From d5af2f6ceddf84ae488cf5a05ff5fff9511d67e6 Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Mon, 19 Feb 2024 22:30:07 +0300
Subject: [PATCH] Save time zones to binlog.

---
 td/telegram/TimeZoneManager.cpp | 63 +++++++++++++++++++++++++++++++++
 td/telegram/TimeZoneManager.h   | 19 ++++++++++
 2 files changed, 82 insertions(+)

diff --git a/td/telegram/TimeZoneManager.cpp b/td/telegram/TimeZoneManager.cpp
index c9d2c9301..7df9693fa 100644
--- a/td/telegram/TimeZoneManager.cpp
+++ b/td/telegram/TimeZoneManager.cpp
@@ -7,11 +7,13 @@
 #include "td/telegram/TimeZoneManager.h"
 
 #include "td/telegram/Global.h"
+#include "td/telegram/logevent/LogEvent.h"
 #include "td/telegram/Td.h"
 #include "td/telegram/telegram_api.h"
 
 #include "td/utils/algorithm.h"
 #include "td/utils/buffer.h"
+#include "td/utils/tl_helpers.h"
 
 namespace td {
 
@@ -60,11 +62,42 @@ bool operator!=(const TimeZoneManager::TimeZone &lhs, const TimeZoneManager::Tim
   return !(lhs == rhs);
 }
 
+template <class StorerT>
+void TimeZoneManager::TimeZone::store(StorerT &storer) const {
+  BEGIN_STORE_FLAGS();
+  END_STORE_FLAGS();
+  td::store(id_, storer);
+  td::store(name_, storer);
+  td::store(utc_offset_, storer);
+}
+
+template <class ParserT>
+void TimeZoneManager::TimeZone::parse(ParserT &parser) {
+  BEGIN_PARSE_FLAGS();
+  END_PARSE_FLAGS();
+  td::parse(id_, parser);
+  td::parse(name_, parser);
+  td::parse(utc_offset_, parser);
+}
+
 td_api::object_ptr<td_api::timeZones> TimeZoneManager::TimeZoneList::get_time_zones_object() const {
   return td_api::make_object<td_api::timeZones>(
       transform(time_zones_, [](const TimeZone &time_zone) { return time_zone.get_time_zone_object(); }));
 }
 
+template <class StorerT>
+void TimeZoneManager::TimeZoneList::store(StorerT &storer) const {
+  td::store(time_zones_, storer);
+  td::store(hash_, storer);
+}
+
+template <class ParserT>
+void TimeZoneManager::TimeZoneList::parse(ParserT &parser) {
+  td::parse(time_zones_, parser);
+  td::parse(hash_, parser);
+  is_loaded_ = true;
+}
+
 TimeZoneManager::TimeZoneManager(Td *td, ActorShared<> parent) : td_(td), parent_(std::move(parent)) {
 }
 
@@ -75,6 +108,7 @@ void TimeZoneManager::tear_down() {
 }
 
 void TimeZoneManager::get_time_zones(Promise<td_api::object_ptr<td_api::timeZones>> &&promise) {
+  load_time_zones();
   if (time_zones_.hash_ != 0) {
     return promise.set_value(time_zones_.get_time_zones_object());
   }
@@ -82,6 +116,7 @@ void TimeZoneManager::get_time_zones(Promise<td_api::object_ptr<td_api::timeZone
 }
 
 void TimeZoneManager::reload_time_zones(Promise<td_api::object_ptr<td_api::timeZones>> &&promise) {
+  load_time_zones();
   get_time_zones_queries_.push_back(std::move(promise));
   if (get_time_zones_queries_.size() == 1) {
     auto query_promise = PromiseCreator::lambda(
@@ -112,12 +147,15 @@ void TimeZoneManager::on_get_time_zones(
       if (time_zones_.time_zones_ != time_zones || time_zones_.hash_ != zone_list->hash_) {
         time_zones_.time_zones_ = std::move(time_zones);
         time_zones_.hash_ = zone_list->hash_;
+        save_time_zones();
       }
       break;
     }
     default:
       UNREACHABLE();
   }
+  time_zones_.is_loaded_ = true;
+
   auto promises = std::move(get_time_zones_queries_);
   reset_to_empty(get_time_zones_queries_);
   for (auto &promise : promises) {
@@ -127,4 +165,29 @@ void TimeZoneManager::on_get_time_zones(
   }
 }
 
+string TimeZoneManager::get_time_zones_database_key() {
+  return "time_zones";
+}
+
+void TimeZoneManager::load_time_zones() {
+  if (time_zones_.is_loaded_) {
+    return;
+  }
+  time_zones_.is_loaded_ = true;
+
+  auto log_event_string = G()->td_db()->get_binlog_pmc()->get(get_time_zones_database_key());
+  if (log_event_string.empty()) {
+    return;
+  }
+  auto status = log_event_parse(time_zones_, log_event_string);
+  if (status.is_error()) {
+    LOG(ERROR) << "Failed to parse time zones from binlog: " << status;
+    time_zones_ = TimeZoneList();
+  }
+}
+
+void TimeZoneManager::save_time_zones() {
+  G()->td_db()->get_binlog_pmc()->set(get_time_zones_database_key(), log_event_store(time_zones_).as_slice().str());
+}
+
 }  // namespace td
diff --git a/td/telegram/TimeZoneManager.h b/td/telegram/TimeZoneManager.h
index 65c1c3962..1758543f1 100644
--- a/td/telegram/TimeZoneManager.h
+++ b/td/telegram/TimeZoneManager.h
@@ -43,13 +43,26 @@ class TimeZoneManager final : public Actor {
     TimeZone(string &&id, string &&name, int32 utc_offset);
 
     td_api::object_ptr<td_api::timeZone> get_time_zone_object() const;
+
+    template <class StorerT>
+    void store(StorerT &storer) const;
+
+    template <class ParserT>
+    void parse(ParserT &parser);
   };
 
   struct TimeZoneList {
     vector<TimeZone> time_zones_;
     int32 hash_ = 0;
+    bool is_loaded_ = false;
 
     td_api::object_ptr<td_api::timeZones> get_time_zones_object() const;
+
+    template <class StorerT>
+    void store(StorerT &storer) const;
+
+    template <class ParserT>
+    void parse(ParserT &parser);
   };
 
   friend bool operator==(const TimeZone &lhs, const TimeZone &rhs);
@@ -58,6 +71,12 @@ class TimeZoneManager final : public Actor {
 
   void on_get_time_zones(Result<telegram_api::object_ptr<telegram_api::help_TimezonesList>> &&r_time_zones);
 
+  static string get_time_zones_database_key();
+
+  void load_time_zones();
+
+  void save_time_zones();
+
   vector<Promise<td_api::object_ptr<td_api::timeZones>>> get_time_zones_queries_;
 
   TimeZoneList time_zones_;