From 58841ef12f6cba1bb622353c1fcaa0e3c6fb46c9 Mon Sep 17 00:00:00 2001 From: Ilya Zhuravlev Date: Tue, 23 Oct 2012 01:18:44 +0400 Subject: Add dummy and LevelDB database backends --- src/leveldb/util/histogram.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 src/leveldb/util/histogram.h (limited to 'src/leveldb/util/histogram.h') diff --git a/src/leveldb/util/histogram.h b/src/leveldb/util/histogram.h new file mode 100644 index 000000000..1ef9f3c8a --- /dev/null +++ b/src/leveldb/util/histogram.h @@ -0,0 +1,42 @@ +// 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 + +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_ -- cgit v1.2.3