1 files changed, 71 insertions, 0 deletions
diff --git a/libs/tdlib/td/tdutils/td/utils/TimedStat.h b/libs/tdlib/td/tdutils/td/utils/TimedStat.h
new file mode 100644
index 0000000000..fc4197470d
--- /dev/null
+++ b/libs/tdlib/td/tdutils/td/utils/TimedStat.h
@@ -0,0 +1,71 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#pragma once
+
+#include "td/utils/logging.h"
+
+#include <utility>
+
+namespace td {
+
+template <class StatT>
+class TimedStat {
+ public:
+  TimedStat(double duration, double now)
+      : duration_(duration), current_(), current_timestamp_(now), next_(), next_timestamp_(now) {
+  }
+  TimedStat() : TimedStat(0, 0) {
+  }
+  template <class EventT>
+  void add_event(const EventT &e, double now) {
+    update(now);
+    current_.on_event(e);
+    next_.on_event(e);
+  }
+  const StatT &get_stat(double now) {
+    update(now);
+    return current_;
+  }
+  std::pair<StatT, double> stat_duration(double now) {
+    update(now);
+    return std::make_pair(current_, now - current_timestamp_);
+  }
+  void clear_events() {
+    current_.clear();
+    next_.clear();
+  }
+
+ private:
+  double duration_;
+  StatT current_;
+  double current_timestamp_;
+  StatT next_;
+  double next_timestamp_;
+
+  void update(double &now) {
+    if (now < next_timestamp_) {
+      CHECK(now >= next_timestamp_ * (1 - 1e-14)) << now << " " << next_timestamp_;
+      now = next_timestamp_;
+    }
+    if (duration_ == 0) {
+      return;
+    }
+    if (next_timestamp_ + 2 * duration_ < now) {
+      current_ = StatT();
+      current_timestamp_ = now;
+      next_ = StatT();
+      next_timestamp_ = now;
+    } else if (next_timestamp_ + duration_ < now) {
+      current_ = next_;
+      current_timestamp_ = next_timestamp_;
+      next_ = StatT();
+      next_timestamp_ = now;
+    }
+  }
+};
+
+}  // namespace td