rocksdb/util/stop_watch.h

68 lines
1.6 KiB
C++

// Copyright (c) 2013, 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/env.h"
#include "util/statistics.h"
namespace rocksdb {
// Auto-scoped.
// Records the statistic into the corresponding histogram.
class StopWatch {
public:
explicit StopWatch(
Env * const env,
Statistics* statistics = nullptr,
const Histograms histogram_name = DB_GET,
bool auto_start = true) :
env_(env),
start_time_((!auto_start && !statistics) ? 0 : env->NowMicros()),
statistics_(statistics),
histogram_name_(histogram_name) {}
uint64_t ElapsedMicros() {
return env_->NowMicros() - start_time_;
}
~StopWatch() { MeasureTime(statistics_, histogram_name_, ElapsedMicros()); }
private:
Env* const env_;
const uint64_t start_time_;
Statistics* statistics_;
const Histograms histogram_name_;
};
// a nano second precision stopwatch
class StopWatchNano {
public:
explicit StopWatchNano(Env* const env, bool auto_start = false)
: env_(env), start_(0) {
if (auto_start) {
Start();
}
}
void Start() { start_ = env_->NowNanos(); }
uint64_t ElapsedNanos(bool reset = false) {
auto now = env_->NowNanos();
auto elapsed = now - start_;
if (reset) {
start_ = now;
}
return elapsed;
}
private:
Env* const env_;
uint64_t start_;
};
} // namespace rocksdb