chrono::system_clock::time_point cppkit::ck_iso_8601_to_time_point( const ck_string& str )
{
const size_t tDex = str.find('T');
if (tDex == string::npos)
CK_THROW(("Invalid iso 8601 string: %s",str.c_str()));
const size_t dotDex = str.find('.');
const size_t zDex = str.find('Z');
const size_t plusDex = str.find('+', 1);
const size_t subDex = str.find('-', str.find('-', str.find('-') + 1) + 1);
if (plusDex != string::npos && subDex != string::npos)
CK_THROW(("Invalid iso 8601 string: %s",str.c_str()));
size_t dtEnd = dotDex;
if (dtEnd == string::npos || dtEnd > zDex)
dtEnd = zDex;
if (dtEnd == string::npos || dtEnd > plusDex)
dtEnd = plusDex;
if (dtEnd == string::npos || dtEnd > subDex)
dtEnd = subDex;
const string dateStr = str.substr(0, tDex);
const string timeStr = str.substr(tDex + 1, (dtEnd - tDex) - 1);
string fracSecStr;
if (dotDex != string::npos)
{
size_t fsEnd = zDex;
if (fsEnd == string::npos || fsEnd > plusDex)
fsEnd = plusDex;
if (fsEnd == string::npos || fsEnd > subDex)
fsEnd = subDex;
const size_t fsStart = dateStr.size() + 1 + timeStr.size();
const size_t fsLen = fsEnd == string::npos ? string::npos : fsEnd - fsStart;
fracSecStr = str.substr(fsStart, fsLen);
}
const size_t zoneDex = dateStr.size() + 1 + timeStr.size() + fracSecStr.size();
const string zoneStr = zDex == str.size() ? "" : str.substr(zoneDex);
tm ttm = tm();
int yyyy = 0, mm = 0, dd = 0;
SSCANF(dateStr.c_str(), "%4d-%2d-%2d", &yyyy, &mm, &dd);
ttm.tm_year = yyyy - 1900;
ttm.tm_mon = mm - 1; // Month since January
ttm.tm_mday = dd; // Day of the month [1-31]
int HH = 0, MM = 0, SS = 0;
SSCANF(timeStr.c_str(), "%2d:%2d:%2d", &HH, &MM, &SS);
ttm.tm_hour = HH; // Hour of the day [00-23]
ttm.tm_min = MM;
ttm.tm_sec = SS;
// We need to go from a broken down time (struct tm) to a time_t. BUT, we have to use the right function when converting
// from struct tm. mktime() assumes the struct tm is in localtime. gmtime() assumes the struct tm is in UTC. If the incoming
// iso 8601 string has a 'Z' then we need to use gmtime() (or _mkgmtime() on windows), else we can use mktime().
time_t theTime = 0;
if (zDex == string::npos) // input is local time
theTime = mktime(&ttm);
else // input is UTC
{
#ifdef IS_WINDOWS
theTime = _mkgmtime(&ttm);
#else
theTime = timegm(&ttm);
#endif
}
system_clock::time_point time_point_result = std::chrono::system_clock::from_time_t(theTime);
double fracSec = stod(fracSecStr);
uint32_t numMillis = (uint32_t)(fracSec * 1000);
time_point_result += std::chrono::milliseconds(numMillis);
return time_point_result;
}
