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diff --git a/src/rocksdb/monitoring/in_memory_stats_history.h b/src/rocksdb/monitoring/in_memory_stats_history.h
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+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#pragma once
+
+#include "rocksdb/stats_history.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// InMemoryStatsHistoryIterator can be used to access stats history that was
+// stored by an in-memory two level std::map(DBImpl::stats_history_). It keeps
+// a copy of the stats snapshot (in stats_map_) that is currently being pointed
+// to, which allows the iterator to access the stats snapshot even when
+// the background garbage collecting thread purges it from the source of truth
+// (`DBImpl::stats_history_`). In that case, the iterator will continue to be
+// valid until a call to `Next()` returns no result and invalidates it. In
+// some extreme cases, the iterator may also return fragmented segments of
+// stats snapshots due to long gaps between `Next()` calls and interleaved
+// garbage collection.
+class InMemoryStatsHistoryIterator final : public StatsHistoryIterator {
+ public:
+  // Setup InMemoryStatsHistoryIterator to return stats snapshots between
+  // seconds timestamps [start_time, end_time)
+  InMemoryStatsHistoryIterator(uint64_t start_time, uint64_t end_time,
+                               DBImpl* db_impl)
+      : start_time_(start_time),
+        end_time_(end_time),
+        valid_(true),
+        db_impl_(db_impl) {
+    AdvanceIteratorByTime(start_time_, end_time_);
+  }
+  // no copying allowed
+  InMemoryStatsHistoryIterator(const InMemoryStatsHistoryIterator&) = delete;
+  void operator=(const InMemoryStatsHistoryIterator&) = delete;
+  InMemoryStatsHistoryIterator(InMemoryStatsHistoryIterator&&) = delete;
+  InMemoryStatsHistoryIterator& operator=(InMemoryStatsHistoryIterator&&) =
+      delete;
+
+  ~InMemoryStatsHistoryIterator() override;
+  bool Valid() const override;
+  Status status() const override;
+
+  // Move to the next stats snapshot currently available
+  // This function may invalidate the iterator
+  // REQUIRES: Valid()
+  void Next() override;
+
+  // REQUIRES: Valid()
+  uint64_t GetStatsTime() const override;
+
+  // This function is idempotent
+  // REQUIRES: Valid()
+  const std::map<std::string, uint64_t>& GetStatsMap() const override;
+
+ private:
+  // advance the iterator to the next stats history record with timestamp
+  // between [start_time, end_time)
+  void AdvanceIteratorByTime(uint64_t start_time, uint64_t end_time);
+
+  uint64_t time_;
+  uint64_t start_time_;
+  uint64_t end_time_;
+  std::map<std::string, uint64_t> stats_map_;
+  Status status_;
+  bool valid_;
+  DBImpl* db_impl_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE