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authorB. Stack <bgstack15@gmail.com>2021-05-10 12:09:24 +0000
committerB. Stack <bgstack15@gmail.com>2021-05-10 12:09:24 +0000
commit692fd264ae30b5b844f748626262e79bc3d5a7e2 (patch)
tree9261c60b81eb28e068f0f2f44fd8e60214462b2a /zen/time.h
parentMerge branch '11.9' into 'master' (diff)
parentadd upstream 11.10 (diff)
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Merge branch '11.10' into 'master'11.10
add upstream 11.10 See merge request opensource-tracking/FreeFileSync!33
Diffstat (limited to 'zen/time.h')
-rw-r--r--zen/time.h112
1 files changed, 105 insertions, 7 deletions
diff --git a/zen/time.h b/zen/time.h
index e038eca3..b3b903b6 100644
--- a/zen/time.h
+++ b/zen/time.h
@@ -152,20 +152,116 @@ TimeComp getLocalTime(time_t utc)
constexpr auto fileTimeTimetOffset = 11'644'473'600;
-warn_static("remove after test")
#if 0
+warn_static("remove after test")
inline
TimeComp getUtcTime2(time_t utc)
{
- utc += year100UnixOffset; //first century not divisible by 400
+ //1. convert: seconds since year 1:
+ //...
+
+ //TODO: what if < 0?
+ long long remDays = utc / (24 * 3600);
+ long long remSecs = utc % (24 * 3600);
+
+ const int daysPer4Years = 4 * 365 /*usual days per year*/ + 1 /*including leap day*/;
+ const int daysPerYear = 365; //non-leap
+ const int daysPer100Years = 25 * daysPer4Years - 1;
+ const int daysPer400Years = 100 * daysPer4Years - 3 /*no leap days for centuries, except if divisible by 400 */;
+
+ const lldiv_t cycles400 = std::lldiv(remDays, daysPer400Years);
+ remDays = cycles400.rem;
+
+
+ int cycles100 = (remDays / daysPer100Years);
+ if (cycles100 == 4)
+ --cycles100;
+
+ remDays -= cycles100 * daysPer100Years;
+
+
+ int cycles4 = (remDays / daysPer4Years);
+ if (cycles4 == 25)
+ --cycles4;
+
+ remDays -= cycles4 * daysPer4Years;
+
+
+ int cycles1 = remDays / daysPerYear;
+ if (cycles1 == 4)
+ --cycles1;
- long long remSecs = year100UnixOffset % (24 * 3600);
- long long remDays = year100UnixOffset / (24 * 3600);
+ remDays -= cycles1 * daysPerYears;
+
+ const int year = 1 + cycles400.quot * 400 + cycles100 * 100; + cycles4 * 4 + cycles1;;
+
+
+
+
+
+ //first four years of century:
+ if (skipCenturyLeapDay)
+ {
+ if (remDays < 4 * daysPerYear)
+ {
+ year += remDays / daysPerYear;
+ remDays %= daysPerYear;
+ }
+ else
+ {
+ remDays -= 4 * daysPerYear;
+ year += 4;
+ => go to if block;
+ }
+ }
+ else
+ {
+ year += (remDays / daysPer4Years) * 4;
+ remDays %= daysPer4Years;
+
+ if (remDays < daysPerYear + 1 /*including leap day*/)
+ isLeapYear = true;
+ else
+ {
+ remDays -= daysPerYear + 1;
+ ++year;
+
+ year += remDays / daysPerYear;
+ remDays %= daysPerYear;
+ }
+ }
+
+
+
+
+
+
+
+
+ const int daysPer100Years = 25 * (4 * 365 /*usual days per year*/ + 1)/*leap days */;
+
+
+ const int daysPer100Years = 100 * 365 /*usual days per year*/ + 25 /*leap days */;
+ const int daysPer200Years = 200 * 365 /*usual days per year*/ + 50 /*leap days */ - 1 /*no leap days for centuries, except if divisible by 400 */;
+ const int daysPer300Years = 300 * 365 /*usual days per year*/ + 75 /*leap days */ - 2 /*no leap days for centuries, except if divisible by 400 */;
+
+ if (remDays >= daysPer300Years)
+ {
+ year += 300;
+ remDays -= daysPer300Years;
+ }
+ else if (remDays >= daysPer200Years)
+ {
+ year += 200;
+ remDays -= daysPer200Years;
+ }
+ else if (remDays >= daysPer100Years)
+ {
+ year += 100;
+ remDays -= daysPer100Years;
+ }
- constexpr int daysPer400Years = 400 * 365 /*usual days per year*/ + 100 /*leap days */ - 3 /*no leap days for centuries not divisible by 400 */;
- int year = 100 + (remDays / daysPer400Years) * 400;
- remDays %= 400;
constexpr int daysPer100Years = 100 * 365 /*usual days per year*/ + 25 /*leap days */ - 1 /*no leap days for centuries not divisible by 400 */;
@@ -188,6 +284,8 @@ TimeComp getUtcTime2(time_t utc)
}
+
+warn_static("get rid of fileTimeTimetOffset!")
#endif
bgstack15