fix ya.make

1 files changed, 102 insertions, 0 deletions

diff --git a/library/cpp/yt/cpu_clock/clock.cpp b/library/cpp/yt/cpu_clock/clock.cpp
new file mode 100644
index 0000000000..eda3f03bbc
--- /dev/null
+++ b/library/cpp/yt/cpu_clock/clock.cpp
@@ -0,0 +1,102 @@
+#include "clock.h"
+
+#include <util/system/hp_timer.h>
+
+#include <library/cpp/yt/assert/assert.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+// Re-calibrate every 1B CPU ticks.
+constexpr auto CalibrationCpuPeriod = 1'000'000'000;
+
+struct TCalibrationState
+{
+    TCpuInstant CpuInstant;
+    TInstant Instant;
+};
+
+double GetMicrosecondsToTicks()
+{
+    static const auto MicrosecondsToTicks = static_cast<double>(NHPTimer::GetCyclesPerSecond()) / 1'000'000;
+    return MicrosecondsToTicks;
+}
+
+double GetTicksToMicroseconds()
+{
+    static const auto TicksToMicroseconds = 1.0 / GetMicrosecondsToTicks();
+    return TicksToMicroseconds;
+}
+
+TCalibrationState GetCalibrationState(TCpuInstant cpuInstant)
+{
+    thread_local TCalibrationState State;
+
+    if (State.CpuInstant + CalibrationCpuPeriod < cpuInstant) {
+        State.CpuInstant = cpuInstant;
+        State.Instant = TInstant::Now();
+    }
+
+    return State;
+}
+
+TCalibrationState GetCalibrationState()
+{
+    return GetCalibrationState(GetCpuInstant());
+}
+
+TDuration CpuDurationToDuration(TCpuDuration cpuDuration, double ticksToMicroseconds)
+{
+    // TDuration is unsigned and thus does not support negative values.
+    if (cpuDuration < 0) {
+        return TDuration::Zero();
+    }
+    return TDuration::MicroSeconds(static_cast<ui64>(cpuDuration * ticksToMicroseconds));
+}
+
+TCpuDuration DurationToCpuDuration(TDuration duration, double microsecondsToTicks)
+{
+    return static_cast<TCpuDuration>(duration.MicroSeconds() * microsecondsToTicks);
+}
+
+TInstant GetInstant()
+{
+    auto cpuInstant = GetCpuInstant();
+    auto state = GetCalibrationState(cpuInstant);
+    YT_ASSERT(cpuInstant >= state.CpuInstant);
+    return state.Instant + CpuDurationToDuration(cpuInstant - state.CpuInstant, GetTicksToMicroseconds());
+}
+
+TDuration CpuDurationToDuration(TCpuDuration cpuDuration)
+{
+    return CpuDurationToDuration(cpuDuration, GetTicksToMicroseconds());
+}
+
+TCpuDuration DurationToCpuDuration(TDuration duration)
+{
+    return DurationToCpuDuration(duration, GetMicrosecondsToTicks());
+}
+
+TInstant CpuInstantToInstant(TCpuInstant cpuInstant)
+{
+    // TDuration is unsigned and does not support negative values,
+    // thus we consider two cases separately.
+    auto state = GetCalibrationState();
+    return cpuInstant >= state.CpuInstant
+        ? state.Instant + CpuDurationToDuration(cpuInstant - state.CpuInstant, GetTicksToMicroseconds())
+        : state.Instant - CpuDurationToDuration(state.CpuInstant - cpuInstant, GetTicksToMicroseconds());
+}
+
+TCpuInstant InstantToCpuInstant(TInstant instant)
+{
+    // See above.
+    auto state = GetCalibrationState();
+    return instant >= state.Instant
+        ? state.CpuInstant + DurationToCpuDuration(instant - state.Instant, GetMicrosecondsToTicks())
+        : state.CpuInstant - DurationToCpuDuration(state.Instant - instant, GetMicrosecondsToTicks());
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT