log4cplus  2.0.0
timehelper.h
Go to the documentation of this file.
00001 // -*- C++ -*-
00002 // Module:  Log4CPLUS
00003 // File:    timehelper.h
00004 // Created: 6/2003
00005 // Author:  Tad E. Smith
00006 //
00007 //
00008 // Copyright 2003-2015 Tad E. Smith
00009 //
00010 // Licensed under the Apache License, Version 2.0 (the "License");
00011 // you may not use this file except in compliance with the License.
00012 // You may obtain a copy of the License at
00013 //
00014 //     http://www.apache.org/licenses/LICENSE-2.0
00015 //
00016 // Unless required by applicable law or agreed to in writing, software
00017 // distributed under the License is distributed on an "AS IS" BASIS,
00018 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00019 // See the License for the specific language governing permissions and
00020 // limitations under the License.
00021 
00024 #ifndef LOG4CPLUS_HELPERS_TIME_HELPER_HEADER_
00025 #define LOG4CPLUS_HELPERS_TIME_HELPER_HEADER_
00026 
00027 #include <log4cplus/config.hxx>
00028 
00029 #if defined (LOG4CPLUS_HAVE_PRAGMA_ONCE)
00030 #pragma once
00031 #endif
00032 
00033 #include <log4cplus/tstring.h>
00034 
00035 #if defined (LOG4CPLUS_HAVE_TIME_H)
00036 #include <time.h>
00037 #endif
00038 
00039 #include <ctime>
00040 #include <chrono>
00041 
00042 
00043 namespace log4cplus {
00044 
00045 namespace helpers {
00046 
00047 
00048 using std::time_t;
00049 using std::tm;
00050 namespace chrono = std::chrono;
00051 
00052 typedef chrono::system_clock Clock;
00053 typedef chrono::duration<long long, std::micro> Duration;
00054 typedef chrono::time_point<Clock, Duration> Time;
00055 
00056 
00057 template <typename FromDuration>
00058 inline
00059 Time
00060 time_cast (chrono::time_point<Clock, FromDuration> const & tp)
00061 {
00062     return chrono::time_point_cast<Duration, Clock> (tp);
00063 }
00064 
00065 
00066 inline
00067 Time
00068 now ()
00069 {
00070     return time_cast (Clock::now ());
00071 }
00072 
00073 
00074 inline
00075 Time
00076 from_time_t (time_t t_time)
00077 {
00078     return time_cast (Clock::from_time_t (t_time));
00079 }
00080 
00081 
00082 inline
00083 time_t
00084 to_time_t (Time const & the_time)
00085 {
00086     // This is based on <http://stackoverflow.com/a/17395137/341065> It is
00087     // possible that to_time_t() returns rounded time and we want truncation.
00088 
00089     time_t time = Clock::to_time_t (the_time);
00090     auto const rounded_time = from_time_t (time);
00091     if (rounded_time > the_time)
00092         --time;
00093 
00094     return time;
00095 }
00096 
00097 
00098 LOG4CPLUS_EXPORT Time from_struct_tm (tm * t);
00099 
00100 
00101 inline
00102 Time
00103 truncate_fractions (Time const & the_time)
00104 {
00105     return from_time_t (to_time_t (the_time));
00106 }
00107 
00108 
00109 inline
00110 long
00111 microseconds_part (Time const & the_time)
00112 {
00113     static_assert (std::ratio_equal<Duration::period, std::micro>::value,
00114         "microseconds");
00115 
00116     // This is based on <http://stackoverflow.com/a/17395137/341065>
00117     return static_cast<long>(
00118         (the_time - from_time_t (to_time_t (the_time))).count ());
00119 }
00120 
00121 
00122 inline
00123 Time
00124 time_from_parts (time_t tv_sec, long tv_usec)
00125 {
00126     return from_time_t (tv_sec) + chrono::microseconds (tv_usec);
00127 }
00128 
00129 
00135 LOG4CPLUS_EXPORT
00136 void gmTime (tm* t, Time const &);
00137 
00143 LOG4CPLUS_EXPORT
00144 void localTime (tm* t, Time const &);
00145 
00159 LOG4CPLUS_EXPORT
00160 log4cplus::tstring getFormattedTime (log4cplus::tstring const & fmt,
00161     Time const & the_time, bool use_gmtime = false);
00162 
00163 
00164 } // namespace helpers
00165 
00166 } // namespace log4cplus
00167 
00168 
00169 #endif // LOG4CPLUS_HELPERS_TIME_HELPER_HEADER_