text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2019 The BitSilver Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #if defined(HAVE_CONFIG_H)
  #include <config/bitsilver-config.h>
  #endif
  
  #include <util/time.h>
  
  #include <atomic>
  #include <boost/date_time/posix_time/posix_time.hpp>
  #include <ctime>
  #include <thread>
  
  #include <tinyformat.h>
  
  void UninterruptibleSleep(const std::chrono::microseconds& n) { std::this_thread::sleep_for(n); }
  
  static std::atomic<int64_t> nMockTime(0); //!< For unit testing
  
  int64_t GetTime()
  {
      int64_t mocktime = nMockTime.load(std::memory_order_relaxed);
      if (mocktime) return mocktime;
  
      time_t now = time(nullptr);
      assert(now > 0);
      return now;
  }
  
  template <typename T>
  T GetTime()
  {
      const std::chrono::seconds mocktime{nMockTime.load(std::memory_order_relaxed)};
  
      return std::chrono::duration_cast<T>(
          mocktime.count() ?
              mocktime :
              std::chrono::microseconds{GetTimeMicros()});
  }
  template std::chrono::seconds GetTime();
  template std::chrono::milliseconds GetTime();
  template std::chrono::microseconds GetTime();
  
  void SetMockTime(int64_t nMockTimeIn)
  {
      nMockTime.store(nMockTimeIn, std::memory_order_relaxed);
  }
  
  int64_t GetMockTime()
  {
      return nMockTime.load(std::memory_order_relaxed);
  }
  
  int64_t GetTimeMillis()
  {
      int64_t now = (boost::posix_time::microsec_clock::universal_time() -
                     boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_milliseconds();
      assert(now > 0);
      return now;
  }
  
  int64_t GetTimeMicros()
  {
      int64_t now = (boost::posix_time::microsec_clock::universal_time() -
                     boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_microseconds();
      assert(now > 0);
      return now;
  }
  
  int64_t GetSystemTimeInSeconds()
  {
      return GetTimeMicros()/1000000;
  }
  
  std::string FormatISO8601DateTime(int64_t nTime) {
      struct tm ts;
      time_t time_val = nTime;
  #ifdef _MSC_VER
      if (gmtime_s(&ts, &time_val) != 0) {
  #else
      if (gmtime_r(&time_val, &ts) == nullptr) {
  #endif
          return {};
      }
      return strprintf("%04i-%02i-%02iT%02i:%02i:%02iZ", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday, ts.tm_hour, ts.tm_min, ts.tm_sec);
  }
  
  std::string FormatISO8601Date(int64_t nTime) {
      struct tm ts;
      time_t time_val = nTime;
  #ifdef _MSC_VER
      if (gmtime_s(&ts, &time_val) != 0) {
  #else
      if (gmtime_r(&time_val, &ts) == nullptr) {
  #endif
          return {};
      }
      return strprintf("%04i-%02i-%02i", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday);
  }
  
  int64_t ParseISO8601DateTime(const std::string& str)
  {
      static const boost::posix_time::ptime epoch = boost::posix_time::from_time_t(0);
      static const std::locale loc(std::locale::classic(),
          new boost::posix_time::time_input_facet("%Y-%m-%dT%H:%M:%SZ"));
      std::istringstream iss(str);
      iss.imbue(loc);
      boost::posix_time::ptime ptime(boost::date_time::not_a_date_time);
      iss >> ptime;
      if (ptime.is_not_a_date_time() || epoch > ptime)
          return 0;
      return (ptime - epoch).total_seconds();
  }
  