ceph/src/rocksdb/monitoring/perf_step_timer.h

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 //
   6 #pragma once
   7 #include "monitoring/perf_level_imp.h"
   8 #include "rocksdb/env.h"
   9 #include "util/stop_watch.h"
  10
  11 namespace ROCKSDB_NAMESPACE {
  12
  13 class PerfStepTimer {
  14  public:
  15   explicit PerfStepTimer(
  16       uint64_t* metric, Env* env = nullptr, bool use_cpu_time = false,
  17       PerfLevel enable_level = PerfLevel::kEnableTimeExceptForMutex,
  18       Statistics* statistics = nullptr, uint32_t ticker_type = 0)
  19       : perf_counter_enabled_(perf_level >= enable_level),
  20         use_cpu_time_(use_cpu_time),
  21         env_((perf_counter_enabled_ || statistics != nullptr)
  22                  ? ((env != nullptr) ? env : Env::Default())
  23                  : nullptr),
  24         start_(0),
  25         metric_(metric),
  26         statistics_(statistics),
  27         ticker_type_(ticker_type) {}
  28
  29   ~PerfStepTimer() {
  30     Stop();
  31   }
  32
  33   void Start() {
  34     if (perf_counter_enabled_ || statistics_ != nullptr) {
  35       start_ = time_now();
  36     }
  37   }
  38
  39   uint64_t time_now() {
  40     if (!use_cpu_time_) {
  41       return env_->NowNanos();
  42     } else {
  43       return env_->NowCPUNanos();
  44     }
  45   }
  46
  47   void Measure() {
  48     if (start_) {
  49       uint64_t now = time_now();
  50       *metric_ += now - start_;
  51       start_ = now;
  52     }
  53   }
  54
  55   void Stop() {
  56     if (start_) {
  57       uint64_t duration = time_now() - start_;
  58       if (perf_counter_enabled_) {
  59         *metric_ += duration;
  60       }
  61
  62       if (statistics_ != nullptr) {
  63         RecordTick(statistics_, ticker_type_, duration);
  64       }
  65       start_ = 0;
  66     }
  67   }
  68
  69  private:
  70   const bool perf_counter_enabled_;
  71   const bool use_cpu_time_;
  72   Env* const env_;
  73   uint64_t start_;
  74   uint64_t* metric_;
  75   Statistics* statistics_;
  76   uint32_t ticker_type_;
  77 };
  78
  79 }  // namespace ROCKSDB_NAMESPACE