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44 行
925 B
44 行
925 B
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#ifndef STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
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#define STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
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#include <string>
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namespace leveldb {
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class Histogram {
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public:
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Histogram() {}
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~Histogram() {}
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void Clear();
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void Add(double value);
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void Merge(const Histogram& other);
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std::string ToString() const;
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private:
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enum { kNumBuckets = 154 };
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double Median() const;
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double Percentile(double p) const;
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double Average() const;
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double StandardDeviation() const;
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static const double kBucketLimit[kNumBuckets];
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double min_;
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double max_;
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double num_;
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double sum_;
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double sum_squares_;
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double buckets_[kNumBuckets];
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};
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} // namespace leveldb
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#endif // STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
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