Using cctz library [#CLICKHOUSE-2].

libs/libcommon/CMakeLists.txt

@@ -4,6 +4,8 @@ SET(CONFIG_VERSION ${CMAKE_CURRENT_BINARY_DIR}/include/common/config_version.h)
 SET(CONFIG_COMMON ${CMAKE_CURRENT_BINARY_DIR}/include/common/config_common.h)
 
 include_directories (include)
+include_directories (BEFORE ${CMAKE_SOURCE_DIR}/contrib/libcctz/include)
+
 include(${CMAKE_SOURCE_DIR}/cmake/dbms_include.cmake)
 
 if (APPLE)
@@ -77,16 +79,14 @@ else ()
 	message (STATUS "Disabling libtcmalloc for valgrind better analysis")
 endif ()
 
-include (${ClickHouse_SOURCE_DIR}/cmake/find_glib.cmake)
-
 find_package (Threads)
 
 target_link_libraries (
 	common
 	pocoext
+	cctz
 	${MALLOC_LIBRARIES}
 	${CMAKE_THREAD_LIBS_INIT}
-	${GLIB_LIBS}
 	${ICU_LIBS}
 	${RT_LIBRARIES})
 

libs/libcommon/src/DateLUTImpl.cpp

@@ -1,121 +1,35 @@
-#pragma GCC diagnostic push
+#include <civil_time.h>
-#pragma GCC diagnostic ignored "-Wold-style-cast"
+#include <time_zone.h>
-#if __clang__
-	#pragma GCC diagnostic ignored "-Wdeprecated-register"
-#endif
-	#include <glib.h>
-#pragma GCC diagnostic pop
 
 #include <common/DateLUTImpl.h>
 #include <Poco/Exception.h>
 
 #include <memory>
+#include <chrono>
 #include <cstring>
-
 #include <iostream>
 
 
-namespace details
-{
 namespace
 {
 
-struct GTimeZoneUnref
+UInt8 getDayOfWeek(const cctz::civil_day & date)
 {
-	void operator()(GTimeZone * tz) const
+	cctz::weekday day_of_week = cctz::get_weekday(date);
+	switch (day_of_week)
 	{
-		g_time_zone_unref(tz);
+		case cctz::weekday::monday: 	return 1;
+		case cctz::weekday::tuesday: 	return 2;
+		case cctz::weekday::wednesday: 	return 3;
+		case cctz::weekday::thursday: 	return 4;
+		case cctz::weekday::friday: 	return 5;
+		case cctz::weekday::saturday: 	return 6;
+		case cctz::weekday::sunday: 	return 7;
+		default:
+			throw Poco::Exception("Logical error: incorrect week day.");
 	}
-};
-
-using GTimeZonePtr = std::unique_ptr<GTimeZone, GTimeZoneUnref>;
-
-struct GDateTimeUnref
-{
-	void operator()(GDateTime * dt) const
-	{
-		g_date_time_unref(dt);
-	}
-};
-
-using GDateTimePtr = std::unique_ptr<GDateTime, GDateTimeUnref>;
-
-
-GTimeZonePtr createGTimeZone(const std::string & description)
-{
-	GTimeZone * tz = g_time_zone_new(description.c_str());
-	if (tz == nullptr)
-		throw Poco::Exception("Failed to create GTimeZone object.");
-
-	return GTimeZonePtr(tz);
 }
 
-
-GDateTimePtr createGDateTimeUTC(time_t timestamp)
-{
-	GDateTime * dt = g_date_time_new_from_unix_utc(timestamp);
-	if (dt == nullptr)
-		throw Poco::Exception("Failed to create GDateTime object.");
-
-	return GDateTimePtr(dt);
-}
-
-
-/// Create GDateTime object, interpreting passed unix timestamp in passed timezone.
-GDateTimePtr createGDateTimeLocal(const GTimeZonePtr & p_tz, time_t timestamp)
-{
-	GDateTimePtr utc = createGDateTimeUTC(timestamp);
-	GDateTime * local = g_date_time_to_timezone(utc.get(), p_tz.get());
-	if (local == nullptr)
-		throw Poco::Exception("Failed to create GDateTime object.");
-
-	return GDateTimePtr(local);
-}
-
-
-/// Create GDateTime object, at beginning of same day in passed time zone.
-GDateTimePtr createSameDayInDifferentTimeZone(const GTimeZonePtr & p_tz, const GDateTimePtr & p_dt)
-{
-	GDateTime * dt = p_dt.get();
-
-	gint year;
-	gint month;
-	gint day;
-	g_date_time_get_ymd(dt, &year, &month, &day);
-
-	GDateTime * local_dt = g_date_time_new(p_tz.get(), year, month, day, 0, 0, 0);
-	if (local_dt == nullptr)
-		throw Poco::Exception("Failed to create GDateTime object.");
-
-	return GDateTimePtr(local_dt);
-}
-
-GDateTimePtr toNextDay(const GTimeZonePtr & p_tz, const GDateTimePtr & p_dt)
-{
-	GDateTime * dt = p_dt.get();
-	if (dt == nullptr)
-		throw Poco::Exception("Null pointer.");
-
-	dt = g_date_time_add_days(dt, 1);
-	if (dt == nullptr)
-		throw Poco::Exception("Failed to create GDateTime object.");
-
-	GDateTimePtr p_next_dt = GDateTimePtr(dt);
-	GDateTime * next_dt = p_next_dt.get();
-
-	gint year;
-	gint month;
-	gint day;
-	g_date_time_get_ymd(next_dt, &year, &month, &day);
-
-	dt = g_date_time_new(p_tz.get(), year, month, day, 0, 0, 0);
-	if (dt == nullptr)
-		throw Poco::Exception("Failed to create GDateTime object.");
-
-	return GDateTimePtr(dt);
-}
-
-}
 }
 
 
@@ -125,28 +39,29 @@ DateLUTImpl::DateLUTImpl(const std::string & time_zone_)
 	size_t i = 0;
 	time_t start_of_day = DATE_LUT_MIN;
 
-	details::GTimeZonePtr p_tz = details::createGTimeZone(time_zone);
+	cctz::time_zone cctz_time_zone;
-	details::GDateTimePtr p_dt = details::createSameDayInDifferentTimeZone(p_tz, details::createGDateTimeUTC(start_of_day));
+	if (!cctz::load_time_zone(time_zone.data(), &cctz_time_zone))
+		throw Poco::Exception("Cannot load time zone " + time_zone_);
+
+	cctz::time_zone::absolute_lookup start_of_epoch_lookup = cctz_time_zone.lookup(std::chrono::system_clock::from_time_t(start_of_day));
+	cctz::civil_day date{start_of_epoch_lookup.cs};
+
+	offset_at_start_of_epoch = start_of_epoch_lookup.offset;
 
 	do
 	{
 		if (i > DATE_LUT_MAX_DAY_NUM)
 			throw Poco::Exception("Cannot create DateLUTImpl: i > DATE_LUT_MAX_DAY_NUM.");
 
-		GDateTime * dt = p_dt.get();
+		cctz::time_zone::civil_lookup lookup = cctz_time_zone.lookup(date);
 
-		start_of_day = g_date_time_to_unix(dt);
+		start_of_day = std::chrono::system_clock::to_time_t(lookup.pre);	/// Ambiguouty is possible.
-
-		gint year;
-		gint month;
-		gint day;
-		g_date_time_get_ymd(dt, &year, &month, &day);
 
 		Values & values = lut[i];
-		values.year = year;
+		values.year = date.year();
-		values.month = month;
+		values.month = date.month();
-		values.day_of_month = day;
+		values.day_of_month = date.day();
-		values.day_of_week = g_date_time_get_day_of_week(dt);
+		values.day_of_week = getDayOfWeek(date);
 		values.date = start_of_day;
 
 		values.time_at_offset_change = 0;
@@ -160,8 +75,7 @@ DateLUTImpl::DateLUTImpl(const std::string & time_zone_)
 			{
 				lut[i - 1].amount_of_offset_change = amount_of_offset_change_at_prev_day;
 
-				const auto utc_offset_at_beginning_of_day = g_date_time_get_utc_offset(
+				const auto utc_offset_at_beginning_of_day = cctz_time_zone.lookup(std::chrono::system_clock::from_time_t(lut[i - 1].date)).offset;
-					details::createGDateTimeLocal(p_tz, lut[i - 1].date).get());
 
 				/// Find a time (timestamp offset from beginning of day),
 				///  when UTC offset was changed. Search is performed with 15-minute granularity, assuming it is enough.
@@ -169,8 +83,8 @@ DateLUTImpl::DateLUTImpl(const std::string & time_zone_)
 				time_t time_at_offset_change = 900;
 				while (time_at_offset_change < 65536)
 				{
-					auto utc_offset_at_current_time = g_date_time_get_utc_offset(
+					auto utc_offset_at_current_time = cctz_time_zone.lookup(std::chrono::system_clock::from_time_t(
-						details::createGDateTimeLocal(p_tz, lut[i - 1].date + time_at_offset_change).get());
+						lut[i - 1].date + time_at_offset_change)).offset;
 
 					if (utc_offset_at_current_time != utc_offset_at_beginning_of_day)
 						break;
@@ -186,7 +100,7 @@ DateLUTImpl::DateLUTImpl(const std::string & time_zone_)
 		}
 
 		/// Going to next day.
-		p_dt = details::toNextDay(p_tz, p_dt);
+		++date;
 		++i;
 	}
 	while (start_of_day <= DATE_LUT_MAX);
@@ -198,6 +112,4 @@ DateLUTImpl::DateLUTImpl(const std::string & time_zone_)
 		if (lut[day].month == 1 && lut[day].day_of_month == 1)
 			years_lut[lut[day].year - DATE_LUT_MIN_YEAR] = day;
 	}
-
-	offset_at_start_of_epoch = g_time_zone_get_offset(p_tz.get(), g_time_zone_find_interval(p_tz.get(), G_TIME_TYPE_UNIVERSAL, 0));
 }