From 1b9a8cc6fe05047d5a117531ddf146e2930d148d Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Thu, 27 Oct 2022 14:58:21 +0300
Subject: [PATCH] Add ForumTopicInfo cache.

---
 td/telegram/ForumTopicManager.cpp | 45 +++++++++++++++++++++++++------
 td/telegram/ForumTopicManager.h   | 13 ++++++++-
 2 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/td/telegram/ForumTopicManager.cpp b/td/telegram/ForumTopicManager.cpp
index 8ec773236..a2e2107f1 100644
--- a/td/telegram/ForumTopicManager.cpp
+++ b/td/telegram/ForumTopicManager.cpp
@@ -85,13 +85,15 @@ class CreateForumTopicQuery final : public Td::ResultHandler {
     }
 
     auto action = static_cast<const telegram_api::messageActionTopicCreate *>(service_message->action_.get());
-    ForumTopicInfo forum_topic_info(MessageId(ServerMessageId(service_message->id_)), action->title_,
-                                    ForumTopicIcon(action->icon_color_, action->icon_emoji_id_), service_message->date_,
-                                    creator_dialog_id_, true, false);
+    auto forum_topic_info =
+        td::make_unique<ForumTopicInfo>(MessageId(ServerMessageId(service_message->id_)), action->title_,
+                                        ForumTopicIcon(action->icon_color_, action->icon_emoji_id_),
+                                        service_message->date_, creator_dialog_id_, true, false);
     td_->updates_manager_->on_get_updates(
-        std::move(ptr), PromiseCreator::lambda([forum_topic_info = std::move(forum_topic_info),
-                                                promise = std::move(promise_)](Unit result) mutable {
-          send_closure(G()->forum_topic_manager(), &ForumTopicManager::on_forum_topic_created,
+        std::move(ptr),
+        PromiseCreator::lambda([dialog_id = DialogId(channel_id_), forum_topic_info = std::move(forum_topic_info),
+                                promise = std::move(promise_)](Unit result) mutable {
+          send_closure(G()->forum_topic_manager(), &ForumTopicManager::on_forum_topic_created, dialog_id,
                        std::move(forum_topic_info), std::move(promise));
         }));
   }
@@ -142,11 +144,22 @@ void ForumTopicManager::create_forum_topic(DialogId dialog_id, string &&title,
       ->send(channel_id, new_title, icon_color, icon_custom_emoji_id, as_dialog_id);
 }
 
-void ForumTopicManager::on_forum_topic_created(ForumTopicInfo &&forum_topic_info,
+void ForumTopicManager::on_forum_topic_created(DialogId dialog_id, unique_ptr<ForumTopicInfo> &&forum_topic_info,
                                                Promise<td_api::object_ptr<td_api::forumTopicInfo>> &&promise) {
   TRY_STATUS_PROMISE(promise, G()->close_status());
 
-  promise.set_value(forum_topic_info.get_forum_topic_info_object(td_));
+  MessageId top_thread_message_id = forum_topic_info->get_thread_id();
+  auto topic_info = get_topic_info(dialog_id, top_thread_message_id);
+  if (topic_info == nullptr) {
+    if (dialog_topics_.get_pointer(dialog_id) == nullptr) {
+      dialog_topics_.set(dialog_id, make_unique<DialogTopics>());
+    }
+    dialog_topics_.get_pointer(dialog_id)->topic_infos_.set(top_thread_message_id, std::move(forum_topic_info));
+    topic_info = get_topic_info(dialog_id, top_thread_message_id);
+    CHECK(topic_info != nullptr);
+  }
+
+  promise.set_value(topic_info->get_forum_topic_info_object(td_));
 }
 
 Status ForumTopicManager::is_forum(DialogId dialog_id) {
@@ -160,4 +173,20 @@ Status ForumTopicManager::is_forum(DialogId dialog_id) {
   return Status::OK();
 }
 
+ForumTopicInfo *ForumTopicManager::get_topic_info(DialogId dialog_id, MessageId top_thread_message_id) {
+  auto *dialog_info = dialog_topics_.get_pointer(dialog_id);
+  if (dialog_info == nullptr) {
+    return nullptr;
+  }
+  return dialog_info->topic_infos_.get_pointer(top_thread_message_id);
+}
+
+const ForumTopicInfo *ForumTopicManager::get_topic_info(DialogId dialog_id, MessageId top_thread_message_id) const {
+  auto *dialog_info = dialog_topics_.get_pointer(dialog_id);
+  if (dialog_info == nullptr) {
+    return nullptr;
+  }
+  return dialog_info->topic_infos_.get_pointer(top_thread_message_id);
+}
+
 }  // namespace td
diff --git a/td/telegram/ForumTopicManager.h b/td/telegram/ForumTopicManager.h
index e2e0393a1..ae4ee50dd 100644
--- a/td/telegram/ForumTopicManager.h
+++ b/td/telegram/ForumTopicManager.h
@@ -14,6 +14,7 @@
 
 #include "td/utils/common.h"
 #include "td/utils/Promise.h"
+#include "td/utils/WaitFreeHashMap.h"
 
 namespace td {
 
@@ -31,18 +32,28 @@ class ForumTopicManager final : public Actor {
   void create_forum_topic(DialogId dialog_id, string &&title, td_api::object_ptr<td_api::forumTopicIcon> &&icon,
                           Promise<td_api::object_ptr<td_api::forumTopicInfo>> &&promise);
 
-  void on_forum_topic_created(ForumTopicInfo &&forum_topic_info,
+  void on_forum_topic_created(DialogId dialog_id, unique_ptr<ForumTopicInfo> &&forum_topic_info,
                               Promise<td_api::object_ptr<td_api::forumTopicInfo>> &&promise);
 
  private:
   static constexpr size_t MAX_FORUM_TOPIC_TITLE_LENGTH = 128;  // server side limit for forum topic title
 
+  struct DialogTopics {
+    WaitFreeHashMap<MessageId, unique_ptr<ForumTopicInfo>, MessageIdHash> topic_infos_;
+  };
+
   void tear_down() final;
 
   Status is_forum(DialogId dialog_id);
 
+  ForumTopicInfo *get_topic_info(DialogId dialog_id, MessageId top_thread_message_id);
+
+  const ForumTopicInfo *get_topic_info(DialogId dialog_id, MessageId top_thread_message_id) const;
+
   Td *td_;
   ActorShared<> parent_;
+
+  WaitFreeHashMap<DialogId, unique_ptr<DialogTopics>, DialogIdHash> dialog_topics_;
 };
 
 }  // namespace td