rocksdb/util/stop_watch.h
Haobo Xu 5b825d6964 [RocksDB] Use raw pointer instead of shared pointer when passing Statistics object internally
Summary: liveness of the statistics object is already ensured by the shared pointer in DB options. There's no reason to pass again shared pointer among internal functions. Raw pointer is sufficient and efficient.

Test Plan: make check

Reviewers: dhruba, MarkCallaghan, igor

Reviewed By: dhruba

CC: leveldb, reconnect.grayhat

Differential Revision: https://reviews.facebook.net/D14289
2013-11-25 10:38:15 -08:00

71 lines
1.5 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_imp.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) :
env_(env),
start_time_(env->NowMicros()),
statistics_(statistics),
histogram_name_(histogram_name) {}
uint64_t ElapsedMicros() {
return env_->NowMicros() - start_time_;
}
~StopWatch() {
if (statistics_) {
statistics_->measureTime(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