Add utility functions TimePointToString and SystemTimePointToString

src/CMakeLists.txt

@@ -60,6 +60,7 @@ set(ZM_BIN_SRC_FILES
   zm_signal.cpp
   zm_stream.cpp
   zm_swscale.cpp
+  zm_time.cpp
   zm_user.cpp
   zm_utils.cpp
   zm_videostore.cpp

src/zm_time.cpp

@@ -0,0 +1,52 @@
+//
+// ZoneMinder Time Functions & Definitions, $Date$, $Revision$
+// Copyright (C) 2001-2008 Philip Coombes
+// 
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+// 
+
+#include "zm_time.h"
+
+#include <cinttypes>
+
+std::string SystemTimePointToString(SystemTimePoint tp) {
+  time_t tp_sec = std::chrono::system_clock::to_time_t(tp);
+  Microseconds now_frac = std::chrono::duration_cast<Microseconds>(
+      tp.time_since_epoch() - std::chrono::duration_cast<Seconds>(tp.time_since_epoch()));
+
+  std::string timeString;
+  timeString.reserve(64);
+  char *timePtr = timeString.data();
+  tm tp_tm = {};
+  timePtr += strftime(timePtr, timeString.capacity(), "%x %H:%M:%S", localtime_r(&tp_sec, &tp_tm));
+  snprintf(timePtr, timeString.capacity() - (timePtr - timeString.data()), ".%06" PRIi64, static_cast<int64_t>(now_frac.count()));
+  return timeString;
+}
+
+std::string TimePointToString(TimePoint tp) {
+  time_t tp_sec = std::chrono::system_clock::to_time_t(
+      std::chrono::system_clock::now() + (tp - std::chrono::steady_clock::now()));
+
+  Microseconds now_frac = std::chrono::duration_cast<Microseconds>(
+      tp.time_since_epoch() - std::chrono::duration_cast<Seconds>(tp.time_since_epoch()));
+
+  std::string timeString;
+  timeString.reserve(64);
+  char *timePtr = timeString.data();
+  tm tp_tm = {};
+  timePtr += strftime(timePtr, timeString.capacity(), "%x %H:%M:%S", localtime_r(&tp_sec, &tp_tm));
+  snprintf(timePtr, timeString.capacity() - (timePtr - timeString.data()), ".%06" PRIi64, static_cast<int64_t>(now_frac.count()));
+  return timeString;
+}

src/zm_time.h

@@ -21,6 +21,7 @@
 #define ZM_TIME_H
 
 #include <chrono>
+#include <string>
 #include <sys/time.h>
 
 typedef std::chrono::microseconds Microseconds;
@@ -120,4 +121,7 @@ class TimeSegmentAdder {
   bool finished_;
 };
 
+std::string SystemTimePointToString(SystemTimePoint tp);
+std::string TimePointToString(TimePoint tp);
+
 #endif // ZM_TIME_H