text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2012 The Bitcoin developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "init.h"
  #include "main.h"
  #include "chainparams.h"
  #include "txdb.h"
  #include "rpcserver.h"
  #include "net.h"
  #include "util.h"
  #include "ui_interface.h"
  #include "checkpoints.h"
  #ifdef ENABLE_WALLET
  #include "wallet.h"
  #include "walletdb.h"
  #endif
  
  #include <boost/filesystem.hpp>
  #include <boost/filesystem/fstream.hpp>
  #include <boost/filesystem/convenience.hpp>
  #include <boost/interprocess/sync/file_lock.hpp>
  #include <boost/algorithm/string/predicate.hpp>
  #include <openssl/crypto.h>
  
  #ifndef WIN32
  #include <signal.h>
  #endif
  
  
  using namespace std;
  using namespace boost;
  
  #ifdef ENABLE_WALLET
  CWallet* pwalletMain = NULL;
  #endif
  CClientUIInterface uiInterface;
  bool fConfChange;
  bool fMinimizeCoinAge;
  unsigned int nNodeLifespan;
  unsigned int nDerivationMethodIndex;
  unsigned int nMinerSleep;
  bool fUseFastIndex;
  enum Checkpoints::CPMode CheckpointsMode;
  
  //////////////////////////////////////////////////////////////////////////////
  //
  // Shutdown
  //
  
  //
  // Thread management and startup/shutdown:
  //
  // The network-processing threads are all part of a thread group
  // created by AppInit() or the Qt main() function.
  //
  // A clean exit happens when StartShutdown() or the SIGTERM
  // signal handler sets fRequestShutdown, which triggers
  // the DetectShutdownThread(), which interrupts the main thread group.
  // DetectShutdownThread() then exits, which causes AppInit() to
  // continue (it .joins the shutdown thread).
  // Shutdown() is then
  // called to clean up database connections, and stop other
  // threads that should only be stopped after the main network-processing
  // threads have exited.
  //
  // Note that if running -daemon the parent process returns from AppInit2
  // before adding any threads to the threadGroup, so .join_all() returns
  // immediately and the parent exits from main().
  //
  // Shutdown for Qt is very similar, only it uses a QTimer to detect
  // fRequestShutdown getting set, and then does the normal Qt
  // shutdown thing.
  //
  
  volatile bool fRequestShutdown = false;
  
  void StartShutdown()
  {
      fRequestShutdown = true;
  }
  bool ShutdownRequested()
  {
      return fRequestShutdown;
  }
  
  void Shutdown()
  {
      LogPrintf("Shutdown : In progress...\n");
      static CCriticalSection cs_Shutdown;
      TRY_LOCK(cs_Shutdown, lockShutdown);
      if (!lockShutdown) return;
  
      RenameThread("ducoin-shutoff");
      mempool.AddTransactionsUpdated(1);
      StopRPCThreads();
  #ifdef ENABLE_WALLET
      ShutdownRPCMining();
      if (pwalletMain)
          bitdb.Flush(false);
  #endif
      StopNode();
      {
          LOCK(cs_main);
  #ifdef ENABLE_WALLET
          if (pwalletMain)
              pwalletMain->SetBestChain(CBlockLocator(pindexBest));
  #endif
      }
  #ifdef ENABLE_WALLET
      if (pwalletMain)
          bitdb.Flush(true);
  #endif
      boost::filesystem::remove(GetPidFile());
      UnregisterAllWallets();
  #ifdef ENABLE_WALLET
      delete pwalletMain;
      pwalletMain = NULL;
  #endif
      LogPrintf("Shutdown : done\n");
  }
  
  //
  // Signal handlers are very limited in what they are allowed to do, so:
  //
  void HandleSIGTERM(int)
  {
      fRequestShutdown = true;
  }
  
  void HandleSIGHUP(int)
  {
      fReopenDebugLog = true;
  }
  
  bool static InitError(const std::string &str)
  {
      uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_ERROR);
      return false;
  }
  
  bool static InitWarning(const std::string &str)
  {
      uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_WARNING);
      return true;
  }
  
  bool static Bind(const CService &addr, bool fError = true) {
      if (IsLimited(addr))
          return false;
      std::string strError;
      if (!BindListenPort(addr, strError)) {
          if (fError)
              return InitError(strError);
          return false;
      }
      return true;
  }
  
  // Core-specific options shared between UI and daemon
  std::string HelpMessage()
  {
      string strUsage = _("Options:") + "\n";
      strUsage += "  -?                     " + _("This help message") + "\n";
      strUsage += "  -conf=<file>           " + _("Specify configuration file (default: ducoin.conf)") + "\n";
      strUsage += "  -pid=<file>            " + _("Specify pid file (default: ducoind.pid)") + "\n";
      strUsage += "  -datadir=<dir>         " + _("Specify data directory") + "\n";
      strUsage += "  -wallet=<dir>          " + _("Specify wallet file (within data directory)") + "\n";
      strUsage += "  -dbcache=<n>           " + _("Set database cache size in megabytes (default: 25)") + "\n";
      strUsage += "  -dblogsize=<n>         " + _("Set database disk log size in megabytes (default: 100)") + "\n";
      strUsage += "  -timeout=<n>           " + _("Specify connection timeout in milliseconds (default: 5000)") + "\n";
      strUsage += "  -proxy=<ip:port>       " + _("Connect through socks proxy") + "\n";
      strUsage += "  -socks=<n>             " + _("Select the version of socks proxy to use (4-5, default: 5)") + "\n";
      strUsage += "  -tor=<ip:port>         " + _("Use proxy to reach tor hidden services (default: same as -proxy)") + "\n";
      strUsage += "  -dns                   " + _("Allow DNS lookups for -addnode, -seednode and -connect") + "\n";
      strUsage += "  -port=<port>           " + _("Listen for connections on <port> (default: 6833 or testnet: 20556)") + "\n";
      strUsage += "  -maxconnections=<n>    " + _("Maintain at most <n> connections to peers (default: 125)") + "\n";
      strUsage += "  -addnode=<ip>          " + _("Add a node to connect to and attempt to keep the connection open") + "\n";
      strUsage += "  -connect=<ip>          " + _("Connect only to the specified node(s)") + "\n";
      strUsage += "  -seednode=<ip>         " + _("Connect to a node to retrieve peer addresses, and disconnect") + "\n";
      strUsage += "  -externalip=<ip>       " + _("Specify your own public address") + "\n";
      strUsage += "  -onlynet=<net>         " + _("Only connect to nodes in network <net> (IPv4, IPv6 or Tor)") + "\n";
      strUsage += "  -discover              " + _("Discover own IP address (default: 1 when listening and no -externalip)") + "\n";
      strUsage += "  -listen                " + _("Accept connections from outside (default: 1 if no -proxy or -connect)") + "\n";
      strUsage += "  -bind=<addr>           " + _("Bind to given address. Use [host]:port notation for IPv6") + "\n";
      strUsage += "  -dnsseed               " + _("Query for peer addresses via DNS lookup, if low on addresses (default: 1 unless -connect)") + "\n";
      strUsage += "  -forcednsseed          " + _("Always query for peer addresses via DNS lookup (default: 0)") + "\n";
      strUsage += "  -synctime              " + _("Sync time with other nodes. Disable if time on your system is precise e.g. syncing with NTP (default: 1)") + "\n";
      strUsage += "  -cppolicy              " + _("Sync checkpoints policy (default: strict)") + "\n";
      strUsage += "  -banscore=<n>          " + _("Threshold for disconnecting misbehaving peers (default: 100)") + "\n";
      strUsage += "  -bantime=<n>           " + _("Number of seconds to keep misbehaving peers from reconnecting (default: 86400)") + "\n";
      strUsage += "  -maxreceivebuffer=<n>  " + _("Maximum per-connection receive buffer, <n>*1000 bytes (default: 5000)") + "\n";
      strUsage += "  -maxsendbuffer=<n>     " + _("Maximum per-connection send buffer, <n>*1000 bytes (default: 1000)") + "\n";
  #ifdef USE_UPNP
  #if USE_UPNP
      strUsage += "  -upnp                  " + _("Use UPnP to map the listening port (default: 1 when listening)") + "\n";
  #else
      strUsage += "  -upnp                  " + _("Use UPnP to map the listening port (default: 0)") + "\n";
  #endif
  #endif
      strUsage += "  -paytxfee=<amt>        " + _("Fee per KB to add to transactions you send") + "\n";
      strUsage += "  -mininput=<amt>        " + _("When creating transactions, ignore inputs with value less than this (default: 0.01)") + "\n";
      if (fHaveGUI)
          strUsage += "  -server                " + _("Accept command line and JSON-RPC commands") + "\n";
  #if !defined(WIN32)
      if (fHaveGUI)
          strUsage += "  -daemon                " + _("Run in the background as a daemon and accept commands") + "\n";
  #endif
      strUsage += "  -testnet               " + _("Use the test network") + "\n";
      strUsage += "  -debug=<category>      " + _("Output debugging information (default: 0, supplying <category> is optional)") + "\n";
      strUsage +=                               _("If <category> is not supplied, output all debugging information.") + "\n";
      strUsage +=                               _("<category> can be:");
      strUsage +=                                 " addrman, alert, db, lock, rand, rpc, selectcoins, mempool, net,"; // Don't translate these and qt below
      strUsage +=                                 " coinage, coinstake, creation, stakemodifier";
      if (fHaveGUI)
      {
          strUsage += ", qt.\n";
      }
      else
      {
          strUsage += ".\n";
      }
      strUsage += "  -logtimestamps         " + _("Prepend debug output with timestamp") + "\n";
      strUsage += "  -shrinkdebugfile       " + _("Shrink debug.log file on client startup (default: 1 when no -debug)") + "\n";
      strUsage += "  -printtoconsole        " + _("Send trace/debug info to console instead of debug.log file") + "\n";
      strUsage += "  -regtest               " + _("Enter regression test mode, which uses a special chain in which blocks can be "
                                                  "solved instantly. This is intended for regression testing tools and app development.") + "\n";
      strUsage += "  -rpcuser=<user>        " + _("Username for JSON-RPC connections") + "\n";
      strUsage += "  -rpcpassword=<pw>      " + _("Password for JSON-RPC connections") + "\n";
      strUsage += "  -rpcport=<port>        " + _("Listen for JSON-RPC connections on <port> (default: 6832 or testnet: 20555)") + "\n";
      strUsage += "  -rpcallowip=<ip>       " + _("Allow JSON-RPC connections from specified IP address") + "\n";
      if (!fHaveGUI)
      {
          strUsage += "  -rpcconnect=<ip>       " + _("Send commands to node running on <ip> (default: 127.0.0.1)") + "\n";
          strUsage += "  -rpcwait               " + _("Wait for RPC server to start") + "\n";
      }
      strUsage += "  -rpcthreads=<n>        " + _("Set the number of threads to service RPC calls (default: 4)") + "\n";
      strUsage += "  -blocknotify=<cmd>     " + _("Execute command when the best block changes (%s in cmd is replaced by block hash)") + "\n";
      strUsage += "  -walletnotify=<cmd>    " + _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)") + "\n";
      strUsage += "  -confchange            " + _("Require a confirmations for change (default: 0)") + "\n";
      strUsage += "  -minimizecoinage       " + _("Minimize weight consumption (experimental) (default: 0)") + "\n";
      strUsage += "  -alertnotify=<cmd>     " + _("Execute command when a relevant alert is received (%s in cmd is replaced by message)") + "\n";
      strUsage += "  -upgradewallet         " + _("Upgrade wallet to latest format") + "\n";
      strUsage += "  -keypool=<n>           " + _("Set key pool size to <n> (default: 100)") + "\n";
      strUsage += "  -rescan                " + _("Rescan the block chain for missing wallet transactions") + "\n";
      strUsage += "  -salvagewallet         " + _("Attempt to recover private keys from a corrupt wallet.dat") + "\n";
      strUsage += "  -checkblocks=<n>       " + _("How many blocks to check at startup (default: 500, 0 = all)") + "\n";
      strUsage += "  -checklevel=<n>        " + _("How thorough the block verification is (0-6, default: 1)") + "\n";
      strUsage += "  -loadblock=<file>      " + _("Imports blocks from external blk000?.dat file") + "\n";
      strUsage += "  -maxorphanblocks=<n>   " + strprintf(_("Keep at most <n> unconnectable blocks in memory (default: %u)"), DEFAULT_MAX_ORPHAN_BLOCKS) + "\n";
  
      strUsage += "\n" + _("Block creation options:") + "\n";
      strUsage += "  -blockminsize=<n>      "   + _("Set minimum block size in bytes (default: 0)") + "\n";
      strUsage += "  -blockmaxsize=<n>      "   + _("Set maximum block size in bytes (default: 250000)") + "\n";
      strUsage += "  -blockprioritysize=<n> "   + _("Set maximum size of high-priority/low-fee transactions in bytes (default: 27000)") + "\n";
  
      strUsage += "\n" + _("SSL options: (see the Bitcoin Wiki for SSL setup instructions)") + "\n";
      strUsage += "  -rpcssl                                  " + _("Use OpenSSL (https) for JSON-RPC connections") + "\n";
      strUsage += "  -rpcsslcertificatechainfile=<file.cert>  " + _("Server certificate file (default: server.cert)") + "\n";
      strUsage += "  -rpcsslprivatekeyfile=<file.pem>         " + _("Server private key (default: server.pem)") + "\n";
      strUsage += "  -rpcsslciphers=<ciphers>                 " + _("Acceptable ciphers (default: TLSv1.2+HIGH:TLSv1+HIGH:!SSLv2:!aNULL:!eNULL:!3DES:@STRENGTH)") + "\n";
  
      return strUsage;
  }
  
  /** Sanity checks
   *  Ensure that Bitcoin is running in a usable environment with all
   *  necessary library support.
   */
  bool InitSanityCheck(void)
  {
      if(!ECC_InitSanityCheck()) {
          InitError("OpenSSL appears to lack support for elliptic curve cryptography. For more "
                    "information, visit https://en.bitcoin.it/wiki/OpenSSL_and_EC_Libraries");
          return false;
      }
  
      // TODO: remaining sanity checks, see #4081
  
      return true;
  }
  
  /** Initialize bitcoin.
   *  @pre Parameters should be parsed and config file should be read.
   */
  bool AppInit2(boost::thread_group& threadGroup)
  {
      // ********************************************************* Step 1: setup
  #ifdef _MSC_VER
      // Turn off Microsoft heap dump noise
      _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
      _CrtSetReportFile(_CRT_WARN, CreateFileA("NUL", GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, 0));
  #endif
  #if _MSC_VER >= 1400
      // Disable confusing "helpful" text message on abort, Ctrl-C
      _set_abort_behavior(0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
  #endif
  #ifdef WIN32
      // Enable Data Execution Prevention (DEP)
      // Minimum supported OS versions: WinXP SP3, WinVista >= SP1, Win Server 2008
      // A failure is non-critical and needs no further attention!
  #ifndef PROCESS_DEP_ENABLE
      // We define this here, because GCCs winbase.h limits this to _WIN32_WINNT >= 0x0601 (Windows 7),
      // which is not correct. Can be removed, when GCCs winbase.h is fixed!
  #define PROCESS_DEP_ENABLE 0x00000001
  #endif
      typedef BOOL (WINAPI *PSETPROCDEPPOL)(DWORD);
      PSETPROCDEPPOL setProcDEPPol = (PSETPROCDEPPOL)GetProcAddress(GetModuleHandleA("Kernel32.dll"), "SetProcessDEPPolicy");
      if (setProcDEPPol != NULL) setProcDEPPol(PROCESS_DEP_ENABLE);
  #endif
  #ifndef WIN32
      umask(077);
  
      // Clean shutdown on SIGTERM
      struct sigaction sa;
      sa.sa_handler = HandleSIGTERM;
      sigemptyset(&sa.sa_mask);
      sa.sa_flags = 0;
      sigaction(SIGTERM, &sa, NULL);
      sigaction(SIGINT, &sa, NULL);
  
      // Reopen debug.log on SIGHUP
      struct sigaction sa_hup;
      sa_hup.sa_handler = HandleSIGHUP;
      sigemptyset(&sa_hup.sa_mask);
      sa_hup.sa_flags = 0;
      sigaction(SIGHUP, &sa_hup, NULL);
  #endif
  
      // ********************************************************* Step 2: parameter interactions
  
      nNodeLifespan = GetArg("-addrlifespan", 7);
      fUseFastIndex = GetBoolArg("-fastindex", true);
      nMinerSleep = GetArg("-minersleep", 500);
  
      CheckpointsMode = Checkpoints::STRICT;
      std::string strCpMode = GetArg("-cppolicy", "strict");
  
      if(strCpMode == "strict")
          CheckpointsMode = Checkpoints::STRICT;
  
      if(strCpMode == "advisory")
          CheckpointsMode = Checkpoints::ADVISORY;
  
      if(strCpMode == "permissive")
          CheckpointsMode = Checkpoints::PERMISSIVE;
  
      nDerivationMethodIndex = 0;
  
      if (!SelectParamsFromCommandLine()) {
          return InitError("Invalid combination of -testnet and -regtest.");
      }
  
      if (mapArgs.count("-bind")) {
          // when specifying an explicit binding address, you want to listen on it
          // even when -connect or -proxy is specified
          if (SoftSetBoolArg("-listen", true))
              LogPrintf("AppInit2 : parameter interaction: -bind set -> setting -listen=1\n");
      }
  
      if (mapArgs.count("-connect") && mapMultiArgs["-connect"].size() > 0) {
          // when only connecting to trusted nodes, do not seed via DNS, or listen by default
          if (SoftSetBoolArg("-dnsseed", false))
              LogPrintf("AppInit2 : parameter interaction: -connect set -> setting -dnsseed=0\n");
          if (SoftSetBoolArg("-listen", false))
              LogPrintf("AppInit2 : parameter interaction: -connect set -> setting -listen=0\n");
      }
  
      if (mapArgs.count("-proxy")) {
          // to protect privacy, do not listen by default if a default proxy server is specified
          if (SoftSetBoolArg("-listen", false))
              LogPrintf("AppInit2 : parameter interaction: -proxy set -> setting -listen=0\n");
          // to protect privacy, do not discover addresses by default
          if (SoftSetBoolArg("-discover", false))
              LogPrintf("AppInit2 : parameter interaction: -proxy set -> setting -discover=0\n");
      }
  
      if (!GetBoolArg("-listen", true)) {
          // do not map ports or try to retrieve public IP when not listening (pointless)
          if (SoftSetBoolArg("-upnp", false))
              LogPrintf("AppInit2 : parameter interaction: -listen=0 -> setting -upnp=0\n");
          if (SoftSetBoolArg("-discover", false))
              LogPrintf("AppInit2 : parameter interaction: -listen=0 -> setting -discover=0\n");
      }
  
      if (mapArgs.count("-externalip")) {
          // if an explicit public IP is specified, do not try to find others
          if (SoftSetBoolArg("-discover", false))
              LogPrintf("AppInit2 : parameter interaction: -externalip set -> setting -discover=0\n");
      }
  
      if (GetBoolArg("-salvagewallet", false)) {
          // Rewrite just private keys: rescan to find transactions
          if (SoftSetBoolArg("-rescan", true))
              LogPrintf("AppInit2 : parameter interaction: -salvagewallet=1 -> setting -rescan=1\n");
      }
  
      // ********************************************************* Step 3: parameter-to-internal-flags
  
      fDebug = !mapMultiArgs["-debug"].empty();
      // Special-case: if -debug=0/-nodebug is set, turn off debugging messages
      const vector<string>& categories = mapMultiArgs["-debug"];
      if (GetBoolArg("-nodebug", false) || find(categories.begin(), categories.end(), string("0")) != categories.end())
          fDebug = false;
  
      // Check for -debugnet (deprecated)
      if (GetBoolArg("-debugnet", false))
          InitWarning(_("Warning: Deprecated argument -debugnet ignored, use -debug=net"));
  
      if (fDaemon)
          fServer = true;
      else
          fServer = GetBoolArg("-server", false);
  
      /* force fServer when running without GUI */
      if (!fHaveGUI)
          fServer = true;
      fPrintToConsole = GetBoolArg("-printtoconsole", false);
      fLogTimestamps = GetBoolArg("-logtimestamps", false);
  #ifdef ENABLE_WALLET
      bool fDisableWallet = GetBoolArg("-disablewallet", false);
  #endif
  
      if (mapArgs.count("-timeout"))
      {
          int nNewTimeout = GetArg("-timeout", 5000);
          if (nNewTimeout > 0 && nNewTimeout < 600000)
              nConnectTimeout = nNewTimeout;
      }
  
  #ifdef ENABLE_WALLET
      if (mapArgs.count("-paytxfee"))
      {
          if (!ParseMoney(mapArgs["-paytxfee"], nTransactionFee))
              return InitError(strprintf(_("Invalid amount for -paytxfee=<amount>: '%s'"), mapArgs["-paytxfee"]));
          if (nTransactionFee > 0.25 * COIN)
              InitWarning(_("Warning: -paytxfee is set very high! This is the transaction fee you will pay if you send a transaction."));
      }
  #endif
  
      fConfChange = GetBoolArg("-confchange", false);
      fMinimizeCoinAge = GetBoolArg("-minimizecoinage", false);
  
  #ifdef ENABLE_WALLET
      if (mapArgs.count("-mininput"))
      {
          if (!ParseMoney(mapArgs["-mininput"], nMinimumInputValue))
              return InitError(strprintf(_("Invalid amount for -mininput=<amount>: '%s'"), mapArgs["-mininput"]));
      }
  #endif
  
      // ********************************************************* Step 4: application initialization: dir lock, daemonize, pidfile, debug log
  
      // Sanity check
      if (!InitSanityCheck())
          return InitError(_("Initialization sanity check failed. DUCOIN is shutting down."));
  
      std::string strDataDir = GetDataDir().string();
  #ifdef ENABLE_WALLET
      std::string strWalletFileName = GetArg("-wallet", "wallet.dat");
  
      // strWalletFileName must be a plain filename without a directory
      if (strWalletFileName != boost::filesystem::basename(strWalletFileName) + boost::filesystem::extension(strWalletFileName))
          return InitError(strprintf(_("Wallet %s resides outside data directory %s."), strWalletFileName, strDataDir));
  #endif
      // Make sure only a single Bitcoin process is using the data directory.
      boost::filesystem::path pathLockFile = GetDataDir() / ".lock";
      FILE* file = fopen(pathLockFile.string().c_str(), "a"); // empty lock file; created if it doesn't exist.
      if (file) fclose(file);
      static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
      if (!lock.try_lock())
          return InitError(strprintf(_("Cannot obtain a lock on data directory %s. DUCOIN is probably already running."), strDataDir));
  
      if (GetBoolArg("-shrinkdebugfile", !fDebug))
          ShrinkDebugFile();
      LogPrintf("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
      LogPrintf("DUCOIN version %s (%s)\n", FormatFullVersion(), CLIENT_DATE);
      LogPrintf("Using OpenSSL version %s\n", SSLeay_version(SSLEAY_VERSION));
      if (!fLogTimestamps)
          LogPrintf("Startup time: %s\n", DateTimeStrFormat("%x %H:%M:%S", GetTime()));
      LogPrintf("Default data directory %s\n", GetDefaultDataDir().string());
      LogPrintf("Used data directory %s\n", strDataDir);
      std::ostringstream strErrors;
  
      if (fDaemon)
          fprintf(stdout, "DUCOIN server starting\n");
  
      int64_t nStart;
  
      // ********************************************************* Step 5: verify database integrity
  #ifdef ENABLE_WALLET
      if (!fDisableWallet) {
          uiInterface.InitMessage(_("Verifying database integrity..."));
  
          if (!bitdb.Open(GetDataDir()))
          {
              // try moving the database env out of the way
              boost::filesystem::path pathDatabase = GetDataDir() / "database";
              boost::filesystem::path pathDatabaseBak = GetDataDir() / strprintf("database.%d.bak", GetTime());
              try {
                  boost::filesystem::rename(pathDatabase, pathDatabaseBak);
                  LogPrintf("Moved old %s to %s. Retrying.\n", pathDatabase.string(), pathDatabaseBak.string());
              } catch(boost::filesystem::filesystem_error &error) {
                   // failure is ok (well, not really, but it's not worse than what we started with)
              }
  
              // try again
              if (!bitdb.Open(GetDataDir())) {
                  // if it still fails, it probably means we can't even create the database env
                  string msg = strprintf(_("Error initializing wallet database environment %s!"), strDataDir);
                  return InitError(msg);
              }
          }
  
          if (GetBoolArg("-salvagewallet", false))
          {
              // Recover readable keypairs:
              if (!CWalletDB::Recover(bitdb, strWalletFileName, true))
                  return false;
          }
  
          if (filesystem::exists(GetDataDir() / strWalletFileName))
          {
              CDBEnv::VerifyResult r = bitdb.Verify(strWalletFileName, CWalletDB::Recover);
              if (r == CDBEnv::RECOVER_OK)
              {
                  string msg = strprintf(_("Warning: wallet.dat corrupt, data salvaged!"
                                           " Original wallet.dat saved as wallet.{timestamp}.bak in %s; if"
                                           " your balance or transactions are incorrect you should"
                                           " restore from a backup."), strDataDir);
                  InitWarning(msg);
              }
              if (r == CDBEnv::RECOVER_FAIL)
                  return InitError(_("wallet.dat corrupt, salvage failed"));
          }
      } // (!fDisableWallet)
  #endif // ENABLE_WALLET
      // ********************************************************* Step 6: network initialization
  
      RegisterNodeSignals(GetNodeSignals());
  
      int nSocksVersion = GetArg("-socks", 5);
  
      if (nSocksVersion != 4 && nSocksVersion != 5)
          return InitError(strprintf(_("Unknown -socks proxy version requested: %i"), nSocksVersion));
  
      if (mapArgs.count("-onlynet")) {
          std::set<enum Network> nets;
          BOOST_FOREACH(std::string snet, mapMultiArgs["-onlynet"]) {
              enum Network net = ParseNetwork(snet);
              if (net == NET_UNROUTABLE)
                  return InitError(strprintf(_("Unknown network specified in -onlynet: '%s'"), snet));
              nets.insert(net);
          }
          for (int n = 0; n < NET_MAX; n++) {
              enum Network net = (enum Network)n;
              if (!nets.count(net))
                  SetLimited(net);
          }
      }
  
      CService addrProxy;
      bool fProxy = false;
      if (mapArgs.count("-proxy")) {
          addrProxy = CService(mapArgs["-proxy"], 9050);
          if (!addrProxy.IsValid())
              return InitError(strprintf(_("Invalid -proxy address: '%s'"), mapArgs["-proxy"]));
  
          if (!IsLimited(NET_IPV4))
              SetProxy(NET_IPV4, addrProxy, nSocksVersion);
          if (nSocksVersion > 4) {
              if (!IsLimited(NET_IPV6))
                  SetProxy(NET_IPV6, addrProxy, nSocksVersion);
              SetNameProxy(addrProxy, nSocksVersion);
          }
          fProxy = true;
      }
  
      // -tor can override normal proxy, -notor disables tor entirely
      if (!(mapArgs.count("-tor") && mapArgs["-tor"] == "0") && (fProxy || mapArgs.count("-tor"))) {
          CService addrOnion;
          if (!mapArgs.count("-tor"))
              addrOnion = addrProxy;
          else
              addrOnion = CService(mapArgs["-tor"], 9050);
          if (!addrOnion.IsValid())
              return InitError(strprintf(_("Invalid -tor address: '%s'"), mapArgs["-tor"]));
          SetProxy(NET_TOR, addrOnion, 5);
          SetReachable(NET_TOR);
      }
  
      // see Step 2: parameter interactions for more information about these
      fNoListen = !GetBoolArg("-listen", true);
      fDiscover = GetBoolArg("-discover", true);
      fNameLookup = GetBoolArg("-dns", true);
  
      bool fBound = false;
      if (!fNoListen)
      {
          std::string strError;
          if (mapArgs.count("-bind")) {
              BOOST_FOREACH(std::string strBind, mapMultiArgs["-bind"]) {
                  CService addrBind;
                  if (!Lookup(strBind.c_str(), addrBind, GetListenPort(), false))
                      return InitError(strprintf(_("Cannot resolve -bind address: '%s'"), strBind));
                  fBound |= Bind(addrBind);
              }
          } else {
              struct in_addr inaddr_any;
              inaddr_any.s_addr = INADDR_ANY;
              if (!IsLimited(NET_IPV6))
                  fBound |= Bind(CService(in6addr_any, GetListenPort()), false);
              if (!IsLimited(NET_IPV4))
                  fBound |= Bind(CService(inaddr_any, GetListenPort()), !fBound);
          }
          if (!fBound)
              return InitError(_("Failed to listen on any port. Use -listen=0 if you want this."));
      }
  
      if (mapArgs.count("-externalip"))
      {
          BOOST_FOREACH(string strAddr, mapMultiArgs["-externalip"]) {
              CService addrLocal(strAddr, GetListenPort(), fNameLookup);
              if (!addrLocal.IsValid())
                  return InitError(strprintf(_("Cannot resolve -externalip address: '%s'"), strAddr));
              AddLocal(CService(strAddr, GetListenPort(), fNameLookup), LOCAL_MANUAL);
          }
      }
  
  #ifdef ENABLE_WALLET
      if (mapArgs.count("-reservebalance")) // ppcoin: reserve balance amount
      {
          if (!ParseMoney(mapArgs["-reservebalance"], nReserveBalance))
          {
              InitError(_("Invalid amount for -reservebalance=<amount>"));
              return false;
          }
      }
  #endif
  
      if (mapArgs.count("-checkpointkey")) // ppcoin: checkpoint master priv key
      {
          if (!Checkpoints::SetCheckpointPrivKey(GetArg("-checkpointkey", "")))
              InitError(_("Unable to sign checkpoint, wrong checkpointkey?\n"));
      }
  
      BOOST_FOREACH(string strDest, mapMultiArgs["-seednode"])
          AddOneShot(strDest);
  
      // ********************************************************* Step 7: load blockchain
  
      if (GetBoolArg("-loadblockindextest", false))
      {
          CTxDB txdb("r");
          txdb.LoadBlockIndex();
          PrintBlockTree();
          return false;
      }
  
      uiInterface.InitMessage(_("Loading block index..."));
  
      nStart = GetTimeMillis();
      if (!LoadBlockIndex())
          return InitError(_("Error loading block database"));
  
  
      // as LoadBlockIndex can take several minutes, it's possible the user
      // requested to kill bitcoin-qt during the last operation. If so, exit.
      // As the program has not fully started yet, Shutdown() is possibly overkill.
      if (fRequestShutdown)
      {
          LogPrintf("Shutdown requested. Exiting.\n");
          return false;
      }
      LogPrintf(" block index %15dms\n", GetTimeMillis() - nStart);
  
      if (GetBoolArg("-printblockindex", false) || GetBoolArg("-printblocktree", false))
      {
          PrintBlockTree();
          return false;
      }
  
      if (mapArgs.count("-printblock"))
      {
          string strMatch = mapArgs["-printblock"];
          int nFound = 0;
          for (map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.begin(); mi != mapBlockIndex.end(); ++mi)
          {
              uint256 hash = (*mi).first;
              if (strncmp(hash.ToString().c_str(), strMatch.c_str(), strMatch.size()) == 0)
              {
                  CBlockIndex* pindex = (*mi).second;
                  CBlock block;
                  block.ReadFromDisk(pindex);
                  block.BuildMerkleTree();
                  LogPrintf("%s\n", block.ToString());
                  nFound++;
              }
          }
          if (nFound == 0)
              LogPrintf("No blocks matching %s were found\n", strMatch);
          return false;
      }
  
      // ********************************************************* Step 8: load wallet
  #ifdef ENABLE_WALLET
      if (fDisableWallet) {
          pwalletMain = NULL;
          LogPrintf("Wallet disabled!\n");
      } else {
          uiInterface.InitMessage(_("Loading wallet..."));
  
          nStart = GetTimeMillis();
          bool fFirstRun = true;
          pwalletMain = new CWallet(strWalletFileName);
          DBErrors nLoadWalletRet = pwalletMain->LoadWallet(fFirstRun);
          if (nLoadWalletRet != DB_LOAD_OK)
          {
              if (nLoadWalletRet == DB_CORRUPT)
                  strErrors << _("Error loading wallet.dat: Wallet corrupted") << "\n";
              else if (nLoadWalletRet == DB_NONCRITICAL_ERROR)
              {
                  string msg(_("Warning: error reading wallet.dat! All keys read correctly, but transaction data"
                               " or address book entries might be missing or incorrect."));
                  InitWarning(msg);
              }
              else if (nLoadWalletRet == DB_TOO_NEW)
                  strErrors << _("Error loading wallet.dat: Wallet requires newer version of DUCOIN") << "\n";
              else if (nLoadWalletRet == DB_NEED_REWRITE)
              {
                  strErrors << _("Wallet needed to be rewritten: restart DUCOIN to complete") << "\n";
                  LogPrintf("%s", strErrors.str());
                  return InitError(strErrors.str());
              }
              else
                  strErrors << _("Error loading wallet.dat") << "\n";
          }
  
          if (GetBoolArg("-upgradewallet", fFirstRun))
          {
              int nMaxVersion = GetArg("-upgradewallet", 0);
              if (nMaxVersion == 0) // the -upgradewallet without argument case
              {
                  LogPrintf("Performing wallet upgrade to %i\n", FEATURE_LATEST);
                  nMaxVersion = CLIENT_VERSION;
                  pwalletMain->SetMinVersion(FEATURE_LATEST); // permanently upgrade the wallet immediately
              }
              else
                  LogPrintf("Allowing wallet upgrade up to %i\n", nMaxVersion);
              if (nMaxVersion < pwalletMain->GetVersion())
                  strErrors << _("Cannot downgrade wallet") << "\n";
              pwalletMain->SetMaxVersion(nMaxVersion);
          }
  
          if (fFirstRun)
          {
              // Create new keyUser and set as default key
              RandAddSeedPerfmon();
  
              CPubKey newDefaultKey;
              if (pwalletMain->GetKeyFromPool(newDefaultKey)) {
                  pwalletMain->SetDefaultKey(newDefaultKey);
                  if (!pwalletMain->SetAddressBookName(pwalletMain->vchDefaultKey.GetID(), ""))
                      strErrors << _("Cannot write default address") << "\n";
              }
  
              pwalletMain->SetBestChain(CBlockLocator(pindexBest));
          }
  
          LogPrintf("%s", strErrors.str());
          LogPrintf(" wallet      %15dms\n", GetTimeMillis() - nStart);
  
          RegisterWallet(pwalletMain);
  
          CBlockIndex *pindexRescan = pindexBest;
          if (GetBoolArg("-rescan", false))
              pindexRescan = pindexGenesisBlock;
          else
          {
              CWalletDB walletdb(strWalletFileName);
              CBlockLocator locator;
              if (walletdb.ReadBestBlock(locator))
                  pindexRescan = locator.GetBlockIndex();
              else
                  pindexRescan = pindexGenesisBlock;
          }
          if (pindexBest != pindexRescan && pindexBest && pindexRescan && pindexBest->nHeight > pindexRescan->nHeight)
          {
              uiInterface.InitMessage(_("Rescanning..."));
              LogPrintf("Rescanning last %i blocks (from block %i)...\n", pindexBest->nHeight - pindexRescan->nHeight, pindexRescan->nHeight);
              nStart = GetTimeMillis();
              pwalletMain->ScanForWalletTransactions(pindexRescan, true);
              LogPrintf(" rescan      %15dms\n", GetTimeMillis() - nStart);
              pwalletMain->SetBestChain(CBlockLocator(pindexBest));
              nWalletDBUpdated++;
          }
      } // (!fDisableWallet)
  #else // ENABLE_WALLET
      LogPrintf("No wallet compiled in!\n");
  #endif // !ENABLE_WALLET
      // ********************************************************* Step 9: import blocks
  
      std::vector<boost::filesystem::path> vImportFiles;
      if (mapArgs.count("-loadblock"))
      {
          BOOST_FOREACH(string strFile, mapMultiArgs["-loadblock"])
              vImportFiles.push_back(strFile);
      }
      threadGroup.create_thread(boost::bind(&ThreadImport, vImportFiles));
  
      // ********************************************************* Step 10: load peers
  
      uiInterface.InitMessage(_("Loading addresses..."));
  
      nStart = GetTimeMillis();
  
      {
          CAddrDB adb;
          if (!adb.Read(addrman))
              LogPrintf("Invalid or missing peers.dat; recreating\n");
      }
  
      LogPrintf("Loaded %i addresses from peers.dat  %dms\n",
             addrman.size(), GetTimeMillis() - nStart);
  
      // ********************************************************* Step 11: start node
  
      if (!CheckDiskSpace())
          return false;
  
      if (!strErrors.str().empty())
          return InitError(strErrors.str());
  
      RandAddSeedPerfmon();
  
      //// debug print
      LogPrintf("mapBlockIndex.size() = %"PRIszu"\n",   mapBlockIndex.size());
      LogPrintf("nBestHeight = %d\n",                   nBestHeight);
  #ifdef ENABLE_WALLET
      LogPrintf("setKeyPool.size() = %"PRIszu"\n",      pwalletMain ? pwalletMain->setKeyPool.size() : 0);
      LogPrintf("mapWallet.size() = %"PRIszu"\n",       pwalletMain ? pwalletMain->mapWallet.size() : 0);
      LogPrintf("mapAddressBook.size() = %"PRIszu"\n",  pwalletMain ? pwalletMain->mapAddressBook.size() : 0);
  #endif
  
      StartNode(threadGroup);
  #ifdef ENABLE_WALLET
      // InitRPCMining is needed here so getwork/getblocktemplate in the GUI debug console works properly.
      InitRPCMining();
  #endif
      if (fServer)
          StartRPCThreads();
  
  #ifdef ENABLE_WALLET
      // Mine proof-of-stake blocks in the background
      if (!GetBoolArg("-staking", true))
          LogPrintf("Staking disabled\n");
      else if (pwalletMain)
          threadGroup.create_thread(boost::bind(&ThreadStakeMiner, pwalletMain));
  #endif
  
      // ********************************************************* Step 12: finished
  
      uiInterface.InitMessage(_("Done loading"));
  
  #ifdef ENABLE_WALLET
      if (pwalletMain) {
          // Add wallet transactions that aren't already in a block to mapTransactions
          pwalletMain->ReacceptWalletTransactions();
  
          // Run a thread to flush wallet periodically
          threadGroup.create_thread(boost::bind(&ThreadFlushWalletDB, boost::ref(pwalletMain->strWalletFile)));
      }
  #endif
  
      return !fRequestShutdown;
  }
  