rocksdb/util/statistics.h
2016-02-09 15:12:00 -08:00

98 lines
2.9 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
#pragma once
#include "rocksdb/statistics.h"
#include <vector>
#include <atomic>
#include <string>
#include "util/histogram.h"
#include "util/mutexlock.h"
#include "port/likely.h"
namespace rocksdb {
enum TickersInternal : uint32_t {
INTERNAL_TICKER_ENUM_START = TICKER_ENUM_MAX,
INTERNAL_TICKER_ENUM_MAX
};
enum HistogramsInternal : uint32_t {
INTERNAL_HISTOGRAM_START = HISTOGRAM_ENUM_MAX,
INTERNAL_HISTOGRAM_ENUM_MAX
};
class StatisticsImpl : public Statistics {
public:
StatisticsImpl(std::shared_ptr<Statistics> stats,
bool enable_internal_stats);
virtual ~StatisticsImpl();
virtual uint64_t getTickerCount(uint32_t ticker_type) const override;
virtual void histogramData(uint32_t histogram_type,
HistogramData* const data) const override;
std::string getHistogramString(uint32_t histogram_type) const override;
virtual void setTickerCount(uint32_t ticker_type, uint64_t count) override;
virtual void recordTick(uint32_t ticker_type, uint64_t count) override;
virtual void measureTime(uint32_t histogram_type, uint64_t value) override;
virtual std::string ToString() const override;
virtual bool HistEnabledForType(uint32_t type) const override;
private:
std::shared_ptr<Statistics> stats_shared_;
Statistics* stats_;
bool enable_internal_stats_;
struct Ticker {
Ticker() : value(uint_fast64_t()) {}
std::atomic_uint_fast64_t value;
// Pad the structure to make it size of 64 bytes. A plain array of
// std::atomic_uint_fast64_t results in huge performance degradataion
// due to false sharing.
char padding[64 - sizeof(std::atomic_uint_fast64_t)];
};
static_assert(sizeof(Ticker) == 64, "Expecting to fit into 64 bytes");
// Attributes expand to nothing depending on the platform
__declspec(align(64))
Ticker tickers_[INTERNAL_TICKER_ENUM_MAX]
__attribute__((aligned(64)));
__declspec(align(64))
HistogramImpl histograms_[INTERNAL_HISTOGRAM_ENUM_MAX]
__attribute__((aligned(64)));
};
// Utility functions
inline void MeasureTime(Statistics* statistics, uint32_t histogram_type,
uint64_t value) {
if (statistics) {
statistics->measureTime(histogram_type, value);
}
}
inline void RecordTick(Statistics* statistics, uint32_t ticker_type,
uint64_t count = 1) {
if (statistics) {
statistics->recordTick(ticker_type, count);
}
}
inline void SetTickerCount(Statistics* statistics, uint32_t ticker_type,
uint64_t count) {
if (statistics) {
statistics->setTickerCount(ticker_type, count);
}
}
}