Commit 992f7257b50589d3cd6fc5b95448dd31d06c34e8

Sergey 'Jin' Bostandzhyan <jin @deve…per.digitalstrom.org>
Sun Aug 08 16:05:48 CEST 2010

Tree SHA1: fa45aea
Parent SHA1: 54889af (Webroot will be handled by a separate packge)
raw diff | raw patch

Localtime <-> UTC setup

Added a way to remember the local time offsets before we switch to the
UTC timezone. This will allow us to correctly convert UTC to local time
and also to convert local time input to UTC.

A possibility to solve this would be to write an own singleton class that would
get initialized with the correct offset in the main function, however I
considered this an overhead and went for an static function in the DateTime
class which initializes a static variable.

Note, that on non linux system the conversion will not account for
daylight savings and might be off (this is how the existing
implementation was handling it).

Added code for linux systems, that will use tm_gmtoff which does deliver
the correct offset accounting for daylight savings and thus ensures taht
the conversion is correct.

Diff rendering mode:
inline
side by side


26	26
27	27	namespace dss {
28	28
	29	static long int g_GMT_Offset = 0;
	30
29	31	//================================================== DateTime
30	32
31	33	DateTime::DateTime() {
…	…
298	298	tm.tm_hour = hour;
299	299	tm.tm_min = min;
300	300	tm.tm_sec = sec;
	301	tm.tm_isdst = -1;
301	302
302		return DateTime::fromUTC(mktime(&tm));
	303	// if string ends with "Z" it is in UTC, otherwise it is considered to
	304	// be in local time
	305	if(_isoStr.at(_isoStr.size()-1) != 'Z') {
	306	return DateTime::toUTC(mktime(&tm));
	307	} else {
	308	return DateTime(tm);
	309	}
303	310	} // fromISO
304	311
305	312	DateTime DateTime::fromUTC(const time_t& _time) {
306		return DateTime(_time - timezone);
	313	return DateTime(_time - g_GMT_Offset);
307	314	} // fromUTC
308	315
309	316	DateTime DateTime::toUTC(const time_t& _time) {
310		return DateTime(_time + timezone);
	317	return DateTime(_time + g_GMT_Offset);
311	318	} // toUTC
	319
	320	DateTime DateTime::fromUTC() {
	321	return DateTime(mktime(&m_DateTime) - g_GMT_Offset);
	322	}
	323
	324	DateTime DateTime::toUTC() {
	325	return DateTime(mktime(&m_DateTime) + g_GMT_Offset);
	326	}
	327
	328	void DateTime::configureUTCOffset(long int _offset) {
	329	g_GMT_Offset = _offset;
	330	}
312	331
313	332	DateTime DateTime::NullDate(0);
314	333


171	171	/** Creates an instance from a time_t struct and converts the internal
172	172	* time to UTC */
173	173	static DateTime toUTC(const time_t& _time);
	174
	175	/** Assumes current DateTime instance to be in UTC and creates an
	176	* instance a DateTime instance that is in local time */
	177	DateTime fromUTC();
	178
	179	/** Assumes current DateTime instance to be in local time and creates an
	180	* instance a DateTime instance that is in UTC */
	181	DateTime toUTC();
	182
	183	/** Configures the offset between UTC and local time which will be used
	184	* for all subsequent calculations; the offset mst be in seconds West
	185	* of GMT */
	186	static void configureUTCOffset(long int _offset);
174	187	}; // DateTime
175	188
176	189	std::ostream& operator<<(std::ostream& out, const DateTime& _dt);


32	32	#include "core/logger.h"
33	33	#include "core/ds485client.h"
34	34	#include "core/ds485/ds485.h"
	35	#include "core/datetools.h"
35	36	#ifdef WITH_TESTS
36	37	#include "tests/tests.h"
37	38	#endif
…	…
70	70
71	71	// make sure timezone gets set
72	72	tzset();
	73
	74	long int time_offset = timezone;
	75
	76	#if defined(__linux__)
	77	time_t now;
	78	struct tm t;
	79	time(&now);
	80	localtime_r(&now, &t);
	81	mktime(&t);
	82	// gmtoff is east of UTC, however timezone is west of UTC
	83	time_offset = t.tm_gmtoff * (-1);
	84	#endif
	85
	86	dss::DateTime::configureUTCOffset(time_offset);
73	87
74	88	char* tzNameCopy = strdup("GMT");
75	89	tzname[0] = tzname[1] = tzNameCopy;

Commit 992f7257b50589d3cd6fc5b95448dd31d06c34e8

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