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Diffstat (limited to 'src/leveldb/util/histogram.h')
-rw-r--r-- | src/leveldb/util/histogram.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/leveldb/util/histogram.h b/src/leveldb/util/histogram.h new file mode 100644 index 0000000000..4da60fba45 --- /dev/null +++ b/src/leveldb/util/histogram.h @@ -0,0 +1,44 @@ +// 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: + enum { kNumBuckets = 154 }; + + double Median() const; + double Percentile(double p) const; + double Average() const; + double StandardDeviation() const; + + static const double kBucketLimit[kNumBuckets]; + + double min_; + double max_; + double num_; + double sum_; + double sum_squares_; + + double buckets_[kNumBuckets]; +}; + +} // namespace leveldb + +#endif // STORAGE_LEVELDB_UTIL_HISTOGRAM_H_ |