Add QueryMerger.

1 files changed, 54 insertions, 0 deletions

diff --git a/td/telegram/QueryMerger.h b/td/telegram/QueryMerger.h
new file mode 100644
index 000000000..e87f81666
--- /dev/null
+++ b/td/telegram/QueryMerger.h
@@ -0,0 +1,54 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2023
+//
+// 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/actor/actor.h"
+
+#include "td/utils/common.h"
+#include "td/utils/FlatHashMap.h"
+#include "td/utils/Promise.h"
+#include "td/utils/Slice.h"
+#include "td/utils/Status.h"
+
+#include <functional>
+#include <queue>
+
+namespace td {
+
+// merges queries into a single request
+class QueryMerger final : public Actor {
+ public:
+  QueryMerger(Slice name, size_t max_concurrent_query_count, size_t max_merged_query_count);
+
+  using MergeFunction = std::function<void(vector<int64> query_ids, Promise<Unit> &&promise)>;
+  void set_merge_function(MergeFunction merge_function) {
+    merge_function_ = std::move(merge_function);
+  }
+
+  void add_query(int64 query_id, Promise<Unit> &&promise);
+
+ private:
+  struct QueryInfo {
+    vector<Promise<Unit>> promises_;
+  };
+
+  size_t query_count_ = 0;
+  size_t max_concurrent_query_count_;
+  size_t max_merged_query_count_;
+
+  MergeFunction merge_function_;
+  std::queue<int64> pending_queries_;
+  FlatHashMap<int64, QueryInfo> queries_;
+
+  void send_query(vector<int64> query_ids);
+
+  void on_get_query_result(vector<int64> query_ids, Result<Unit> &&result);
+
+  void loop() final;
+};
+
+}  // namespace td