text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2016 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  /**
   * Server/client environment: argument handling, config file parsing,
   * logging, thread wrappers, startup time
   */
  #ifndef BITCOIN_UTIL_H
  #define BITCOIN_UTIL_H
  
  #if defined(HAVE_CONFIG_H)
  #include <config/bitcoin-config.h>
  #endif
  
  #include <compat.h>
  #include <fs.h>
  #include <sync.h>
  #include <tinyformat.h>
  #include <utiltime.h>
  
  #include <atomic>
  #include <exception>
  #include <map>
  #include <stdint.h>
  #include <string>
  #include <vector>
  
  #include <boost/signals2/signal.hpp>
  #include <boost/thread/condition_variable.hpp> // for boost::thread_interrupted
  
  // Application startup time (used for uptime calculation)
  int64_t GetStartupTime();
  
  static const bool DEFAULT_LOGTIMEMICROS = false;
  static const bool DEFAULT_LOGIPS        = false;
  static const bool DEFAULT_LOGTIMESTAMPS = true;
  extern const char * const DEFAULT_DEBUGLOGFILE;
  
  /** Signals for translation. */
  class CTranslationInterface
  {
  public:
      /** Translate a message to the native language of the user. */
      boost::signals2::signal<std::string (const char* psz)> Translate;
  };
  
  extern bool fPrintToConsole;
  extern bool fPrintToDebugLog;
  
  extern bool fLogTimestamps;
  extern bool fLogTimeMicros;
  extern bool fLogIPs;
  extern std::atomic<bool> fReopenDebugLog;
  extern CTranslationInterface translationInterface;
  
  extern const char * const BITCOIN_CONF_FILENAME;
  extern const char * const BITCOIN_PID_FILENAME;
  
  extern std::atomic<uint32_t> logCategories;
  
  /**
   * Translation function: Call Translate signal on UI interface, which returns a boost::optional result.
   * If no translation slot is registered, nothing is returned, and simply return the input.
   */
  inline std::string _(const char* psz)
  {
      boost::optional<std::string> rv = translationInterface.Translate(psz);
      return rv ? (*rv) : psz;
  }
  
  void SetupEnvironment();
  bool SetupNetworking();
  
  struct CLogCategoryActive
  {
      std::string category;
      bool active;
  };
  
  namespace BCLog {
      enum LogFlags : uint32_t {
          NONE        = 0,
          NET         = (1 <<  0),
          TOR         = (1 <<  1),
          MEMPOOL     = (1 <<  2),
          HTTP        = (1 <<  3),
          BENCH       = (1 <<  4),
          ZMQ         = (1 <<  5),
          DB          = (1 <<  6),
          RPC         = (1 <<  7),
          ESTIMATEFEE = (1 <<  8),
          ADDRMAN     = (1 <<  9),
          SELECTCOINS = (1 << 10),
          REINDEX     = (1 << 11),
          CMPCTBLOCK  = (1 << 12),
          RAND        = (1 << 13),
          PRUNE       = (1 << 14),
          PROXY       = (1 << 15),
          MEMPOOLREJ  = (1 << 16),
          LIBEVENT    = (1 << 17),
          COINDB      = (1 << 18),
          QT          = (1 << 19),
          LEVELDB     = (1 << 20),
          ALL         = ~(uint32_t)0,
      };
  }
  /** Return true if log accepts specified category */
  static inline bool LogAcceptCategory(uint32_t category)
  {
      return (logCategories.load(std::memory_order_relaxed) & category) != 0;
  }
  
  /** Returns a string with the log categories. */
  std::string ListLogCategories();
  
  /** Returns a vector of the active log categories. */
  std::vector<CLogCategoryActive> ListActiveLogCategories();
  
  /** Return true if str parses as a log category and set the flags in f */
  bool GetLogCategory(uint32_t *f, const std::string *str);
  
  /** Send a string to the log output */
  int LogPrintStr(const std::string &str);
  
  /** Get format string from VA_ARGS for error reporting */
  template<typename... Args> std::string FormatStringFromLogArgs(const char *fmt, const Args&... args) { return fmt; }
  
  static inline void MarkUsed() {}
  template<typename T, typename... Args> static inline void MarkUsed(const T& t, const Args&... args)
  {
      (void)t;
      MarkUsed(args...);
  }
  
  #ifdef USE_COVERAGE
  #define LogPrintf(...) do { MarkUsed(__VA_ARGS__); } while(0)
  #define LogPrint(category, ...) do { MarkUsed(__VA_ARGS__); } while(0)
  #else
  #define LogPrintf(...) do { \
      std::string _log_msg_; /* Unlikely name to avoid shadowing variables */ \
      try { \
          _log_msg_ = tfm::format(__VA_ARGS__); \
      } catch (tinyformat::format_error &fmterr) { \
          /* Original format string will have newline so don't add one here */ \
          _log_msg_ = "Error \"" + std::string(fmterr.what()) + "\" while formatting log message: " + FormatStringFromLogArgs(__VA_ARGS__); \
      } \
      LogPrintStr(_log_msg_); \
  } while(0)
  
  #define LogPrint(category, ...) do { \
      if (LogAcceptCategory((category))) { \
          LogPrintf(__VA_ARGS__); \
      } \
  } while(0)
  #endif
  
  template<typename... Args>
  bool error(const char* fmt, const Args&... args)
  {
      LogPrintStr("ERROR: " + tfm::format(fmt, args...) + "\n");
      return false;
  }
  
  void PrintExceptionContinue(const std::exception *pex, const char* pszThread);
  void FileCommit(FILE *file);
  bool TruncateFile(FILE *file, unsigned int length);
  int RaiseFileDescriptorLimit(int nMinFD);
  void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
  bool RenameOver(fs::path src, fs::path dest);
  bool TryCreateDirectories(const fs::path& p);
  fs::path GetDefaultDataDir();
  const fs::path &GetDataDir(bool fNetSpecific = true);
  void ClearDatadirCache();
  fs::path GetConfigFile(const std::string& confPath);
  #ifndef WIN32
  fs::path GetPidFile();
  void CreatePidFile(const fs::path &path, pid_t pid);
  #endif
  #ifdef WIN32
  fs::path GetSpecialFolderPath(int nFolder, bool fCreate = true);
  #endif
  fs::path GetDebugLogPath();
  bool OpenDebugLog();
  void ShrinkDebugFile();
  void runCommand(const std::string& strCommand);
  
  inline bool IsSwitchChar(char c)
  {
  #ifdef WIN32
      return c == '-' || c == '/';
  #else
      return c == '-';
  #endif
  }
  
  class ArgsManager
  {
  protected:
      mutable CCriticalSection cs_args;
      std::map<std::string, std::string> mapArgs;
      std::map<std::string, std::vector<std::string>> mapMultiArgs;
  public:
      void ParseParameters(int argc, const char*const argv[]);
      void ReadConfigFile(const std::string& confPath);
  
      /**
       * Return a vector of strings of the given argument
       *
       * @param strArg Argument to get (e.g. "-foo")
       * @return command-line arguments
       */
      std::vector<std::string> GetArgs(const std::string& strArg) const;
  
      /**
       * Return true if the given argument has been manually set
       *
       * @param strArg Argument to get (e.g. "-foo")
       * @return true if the argument has been set
       */
      bool IsArgSet(const std::string& strArg) const;
  
      /**
       * Return string argument or default value
       *
       * @param strArg Argument to get (e.g. "-foo")
       * @param strDefault (e.g. "1")
       * @return command-line argument or default value
       */
      std::string GetArg(const std::string& strArg, const std::string& strDefault) const;
  
      /**
       * Return integer argument or default value
       *
       * @param strArg Argument to get (e.g. "-foo")
       * @param nDefault (e.g. 1)
       * @return command-line argument (0 if invalid number) or default value
       */
      int64_t GetArg(const std::string& strArg, int64_t nDefault) const;
  
      /**
       * Return boolean argument or default value
       *
       * @param strArg Argument to get (e.g. "-foo")
       * @param fDefault (true or false)
       * @return command-line argument or default value
       */
      bool GetBoolArg(const std::string& strArg, bool fDefault) const;
  
      /**
       * Set an argument if it doesn't already have a value
       *
       * @param strArg Argument to set (e.g. "-foo")
       * @param strValue Value (e.g. "1")
       * @return true if argument gets set, false if it already had a value
       */
      bool SoftSetArg(const std::string& strArg, const std::string& strValue);
  
      /**
       * Set a boolean argument if it doesn't already have a value
       *
       * @param strArg Argument to set (e.g. "-foo")
       * @param fValue Value (e.g. false)
       * @return true if argument gets set, false if it already had a value
       */
      bool SoftSetBoolArg(const std::string& strArg, bool fValue);
  
      // Forces an arg setting. Called by SoftSetArg() if the arg hasn't already
      // been set. Also called directly in testing.
      void ForceSetArg(const std::string& strArg, const std::string& strValue);
  };
  
  extern ArgsManager gArgs;
  
  /**
   * Format a string to be used as group of options in help messages
   *
   * @param message Group name (e.g. "RPC server options:")
   * @return the formatted string
   */
  std::string HelpMessageGroup(const std::string& message);
  
  /**
   * Format a string to be used as option description in help messages
   *
   * @param option Option message (e.g. "-rpcuser=<user>")
   * @param message Option description (e.g. "Username for JSON-RPC connections")
   * @return the formatted string
   */
  std::string HelpMessageOpt(const std::string& option, const std::string& message);
  
  /**
   * Return the number of physical cores available on the current system.
   * @note This does not count virtual cores, such as those provided by HyperThreading
   * when boost is newer than 1.56.
   */
  int GetNumCores();
  
  void RenameThread(const char* name);
  
  /**
   * .. and a wrapper that just calls func once
   */
  template <typename Callable> void TraceThread(const char* name,  Callable func)
  {
      std::string s = strprintf("bitcoin-%s", name);
      RenameThread(s.c_str());
      try
      {
          LogPrintf("%s thread start\n", name);
          func();
          LogPrintf("%s thread exit\n", name);
      }
      catch (const boost::thread_interrupted&)
      {
          LogPrintf("%s thread interrupt\n", name);
          throw;
      }
      catch (const std::exception& e) {
          PrintExceptionContinue(&e, name);
          throw;
      }
      catch (...) {
          PrintExceptionContinue(nullptr, name);
          throw;
      }
  }
  
  std::string CopyrightHolders(const std::string& strPrefix);
  
  //! Substitute for C++14 std::make_unique.
  template <typename T, typename... Args>
  std::unique_ptr<T> MakeUnique(Args&&... args)
  {
      return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
  }
  
  #endif // BITCOIN_UTIL_H
  