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diff --git a/src/rocksdb/monitoring/histogram.h b/src/rocksdb/monitoring/histogram.h
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+++ b/src/rocksdb/monitoring/histogram.h
@@ -0,0 +1,143 @@
+//  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 <cassert>
+#include <map>
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include "rocksdb/statistics.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class HistogramBucketMapper {
+ public:
+  HistogramBucketMapper();
+
+  // converts a value to the bucket index.
+  size_t IndexForValue(uint64_t value) const;
+  // number of buckets required.
+
+  size_t BucketCount() const { return bucketValues_.size(); }
+
+  uint64_t LastValue() const { return maxBucketValue_; }
+
+  uint64_t FirstValue() const { return minBucketValue_; }
+
+  uint64_t BucketLimit(const size_t bucketNumber) const {
+    assert(bucketNumber < BucketCount());
+    return bucketValues_[bucketNumber];
+  }
+
+ private:
+  std::vector<uint64_t> bucketValues_;
+  uint64_t maxBucketValue_;
+  uint64_t minBucketValue_;
+};
+
+struct HistogramStat {
+  HistogramStat();
+  ~HistogramStat() {}
+
+  HistogramStat(const HistogramStat&) = delete;
+  HistogramStat& operator=(const HistogramStat&) = delete;
+
+  void Clear();
+  bool Empty() const;
+  void Add(uint64_t value);
+  void Merge(const HistogramStat& other);
+
+  inline uint64_t min() const { return min_.load(std::memory_order_relaxed); }
+  inline uint64_t max() const { return max_.load(std::memory_order_relaxed); }
+  inline uint64_t num() const { return num_.load(std::memory_order_relaxed); }
+  inline uint64_t sum() const { return sum_.load(std::memory_order_relaxed); }
+  inline uint64_t sum_squares() const {
+    return sum_squares_.load(std::memory_order_relaxed);
+  }
+  inline uint64_t bucket_at(size_t b) const {
+    return buckets_[b].load(std::memory_order_relaxed);
+  }
+
+  double Median() const;
+  double Percentile(double p) const;
+  double Average() const;
+  double StandardDeviation() const;
+  void Data(HistogramData* const data) const;
+  std::string ToString() const;
+
+  // To be able to use HistogramStat as thread local variable, it
+  // cannot have dynamic allocated member. That's why we're
+  // using manually values from BucketMapper
+  std::atomic_uint_fast64_t min_;
+  std::atomic_uint_fast64_t max_;
+  std::atomic_uint_fast64_t num_;
+  std::atomic_uint_fast64_t sum_;
+  std::atomic_uint_fast64_t sum_squares_;
+  std::atomic_uint_fast64_t buckets_[109];  // 109==BucketMapper::BucketCount()
+  const uint64_t num_buckets_;
+};
+
+class Histogram {
+ public:
+  Histogram() {}
+  virtual ~Histogram(){};
+
+  virtual void Clear() = 0;
+  virtual bool Empty() const = 0;
+  virtual void Add(uint64_t value) = 0;
+  virtual void Merge(const Histogram&) = 0;
+
+  virtual std::string ToString() const = 0;
+  virtual const char* Name() const = 0;
+  virtual uint64_t min() const = 0;
+  virtual uint64_t max() const = 0;
+  virtual uint64_t num() const = 0;
+  virtual double Median() const = 0;
+  virtual double Percentile(double p) const = 0;
+  virtual double Average() const = 0;
+  virtual double StandardDeviation() const = 0;
+  virtual void Data(HistogramData* const data) const = 0;
+};
+
+class HistogramImpl : public Histogram {
+ public:
+  HistogramImpl() { Clear(); }
+
+  HistogramImpl(const HistogramImpl&) = delete;
+  HistogramImpl& operator=(const HistogramImpl&) = delete;
+
+  virtual void Clear() override;
+  virtual bool Empty() const override;
+  virtual void Add(uint64_t value) override;
+  virtual void Merge(const Histogram& other) override;
+  void Merge(const HistogramImpl& other);
+
+  virtual std::string ToString() const override;
+  virtual const char* Name() const override { return "HistogramImpl"; }
+  virtual uint64_t min() const override { return stats_.min(); }
+  virtual uint64_t max() const override { return stats_.max(); }
+  virtual uint64_t num() const override { return stats_.num(); }
+  virtual double Median() const override;
+  virtual double Percentile(double p) const override;
+  virtual double Average() const override;
+  virtual double StandardDeviation() const override;
+  virtual void Data(HistogramData* const data) const override;
+
+  virtual ~HistogramImpl() {}
+
+  inline HistogramStat& TEST_GetStats() { return stats_; }
+
+ private:
+  HistogramStat stats_;
+  std::mutex mutex_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE