- // 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.
-
- #ifndef STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
- #define STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
-
- #include <string>
-
- namespace leveldb {
-
- class Histogram {
- public:
- Histogram() { }
- ~Histogram() { }
-
- void Clear();
- void Add(double value);
- void Merge(const Histogram& other);
-
- std::string ToString() const;
-
- private:
- double min_;
- double max_;
- double num_;
- double sum_;
- double sum_squares_;
-
- enum { kNumBuckets = 154 };
- static const double kBucketLimit[kNumBuckets];
- double buckets_[kNumBuckets];
-
- double Median() const;
- double Percentile(double p) const;
- double Average() const;
- double StandardDeviation() const;
- };
-
- } // namespace leveldb
-
- #endif // STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
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