mirror of https://github.com/facebook/rocksdb.git
79 lines
1.8 KiB
C++
79 lines
1.8 KiB
C++
// 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 "rocksdb/statistics.h"
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#include <cassert>
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#include <string>
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#include <vector>
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#include <map>
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namespace rocksdb {
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class HistogramBucketMapper {
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public:
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HistogramBucketMapper();
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// converts a value to the bucket index.
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const size_t IndexForValue(const uint64_t value) const;
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// number of buckets required.
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const size_t BucketCount() const {
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return bucketValues_.size();
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}
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uint64_t LastValue() const {
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return maxBucketValue_;
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}
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uint64_t FirstValue() const {
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return minBucketValue_;
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}
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uint64_t BucketLimit(const uint64_t bucketNumber) const {
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assert(bucketNumber < BucketCount());
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return bucketValues_[bucketNumber];
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}
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private:
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const std::vector<uint64_t> bucketValues_;
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const uint64_t maxBucketValue_;
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const uint64_t minBucketValue_;
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std::map<uint64_t, uint64_t> valueIndexMap_;
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};
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class HistogramImpl {
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public:
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HistogramImpl();
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virtual ~HistogramImpl() {}
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virtual void Clear();
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virtual void Add(uint64_t value);
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void Merge(const HistogramImpl& other);
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virtual std::string ToString() const;
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virtual double Median() const;
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virtual double Percentile(double p) const;
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virtual double Average() const;
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virtual double StandardDeviation() const;
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virtual void Data(HistogramData * const data) const;
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private:
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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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std::vector<uint64_t> buckets_;
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};
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} // namespace rocksdb
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#endif // STORAGE_LEVELDB_UTIL_HISTOGRAM_H_
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