YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

//  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.

//

// The following only applies to changes made to this file as part of YugaByte development.

//

// Portions Copyright (c) YugaByte, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License.  You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed under the License

// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

// or implied.  See the License for the specific language governing permissions and limitations

// under the License.

//

#pragma once

#include <string.h>

#include "yb/rocksdb/env.h"

#include "yb/rocksdb/statistics.h"

namespace rocksdb {

// Auto-scoped.

// Records the measure time into the corresponding histogram if statistics

// is not nullptr. It is also saved into *elapsed if the pointer is not nullptr.

class StopWatch {

 public:

  StopWatch(Env * const env, Statistics* statistics,

            const uint32_t hist_type,

            uint64_t* elapsed = nullptr)

    : env_(env),

      statistics_(statistics),

      hist_type_(hist_type),

      elapsed_(elapsed),

      stats_enabled_(statistics && statistics->HistEnabledForType(hist_type)),

      start_time_((stats_enabled_ || elapsed != nullptr) ?

                  env->NowMicros() : 0) {

  }

  ~StopWatch() {

    if (elapsed_) {

      *elapsed_ = env_->NowMicros() - start_time_;

    }

    if (stats_enabled_) {

      statistics_->measureTime(hist_type_,

          (elapsed_ != nullptr) ? *elapsed_ :

                                  (env_->NowMicros() - start_time_));

    }

  }

 private:

  Env* const env_;

  Statistics* statistics_;

  const uint32_t hist_type_;

  uint64_t* elapsed_;

  bool stats_enabled_;

  const uint64_t start_time_;

};

// 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;

  }

  uint64_t ElapsedNanosSafe(bool reset = false) {

    return (env_ != nullptr) ? ElapsedNanos(reset) : 0U;

  }

 private:

  Env* const env_;

  uint64_t start_;

};

} // namespace rocksdb