WriteBlockToDisk(CBlock& block, CDiskBlockPos& pos)
  {
      // Open history file to append
      CAutoFile fileout = CAutoFile(OpenBlockFile(pos), SER_DISK, CLIENT_VERSION);
      if (!fileout)
          return error("WriteBlockToDisk : OpenBlockFile failed");
  
      // Write index header
      unsigned int nSize = fileout.GetSerializeSize(block);
      fileout << FLATDATA(Params().MessageStart()) << nSize;
  
      // Write block
      long fileOutPos = ftell(fileout);
      if (fileOutPos < 0)
          return error("WriteBlockToDisk : ftell failed");
      pos.nPos = (unsigned int)fileOutPos;
      fileout << block;
  
      // Flush stdio buffers and commit to disk before returning
      fflush(fileout);
      if (!IsInitialBlockDownload())
          FileCommit(fileout);
  
      return true;
  }
  
  bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos)
  {
      block.SetNull();
  
      // Open history file to read
      CAutoFile filein = CAutoFile(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
      if (!filein)
          return error("ReadBlockFromDisk : OpenBlockFile failed");
  
      // Read block
      try {
          filein >> block;
      }
      catch (std::exception &e) {
          return error("%s : Deserialize or I/O error - %s", __func__, e.what());
      }
  
      // Check the header
      if (!CheckProofOfWork(block.GetHash(), block.nBits))
          return error("ReadBlockFromDisk : Errors in block header");
  
      return true;
  }
  
  bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex)
  {
      if (!ReadBlockFromDisk(block, pindex->GetBlockPos()))
          return false;
      if (block.GetHash() != pindex->GetBlockHash())
          return error("ReadBlockFromDisk(CBlock&, CBlockIndex*) : GetHash() doesn't match index");
      return true;
  }
  
  uint256 static GetOrphanRoot(const uint256& hash)
  {
      map<uint256, COrphanBlock*>::iterator it = mapOrphanBlocks.find(hash);
      if (it == mapOrphanBlocks.end())
          return hash;
  
      // Work back to the first block in the orphan chain
      do {
          map<uint256, COrphanBlock*>::iterator it2 = mapOrphanBlocks.find(it->second->hashPrev);
          if (it2 == mapOrphanBlocks.end())
              return it->first;
          it = it2;
      } while(true);
  }
  
  // Remove a random orphan block (which does not have any dependent orphans).
  void static PruneOrphanBlocks()
  {
      if (mapOrphanBlocksByPrev.size() <= (size_t)std::max((int64_t)0, GetArg("-maxorphanblocks", DEFAULT_MAX_ORPHAN_BLOCKS)))
          return;
  
      // Pick a random orphan block.
      int pos = insecure_rand() % mapOrphanBlocksByPrev.size();
      std::multimap<uint256, COrphanBlock*>::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, COrphanBlock*>::iterator it2 = mapOrphanBlocksByPrev.find(it->second->hashBlock);
          if (it2 == mapOrphanBlocksByPrev.end())
              break;
          it = it2;
      } while(1);
  
      uint256 hash = it->second->hashBlock;
      delete it->second;
      mapOrphanBlocksByPrev.erase(it);
      mapOrphanBlocks.erase(hash);
  }
  
  double ConvertBitsToDouble(unsigned int nBits)
  {
      int nShift = (nBits >> 24) & 0xff;
  
      double dDiff =
          (double)0x0000ffff / (double)(nBits & 0x00ffffff);
  
      while (nShift < 29)
      {
          dDiff *= 256.0;
          nShift++;
      }
      while (nShift > 29)
      {
          dDiff /= 256.0;
          nShift--;
      }
  
      return dDiff;
  }
  
  int64_t GetBlockValue(int nBits, int nHeight, int64_t nFees)
  {
      double dDiff = (double)0x0000ffff / (double)(nBits & 0x00ffffff);
  
      /* fixed bug caused diff to not be correctly calculated */
      if(nHeight > 4500 || TestNet()) dDiff = ConvertBitsToDouble(nBits);
  
      int64_t nSubsidy = 0;
      if(nHeight >= 5465) {
          if((nHeight >= 17000 && dDiff > 75) || nHeight >= 24000) { // GPU/ASIC difficulty calc
              // 2222222/(((x+2600)/9)^2)
              nSubsidy = (2222222.0 / (pow((dDiff+2600.0)/9.0,2.0)));
              if (nSubsidy > 25) nSubsidy = 25;
              if (nSubsidy < 5) nSubsidy = 5;
          } else { // CPU mining calc
              nSubsidy = (11111.0 / (pow((dDiff+51.0)/6.0,2.0)));
              if (nSubsidy > 500) nSubsidy = 500;
              if (nSubsidy < 25) nSubsidy = 25;
          }
      } else {
          nSubsidy = (1111.0 / (pow((dDiff+1.0),2.0)));
          if (nSubsidy > 500) nSubsidy = 500;
          if (nSubsidy < 1) nSubsidy = 1;
      }
  
      // LogPrintf("height %u diff %4.2f reward %i \n", nHeight, dDiff, nSubsidy);
      nSubsidy *= COIN;
  
      if(TestNet()){
          for(int i = 46200; i <= nHeight; i += 210240) nSubsidy -= nSubsidy/14;
      } else {
          // yearly decline of production by 7.1% per year, projected 21.3M coins max by year 2050.
          for(int i = 210240; i <= nHeight; i += 210240) nSubsidy -= nSubsidy/14;
      }
  
      return nSubsidy + nFees;
  }
  
  int64_t GetMasternodePayment(int nHeight, int64_t blockValue)
  {
      int64_t ret = blockValue/5; // start at 20%
  
      if(TestNet()) {
          if(nHeight > 46000)             ret += blockValue / 20; //25% - 2014-10-07
          if(nHeight > 46000+((576*1)*1)) ret += blockValue / 20; //30% - 2014-10-08
          if(nHeight > 46000+((576*1)*2)) ret += blockValue / 20; //35% - 2014-10-09
          if(nHeight > 46000+((576*1)*3)) ret += blockValue / 20; //40% - 2014-10-10
          if(nHeight > 46000+((576*1)*4)) ret += blockValue / 20; //45% - 2014-10-11
          if(nHeight > 46000+((576*1)*5)) ret += blockValue / 20; //50% - 2014-10-12
          if(nHeight > 46000+((576*1)*6)) ret += blockValue / 20; //55% - 2014-10-13
          if(nHeight > 46000+((576*1)*7)) ret += blockValue / 20; //60% - 2014-10-14
      }
  
      if(nHeight > 158000)               ret += blockValue / 20; // 158000 - 25.0% - 2014-10-24
      if(nHeight > 158000+((576*30)* 1)) ret += blockValue / 20; // 175280 - 30.0% - 2014-11-25
      if(nHeight > 158000+((576*30)* 2)) ret += blockValue / 20; // 192560 - 35.0% - 2014-12-26
      if(nHeight > 158000+((576*30)* 3)) ret += blockValue / 40; // 209840 - 37.5% - 2015-01-26
      if(nHeight > 158000+((576*30)* 4)) ret += blockValue / 40; // 227120 - 40.0% - 2015-02-27
      if(nHeight > 158000+((576*30)* 5)) ret += blockValue / 40; // 244400 - 42.5% - 2015-03-30
      if(nHeight > 158000+((576*30)* 6)) ret += blockValue / 40; // 261680 - 45.0% - 2015-05-01
      if(nHeight > 158000+((576*30)* 7)) ret += blockValue / 40; // 278960 - 47.5% - 2015-06-01
      if(nHeight > 158000+((576*30)* 9)) ret += blockValue / 40; // 313520 - 50.0% - 2015-08-03
      if(nHeight > 158000+((576*30)*11)) ret += blockValue / 40; // 348080 - 52.5% - 2015-10-05
      if(nHeight > 158000+((576*30)*13)) ret += blockValue / 40; // 382640 - 55.0% - 2015-12-07
      if(nHeight > 158000+((576*30)*15)) ret += blockValue / 40; // 417200 - 57.5% - 2016-02-08
      if(nHeight > 158000+((576*30)*17)) ret += blockValue / 40; // 451760 - 60.0% - 2016-04-11
  
      return ret;
  }
  
  static const int64_t nTargetTimespan = 24 * 60 * 60; // Dash: 1 day
  static const int64_t nTargetSpacing = 2.5 * 60; // Dash: 2.5 minutes
  static const int64_t nInterval = nTargetTimespan / nTargetSpacing; // 576 blocks
  
  //
  // minimum amount of work that could possibly be required nTime after
  // minimum work required was nBase
  //
  unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime)
  {
      const CBigNum &bnLimit = Params().ProofOfWorkLimit();
      // Testnet has min-difficulty blocks
      // after nTargetSpacing*2 time between blocks:
      if (TestNet() && nTime > nTargetSpacing*2)
          return bnLimit.GetCompact();
  
      CBigNum bnResult;
      bnResult.SetCompact(nBase);
      while (nTime > 0 && bnResult < bnLimit)
      {
          // Maximum 400% adjustment...
          bnResult *= 4;
          // ... in best-case exactly 4-times-normal target time
          nTime -= nTargetTimespan*4;
      }
      if (bnResult > bnLimit)
          bnResult = bnLimit;
      return bnResult.GetCompact();
  }
  
  unsigned int static KimotoGravityWell(const CBlockIndex* pindexLast, const CBlockHeader *pblock, uint64_t TargetBlocksSpacingSeconds, uint64_t PastBlocksMin, uint64_t PastBlocksMax) {
          const CBlockIndex *BlockLastSolved = pindexLast;
          const CBlockIndex *BlockReading = pindexLast;
          uint64_t PastBlocksMass = 0;
          int64_t PastRateActualSeconds = 0;
          int64_t PastRateTargetSeconds = 0;
          double PastRateAdjustmentRatio = double(1);
          CBigNum PastDifficultyAverage;
          CBigNum PastDifficultyAveragePrev;
          double EventHorizonDeviation;
          double EventHorizonDeviationFast;
          double EventHorizonDeviationSlow;
  
      if (BlockLastSolved == NULL || BlockLastSolved->nHeight == 0 || (uint64_t)BlockLastSolved->nHeight < PastBlocksMin) { return Params().ProofOfWorkLimit().GetCompact(); }
  
          for (unsigned int i = 1; BlockReading && BlockReading->nHeight > 0; i++) {
                  if (PastBlocksMax > 0 && i > PastBlocksMax) { break; }
                  PastBlocksMass++;
  
                  if (i == 1) { PastDifficultyAverage.SetCompact(BlockReading->nBits); }
                  else { PastDifficultyAverage = ((CBigNum().SetCompact(BlockReading->nBits) - PastDifficultyAveragePrev) / i) + PastDifficultyAveragePrev; }
                  PastDifficultyAveragePrev = PastDifficultyAverage;
  
                  PastRateActualSeconds = BlockLastSolved->GetBlockTime() - BlockReading->GetBlockTime();
                  PastRateTargetSeconds = TargetBlocksSpacingSeconds * PastBlocksMass;
                  PastRateAdjustmentRatio = double(1);
                  if (PastRateActualSeconds < 0) { PastRateActualSeconds = 0; }
                  if (PastRateActualSeconds != 0 && PastRateTargetSeconds != 0) {
                  PastRateAdjustmentRatio = double(PastRateTargetSeconds) / double(PastRateActualSeconds);
                  }
                  EventHorizonDeviation = 1 + (0.7084 * pow((double(PastBlocksMass)/double(28.2)), -1.228));
                  EventHorizonDeviationFast = EventHorizonDeviation;
                  EventHorizonDeviationSlow = 1 / EventHorizonDeviation;
  
                  if (PastBlocksMass >= PastBlocksMin) {
                          if ((PastRateAdjustmentRatio <= EventHorizonDeviationSlow) || (PastRateAdjustmentRatio >= EventHorizonDeviationFast)) { assert(BlockReading); break; }
                  }
                  if (BlockReading->pprev == NULL) { assert(BlockReading); break; }
                  BlockReading = BlockReading->pprev;
          }
  
          CBigNum bnNew(PastDifficultyAverage);
          if (PastRateActualSeconds != 0 && PastRateTargetSeconds != 0) {
                  bnNew *= PastRateActualSeconds;
                  bnNew /= PastRateTargetSeconds;
          }
  
      if (bnNew > Params().ProofOfWorkLimit()) {
          bnNew = Params().ProofOfWorkLimit();
      }
  
      return bnNew.GetCompact();
  }
  
  unsigned int static DarkGravityWave(const CBlockIndex* pindexLast, const CBlockHeader *pblock) {
      /* current difficulty formula, dash - DarkGravity v3, written by Evan Duffield - evan@dashpay.io */
      const CBlockIndex *BlockLastSolved = pindexLast;
      const CBlockIndex *BlockReading = pindexLast;
      int64_t nActualTimespan = 0;
      int64_t LastBlockTime = 0;
      int64_t PastBlocksMin = 24;
      int64_t PastBlocksMax = 24;
      int64_t CountBlocks = 0;
      CBigNum PastDifficultyAverage;
      CBigNum PastDifficultyAveragePrev;
  
      if (BlockLastSolved == NULL || BlockLastSolved->nHeight == 0 || BlockLastSolved->nHeight < PastBlocksMin) {
          return Params().ProofOfWorkLimit().GetCompact();
      }
  
      for (unsigned int i = 1; BlockReading && BlockReading->nHeight > 0; i++) {
          if (PastBlocksMax > 0 && i > PastBlocksMax) { break; }
          CountBlocks++;
  
          if(CountBlocks <= PastBlocksMin) {
              if (CountBlocks == 1) { PastDifficultyAverage.SetCompact(BlockReading->nBits); }
              else { PastDifficultyAverage = ((PastDifficultyAveragePrev * CountBlocks)+(CBigNum().SetCompact(BlockReading->nBits))) / (CountBlocks+1); }
              PastDifficultyAveragePrev = PastDifficultyAverage;
          }
  
          if(LastBlockTime > 0){
              int64_t Diff = (LastBlockTime - BlockReading->GetBlockTime());
              nActualTimespan += Diff;
          }
          LastBlockTime = BlockReading->GetBlockTime();
  
          if (BlockReading->pprev == NULL) { assert(BlockReading); break; }
          BlockReading = BlockReading->pprev;
      }
  
      CBigNum bnNew(PastDifficultyAverage);
  
      int64_t _nTargetTimespan = CountBlocks*nTargetSpacing;
  
      if (nActualTimespan < _nTargetTimespan/3)
          nActualTimespan = _nTargetTimespan/3;
      if (nActualTimespan > _nTargetTimespan*3)
          nActualTimespan = _nTargetTimespan*3;
  
      // Retarget
      bnNew *= nActualTimespan;
      bnNew /= _nTargetTimespan;
  
      if (bnNew > Params().ProofOfWorkLimit()){
          bnNew = Params().ProofOfWorkLimit();
      }
  
      return bnNew.GetCompact();
  }
  
  unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock)
  {
          unsigned int retarget = DIFF_DGW;
  
          if (!TestNet()) {
              if (pindexLast->nHeight + 1 >= 34140) retarget = DIFF_DGW;
              else if (pindexLast->nHeight + 1 >= 15200) retarget = DIFF_KGW;
              else retarget = DIFF_BTC;
          } else {
              if (pindexLast->nHeight + 1 >= 2000) retarget = DIFF_DGW;
              else retarget = DIFF_BTC;
          }
  
          // Default Bitcoin style retargeting
          if (retarget == DIFF_BTC)
          {
              unsigned int nProofOfWorkLimit = Params().ProofOfWorkLimit().GetCompact();
  
              // Genesis block
              if (pindexLast == NULL)
                  return nProofOfWorkLimit;
  
              // Only change once per interval
              if ((pindexLast->nHeight+1) % nInterval != 0)
              {
                  // Special difficulty rule for testnet:
                  if (TestNet())
                  {
                      // If the new block's timestamp is more than 2* 10 minutes
                      // then allow mining of a min-difficulty block.
                      if (pblock->nTime > pindexLast->nTime + nTargetSpacing*2)
                          return nProofOfWorkLimit;
                      else
                      {
                          // Return the last non-special-min-difficulty-rules-block
                          const CBlockIndex* pindex = pindexLast;
                          while (pindex->pprev && pindex->nHeight % nInterval != 0 && pindex->nBits == nProofOfWorkLimit)
                              pindex = pindex->pprev;
                          return pindex->nBits;
                      }
                  }
                  return pindexLast->nBits;
              }
  
              // Dash: This fixes an issue where a 51% attack can change difficulty at will.
              // Go back the full period unless it's the first retarget after genesis.
              // Code courtesy of Art Forz.
              int blockstogoback = nInterval-1;
              if ((pindexLast->nHeight+1) != nInterval)
                  blockstogoback = nInterval;
  
              // Go back by what we want to be 14 days worth of blocks
              const CBlockIndex* pindexFirst = pindexLast;
              for (int i = 0; pindexFirst && i < blockstogoback; i++)
                  pindexFirst = pindexFirst->pprev;
              assert(pindexFirst);
  
              // Limit adjustment step
              int64_t nActualTimespan = pindexLast->GetBlockTime() - pindexFirst->GetBlockTime();
              LogPrintf("  nActualTimespan = %d  before bounds\n", nActualTimespan);
              if (nActualTimespan < nTargetTimespan/4)
                  nActualTimespan = nTargetTimespan/4;
              if (nActualTimespan > nTargetTimespan*4)
                  nActualTimespan = nTargetTimespan*4;
  
              // Retarget
              CBigNum bnNew;
              bnNew.SetCompact(pindexLast->nBits);
              bnNew *= nActualTimespan;
              bnNew /= nTargetTimespan;
  
              if (bnNew > Params().ProofOfWorkLimit())
                  bnNew = Params().ProofOfWorkLimit();
  
              /// debug print
              LogPrintf("GetNextWorkRequired RETARGET\n");
              LogPrintf("nTargetTimespan = %d    nActualTimespan = %d\n", nTargetTimespan, nActualTimespan);
              LogPrintf("Before: %08x  %s\n", pindexLast->nBits, CBigNum().SetCompact(pindexLast->nBits).getuint256().ToString());
              LogPrintf("After:  %08x  %s\n", bnNew.GetCompact(), bnNew.getuint256().ToString());
  
              return bnNew.GetCompact();
  
          }
  
          // Retarget using Kimoto Gravity Wave
          else if (retarget == DIFF_KGW)
          {
              static const uint64_t blocksTargetSpacing = 2.5 * 60; // 2.5 minutes
              static const unsigned int timeDaySeconds = 60 * 60 * 24;
              uint64_t pastSecondsMin = timeDaySeconds * 0.025;
              uint64_t pastSecondsMax = timeDaySeconds * 7;
              uint64_t pastBlocksMin = pastSecondsMin / blocksTargetSpacing;
              uint64_t pastBlocksMax = pastSecondsMax / blocksTargetSpacing;
  
              return KimotoGravityWell(pindexLast, pblock, blocksTargetSpacing, pastBlocksMin, pastBlocksMax);
          }
  
          // Retarget using Dark Gravity Wave 3
          else if (retarget == DIFF_DGW)
          {
              return DarkGravityWave(pindexLast, pblock);
          }
  
          return DarkGravityWave(pindexLast, pblock);
  }
  
  bool CheckProofOfWork(uint256 hash, unsigned int nBits)
  {
      CBigNum bnTarget;
      bnTarget.SetCompact(nBits);
  
      // Check range
      if (bnTarget <= 0 || bnTarget > Params().ProofOfWorkLimit())
          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;
  }
  
  bool IsInitialBlockDownload()
  {
      LOCK(cs_main);
      if (fImporting || fReindex || chainActive.Height() < Checkpoints::GetTotalBlocksEstimate())
          return true;
      static int64_t nLastUpdate;
      static CBlockIndex* pindexLastBest;
      if (chainActive.Tip() != pindexLastBest)
      {
          pindexLastBest = chainActive.Tip();
          nLastUpdate = GetTime();
      }
      return (GetTime() - nLastUpdate < 10 &&
              chainActive.Tip()->GetBlockTime() < GetTime() - 6 * 60 * 60); // ~144 blocks behind -> 2 x fork detection time
  }
  
  CBlockIndex *pindexBestForkTip = NULL, *pindexBestForkBase = NULL;
  
  void CheckForkWarningConditions()
  {
      AssertLockHeld(cs_main);
      // Before we get past initial download, we cannot reliably alert about forks
      // (we assume we don't get stuck on a fork before the last checkpoint)
      if (IsInitialBlockDownload())
          return;
  
      // If our best fork is no longer within 72 blocks (+/- 3 hours if no one mines it)
      // of our head, drop it
      if (pindexBestForkTip && chainActive.Height() - pindexBestForkTip->nHeight >= 72)
          pindexBestForkTip = NULL;
  
      if (pindexBestForkTip || (pindexBestInvalid && pindexBestInvalid->nChainWork > chainActive.Tip()->nChainWork + (chainActive.Tip()->GetBlockWork() * 6).getuint256()))
      {
          if (!fLargeWorkForkFound && pindexBestForkBase)
          {
              if(pindexBestForkBase->phashBlock){
                  std::string warning = std::string("'Warning: Large-work fork detected, forking after block ") +
                      pindexBestForkBase->phashBlock->ToString() + std::string("'");
                  CAlert::Notify(warning, true);
              }
          }
          if (pindexBestForkTip && pindexBestForkBase)
          {
              if(pindexBestForkBase->phashBlock){
                  LogPrintf("CheckForkWarningConditions: Warning: Large valid fork found\n  forking the chain at height %d (%s)\n  lasting to height %d (%s).\nChain state database corruption likely.\n",
                         pindexBestForkBase->nHeight, pindexBestForkBase->phashBlock->ToString(),
                         pindexBestForkTip->nHeight, pindexBestForkTip->phashBlock->ToString());
                  fLargeWorkForkFound = true;
              }
          }
          else
          {
              LogPrintf("CheckForkWarningConditions: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n");
              fLargeWorkInvalidChainFound = true;
          }
      }
      else
      {
          fLargeWorkForkFound = false;
          fLargeWorkInvalidChainFound = false;
      }
  }
  
  void CheckForkWarningConditionsOnNewFork(CBlockIndex* pindexNewForkTip)
  {
      AssertLockHeld(cs_main);
      // If we are on a fork that is sufficiently large, set a warning flag
      CBlockIndex* pfork = pindexNewForkTip;
      CBlockIndex* plonger = chainActive.Tip();
      while (pfork && pfork != plonger)
      {
          while (plonger && plonger->nHeight > pfork->nHeight)
              plonger = plonger->pprev;
          if (pfork == plonger)
              break;
          pfork = pfork->pprev;
      }
  
      // We define a condition which we should warn the user about as a fork of at least 7 blocks
      // who's tip is within 72 blocks (+/- 3 hours if no one mines it) of ours
      // We use 7 blocks rather arbitrarily as it represents just under 10% of sustained network
      // hash rate operating on the fork.
      // or a chain that is entirely longer than ours and invalid (note that this should be detected by both)
      // We define it this way because it allows us to only store the highest fork tip (+ base) which meets
      // the 7-block condition and from this always have the most-likely-to-cause-warning fork
      if (pfork && (!pindexBestForkTip || (pindexBestForkTip && pindexNewForkTip->nHeight > pindexBestForkTip->nHeight)) &&
              pindexNewForkTip->nChainWork - pfork->nChainWork > (pfork->GetBlockWork() * 7).getuint256() &&
              chainActive.Height() - pindexNewForkTip->nHeight < 72)
      {
          pindexBestForkTip = pindexNewForkTip;
          pindexBestForkBase = pfork;
      }
  
      CheckForkWarningConditions();
  }
  
  // Requires cs_main.
  void Misbehaving(NodeId pnode, int howmuch)
  {
      if (howmuch == 0)
          return;
  
      CNodeState *state = State(pnode);
      if (state == NULL)
          return;
  
      state->nMisbehavior += howmuch;
      if (state->nMisbehavior >= GetArg("-banscore", 100))
      {
          LogPrintf("Misbehaving: %s (%d -> %d) BAN THRESHOLD EXCEEDED\n", state->name, state->nMisbehavior-howmuch, state->nMisbehavior);
          state->fShouldBan = true;
      } else
          LogPrintf("Misbehaving: %s (%d -> %d)\n", state->name, state->nMisbehavior-howmuch, state->nMisbehavior);
  }
  
  void static InvalidChainFound(CBlockIndex* pindexNew)
  {
      if (!pindexBestInvalid || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
      {
          pindexBestInvalid = pindexNew;
          // The current code doesn't actually read the BestInvalidWork entry in
          // the block database anymore, as it is derived from the flags in block
          // index entry. We only write it for backward compatibility.
          pblocktree->WriteBestInvalidWork(CBigNum(pindexBestInvalid->nChainWork));
          uiInterface.NotifyBlocksChanged();
      }
      LogPrintf("InvalidChainFound: invalid block=%s  height=%d  log2_work=%.8g  date=%s\n",
        pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
        log(pindexNew->nChainWork.getdouble())/log(2.0), DateTimeStrFormat("%Y-%m-%d %H:%M:%S",
        pindexNew->GetBlockTime()));
      LogPrintf("InvalidChainFound:  current best=%s  height=%d  log2_work=%.8g  date=%s\n",
        chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(), log(chainActive.Tip()->nChainWork.getdouble())/log(2.0),
        DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()));
      CheckForkWarningConditions();
  }
  
  void static InvalidBlockFound(CBlockIndex *pindex, const CValidationState &state) {
      int nDoS = 0;
      if (state.IsInvalid(nDoS)) {
          std::map<uint256, NodeId>::iterator it = mapBlockSource.find(pindex->GetBlockHash());
          if (it != mapBlockSource.end() && State(it->second)) {
              CBlockReject reject = {state.GetRejectCode(), state.GetRejectReason(), pindex->GetBlockHash()};
              State(it->second)->rejects.push_back(reject);
              if (nDoS > 0)
                  Misbehaving(it->second, nDoS);
          }
      }
      if (!state.CorruptionPossible()) {
          pindex->nStatus |= BLOCK_FAILED_VALID;
          pblocktree->WriteBlockIndex(CDiskBlockIndex(pindex));
          setBlockIndexValid.erase(pindex);
          InvalidChainFound(pindex);
      }
  }
  
  void UpdateTime(CBlockHeader& block, const CBlockIndex* pindexPrev)
  {
      block.nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
  
      // Updating time can change work required on testnet:
      if (TestNet())
          block.nBits = GetNextWorkRequired(pindexPrev, &block);
  }
  
  void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCache &inputs, CTxUndo &txundo, int nHeight, const uint256 &txhash)
  {
      bool ret;
      // mark inputs spent
      if (!tx.IsCoinBase()) {
          BOOST_FOREACH(const CTxIn &txin, tx.vin) {
              CCoins &coins = inputs.GetCoins(txin.prevout.hash);
              CTxInUndo undo;
              ret = coins.Spend(txin.prevout, undo);
              assert(ret);
              txundo.vprevout.push_back(undo);
          }
      }
  
      // add outputs
      ret = inputs.SetCoins(txhash, CCoins(tx, nHeight));
      assert(ret);
  }
  
  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());
      return true;
  }
  
  bool VerifySignature(const CCoins& txFrom, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType)
  {
      return CScriptCheck(txFrom, txTo, nIn, flags, nHashType)();
  }
  
  bool CheckInputs(const CTransaction& tx, CValidationState &state, CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, std::vector<CScriptCheck> *pvChecks)
  {
      if (!tx.IsCoinBase())
      {
          if (pvChecks)
              pvChecks->reserve(tx.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 (!inputs.HaveInputs(tx))
              return state.Invalid(error("CheckInputs() : %s inputs unavailable", tx.GetHash().ToString()));
  
          // While checking, GetBestBlock() refers to the parent block.
          // This is also true for mempool checks.
          CBlockIndex *pindexPrev = mapBlockIndex.find(inputs.GetBestBlock())->second;
          int nSpendHeight = pindexPrev->nHeight + 1;
          int64_t nValueIn = 0;
          int64_t nFees = 0;
          for (unsigned int i = 0; i < tx.vin.size(); i++)
          {
              const COutPoint &prevout = tx.vin[i].prevout;
              const CCoins &coins = inputs.GetCoins(prevout.hash);
  
              // If prev is coinbase, check that it's matured
              if (coins.IsCoinBase()) {
                  if (nSpendHeight - coins.nHeight < COINBASE_MATURITY)
                      return state.Invalid(
                          error("CheckInputs() : tried to spend coinbase at depth %d", nSpendHeight - coins.nHeight),
                          REJECT_INVALID, "bad-txns-premature-spend-of-coinbase");
              }
  
              // 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"),
                                   REJECT_INVALID, "bad-txns-inputvalues-outofrange");
  
          }
  
          if (nValueIn < tx.GetValueOut())
              return state.DoS(100, error("CheckInputs() : %s value in < value out", tx.GetHash().ToString()),
                               REJECT_INVALID, "bad-txns-in-belowout");
  
          // Tally transaction fees
          int64_t nTxFee = nValueIn - tx.GetValueOut();
          if (nTxFee < 0)
              return state.DoS(100, error("CheckInputs() : %s nTxFee < 0", tx.GetHash().ToString()),
                               REJECT_INVALID, "bad-txns-fee-negative");
          nFees += nTxFee;
          if (!MoneyRange(nFees))
              return state.DoS(100, error("CheckInputs() : nFees out of range"),
                               REJECT_INVALID, "bad-txns-fee-outofrange");
  
          // 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 < tx.vin.size(); i++) {
                  const COutPoint &prevout = tx.vin[i].prevout;
                  const CCoins &coins = inputs.GetCoins(prevout.hash);
  
                  // Verify signature
                  CScriptCheck check(coins, tx, 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, tx, i, flags & (~SCRIPT_VERIFY_STRICTENC), 0);
                          if (check())
                              return state.Invalid(false, REJECT_NONSTANDARD, "non-canonical");
                      }
                      return state.DoS(100,false, REJECT_NONSTANDARD, "non-canonical");
                  }
              }
          }
      }
  
      return true;
  }
  
  bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool* pfClean)
  {
      assert(pindex->GetBlockHash() == 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 != block.vtx.size())
          return error("DisconnectBlock() : block and undo data inconsistent");
  
      // undo transactions in reverse order
      for (int i = block.vtx.size() - 1; i >= 0; i--) {
          const CTransaction &tx = block.vtx[i];
          uint256 hash = tx.GetHash();
  
          // Check that all outputs are available and match the outputs in the block itself
          // exactly. Note that transactions with only provably unspendable outputs won't
          // have outputs available even in the block itself, so we handle that case
          // specially with outsEmpty.
          CCoins outsEmpty;
          CCoins &outs = view.HaveCoins(hash) ? view.GetCoins(hash) : outsEmpty;
          outs.ClearUnspendable();
  
          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;
                  } 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->GetBlockHash());
  
      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("dash-scriptch");
      scriptcheckqueue.Thread();
  }
  
  bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& view, bool fJustCheck)
  {
      AssertLockHeld(cs_main);
      // Check it again in case a previous version let a bad block in
      if (!CheckBlock(block, state, !fJustCheck, !fJustCheck))
          return false;
  
      // verify that the view's current state corresponds to the previous block
      uint256 hashPrevBlock = pindex->pprev == NULL ? uint256(0) : pindex->pprev->GetBlockHash();
      assert(hashPrevBlock == view.GetBestBlock());
  
      // Special case for the genesis block, skipping connection of its transactions
      // (its coinbase is unspendable)
      if (block.GetHash() == Params().HashGenesisBlock()) {
          view.SetBestBlock(pindex->GetBlockHash());
          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 < block.vtx.size(); i++) {
              uint256 hash = block.GetTxHash(i);
              if (view.HaveCoins(hash) && !view.GetCoins(hash).IsPruned())
                  return state.DoS(100, error("ConnectBlock() : tried to overwrite transaction"),
                                   REJECT_INVALID, "bad-txns-BIP30");
          }
      }
  
      // BIP16 didn't become active until Apr 1 2012
      int64_t nBIP16SwitchTime = 1333238400;
      bool fStrictPayToScriptHash = (pindex->nTime >= nBIP16SwitchTime);
  
      unsigned int flags = SCRIPT_VERIFY_NOCACHE |
                           (fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE);
  
      if (block.nVersion >= 3 &&
          ((!TestNet() && CBlockIndex::IsSuperMajority(3, pindex->pprev, 750, 1000)) ||
              (TestNet() && CBlockIndex::IsSuperMajority(3, pindex->pprev, 51, 100)))) {
          flags |= SCRIPT_VERIFY_DERSIG;
      }
  
      CBlockUndo blockundo;
  
      CCheckQueueControl<CScriptCheck> control(fScriptChecks && nScriptCheckThreads ? &scriptcheckqueue : NULL);
  
      int64_t nStart = GetTimeMicros();
      int64_t nFees = 0;
      int nInputs = 0;
      unsigned int nSigOps = 0;
      CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
      std::vector<std::pair<uint256, CDiskTxPos> > vPos;
      vPos.reserve(block.vtx.size());
      for (unsigned int i = 0; i < block.vtx.size(); i++)
      {
          const CTransaction &tx = block.vtx[i];
  
          nInputs += tx.vin.size();
          nSigOps += GetLegacySigOpCount(tx);
          if (nSigOps > MAX_BLOCK_SIGOPS)
              return state.DoS(100, error("ConnectBlock() : too many sigops"),
                               REJECT_INVALID, "bad-blk-sigops");
  
          if (!tx.IsCoinBase())
          {
              if (!view.HaveInputs(tx))
                  return state.DoS(100, error("ConnectBlock() : inputs missing/spent"),
                                   REJECT_INVALID, "bad-txns-inputs-missingorspent");
  
              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 += GetP2SHSigOpCount(tx, view);
                  if (nSigOps > MAX_BLOCK_SIGOPS)
                      return state.DoS(100, error("ConnectBlock() : too many sigops"),
                                       REJECT_INVALID, "bad-blk-sigops");
              }
  
              nFees += view.GetValueIn(tx)-tx.GetValueOut();
  
              std::vector<CScriptCheck> vChecks;
              if (!CheckInputs(tx, state, view, fScriptChecks, flags, nScriptCheckThreads ? &vChecks : NULL))
                  return false;
              control.Add(vChecks);
          }
  
          CTxUndo txundo;
          UpdateCoins(tx, state, view, txundo, pindex->nHeight, block.GetTxHash(i));
          if (!tx.IsCoinBase())
              blockundo.vtxundo.push_back(txundo);
  
          vPos.push_back(std::make_pair(block.GetTxHash(i), pos));
          pos.nTxOffset += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
      }
      int64_t nTime = GetTimeMicros() - nStart;
      if (fBenchmark)
          LogPrintf("- Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin)\n", (unsigned)block.vtx.size(), 0.001 * nTime, 0.001 * nTime / block.vtx.size(), nInputs <= 1 ? 0 : 0.001 * nTime / (nInputs-1));
  
      if (block.vtx[0].GetValueOut() > GetBlockValue(pindex->pprev->nBits, pindex->pprev->nHeight, nFees))
          return state.DoS(100,
                           error("ConnectBlock() : coinbase pays too much (actual=%d vs limit=%d)",
                                 block.vtx[0].GetValueOut(), GetBlockValue(pindex->pprev->nBits, pindex->pprev->nHeight, nFees)),
                                 REJECT_INVALID, "bad-cb-amount");
  
      if (!control.Wait())
          return state.DoS(100, false);
      int64_t nTime2 = GetTimeMicros() - nStart;
      if (fBenchmark)
          LogPrintf("- Verify %u txins: %.2fms (%.3fms/txin)\n", nInputs - 1, 0.001 * nTime2, nInputs <= 1 ? 0 : 0.001 * nTime2 / (nInputs-1));
  
      if (fJustCheck)
          return true;
  
      // 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
      bool ret;
      ret = view.SetBestBlock(pindex->GetBlockHash());
      assert(ret);
  
      // Watch for transactions paying to me
      for (unsigned int i = 0; i < block.vtx.size(); i++)
          g_signals.SyncTransaction(block.GetTxHash(i), block.vtx[i], &block);
  
      return true;
  }
  
  // Update the on-disk chain state.
  bool static WriteChainState(CValidationState &state) {
      static int64_t nLastWrite = 0;
      if (!IsInitialBlockDownload() || pcoinsTip->GetCacheSize() > nCoinCacheSize || GetTimeMicros() > nLastWrite + 600*1000000) {
          // 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("out of disk space");
          FlushBlockFile();
          pblocktree->Sync();
          if (!pcoinsTip->Flush())
              return state.Abort(_("Failed to write to coin database"));
          nLastWrite = GetTimeMicros();
      }
      return true;
  }
  
  // Update chainActive and related internal data structures.
  void static UpdateTip(CBlockIndex *pindexNew) {
      chainActive.SetTip(pindexNew);
  
      // Update best block in wallet (so we can detect restored wallets)
      bool fIsInitialDownload = IsInitialBlockDownload();
      if ((chainActive.Height() % 20160) == 0 || (!fIsInitialDownload && (chainActive.Height() % 144) == 0))
          g_signals.SetBestChain(chainActive.GetLocator());
  
      // New best block
      nTimeBestReceived = GetTime();
      mempool.AddTransactionsUpdated(1);
      LogPrintf("UpdateTip: new best=%s  height=%d  log2_work=%.8g  tx=%lu  date=%s progress=%f\n",
        chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(), log(chainActive.Tip()->nChainWork.getdouble())/log(2.0), (unsigned long)chainActive.Tip()->nChainTx,
        DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()),
        Checkpoints::GuessVerificationProgress(chainActive.Tip()));
  
      // Check the version of the last 100 blocks to see if we need to upgrade:
      if (!fIsInitialDownload)
      {
          int nUpgraded = 0;
          const CBlockIndex* pindex = chainActive.Tip();
          for (int i = 0; i < 100 && pindex != NULL; i++)
          {
              if (pindex->nVersion > CBlock::CURRENT_VERSION)
                  ++nUpgraded;
              pindex = pindex->pprev;
          }
          if (nUpgraded > 0)
              LogPrintf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, (int)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!");
      }
  }
  
  // Disconnect chainActive's tip.
  bool static DisconnectTip(CValidationState &state) {
      CBlockIndex *pindexDelete = chainActive.Tip();
      assert(pindexDelete);
      mempool.check(pcoinsTip);
      // Read block from disk.
      CBlock block;
      if (!ReadBlockFromDisk(block, pindexDelete))
          return state.Abort(_("Failed to read block"));
      // Apply the block atomically to the chain state.
      int64_t nStart = GetTimeMicros();
      {
          CCoinsViewCache view(*pcoinsTip, true);
          if (!DisconnectBlock(block, state, pindexDelete, view))
              return error("DisconnectTip() : DisconnectBlock %s failed", pindexDelete->GetBlockHash().ToString());
          assert(view.Flush());
      }
      if (fBenchmark)
          LogPrintf("- Disconnect: %.2fms\n", (GetTimeMicros() - nStart) * 0.001);
      // Write the chain state to disk, if necessary.
      if (!WriteChainState(state))
          return false;
      // Resurrect mempool transactions from the disconnected block.
      BOOST_FOREACH(const CTransaction &tx, block.vtx) {
          // ignore validation errors in resurrected transactions
          list<CTransaction> removed;
          CValidationState stateDummy;
          if (!tx.IsCoinBase())
              if (!AcceptToMemoryPool(mempool, stateDummy, tx, false, NULL))
                  mempool.remove(tx, removed, true);
      }
      mempool.check(pcoinsTip);
      // Update chainActive and related variables.
      UpdateTip(pindexDelete->pprev);
      // Let wallets know transactions went from 1-confirmed to
      // 0-confirmed or conflicted:
      BOOST_FOREACH(const CTransaction &tx, block.vtx) {
          SyncWithWallets(tx.GetHash(), tx, NULL);
      }
      return true;
  }
  
  // Connect a new block to chainActive.
  bool static ConnectTip(CValidationState &state, CBlockIndex *pindexNew) {
      assert(pindexNew->pprev == chainActive.Tip());
      mempool.check(pcoinsTip);
      // Read block from disk.
      CBlock block;
      if (!ReadBlockFromDisk(block, pindexNew))
          return state.Abort(_("Failed to read block"));
      // Apply the block atomically to the chain state.
      int64_t nStart = GetTimeMicros();
      {
          CCoinsViewCache view(*pcoinsTip, true);
          CInv inv(MSG_BLOCK, pindexNew->GetBlockHash());
          if (!ConnectBlock(block, state, pindexNew, view)) {
              if (state.IsInvalid())
                  InvalidBlockFound(pindexNew, state);
              return error("ConnectTip() : ConnectBlock %s failed", pindexNew->GetBlockHash().ToString());
          }
          mapBlockSource.erase(inv.hash);
          assert(view.Flush());
      }
      if (fBenchmark)
          LogPrintf("- Connect: %.2fms\n", (GetTimeMicros() - nStart) * 0.001);
      // Write the chain state to disk, if necessary.
      if (!WriteChainState(state))
          return false;
      // Remove conflicting transactions from the mempool.
      list<CTransaction> txConflicted;
      BOOST_FOREACH(const CTransaction &tx, block.vtx) {
          list<CTransaction> unused;
          mempool.remove(tx, unused);
          mempool.removeConflicts(tx, txConflicted);
      }
      mempool.check(pcoinsTip);
      // Update chainActive & related variables.
      UpdateTip(pindexNew);
      // Tell wallet about transactions that went from mempool
      // to conflicted:
      BOOST_FOREACH(const CTransaction &tx, txConflicted) {
          SyncWithWallets(tx.GetHash(), tx, NULL);
      }
      // ... and about transactions that got confirmed:
      BOOST_FOREACH(const CTransaction &tx, block.vtx) {
          SyncWithWallets(tx.GetHash(), tx, &block);
      }
      return true;
  }
  
  bool DisconnectBlocksAndReprocess(int blocks)
  {
      LOCK(cs_main);
  
      CValidationState state;
  
      LogPrintf("DisconnectBlocksAndReprocess: Got command to replay %d blocks\n", blocks);
      for(int i = 0; i <= blocks; i++)
          DisconnectTip(state);
  
      return true;
  }
  
  /*
      DisconnectBlockAndInputs
  
      Remove conflicting blocks for successful InstantX transaction locks
      This should be very rare (Probably will never happen)
  */
  bool DisconnectBlockAndInputs(CValidationState &state, CTransaction txLock)
  {
  
      // 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);
  
      CBlockIndex* BlockReading = chainActive.Tip();
      CBlockIndex* pindexNew = NULL;
  
      bool foundConflictingTx = false;
  
      //remove anything conflicting in the memory pool
      list<CTransaction> txConflicted;
      mempool.removeConflicts(txLock, txConflicted);
  
  
      // List of what to disconnect (typically nothing)
      vector<CBlockIndex*> vDisconnect;
  
      for (unsigned int i = 1; BlockReading && BlockReading->nHeight > 0 && !foundConflictingTx && i < 6; i++) {
          vDisconnect.push_back(BlockReading);
          pindexNew = BlockReading->pprev; //new best block
  
          CBlock block;
          if (!ReadBlockFromDisk(block, BlockReading))
              return state.Abort(_("Failed to read block"));
  
          // 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_FOREACH(const CTransaction& tx, block.vtx){
              if (!tx.IsCoinBase()){
                  BOOST_FOREACH(const CTxIn& in1, txLock.vin){
                      BOOST_FOREACH(const CTxIn& in2, tx.vin){
                          if(in1.prevout == in2.prevout) foundConflictingTx = true;
                      }
                  }
              }
          }
  
          if (BlockReading->pprev == NULL) { assert(BlockReading); break; }
          BlockReading = BlockReading->pprev;
      }
  
      if(!foundConflictingTx) {
          LogPrintf("DisconnectBlockAndInputs: Can't find a conflicting transaction to inputs\n");
          return false;
      }
  
      if (vDisconnect.size() > 0) {
          LogPrintf("REORGANIZE: Disconnect Conflicting Blocks %lli blocks; %s..\n", vDisconnect.size(), pindexNew->GetBlockHash().ToString().c_str());
          BOOST_FOREACH(CBlockIndex* pindex, vDisconnect) {
              LogPrintf(" -- disconnect %s\n", pindex->GetBlockHash().ToString().c_str());
              DisconnectTip(state);
          }
      }
  
      return true;
  }
  
  
  // Make chainMostWork correspond to the chain with the most work in it, that isn't
  // known to be invalid (it's however far from certain to be valid).
  void static FindMostWorkChain() {
      CBlockIndex *pindexNew = NULL;
  
      // In case the current best is invalid, do not consider it.
      while (chainMostWork.Tip() && (chainMostWork.Tip()->nStatus & BLOCK_FAILED_MASK)) {
          setBlockIndexValid.erase(chainMostWork.Tip());
          chainMostWork.SetTip(chainMostWork.Tip()->pprev);
      }
  
      do {
          // Find the best candidate header.
          {
              std::set<CBlockIndex*, CBlockIndexWorkComparator>::reverse_iterator it = setBlockIndexValid.rbegin();
              if (it == setBlockIndexValid.rend())
                  return;
              pindexNew = *it;
          }
  
          // Check whether all blocks on the path between the currently active chain and the candidate are valid.
          // Just going until the active chain is an optimization, as we know all blocks in it are valid already.
          CBlockIndex *pindexTest = pindexNew;
          bool fInvalidAncestor = false;
          while (pindexTest && !chainActive.Contains(pindexTest)) {
              if (pindexTest->nStatus & BLOCK_FAILED_MASK) {
                  // Candidate has an invalid ancestor, remove entire chain from the set.
                  if (pindexBestInvalid == NULL || pindexNew->nChainWork > pindexBestInvalid->nChainWork)
                      pindexBestInvalid = pindexNew;                CBlockIndex *pindexFailed = pindexNew;
                  while (pindexTest != pindexFailed) {
                      pindexFailed->nStatus |= BLOCK_FAILED_CHILD;
                      setBlockIndexValid.erase(pindexFailed);
                      pindexFailed = pindexFailed->pprev;
                  }
                  fInvalidAncestor = true;
                  break;
              }
              pindexTest = pindexTest->pprev;
          }
          if (fInvalidAncestor)
              continue;
  
          break;
      } while(true);
  
      // Check whether it's actually an improvement.
      if (chainMostWork.Tip() && !CBlockIndexWorkComparator()(chainMostWork.Tip(), pindexNew))
          return;
  
      // We have a new best.
      chainMostWork.SetTip(pindexNew);
  }
  
  // Try to activate to the most-work chain (thereby connecting it).
  bool ActivateBestChain(CValidationState &state) {
      LOCK(cs_main);
      CBlockIndex *pindexOldTip = chainActive.Tip();
      bool fComplete = false;
      while (!fComplete) {
          FindMostWorkChain();
          fComplete = true;
  
          // Check whether we have something to do.
          if (chainMostWork.Tip() == NULL) break;
  
          // Disconnect active blocks which are no longer in the best chain.
          while (chainActive.Tip() && !chainMostWork.Contains(chainActive.Tip())) {
              if (!DisconnectTip(state))
                  return false;
          }
  
          // Connect new blocks.
          while (!chainActive.Contains(chainMostWork.Tip())) {
              CBlockIndex *pindexConnect = chainMostWork[chainActive.Height() + 1];
              if (!ConnectTip(state, pindexConnect)) {
                  if (state.IsInvalid()) {
                      // The block violates a consensus rule.
                      if (!state.CorruptionPossible())
                          InvalidChainFound(chainMostWork.Tip());
                      fComplete = false;
                      state = CValidationState();
                      break;
                  } else {
                      // A system error occurred (disk space, database error, ...).
                      return false;
                  }
              }
          }
      }
  
      if (chainActive.Tip() != pindexOldTip) {
          std::string strCmd = GetArg("-blocknotify", "");
          if (!IsInitialBlockDownload() && !strCmd.empty())
          {
              boost::replace_all(strCmd, "%s", chainActive.Tip()->GetBlockHash().GetHex());
              boost::thread t(runCommand, strCmd); // thread runs free
          }
      }
  
      return true;
  }
  
  bool AddToBlockIndex(CBlock& block, CValidationState& state, const CDiskBlockPos& pos)
  {
      // Check for duplicate
      uint256 hash = block.GetHash();
      if (mapBlockIndex.count(hash))
          return state.Invalid(error("AddToBlockIndex() : %s already exists", hash.ToString()), 0, "duplicate");
  
      // Construct new block index object
      CBlockIndex* pindexNew = new CBlockIndex(block);
      assert(pindexNew);
      {
           LOCK(cs_nBlockSequenceId);
           pindexNew->nSequenceId = nBlockSequenceId++;
      }
      map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
      pindexNew->phashBlock = &((*mi).first);
      map<uint256, CBlockIndex*>::iterator miPrev = mapBlockIndex.find(block.hashPrevBlock);
      if (miPrev != mapBlockIndex.end())
      {
          pindexNew->pprev = (*miPrev).second;
          pindexNew->nHeight = pindexNew->pprev->nHeight + 1;
      }
      pindexNew->nTx = block.vtx.size();
      pindexNew->nChainWork = (pindexNew->pprev ? pindexNew->pprev->nChainWork : 0) + pindexNew->GetBlockWork().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;
      setBlockIndexValid.insert(pindexNew);
  
      if (!pblocktree->WriteBlockIndex(CDiskBlockIndex(pindexNew)))
          return state.Abort(_("Failed to write block index"));
  
      // New best?
      if (!ActivateBestChain(state))
          return false;
  
      LOCK(cs_main);
      if (pindexNew == chainActive.Tip())
      {
          // Clear fork warning if its no longer applicable
          CheckForkWarningConditions();
          // Notify UI to display prev block's coinbase if it was ours
          static uint256 hashPrevBestCoinBase;
          g_signals.UpdatedTransaction(hashPrevBestCoinBase);
          hashPrevBestCoinBase = block.GetTxHash(0);
      } else
          CheckForkWarningConditionsOnNewFork(pindexNew);
  
      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_t 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) {
              LogPrintf("Leaving block file %i: %s\n", nLastBlockFile, infoLastBlockFile.ToString());
              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.AddBlock(nHeight, nTime);
      if (fKnown)
          infoLastBlockFile.nSize = std::max(pos.nPos + nAddSize, infoLastBlockFile.nSize);
      else
          infoLastBlockFile.nSize += nAddSize;
  
      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) {
                      LogPrintf("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("out of disk space");
          }
      }
  
      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) {
                  LogPrintf("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("out of disk space");
      }
  
      return true;
  }
  
  
  bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bool fCheckMerkleRoot)
  {
      // These are checks that are independent of context
      // that can be verified before saving an orphan block.
  
      // Size limits
      if (block.vtx.empty() || block.vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
          return state.DoS(100, error("CheckBlock() : size limits failed"),
                           REJECT_INVALID, "bad-blk-length");
  
      // Check proof of work matches claimed amount
      if (fCheckPOW && !CheckProofOfWork(block.GetHash(), block.nBits))
          return state.DoS(50, error("CheckBlock() : proof of work failed"),
                           REJECT_INVALID, "high-hash");
  
      // Check timestamp
      if (block.GetBlockTime() > GetAdjustedTime() + 2 * 60 * 60)
          return state.Invalid(error("CheckBlock() : block timestamp too far in the future"),
                               REJECT_INVALID, "time-too-new");
  
      // First transaction must be coinbase, the rest must not be
      if (block.vtx.empty() || !block.vtx[0].IsCoinBase())
          return state.DoS(100, error("CheckBlock() : first tx is not coinbase"),
                           REJECT_INVALID, "bad-cb-missing");
      for (unsigned int i = 1; i < block.vtx.size(); i++)
          if (block.vtx[i].IsCoinBase())
              return state.DoS(100, error("CheckBlock() : more than one coinbase"),
                               REJECT_INVALID, "bad-cb-multiple");
  
  
      // ----------- instantX transaction scanning -----------
  
      if(IsSporkActive(SPORK_3_INSTANTX_BLOCK_FILTERING)){
          BOOST_FOREACH(const CTransaction& tx, block.vtx){
              if (!tx.IsCoinBase()){
                  //only reject blocks when it's based on complete consensus
                  BOOST_FOREACH(const CTxIn& in, tx.vin){
                      if(mapLockedInputs.count(in.prevout)){
                          if(mapLockedInputs[in.prevout] != tx.GetHash()){
                              LogPrintf("CheckBlock() : found conflicting transaction with transaction lock %s %s\n", mapLockedInputs[in.prevout].ToString().c_str(), tx.GetHash().ToString().c_str());
                              return state.DoS(0, error("CheckBlock() : found conflicting transaction with transaction lock"),
                                               REJECT_INVALID, "conflicting-tx-ix");
                          }
                      }
                  }
              }
          }
      } else {
          LogPrintf("CheckBlock() : skipping transaction locking checks\n");
      }
  
  
      // ----------- masternode payments -----------
  
      bool MasternodePayments = false;
  
      if(TestNet()){
          if(block.nTime > START_MASTERNODE_PAYMENTS_TESTNET) MasternodePayments = true;
      } else {
          if(block.nTime > START_MASTERNODE_PAYMENTS) MasternodePayments = true;
      }
  
      if(!IsSporkActive(SPORK_1_MASTERNODE_PAYMENTS_ENFORCEMENT)){
          MasternodePayments = false;
          if(fDebug) LogPrintf("CheckBlock() : Masternode payment enforcement is off\n");
      }
  
      if(MasternodePayments)
      {
          LOCK2(cs_main, mempool.cs);
  
          CBlockIndex *pindex = chainActive.Tip();
          if(pindex != NULL){
              if(pindex->GetBlockHash() == block.hashPrevBlock){
                  int64_t masternodePaymentAmount = GetMasternodePayment(pindex->nHeight+1, block.vtx[0].GetValueOut());
                  bool fIsInitialDownload = IsInitialBlockDownload();
  
                  // If we don't already have its previous block, skip masternode payment step
                  if (!fIsInitialDownload && pindex != NULL)
                  {
                      bool foundPaymentAmount = false;
                      bool foundPayee = false;
                      bool foundPaymentAndPayee = false;
  
                      CScript payee;
                      if(!masternodePayments.GetBlockPayee(chainActive.Tip()->nHeight+1, payee) || payee == CScript()){
                          foundPayee = true; //doesn't require a specific payee
                          foundPaymentAmount = true;
                          foundPaymentAndPayee = true;
                          LogPrintf("CheckBlock() : Using non-specific masternode payments %d\n", chainActive.Tip()->nHeight+1);
                      }
  
                      for (unsigned int i = 0; i < block.vtx[0].vout.size(); i++) {
                          if(block.vtx[0].vout[i].nValue == masternodePaymentAmount )
                              foundPaymentAmount = true;
                          if(block.vtx[0].vout[i].scriptPubKey == payee )
                              foundPayee = true;
                          if(block.vtx[0].vout[i].nValue == masternodePaymentAmount && block.vtx[0].vout[i].scriptPubKey == payee)
                              foundPaymentAndPayee = true;
                      }
  
  
                      CTxDestination address1;
                      ExtractDestination(payee, address1);
                      CBitcoinAddress address2(address1);
  
                      if(!foundPaymentAndPayee) {
                          LogPrintf("CheckBlock() : Couldn't find masternode payment(%d|%d) or payee(%d|%s) nHeight %d. \n", foundPaymentAmount, masternodePaymentAmount, foundPayee, address2.ToString().c_str(), chainActive.Tip()->nHeight+1);
                          if(!RegTest()) return state.DoS(100, error("CheckBlock() : Couldn't find masternode payment or payee"));
                      } else {
                          LogPrintf("CheckBlock() : Found payment(%d|%d) or payee(%d|%s) nHeight %d. \n", foundPaymentAmount, masternodePaymentAmount, foundPayee, address2.ToString().c_str(), chainActive.Tip()->nHeight+1);
                      }
                  } else {
                      LogPrintf("CheckBlock() : Is initial download, skipping masternode payment check %d\n", chainActive.Tip()->nHeight+1);
                  }
              } else {
                  LogPrintf("CheckBlock() : Skipping masternode payment check - nHeight %d Hash %s\n", chainActive.Tip()->nHeight+1, block.GetHash().ToString().c_str());
              }
          } else {
              LogPrintf("CheckBlock() : pindex is null, skipping masternode payment check\n");
          }
      } else {
          LogPrintf("CheckBlock() : skipping masternode payment checks\n");
      }
  
  
      // Check transactions
      BOOST_FOREACH(const CTransaction& tx, block.vtx)
          if (!CheckTransaction(tx, state))
              return error("CheckBlock() : CheckTransaction failed");
  
      // 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.
      block.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 < block.vtx.size(); i++) {
          uniqueTx.insert(block.GetTxHash(i));
      }
      if (uniqueTx.size() != block.vtx.size())
          return state.DoS(100, error("CheckBlock() : duplicate transaction"),
                           REJECT_INVALID, "bad-txns-duplicate", true);
  
      unsigned int nSigOps = 0;
      BOOST_FOREACH(const CTransaction& tx, block.vtx)
      {
          nSigOps += GetLegacySigOpCount(tx);
      }
      if (nSigOps > MAX_BLOCK_SIGOPS)
          return state.DoS(100, error("CheckBlock() : out-of-bounds SigOpCount"),
                           REJECT_INVALID, "bad-blk-sigops", true);
  
      // Check merkle root
      if (fCheckMerkleRoot && block.hashMerkleRoot != block.vMerkleTree.back())
          return state.DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"),
                           REJECT_INVALID, "bad-txnmrklroot", true);
  
      return true;
  }
  
  bool AcceptBlock(CBlock& block, CValidationState& state, CDiskBlockPos* dbp)
  {
      AssertLockHeld(cs_main);
      // Check for duplicate
      uint256 hash = block.GetHash();
      if (mapBlockIndex.count(hash))
          return state.Invalid(error("AcceptBlock() : block already in mapBlockIndex"), 0, "duplicate");
  
      // Get prev block index
      CBlockIndex* pindexPrev = NULL;
      int nHeight = 0;
      if (hash != Params().HashGenesisBlock()) {
          map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
          if (mi == mapBlockIndex.end())
              return state.DoS(10, error("AcceptBlock() : prev block not found"), 0, "bad-prevblk");
          pindexPrev = (*mi).second;
          nHeight = pindexPrev->nHeight+1;
  
          if(TestNet()) {
              if (block.nBits != GetNextWorkRequired(pindexPrev, &block))
                  return state.DoS(100, error("AcceptBlock() : incorrect proof of work"),
                                   REJECT_INVALID, "bad-diffbits");
          } else {
              // Check proof of work (Here for the architecture issues with DGW v1 and v2)
              if(nHeight <= 68589){
                  unsigned int nBitsNext = GetNextWorkRequired(pindexPrev, &block);
                  double n1 = ConvertBitsToDouble(block.nBits);
                  double n2 = ConvertBitsToDouble(nBitsNext);
  
                  if (abs(n1-n2) > n1*0.5)
                      return state.DoS(100, error("AcceptBlock() : incorrect proof of work (DGW pre-fork) - %f", abs(n1-n2)),
                                      REJECT_INVALID, "bad-diffbits");
              } else {
                  if (block.nBits != GetNextWorkRequired(pindexPrev, &block))
                      return state.DoS(100, error("AcceptBlock() : incorrect proof of work"),
                                      REJECT_INVALID, "bad-diffbits");
              }
          }
  
          // Check timestamp against prev
          if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
              return state.Invalid(error("AcceptBlock() : block's timestamp is too early"),
                                   REJECT_INVALID, "time-too-old");
  
          // Check that all transactions are finalized
          BOOST_FOREACH(const CTransaction& tx, block.vtx)
              if (!IsFinalTx(tx, nHeight, block.GetBlockTime()))
                  return state.DoS(10, error("AcceptBlock() : contains a non-final transaction"),
                                   REJECT_INVALID, "bad-txns-nonfinal");
  
          // Check that the block chain matches the known block chain up to a checkpoint
          if (!Checkpoints::CheckBlock(nHeight, hash))
              return state.DoS(100, error("AcceptBlock() : rejected by checkpoint lock-in at %d", nHeight),
                               REJECT_CHECKPOINT, "checkpoint mismatch");
  
          // Don't accept any forks from the main chain prior to last checkpoint
          CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(mapBlockIndex);
          if (pcheckpoint && nHeight < pcheckpoint->nHeight)
              return state.DoS(100, error("AcceptBlock() : forked chain older than last checkpoint (height %d)", nHeight));
  
          // Reject block.nVersion=1 blocks when 95% (75% on testnet) of the network has upgraded:
          if (block.nVersion < 2)
          {
              if ((!TestNet() && CBlockIndex::IsSuperMajority(2, pindexPrev, 950, 1000)) ||
                  (TestNet() && CBlockIndex::IsSuperMajority(2, pindexPrev, 75, 100)))
              {
                  return state.Invalid(error("AcceptBlock() : rejected nVersion=1 block"),
                                       REJECT_OBSOLETE, "bad-version");
              }
          }
          // Reject block.nVersion=2 blocks when 95% (75% on testnet) of the network has upgraded:
          if (block.nVersion < 3)
          {
              if ((!TestNet() && CBlockIndex::IsSuperMajority(3, pindexPrev, 950, 1000)) ||
                  (TestNet() && CBlockIndex::IsSuperMajority(3, pindexPrev, 75, 100)))
              {
                  return state.Invalid(error("AcceptBlock() : rejected nVersion=2 block"),
                                       REJECT_OBSOLETE, "bad-version");
              }
          }
          // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
          if (block.nVersion >= 2)
          {
              // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
              if ((!TestNet() && CBlockIndex::IsSuperMajority(2, pindexPrev, 750, 1000)) ||
                  (TestNet() && CBlockIndex::IsSuperMajority(2, pindexPrev, 51, 100)))
              {
                  CScript expect = CScript() << nHeight;
                  if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
                      !std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin()))
                      return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"),
                                       REJECT_INVALID, "bad-cb-height");
              }
          }
      }
  
      // Write block to history file
      try {
          unsigned int nBlockSize = ::GetSerializeSize(block, SER_DISK, CLIENT_VERSION);
          CDiskBlockPos blockPos;
          if (dbp != NULL)
              blockPos = *dbp;
          if (!FindBlockPos(state, blockPos, nBlockSize+8, nHeight, block.nTime, dbp != NULL))
              return error("AcceptBlock() : FindBlockPos failed");
          if (dbp == NULL)
              if (!WriteBlockToDisk(block, blockPos))
                  return state.Abort(_("Failed to write block"));
          if (!AddToBlockIndex(block, 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 (chainActive.Tip()->GetBlockHash() == hash)
      {
          LOCK(cs_vNodes);
          BOOST_FOREACH(CNode* pnode, vNodes)
              if (chainActive.Height() > (pnode->nStartingHeight != -1 ? pnode->nStartingHeight - 2000 : nBlockEstimate))
                  pnode->PushInventory(CInv(MSG_BLOCK, hash));
      }
  
      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; i++)
      {
          if (pstart->nVersion >= minVersion)
              ++nFound;
          pstart = pstart->pprev;
      }
      return (nFound >= nRequired);
  }
  
  int64_t CBlockIndex::GetMedianTime() const
  {
      AssertLockHeld(cs_main);
      const CBlockIndex* pindex = this;
      for (int i = 0; i < nMedianTimeSpan/2; i++)
      {
          if (!chainActive.Next(pindex))
              return GetBlockTime();
          pindex = chainActive.Next(pindex);
      }
      return pindex->GetMedianTimePast();
  }
  
  void PushGetBlocks(CNode* pnode, CBlockIndex* pindexBegin, uint256 hashEnd)
  {
      AssertLockHeld(cs_main);
      // Filter out duplicate requests
      if (pindexBegin == pnode->pindexLastGetBlocksBegin && hashEnd == pnode->hashLastGetBlocksEnd)
          return;
      pnode->pindexLastGetBlocksBegin = pindexBegin;
      pnode->hashLastGetBlocksEnd = hashEnd;
  
      pnode->PushMessage("getblocks", chainActive.GetLocator(pindexBegin), hashEnd);
  }
  
  bool ProcessBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDiskBlockPos *dbp)
  {
      AssertLockHeld(cs_main);
  
  /*
      block-a-block
  
      std::string s = "0000000234ebe01657601a9ed22f9e4459789d4b966b3b7f8f7cc90d1c039ee6";
      if(pblock->GetHash().ToString() == s){
          printf("Nope, get outta here!\n");
          return false;
      }
  */
  
      // 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()), 0, "duplicate");
      if (mapOrphanBlocks.count(hash))
          return state.Invalid(error("ProcessBlock() : already have block (orphan) %s", hash.ToString()), 0, "duplicate");
  
      // Preliminary checks
      if (!CheckBlock(*pblock, state))
          return error("ProcessBlock() : CheckBlock FAILED");
  
      CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(mapBlockIndex);
      if (pcheckpoint && pblock->hashPrevBlock != (chainActive.Tip() ? chainActive.Tip()->GetBlockHash() : uint256(0)))
      {
          // Extra checks to prevent "fill up memory by spamming with bogus blocks"
          int64_t deltaTime = pblock->GetBlockTime() - pcheckpoint->nTime;
          if (deltaTime < 0)
          {
              return state.DoS(100, error("ProcessBlock() : block with timestamp before last checkpoint"),
                               REJECT_CHECKPOINT, "time-too-old");
          }
          CBigNum bnNewBlock;
          bnNewBlock.SetCompact(pblock->nBits);
          CBigNum bnRequired;
          bnRequired.SetCompact(ComputeMinWork(pcheckpoint->nBits, deltaTime));
          if (bnNewBlock > bnRequired)
          {
              return state.DoS(100, error("ProcessBlock() : block with too little proof-of-work"),
                               REJECT_INVALID, "bad-diffbits");
          }
      }
  
  
      // 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))
      {
          LogPrintf("ProcessBlock: ORPHAN BLOCK %lu, prev=%s\n", (unsigned long)mapOrphanBlocks.size(), pblock->hashPrevBlock.ToString());
  
          // Accept orphans as long as there is a node to request its parents from
          if (pfrom) {
              PruneOrphanBlocks();
              COrphanBlock* pblock2 = new COrphanBlock();
              {
                  CDataStream ss(SER_DISK, CLIENT_VERSION);
                  ss << *pblock;
                  pblock2->vchBlock = std::vector<unsigned char>(ss.begin(), ss.end());
              }
              pblock2->hashBlock = hash;
              pblock2->hashPrev = pblock->hashPrevBlock;
              mapOrphanBlocks.insert(make_pair(hash, pblock2));
              mapOrphanBlocksByPrev.insert(make_pair(pblock2->hashPrev, pblock2));
  
              // Ask this guy to fill in what we're missing
              PushGetBlocks(pfrom, chainActive.Tip(), GetOrphanRoot(hash));
          }
          return true;
      }
  
      // Store to disk
      if (!AcceptBlock(*pblock, 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, COrphanBlock*>::iterator mi = mapOrphanBlocksByPrev.lower_bound(hashPrev);
               mi != mapOrphanBlocksByPrev.upper_bound(hashPrev);
               ++mi)
          {
              CBlock block;
              {
                  CDataStream ss(mi->second->vchBlock, SER_DISK, CLIENT_VERSION);
                  ss >> block;
              }
              block.BuildMerkleTree();
              // 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 (AcceptBlock(block, stateDummy))
                  vWorkQueue.push_back(mi->second->hashBlock);
              mapOrphanBlocks.erase(mi->second->hashBlock);
              delete mi->second;
          }
          mapOrphanBlocksByPrev.erase(hashPrev);
      }
  
      if(!fLiteMode){
          if (!fImporting && !fReindex && chainActive.Height() > Checkpoints::GetTotalBlocksEstimate()){
              darkSendPool.NewBlock();
              masternodePayments.ProcessBlock(GetHeight()+10);
              mnscan.DoMasternodePOSChecks();
          }
      }
  
      LogPrintf("ProcessBlock: ACCEPTED\n");
      return true;
  }
  
  
  
  
  
  
  
  
  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;
      LogPrintf("*** %s\n", strMessage);
      uiInterface.ThreadSafeMessageBox(strMessage, "", CClientUIInterface::MSG_ERROR);
      StartShutdown();
      return false;
  }
  
  bool CheckDiskSpace(uint64_t nAdditionalBytes)
  {
      uint64_t nFreeBytesAvailable = filesystem::space(GetDataDir()).available;
  
      // Check for nMinDiskSpace bytes (currently 50MB)
      if (nFreeBytesAvailable < nMinDiskSpace + nAdditionalBytes)
          return AbortNode(_("Error: Disk space is low!"));
  
      return true;
  }
  
  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) {
          LogPrintf("Unable to open file %s\n", path.string());
          return NULL;
      }
      if (pos.nPos) {
          if (fseek(file, pos.nPos, SEEK_SET)) {
              LogPrintf("Unable to seek to position %u of %s\n", pos.nPos, path.string());
              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 nChainWork
      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->nChainWork = (pindex->pprev ? pindex->pprev->nChainWork : 0) + pindex->GetBlockWork().getuint256();
          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);
          if (pindex->nStatus & BLOCK_FAILED_MASK && (!pindexBestInvalid || pindex->nChainWork > pindexBestInvalid->nChainWork))
              pindexBestInvalid = pindex;
      }
  
      // Load block file info
      pblocktree->ReadLastBlockFile(nLastBlockFile);
      LogPrintf("LoadBlockIndexDB(): last block file = %i\n", nLastBlockFile);
      if (pblocktree->ReadBlockFileInfo(nLastBlockFile, infoLastBlockFile))
          LogPrintf("LoadBlockIndexDB(): last block file info: %s\n", infoLastBlockFile.ToString());
  
      // 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);
      LogPrintf("LoadBlockIndexDB(): transaction index %s\n", fTxIndex ? "enabled" : "disabled");
  
      // Load pointer to end of best chain
      std::map<uint256, CBlockIndex*>::iterator it = mapBlockIndex.find(pcoinsTip->GetBestBlock());
      if (it == mapBlockIndex.end())
          return true;
      chainActive.SetTip(it->second);
      LogPrintf("LoadBlockIndexDB(): hashBestChain=%s height=%d date=%s progress=%f\n",
          chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(),
          DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()),
          Checkpoints::GuessVerificationProgress(chainActive.Tip()));
  
      return true;
  }
  
  bool VerifyDB(int nCheckLevel, int nCheckDepth)
  {
      LOCK(cs_main);
      if (chainActive.Tip() == NULL || chainActive.Tip()->pprev == NULL)
          return true;
  
      // Verify blocks in the best chain
      if (nCheckDepth <= 0)
          nCheckDepth = 1000000000; // suffices until the year 19000
      if (nCheckDepth > chainActive.Height())
          nCheckDepth = chainActive.Height();
      nCheckLevel = std::max(0, std::min(4, nCheckLevel));
      LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth, nCheckLevel);
      CCoinsViewCache coins(*pcoinsTip, true);
      CBlockIndex* pindexState = chainActive.Tip();
      CBlockIndex* pindexFailure = NULL;
      int nGoodTransactions = 0;
      CValidationState state;
      for (CBlockIndex* pindex = chainActive.Tip(); pindex && pindex->pprev; pindex = pindex->pprev)
      {
          boost::this_thread::interruption_point();
          if (pindex->nHeight < chainActive.Height()-nCheckDepth)
              break;
          CBlock block;
          // check level 0: read from disk
          if (!ReadBlockFromDisk(block, pindex))
              return error("VerifyDB() : *** ReadBlockFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
          // check level 1: verify block validity
          if (nCheckLevel >= 1 && !CheckBlock(block, state))
              return error("VerifyDB() : *** found bad block at %d, hash=%s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
          // 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());
              }
          }
          // 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 (!DisconnectBlock(block, state, pindex, coins, &fClean))
                  return error("VerifyDB() : *** irrecoverable inconsistency in block data at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
              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", chainActive.Height() - pindexFailure->nHeight + 1, nGoodTransactions);
  
      // check level 4: try reconnecting blocks
      if (nCheckLevel >= 4) {
          CBlockIndex *pindex = pindexState;
          while (pindex != chainActive.Tip()) {
              boost::this_thread::interruption_point();
              pindex = chainActive.Next(pindex);
              CBlock block;
              if (!ReadBlockFromDisk(block, pindex))
                  return error("VerifyDB() : *** ReadBlockFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
              if (!ConnectBlock(block, state, pindex, coins))
                  return error("VerifyDB() : *** found unconnectable block at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
          }
      }
  
      LogPrintf("No coin database inconsistencies in last %i blocks (%i transactions)\n", chainActive.Height() - pindexState->nHeight, nGoodTransactions);
  
      return true;
  }
  
  void UnloadBlockIndex()
  {
      mapBlockIndex.clear();
      setBlockIndexValid.clear();
      chainActive.SetTip(NULL);
      pindexBestInvalid = NULL;
  }
  
  bool LoadBlockIndex()
  {
      // Load block index from databases
      if (!fReindex && !LoadBlockIndexDB())
          return false;
      return true;
  }
  
  
  bool InitBlockIndex() {
      LOCK(cs_main);
      // Check whether we're already initialized
      if (chainActive.Genesis() != NULL)
          return true;
  
      // Use the provided setting for -txindex in the new database
      fTxIndex = GetBoolArg("-txindex", false);
      pblocktree->WriteFlag("txindex", fTxIndex);
      LogPrintf("Initializing databases...\n");
  
      // Only add the genesis block if not reindexing (in which case we reuse the one already on disk)
      if (!fReindex) {
          try {
              CBlock &block = const_cast<CBlock&>(Params().GenesisBlock());
              // Start new block file
              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 (!WriteBlockToDisk(block, blockPos))
                  return error("LoadBlockIndex() : writing genesis block to disk failed");
              if (!AddToBlockIndex(block, 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());
          }
      }
  
      return true;
  }
  
  
  
  void PrintBlockTree()
  {
      AssertLockHeld(cs_main);
      // 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, chainActive.Genesis()));
  
      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++)
                  LogPrintf("| ");
              LogPrintf("|\\\n");
          }
          else if (nCol < nPrevCol)
          {
              for (int i = 0; i < nCol; i++)
                  LogPrintf("| ");
              LogPrintf("|\n");
         }
          nPrevCol = nCol;
  
          // print columns
          for (int i = 0; i < nCol; i++)
              LogPrintf("| ");
  
          // print item
          CBlock block;
          ReadBlockFromDisk(block, pindex);
          LogPrintf("%d (blk%05u.dat:0x%x)  %s  tx %u\n",
              pindex->nHeight,
              pindex->GetBlockPos().nFile, pindex->GetBlockPos().nPos,
              DateTimeStrFormat("%Y-%m-%d %H:%M:%S", block.GetBlockTime()),
              block.vtx.size());
  
          // put the main time-chain first
          vector<CBlockIndex*>& vNext = mapNext[pindex];
          for (unsigned int i = 0; i < vNext.size(); i++)
          {
              if (chainActive.Next(vNext[i]))
              {
                  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_t nStart = GetTimeMillis();
  
      int nLoaded = 0;
      try {
          CBufferedFile blkdat(fileIn, 2*MAX_BLOCK_SIZE, MAX_BLOCK_SIZE+8, SER_DISK, CLIENT_VERSION);
          uint64_t 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_t 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[MESSAGE_START_SIZE];
                  blkdat.FindByte(Params().MessageStart()[0]);
                  nRewind = blkdat.GetPos()+1;
                  blkdat >> FLATDATA(buf);
                  if (memcmp(buf, Params().MessageStart(), MESSAGE_START_SIZE))
                      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_t 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) {
                  LogPrintf("%s : Deserialize or I/O error - %s", __func__, e.what());
              }
          }
          fclose(fileIn);
      } catch(std::runtime_error &e) {
          AbortNode(_("Error: system error: ") + e.what());
      }
      if (nLoaded > 0)
          LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded, GetTimeMillis() - nStart);
      return nLoaded > 0;
  }
  
  
  
  
  
  
  
  
  
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // CAlert
  //
  
  string GetWarnings(string strFor)
  {
      int nPriority = 0;
      string strStatusBar;
      string strRPC;
  
      if (GetBoolArg("-testsafemode", false))
          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");
  
      // Misc warnings like out of disk space and clock is wrong
      if (strMiscWarning != "")
      {
          nPriority = 1000;
          strStatusBar = strMiscWarning;
      }
  
      if (fLargeWorkForkFound)
      {
          nPriority = 2000;
          strStatusBar = strRPC = _("Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.");
      }
      else if (fLargeWorkInvalidChainFound)
      {
          nPriority = 2000;
          strStatusBar = strRPC = _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.");
      }
  
      // 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 (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;
              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);
      case MSG_TXLOCK_REQUEST:
          return mapTxLockReq.count(inv.hash) ||
                 mapTxLockReqRejected.count(inv.hash);
      case MSG_TXLOCK_VOTE:
          return mapTxLockVote.count(inv.hash);
      case MSG_SPORK:
          return mapSporks.count(inv.hash);
      case MSG_MASTERNODE_WINNER:
          return mapSeenMasternodeVotes.count(inv.hash);
      case MSG_MASTERNODE_SCANNING_ERROR:
          return mapMasternodeScanningErrors.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;
  
      LOCK(cs_main);
  
      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++;
  
              if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK)
              {
                  bool send = false;
                  map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.find(inv.hash);
                  if (mi != mapBlockIndex.end())
                  {
                      // If the requested block is at a height below our last
                      // checkpoint, only serve it if it's in the checkpointed chain
                      int nHeight = mi->second->nHeight;
                      CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(mapBlockIndex);
                      if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
                          if (!chainActive.Contains(mi->second))
                          {
                              LogPrintf("ProcessGetData(): ignoring request for old block that isn't in the main chain\n");
                          } else {
                              send = true;
                          }
                      } else {
                          send = true;
                      }
                  }
                  if (send)
                  {
                      // Send block from disk
                      CBlock block;
                      ReadBlockFromDisk(block, (*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.
                          vector<CInv> vInv;
                          vInv.push_back(CInv(MSG_BLOCK, chainActive.Tip()->GetBlockHash()));
                          pfrom->PushMessage("inv", vInv);
                          pfrom->hashContinue = 0;
                      }
                  }
              }
              else if (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) {
  
                      if(mapDarksendBroadcastTxes.count(inv.hash)){
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss <<
                              mapDarksendBroadcastTxes[inv.hash].tx <<
                              mapDarksendBroadcastTxes[inv.hash].vin <<
                              mapDarksendBroadcastTxes[inv.hash].vchSig <<
                              mapDarksendBroadcastTxes[inv.hash].sigTime;
  
                          pfrom->PushMessage("dstx", ss);
                          pushed = true;
                      } else {
                          CTransaction tx;
                          if (mempool.lookup(inv.hash, tx)) {
                              CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                              ss.reserve(1000);
                              ss << tx;
                              pfrom->PushMessage("tx", ss);
                              pushed = true;
                          }
                      }
                  }
                  if (!pushed && inv.type == MSG_TXLOCK_VOTE) {
                      if(mapTxLockVote.count(inv.hash)){
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss << mapTxLockVote[inv.hash];
                          pfrom->PushMessage("txlvote", ss);
                          pushed = true;
                      }
                  }
                  if (!pushed && inv.type == MSG_TXLOCK_REQUEST) {
                      if(mapTxLockReq.count(inv.hash)){
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss << mapTxLockReq[inv.hash];
                          pfrom->PushMessage("txlreq", ss);
                          pushed = true;
                      }
                  }
                  if (!pushed && inv.type == MSG_SPORK) {
                      if(mapSporks.count(inv.hash)){
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss << mapSporks[inv.hash];
                          pfrom->PushMessage("spork", ss);
                          pushed = true;
                      }
                  }
                  if (!pushed && inv.type == MSG_MASTERNODE_WINNER) {
                      if(mapSeenMasternodeVotes.count(inv.hash)){
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss << mapSeenMasternodeVotes[inv.hash];
                          pfrom->PushMessage("mnw", ss);
                          pushed = true;
                      }
                  }
                  if (!pushed && inv.type == MSG_MASTERNODE_SCANNING_ERROR) {
                      if(mapMasternodeScanningErrors.count(inv.hash)){
                          CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                          ss.reserve(1000);
                          ss << mapMasternodeScanningErrors[inv.hash];
                          pfrom->PushMessage("mnse", ss);
                          pushed = true;
                      }
                  }
  
                  if (!pushed) {
                      vNotFound.push_back(inv);
                  }
              }
  
              // Track requests for our stuff.
              g_signals.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();
      LogPrint("net", "received: %s (%u bytes)\n", SanitizeString(strCommand), vRecv.size());
      if (mapArgs.count("-dropmessagestest") && GetRand(atoi(mapArgs["-dropmessagestest"])) == 0)
      {
          LogPrintf("dropmessagestest DROPPING RECV MESSAGE\n");
          return true;
      }
  
      {
          LOCK(cs_main);
          State(pfrom->GetId())->nLastBlockProcess = GetTimeMicros();
      }
  
  
  
      if (strCommand == "version")
      {
          // Each connection can only send one version message
          if (pfrom->nVersion != 0)
          {
              pfrom->PushMessage("reject", strCommand, REJECT_DUPLICATE, string("Duplicate version message"));
              Misbehaving(pfrom->GetId(), 1);
              return false;
          }
  
          int64_t nTime;
          CAddress addrMe;
          CAddress addrFrom;
          uint64_t nNonce = 1;
          vRecv >> pfrom->nVersion >> pfrom->nServices >> nTime >> addrMe;
          if (pfrom->nVersion < MIN_PEER_PROTO_VERSION)
          {
              // disconnect from peers older than this proto version
              LogPrintf("partner %s using obsolete version %i; disconnecting\n", pfrom->addr.ToString(), pfrom->nVersion);
              pfrom->PushMessage("reject", strCommand, REJECT_OBSOLETE,
                                 strprintf("Version must be %d or greater", MIN_PEER_PROTO_VERSION));
              pfrom->fDisconnect = true;
              return false;
          }
  
          if (pfrom->nVersion == 10300)
              pfrom->nVersion = 300;
          if (!vRecv.empty())
              vRecv >> addrFrom >> nNonce;
          if (!vRecv.empty()) {
              vRecv >> LIMITED_STRING(pfrom->strSubVer, 256);
              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)
          {
              LogPrintf("connected to self at %s, disconnecting\n", pfrom->addr.ToString());
              pfrom->fDisconnect = true;
              return true;
          }
  
          // Be shy and don't send version until we hear
          if (pfrom->fInbound)
              pfrom->PushVersion();
  
          pfrom->fClient = !(pfrom->nServices & NODE_NETWORK);
  
  
          // 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);
          }
  
          pfrom->fSuccessfullyConnected = true;
  
          LogPrintf("receive version message: %s: version %d, blocks=%d, us=%s, them=%s, peer=%s\n", pfrom->cleanSubVer, pfrom->nVersion, pfrom->nStartingHeight, addrMe.ToString(), addrFrom.ToString(), pfrom->addr.ToString());
  
          AddTimeData(pfrom->addr, nTime);
      }
  
  
      else if (pfrom->nVersion == 0)
      {
          // Must have a version message before anything else
          Misbehaving(pfrom->GetId(), 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)
          {
              Misbehaving(pfrom->GetId(), 20);
              return error("message addr size() = %u", vAddr.size());
          }
  
          // Store the new addresses
          vector<CAddress> vAddrOk;
          int64_t nNow = GetAdjustedTime();
          int64_t 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_t 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)
          {
              Misbehaving(pfrom->GetId(), 20);
              return error("message inv size() = %u", vInv.size());
          }
  
          LOCK(cs_main);
  
          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);
              LogPrint("net", "  got inventory: %s  %s\n", inv.ToString(), fAlreadyHave ? "have" : "new");
  
              if (!fAlreadyHave) {
                  if (!fImporting && !fReindex) {
                      if (inv.type == MSG_BLOCK)
                          AddBlockToQueue(pfrom->GetId(), inv.hash);
                      else
                          pfrom->AskFor(inv);
                  }
              } else if (inv.type == MSG_BLOCK && mapOrphanBlocks.count(inv.hash)) {
                  PushGetBlocks(pfrom, chainActive.Tip(), GetOrphanRoot(inv.hash));
              }
  
              // Track requests for our stuff
              g_signals.Inventory(inv.hash);
  
              if (pfrom->nSendSize > (SendBufferSize() * 2)) {
                  Misbehaving(pfrom->GetId(), 50);
                  return error("send buffer size() = %u", pfrom->nSendSize);
              }
          }
      }
  
  
      else if (strCommand == "getdata")
      {
          vector<CInv> vInv;
          vRecv >> vInv;
          if (vInv.size() > MAX_INV_SZ)
          {
              Misbehaving(pfrom->GetId(), 20);
              return error("message getdata size() = %u", vInv.size());
          }
  
          if (fDebug || (vInv.size() != 1))
              LogPrint("net", "received getdata (%u invsz)\n", vInv.size());
  
          if ((fDebug && vInv.size() > 0) || (vInv.size() == 1))
              LogPrint("net", "received getdata for: %s\n", vInv[0].ToString());
  
          pfrom->vRecvGetData.insert(pfrom->vRecvGetData.end(), vInv.begin(), vInv.end());
          ProcessGetData(pfrom);
      }
  
  
      else if (strCommand == "getblocks")
      {
          CBlockLocator locator;
          uint256 hashStop;
          vRecv >> locator >> hashStop;
  
          LOCK(cs_main);
  
          // Find the last block the caller has in the main chain
          CBlockIndex* pindex = chainActive.FindFork(locator);
  
          // Send the rest of the chain
          if (pindex)
              pindex = chainActive.Next(pindex);
          int nLimit = 500;
          LogPrint("net", "getblocks %d to %s limit %d\n", (pindex ? pindex->nHeight : -1), hashStop.ToString(), nLimit);
          for (; pindex; pindex = chainActive.Next(pindex))
          {
              if (pindex->GetBlockHash() == hashStop)
              {
                  LogPrint("net", "  getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
                  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.
                  LogPrint("net", "  getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString());
                  pfrom->hashContinue = pindex->GetBlockHash();
                  break;
              }
          }
      }
  
  
      else if (strCommand == "getheaders")
      {
          CBlockLocator locator;
          uint256 hashStop;
          vRecv >> locator >> hashStop;
  
          LOCK(cs_main);
  
          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 = chainActive.FindFork(locator);
              if (pindex)
                  pindex = chainActive.Next(pindex);
          }
  
          // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end
          vector<CBlock> vHeaders;
          int nLimit = 2000;
          LogPrint("net", "getheaders %d to %s\n", (pindex ? pindex->nHeight : -1), hashStop.ToString());
          for (; pindex; pindex = chainActive.Next(pindex))
          {
              vHeaders.push_back(pindex->GetBlockHeader());
              if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop)
                  break;
          }
          pfrom->PushMessage("headers", vHeaders);
      }
  
  
      else if (strCommand == "tx"|| strCommand == "dstx")
      {
          vector<uint256> vWorkQueue;
          vector<uint256> vEraseQueue;
          CTransaction tx;
  
          //masternode signed transaction
          bool allowFree = false;
          CTxIn vin;
          vector<unsigned char> vchSig;
          int64_t sigTime;
  
          if(strCommand == "tx") {
              vRecv >> tx;
          } else if (strCommand == "dstx") {
              //these allow masternodes to publish a limited amount of free transactions
              vRecv >> tx >> vin >> vchSig >> sigTime;
  
              CMasternode* pmn = mnodeman.Find(vin);
              if(pmn != NULL)
              {
                  if(!pmn->allowFreeTx){
                      //multiple peers can send us a valid masternode transaction
                      if(fDebug) LogPrintf("dstx: Masternode sending too many transactions %s\n", tx.GetHash().ToString().c_str());
                      return true;
                  }
  
                  std::string strMessage = tx.GetHash().ToString() + boost::lexical_cast<std::string>(sigTime);
  
                  std::string errorMessage = "";
                  if(!darkSendSigner.VerifyMessage(pmn->pubkey2, vchSig, strMessage, errorMessage)){
                      LogPrintf("dstx: Got bad masternode address signature %s \n", vin.ToString().c_str());
                      //pfrom->Misbehaving(20);
                      return false;
                  }
  
                  LogPrintf("dstx: Got Masternode transaction %s\n", tx.GetHash().ToString().c_str());
  
                  allowFree = true;
                  pmn->allowFreeTx = false;
  
                  if(!mapDarksendBroadcastTxes.count(tx.GetHash())){
                      CDarksendBroadcastTx dstx;
                      dstx.tx = tx;
                      dstx.vin = vin;
                      dstx.vchSig = vchSig;
                      dstx.sigTime = sigTime;
  
                      mapDarksendBroadcastTxes.insert(make_pair(tx.GetHash(), dstx));
                  }
              }
          }
  
          CInv inv(MSG_TX, tx.GetHash());
          pfrom->AddInventoryKnown(inv);
  
          LOCK(cs_main);
  
          bool fMissingInputs = false;
          CValidationState state;
          if (AcceptToMemoryPool(mempool, state, tx, true, &fMissingInputs, allowFree))
          {
              mempool.check(pcoinsTip);
              RelayTransaction(tx, inv.hash);
              mapAlreadyAskedFor.erase(inv);
              vWorkQueue.push_back(inv.hash);
              vEraseQueue.push_back(inv.hash);
  
  
              LogPrint("mempool", "AcceptToMemoryPool: %s %s : accepted %s (poolsz %u)\n",
                  pfrom->addr.ToString(), pfrom->cleanSubVer,
                  tx.GetHash().ToString(),
                  mempool.mapTx.size());
  
              // Recursively process any orphan transactions that depended on this one
              set<NodeId> setMisbehaving;
              for (unsigned int i = 0; i < vWorkQueue.size(); i++)
              {
                  map<uint256, set<uint256> >::iterator itByPrev = mapOrphanTransactionsByPrev.find(vWorkQueue[i]);
                  if (itByPrev == mapOrphanTransactionsByPrev.end())
                      continue;
                  for (set<uint256>::iterator mi = itByPrev->second.begin();
                       mi != itByPrev->second.end();
                       ++mi)
                  {
                      const uint256& orphanHash = *mi;
                      const CTransaction& orphanTx = mapOrphanTransactions[orphanHash].tx;
                      NodeId fromPeer = mapOrphanTransactions[orphanHash].fromPeer;
                      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;
  
                      vEraseQueue.push_back(orphanHash);
  
                      if (setMisbehaving.count(fromPeer))
                          continue;
                      if (AcceptToMemoryPool(mempool, stateDummy, orphanTx, true, &fMissingInputs2))
                      {
                          LogPrint("mempool", "   accepted orphan tx %s\n", orphanHash.ToString());
                          RelayTransaction(orphanTx, orphanHash);
                          mapAlreadyAskedFor.erase(CInv(MSG_TX, orphanHash));
                          vWorkQueue.push_back(orphanHash);
                      }
                      else if (!fMissingInputs2)
                      {
                          int nDos = 0;
                          if (stateDummy.IsInvalid(nDos) && nDos > 0)
                          {
                              // Punish peer that gave us an invalid orphan tx
                              Misbehaving(fromPeer, nDos);
                              setMisbehaving.insert(fromPeer);
                              LogPrint("mempool", "   invalid orphan tx %s\n", orphanHash.ToString());
                          }
                          // too-little-fee orphan
                          LogPrint("mempool", "   removed orphan tx %s\n", orphanHash.ToString());
                      }
                      mempool.check(pcoinsTip);
                  }
              }
  
              BOOST_FOREACH(uint256 hash, vEraseQueue)
                  EraseOrphanTx(hash);
          }
          else if (fMissingInputs)
          {
              AddOrphanTx(tx, pfrom->GetId());
  
              // DoS prevention: do not allow mapOrphanTransactions to grow unbounded
              unsigned int nMaxOrphanTx = (unsigned int)std::max((int64_t)0, GetArg("-maxorphantx", DEFAULT_MAX_ORPHAN_TRANSACTIONS));
              unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx);
              if (nEvicted > 0)
                  LogPrint("mempool", "mapOrphan overflow, removed %u tx\n", nEvicted);
          }
          int nDoS = 0;
          if (state.IsInvalid(nDoS))
          {
              LogPrint("mempool", "%s from %s %s was not accepted into the memory pool: %s\n", tx.GetHash().ToString(),
                  pfrom->addr.ToString(), pfrom->cleanSubVer,
                  state.GetRejectReason());
              pfrom->PushMessage("reject", strCommand, state.GetRejectCode(),
                                 state.GetRejectReason(), inv.hash);
              if (nDoS > 0)
                  Misbehaving(pfrom->GetId(), nDoS);
          }
      }
  
  
      else if (strCommand == "block" && !fImporting && !fReindex) // Ignore blocks received while importing
      {
          CBlock block;
          vRecv >> block;
  
  
          LogPrint("net", "received block %s\n", block.GetHash().ToString());
          // block.print();
  
          CInv inv(MSG_BLOCK, block.GetHash());
          pfrom->AddInventoryKnown(inv);
  
          LOCK(cs_main);
          // Remember who we got this block from.
          mapBlockSource[inv.hash] = pfrom->GetId();
          MarkBlockAsReceived(inv.hash, pfrom->GetId());
  
          CValidationState state;
          ProcessBlock(state, pfrom, &block);
      }
  
  
      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")
      {
          LOCK2(cs_main, pfrom->cs_filter);
  
          std::vector<uint256> vtxid;
          mempool.queryHashes(vtxid);
          vector<CInv> vInv;
          BOOST_FOREACH(uint256& hash, vtxid) {
              CInv inv(MSG_TX, hash);
              CTransaction tx;
              bool fInMemPool = mempool.lookup(hash, tx);
              if (!fInMemPool) continue; // another thread removed since queryHashes, maybe...
              if ((pfrom->pfilter && pfrom->pfilter->IsRelevantAndUpdate(tx, hash)) ||
                 (!pfrom->pfilter))
                  vInv.push_back(inv);
              if (vInv.size() == MAX_INV_SZ) {
                  pfrom->PushMessage("inv", vInv);
                  vInv.clear();
              }
          }
          if (vInv.size() > 0)
              pfrom->PushMessage("inv", vInv);
      }
  
  
      else if (strCommand == "ping")
      {
          if (pfrom->nVersion > BIP0031_VERSION)
          {
              uint64_t 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 == "pong")
      {
          int64_t pingUsecEnd = GetTimeMicros();
          uint64_t nonce = 0;
          size_t nAvail = vRecv.in_avail();
          bool bPingFinished = false;
          std::string sProblem;
  
          if (nAvail >= sizeof(nonce)) {
              vRecv >> nonce;
  
              // Only process pong message if there is an outstanding ping (old ping without nonce should never pong)
              if (pfrom->nPingNonceSent != 0) {
                  if (nonce == pfrom->nPingNonceSent) {
                      // Matching pong received, this ping is no longer outstanding
                      bPingFinished = true;
                      int64_t pingUsecTime = pingUsecEnd - pfrom->nPingUsecStart;
                      if (pingUsecTime > 0) {
                          // Successful ping time measurement, replace previous
                          pfrom->nPingUsecTime = pingUsecTime;
                      } else {
                          // This should never happen
                          sProblem = "Timing mishap";
                      }
                  } else {
                      // Nonce mismatches are normal when pings are overlapping
                      sProblem = "Nonce mismatch";
                      if (nonce == 0) {
                          // This is most likely a bug in another implementation somewhere, cancel this ping
                          bPingFinished = true;
                          sProblem = "Nonce zero";
                      }
                  }
              } else {
                  sProblem = "Unsolicited pong without ping";
              }
          } else {
              // This is most likely a bug in another implementation somewhere, cancel this ping
              bPingFinished = true;
              sProblem = "Short payload";
          }
  
          if (!(sProblem.empty())) {
              LogPrint("net", "pong %s %s: %s, %x expected, %x received, %u bytes\n",
                  pfrom->addr.ToString(),
                  pfrom->cleanSubVer,
                  sProblem,
                  pfrom->nPingNonceSent,
                  nonce,
                  nAvail);
          }
          if (bPingFinished) {
              pfrom->nPingNonceSent = 0;
          }
      }
  
  
      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.
                  Misbehaving(pfrom->GetId(), 10);
              }
          }
      }
  
  
      else if (strCommand == "filterload")
      {
          CBloomFilter filter;
          vRecv >> filter;
  
          if (!filter.IsWithinSizeConstraints())
              // There is no excuse for sending a too-large filter
              Misbehaving(pfrom->GetId(), 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)
          {
              Misbehaving(pfrom->GetId(), 100);
          } else {
              LOCK(pfrom->cs_filter);
              if (pfrom->pfilter)
                  pfrom->pfilter->insert(vData);
              else
                  Misbehaving(pfrom->GetId(), 100);
          }
      }
  
  
      else if (strCommand == "filterclear")
      {
          LOCK(pfrom->cs_filter);
          delete pfrom->pfilter;
          pfrom->pfilter = new CBloomFilter();
          pfrom->fRelayTxes = true;
      }
  
  
      else if (strCommand == "reject")
      {
          if (fDebug)
          {
              string strMsg; unsigned char ccode; string strReason;
              vRecv >> LIMITED_STRING(strMsg, CMessageHeader::COMMAND_SIZE) >> ccode >> LIMITED_STRING(strReason, 111);
  
              ostringstream ss;
              ss << strMsg << " code " << itostr(ccode) << ": " << strReason;
  
              if (strMsg == "block" || strMsg == "tx")
              {
                  uint256 hash;
                  vRecv >> hash;
                  ss << ": hash " << hash.ToString();
              }
              LogPrint("net", "Reject %s\n", SanitizeString(ss.str()));
          }
      }
      else
      {
          //probably one the extensions
          darkSendPool.ProcessMessageDarksend(pfrom, strCommand, vRecv);
          mnodeman.ProcessMessage(pfrom, strCommand, vRecv);
          ProcessMessageMasternodePayments(pfrom, strCommand, vRecv);
          ProcessMessageInstantX(pfrom, strCommand, vRecv);
          ProcessSpork(pfrom, strCommand, vRecv);
          ProcessMessageMasternodePOS(pfrom, strCommand, vRecv);
      }
  
  
      // 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)
      //    LogPrintf("ProcessMessages(%u messages)\n", pfrom->vRecvMsg.size());
  
      //
      // Message format
      //  (4) message start
      //  (12) command
      //  (4) size
      //  (4) checksum
      //  (x) data
      //
      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)
          //    LogPrintf("ProcessMessages(message %u msgsz, %u 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, Params().MessageStart(), MESSAGE_START_SIZE) != 0) {
              LogPrintf("PROCESSMESSAGE: INVALID MESSAGESTART %s\n", SanitizeString(msg.hdr.GetCommand()));
              fOk = false;
              break;
          }
  
          // Read header
          CMessageHeader& hdr = msg.hdr;
          if (!hdr.IsValid())
          {
              LogPrintf("PROCESSMESSAGE: ERRORS IN HEADER %s\n", SanitizeString(hdr.GetCommand()));
              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)
          {
              LogPrintf("ProcessMessages(%s, %u bytes): CHECKSUM ERROR nChecksum=%08x hdr.nChecksum=%08x\n",
                 SanitizeString(strCommand), nMessageSize, nChecksum, hdr.nChecksum);
              continue;
          }
  
          // Process message
          bool fRet = false;
          try
          {
              fRet = ProcessMessage(pfrom, strCommand, vRecv);
              boost::this_thread::interruption_point();
          }
          catch (std::ios_base::failure& e)
          {
              pfrom->PushMessage("reject", strCommand, REJECT_MALFORMED, string("error parsing message"));
              if (strstr(e.what(), "end of data"))
              {
                  // Allow exceptions from under-length message on vRecv
                  LogPrintf("ProcessMessages(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", SanitizeString(strCommand), nMessageSize, e.what());
              }
              else if (strstr(e.what(), "size too large"))
              {
                  // Allow exceptions from over-long size
                  LogPrintf("ProcessMessages(%s, %u bytes): Exception '%s' caught\n", SanitizeString(strCommand), 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)
              LogPrintf("ProcessMessage(%s, %u bytes) FAILED\n", SanitizeString(strCommand), 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)
  {
      {
          // Don't send anything until we get their version message
          if (pto->nVersion == 0)
              return true;
  
          //
          // Message: ping
          //
          bool pingSend = false;
          if (pto->fPingQueued) {
              // RPC ping request by user
              pingSend = true;
          }
          if (pto->nLastSend && GetTime() - pto->nLastSend > 30 * 60 && pto->vSendMsg.empty()) {
              // Ping automatically sent as a keepalive
              pingSend = true;
          }
          if (pingSend) {
              uint64_t nonce = 0;
              while (nonce == 0) {
                  RAND_bytes((unsigned char*)&nonce, sizeof(nonce));
              }
              pto->nPingNonceSent = nonce;
              pto->fPingQueued = false;
              if (pto->nVersion > BIP0031_VERSION) {
                  // Take timestamp as close as possible before transmitting ping
                  pto->nPingUsecStart = GetTimeMicros();
                  pto->PushMessage("ping", nonce);
              } else {
                  // Peer is too old to support ping command with nonce, pong will never arrive, disable timing
                  pto->nPingUsecStart = 0;
                  pto->PushMessage("ping");
              }
          }
  
          TRY_LOCK(cs_main, lockMain); // Acquire cs_main for IsInitialBlockDownload() and CNodeState()
          if (!lockMain)
              return true;
  
          // Address refresh broadcast
          static int64_t 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);
          }
  
          CNodeState &state = *State(pto->GetId());
          if (state.fShouldBan) {
              if (pto->addr.IsLocal())
                  LogPrintf("Warning: not banning local node %s!\n", pto->addr.ToString());
              else {
                  pto->fDisconnect = true;
                  CNode::Ban(pto->addr);
              }
              state.fShouldBan = false;
          }
  
          BOOST_FOREACH(const CBlockReject& reject, state.rejects)
              pto->PushMessage("reject", (string)"block", reject.chRejectCode, reject.strRejectReason, reject.hashBlock);
          state.rejects.clear();
  
          // Start block sync
          if (pto->fStartSync && !fImporting && !fReindex) {
              pto->fStartSync = false;
              PushGetBlocks(pto, chainActive.Tip(), 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())
          {
              g_signals.Broadcast();
          }
  
          //
          // 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);
  
                      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);
  
  
          // Detect stalled peers. Require that blocks are in flight, we haven't
          // received a (requested) block in one minute, and that all blocks are
          // in flight for over two minutes, since we first had a chance to
          // process an incoming block.
          int64_t nNow = GetTimeMicros();
          if (!pto->fDisconnect && state.nBlocksInFlight &&
              state.nLastBlockReceive < state.nLastBlockProcess - BLOCK_DOWNLOAD_TIMEOUT*1000000 &&
              state.vBlocksInFlight.front().nTime < state.nLastBlockProcess - 2*BLOCK_DOWNLOAD_TIMEOUT*1000000) {
              LogPrintf("Peer %s is stalling block download, disconnecting\n", state.name.c_str());
              pto->fDisconnect = true;
          }
  
          //
          // Message: getdata (blocks)
          //
          vector<CInv> vGetData;
          while (!pto->fDisconnect && state.nBlocksToDownload && state.nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
              uint256 hash = state.vBlocksToDownload.front();
              vGetData.push_back(CInv(MSG_BLOCK, hash));
              MarkBlockAsInFlight(pto->GetId(), hash);
              LogPrint("net", "Requesting block %s from %s\n", hash.ToString().c_str(), state.name.c_str());
              if (vGetData.size() >= 1000)
              {
                  pto->PushMessage("getdata", vGetData);
                  vGetData.clear();
              }
          }
  
          //
          // Message: getdata (non-blocks)
          //
          while (!pto->fDisconnect && !pto->mapAskFor.empty() && (*pto->mapAskFor.begin()).first <= nNow)
          {
              const CInv& inv = (*pto->mapAskFor.begin()).second;
              if (!AlreadyHave(inv))
              {
                  if (fDebug)
                      LogPrint("net", "sending getdata: %s\n", inv.ToString());
                  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;
  }
  
  
  
  
  
  
  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, COrphanBlock*>::iterator it2 = mapOrphanBlocks.begin();
          for (; it2 != mapOrphanBlocks.end(); it2++)
              delete (*it2).second;
          mapOrphanBlocks.clear();
  
          // orphan transactions
          mapOrphanTransactions.clear();
          mapOrphanTransactionsByPrev.clear();
      }
  } instance_of_cmaincleanup;
  