init

Telegram/lib_crl/crl/crl_time.cpp

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+// This file is part of Desktop App Toolkit,
+// a set of libraries for developing nice desktop applications.
+//
+// For license and copyright information please follow this link:
+// https://github.com/desktop-app/legal/blob/master/LEGAL
+//
+#include <crl/crl_time.h>
+
+#include <atomic>
+#include <ctime>
+#include <limits>
+
+namespace crl {
+namespace details {
+namespace {
+
+time LastAdjustmentTime/* = 0*/;
+std::time_t LastAdjustmentUnixtime/* = 0*/;
+
+using seconds_type = std::uint32_t;
+std::atomic<seconds_type> AdjustSeconds/* = 0*/;
+
+inner_time_type StartValue/* = 0*/;
+inner_profile_type StartProfileValue/* = 0*/;
+
+struct StaticInit {
+	StaticInit();
+};
+
+StaticInit::StaticInit() {
+	StartValue = current_value();
+	StartProfileValue = current_profile_value();
+
+	init();
+
+	LastAdjustmentUnixtime = ::time(nullptr);
+}
+
+StaticInit StaticInitObject;
+
+bool adjust_time() {
+	const auto now = crl::now();
+	const auto delta = (now - LastAdjustmentTime);
+	const auto unixtime = ::time(nullptr);
+	const auto real = (unixtime - LastAdjustmentUnixtime);
+	const auto seconds = (time(real) * 1000 - delta) / 1000;
+
+	LastAdjustmentUnixtime = unixtime;
+	LastAdjustmentTime = now;
+
+	if (seconds <= 0) {
+		return false;
+	}
+	auto current = seconds_type(0);
+	static constexpr auto max = std::numeric_limits<seconds_type>::max();
+	while (true) {
+		if (time(current) + seconds > time(max)) {
+			return false;
+		}
+		const auto next = current + seconds_type(seconds);
+		if (AdjustSeconds.compare_exchange_weak(current, next)) {
+			return true;
+		}
+	}
+	return false;
+}
+
+time compute_adjustment() {
+	return time(AdjustSeconds.load()) * 1000;
+}
+
+profile_time compute_profile_adjustment() {
+	return compute_adjustment() * 1000;
+}
+
+} // namespace
+} // namespace details
+
+time now() {
+	const auto elapsed = details::current_value() - details::StartValue;
+	return details::convert(elapsed) + details::compute_adjustment();
+}
+
+profile_time profile() {
+	const auto elapsed = details::current_profile_value()
+		- details::StartProfileValue;
+	return details::convert_profile(elapsed)
+		+ details::compute_profile_adjustment();
+}
+
+bool adjust_time() {
+	return details::adjust_time();
+}
+
+} // namespace crl