實現了localtime 和 UTCtime的轉換：
Linux多線程編程工具庫liblmp_tool github: https://github.com/Dwyane05/liblmp_tool
Timezone類分析：
頭文件；定義了localtime和utctime 的轉換；使用了shard_ptr 智能指針處理date
/*
* Use of this source code is governed by a BSD-style license
* that can be found in the License file.
*
* TimeZone.h
* Created on: May 30, 2019
* Author: cuiyongfei
*/
#ifndef LMP_TOOL_TIMEZONE_H
#define LMP_TOOL_TIMEZONE_H
#include "copyable.h"
#include <memory>
#include <time.h>
namespace lmp_tool
{
// TimeZone for 1970~2030
class TimeZone : public lmp_tool::copyable
{
public:
explicit TimeZone(const char* zonefile);
TimeZone(int eastOfUtc, const char* tzname); // a fixed timezone
TimeZone() = default; // an invalid timezone
// default copy ctor/assignment/dtor are Okay.
bool valid() const
{
// 'explicit operator bool() const' in C++11
return static_cast<bool>(data_);
}
struct tm toLocalTime(time_t secondsSinceEpoch) const;
time_t fromLocalTime(const struct tm&) const;
// gmtime(3)
static struct tm toUtcTime(time_t secondsSinceEpoch, bool yday = false);
// timegm(3)
static time_t fromUtcTime(const struct tm&);
// year in [1900..2500], month in [1..12], day in [1..31]
static time_t fromUtcTime(int year, int month, int day,
int hour, int minute, int seconds);
struct Data;
private:
std::shared_ptr<Data> data_;
};
} // namespace lmp_tool
#endif // LMP_TOOL_TIMEZONE_H
具體代碼實現太多就不粘貼了，見GitHub：lmp_src目錄下
測試代碼：
測試幾個主要城市 的時間
#include "TimeZone.h"
#include "Common.h"
#include <assert.h>
#include <stdio.h>
#include <string.h>
using lmp_tool::TimeZone;
struct tm getTm(int year, int month, int day,
int hour, int minute, int seconds)
{
struct tm gmt;
lmp_tool::memZero(&gmt, sizeof gmt);
gmt.tm_year = year - 1900;
gmt.tm_mon = month - 1;
gmt.tm_mday = day;
gmt.tm_hour = hour;
gmt.tm_min = minute;
gmt.tm_sec = seconds;
return gmt;
}
struct tm getTm(const char* str)
{
struct tm gmt;
lmp_tool::memZero(&gmt, sizeof gmt);
strptime(str, "%F %T", &gmt);
return gmt;
}
time_t getGmt(int year, int month, int day,
int hour, int minute, int seconds)
{
struct tm gmt = getTm(year, month, day, hour, minute, seconds);
return timegm(&gmt);
}
time_t getGmt(const char* str)
{
struct tm gmt = getTm(str);
return timegm(&gmt);
}
struct TestCase
{
const char* gmt;
const char* local;
bool isdst;
};
void test(const TimeZone& tz, TestCase tc)
{
time_t gmt = getGmt(tc.gmt);
{
struct tm local = tz.toLocalTime(gmt);
char buf[256];
strftime(buf, sizeof buf, "%F %T%z(%Z)", &local);
if (strcmp(buf, tc.local) != 0 || tc.isdst != local.tm_isdst)
{
printf("WRONG: ");
}
printf("%s -> %s\n", tc.gmt, buf);
}
{
struct tm local = getTm(tc.local);
local.tm_isdst = tc.isdst;
time_t result = tz.fromLocalTime(local);
if (result != gmt)
{
struct tm local2 = tz.toLocalTime(result);
char buf[256];
strftime(buf, sizeof buf, "%F %T%z(%Z)", &local2);
printf("WRONG fromLocalTime: %ld %ld %s\n",
static_cast<long>(gmt), static_cast<long>(result), buf);
}
}
}
void testNewYork()
{
TimeZone tz("/usr/share/zoneinfo/America/New_York");
TestCase cases[] =
{
{ "2006-03-07 00:00:00", "2006-03-06 19:00:00-0500(EST)", false },
{ "2006-04-02 06:59:59", "2006-04-02 01:59:59-0500(EST)", false },
{ "2006-04-02 07:00:00", "2006-04-02 03:00:00-0400(EDT)", true },
{ "2006-05-01 00:00:00", "2006-04-30 20:00:00-0400(EDT)", true },
{ "2006-05-02 01:00:00", "2006-05-01 21:00:00-0400(EDT)", true },
{ "2006-10-21 05:00:00", "2006-10-21 01:00:00-0400(EDT)", true },
{ "2006-10-29 05:59:59", "2006-10-29 01:59:59-0400(EDT)", true },
{ "2006-10-29 06:00:00", "2006-10-29 01:00:00-0500(EST)", false },
{ "2006-10-29 06:59:59", "2006-10-29 01:59:59-0500(EST)", false },
{ "2006-12-31 06:00:00", "2006-12-31 01:00:00-0500(EST)", false },
{ "2007-01-01 00:00:00", "2006-12-31 19:00:00-0500(EST)", false },
{ "2007-03-07 00:00:00", "2007-03-06 19:00:00-0500(EST)", false },
{ "2007-03-11 06:59:59", "2007-03-11 01:59:59-0500(EST)", false },
{ "2007-03-11 07:00:00", "2007-03-11 03:00:00-0400(EDT)", true },
{ "2007-05-01 00:00:00", "2007-04-30 20:00:00-0400(EDT)", true },
{ "2007-05-02 01:00:00", "2007-05-01 21:00:00-0400(EDT)", true },
{ "2007-10-31 05:00:00", "2007-10-31 01:00:00-0400(EDT)", true },
{ "2007-11-04 05:59:59", "2007-11-04 01:59:59-0400(EDT)", true },
{ "2007-11-04 06:00:00", "2007-11-04 01:00:00-0500(EST)", false },
{ "2007-11-04 06:59:59", "2007-11-04 01:59:59-0500(EST)", false },
{ "2007-12-31 06:00:00", "2007-12-31 01:00:00-0500(EST)", false },
{ "2008-01-01 00:00:00", "2007-12-31 19:00:00-0500(EST)", false },
{ "2009-03-07 00:00:00", "2009-03-06 19:00:00-0500(EST)", false },
{ "2009-03-08 06:59:59", "2009-03-08 01:59:59-0500(EST)", false },
{ "2009-03-08 07:00:00", "2009-03-08 03:00:00-0400(EDT)", true },
{ "2009-05-01 00:00:00", "2009-04-30 20:00:00-0400(EDT)", true },
{ "2009-05-02 01:00:00", "2009-05-01 21:00:00-0400(EDT)", true },
{ "2009-10-31 05:00:00", "2009-10-31 01:00:00-0400(EDT)", true },
{ "2009-11-01 05:59:59", "2009-11-01 01:59:59-0400(EDT)", true },
{ "2009-11-01 06:00:00", "2009-11-01 01:00:00-0500(EST)", false },
{ "2009-11-01 06:59:59", "2009-11-01 01:59:59-0500(EST)", false },
{ "2009-12-31 06:00:00", "2009-12-31 01:00:00-0500(EST)", false },
{ "2010-01-01 00:00:00", "2009-12-31 19:00:00-0500(EST)", false },
{ "2010-03-13 00:00:00", "2010-03-12 19:00:00-0500(EST)", false },
{ "2010-03-14 06:59:59", "2010-03-14 01:59:59-0500(EST)", false },
{ "2010-03-14 07:00:00", "2010-03-14 03:00:00-0400(EDT)", true },
{ "2010-05-01 00:00:00", "2010-04-30 20:00:00-0400(EDT)", true },
{ "2010-05-02 01:00:00", "2010-05-01 21:00:00-0400(EDT)", true },
{ "2010-11-06 05:00:00", "2010-11-06 01:00:00-0400(EDT)", true },
{ "2010-11-07 05:59:59", "2010-11-07 01:59:59-0400(EDT)", true },
{ "2010-11-07 06:00:00", "2010-11-07 01:00:00-0500(EST)", false },
{ "2010-11-07 06:59:59", "2010-11-07 01:59:59-0500(EST)", false },
{ "2010-12-31 06:00:00", "2010-12-31 01:00:00-0500(EST)", false },
{ "2011-01-01 00:00:00", "2010-12-31 19:00:00-0500(EST)", false },
{ "2011-03-01 00:00:00", "2011-02-28 19:00:00-0500(EST)", false },
{ "2011-03-13 06:59:59", "2011-03-13 01:59:59-0500(EST)", false },
{ "2011-03-13 07:00:00", "2011-03-13 03:00:00-0400(EDT)", true },
{ "2011-05-01 00:00:00", "2011-04-30 20:00:00-0400(EDT)", true },
{ "2011-05-02 01:00:00", "2011-05-01 21:00:00-0400(EDT)", true },
{ "2011-11-06 05:59:59", "2011-11-06 01:59:59-0400(EDT)", true },
{ "2011-11-06 06:00:00", "2011-11-06 01:00:00-0500(EST)", false },
{ "2011-11-06 06:59:59", "2011-11-06 01:59:59-0500(EST)", false },
{ "2011-12-31 06:00:00", "2011-12-31 01:00:00-0500(EST)", false },
{ "2012-01-01 00:00:00", "2011-12-31 19:00:00-0500(EST)", false },
};
for (const auto& c : cases)
{
test(tz, c);
}
}
void testLondon()
{
TimeZone tz("/usr/share/zoneinfo/Europe/London");
TestCase cases[] =
{
{ "2011-03-26 00:00:00", "2011-03-26 00:00:00+0000(GMT)", false },
{ "2011-03-27 00:59:59", "2011-03-27 00:59:59+0000(GMT)", false },
{ "2011-03-27 01:00:00", "2011-03-27 02:00:00+0100(BST)", true },
{ "2011-10-30 00:59:59", "2011-10-30 01:59:59+0100(BST)", true },
{ "2011-10-30 01:00:00", "2011-10-30 01:00:00+0000(GMT)", false },
{ "2012-10-30 01:59:59", "2012-10-30 01:59:59+0000(GMT)", false },
{ "2011-12-31 22:00:00", "2011-12-31 22:00:00+0000(GMT)", false },
{ "2012-01-01 00:00:00", "2012-01-01 00:00:00+0000(GMT)", false },
{ "2012-03-24 00:00:00", "2012-03-24 00:00:00+0000(GMT)", false },
{ "2012-03-25 00:59:59", "2012-03-25 00:59:59+0000(GMT)", false },
{ "2012-03-25 01:00:00", "2012-03-25 02:00:00+0100(BST)", true },
{ "2012-10-28 00:59:59", "2012-10-28 01:59:59+0100(BST)", true },
{ "2012-10-28 01:00:00", "2012-10-28 01:00:00+0000(GMT)", false },
{ "2012-10-28 01:59:59", "2012-10-28 01:59:59+0000(GMT)", false },
{ "2012-12-31 22:00:00", "2012-12-31 22:00:00+0000(GMT)", false },
{ "2013-01-01 00:00:00", "2013-01-01 00:00:00+0000(GMT)", false },
};
for (const auto& c : cases)
{
test(tz, c);
}
}
void testHongKong()
{
TimeZone tz("/usr/share/zoneinfo/Asia/Hong_Kong");
TestCase cases[] =
{
{ "2011-04-03 00:00:00", "2011-04-03 08:00:00+0800(HKT)", false},
};
for (const auto& c : cases)
{
test(tz, c);
}
}
void testSydney()
{
TimeZone tz("/usr/share/zoneinfo/Australia/Sydney");
TestCase cases[] =
{
{ "2011-01-01 00:00:00", "2011-01-01 11:00:00+1100(EST)", true },
{ "2011-04-02 15:59:59", "2011-04-03 02:59:59+1100(EST)", true },
{ "2011-04-02 16:00:00", "2011-04-03 02:00:00+1000(EST)", false },
{ "2011-04-02 16:59:59", "2011-04-03 02:59:59+1000(EST)", false },
{ "2011-05-02 01:00:00", "2011-05-02 11:00:00+1000(EST)", false },
{ "2011-10-01 15:59:59", "2011-10-02 01:59:59+1000(EST)", false },
{ "2011-10-01 16:00:00", "2011-10-02 03:00:00+1100(EST)", true },
{ "2011-12-31 22:00:00", "2012-01-01 09:00:00+1100(EST)", true },
};
for (const auto& c : cases)
{
test(tz, c);
}
}
void testUtc()
{
const int kRange = 100*1000*1000;
for (time_t t = -kRange; t <= kRange; t += 11)
{
struct tm* t1 = gmtime(&t);
struct tm t2 = TimeZone::toUtcTime(t, true);
char buf1[80], buf2[80];
strftime(buf1, sizeof buf1, "%F %T %u %j", t1);
strftime(buf2, sizeof buf2, "%F %T %u %j", &t2);
if (strcmp(buf1, buf2) != 0)
{
printf("'%s' != '%s'\n", buf1, buf2);
assert(0);
}
time_t t3 = TimeZone::fromUtcTime(t2);
if (t != t3)
{
printf("%ld != %ld\n", static_cast<long>(t), static_cast<long>(t3));
assert(0);
}
}
}
void testFixedTimezone()
{
TimeZone tz(8*3600, "CST");
TestCase cases[] =
{
{ "2014-04-03 00:00:00", "2014-04-03 08:00:00+0800(CST)", false},
};
for (const auto& c : cases)
{
test(tz, c);
}
}
int main()
{
testNewYork();
testLondon();
testSydney();
testHongKong();
testFixedTimezone();
testUtc();
}