text: // Copyright 2015 Google Inc. All rights reserved
  //
  // 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.
  
  // +build ignore
  
  #include "stats.h"
  
  #include <algorithm>
  #include <mutex>
  #include <vector>
  
  #include "find.h"
  #include "flags.h"
  #include "log.h"
  #include "stringprintf.h"
  #include "timeutil.h"
  
  namespace {
  
  mutex g_mu;
  vector<Stats*>* g_stats;
  
  }  // namespace
  
  Stats::Stats(const char* name) : name_(name), elapsed_(0), cnt_(0) {
    unique_lock<mutex> lock(g_mu);
    if (g_stats == NULL)
      g_stats = new vector<Stats*>;
    g_stats->push_back(this);
  }
  
  void Stats::DumpTop() const {
    unique_lock<mutex> lock(mu_);
    if (detailed_.size() > 0) {
      vector<pair<string, StatsDetails>> details(detailed_.begin(),
                                                 detailed_.end());
      sort(details.begin(), details.end(),
           [](const pair<string, StatsDetails> a,
              const pair<string, StatsDetails> b) -> bool {
             return a.second.elapsed_ > b.second.elapsed_;
           });
  
      // Only print the top 10
      details.resize(min(details.size(), static_cast<size_t>(10)));
  
      if (!interesting_.empty()) {
        // No need to print anything out twice
        auto interesting = interesting_;
        for (auto& [n, detail] : details) {
          interesting.erase(n);
        }
  
        for (auto& name : interesting) {
          auto detail = detailed_.find(name);
          if (detail == detailed_.end()) {
            details.emplace_back(name, StatsDetails());
            continue;
          }
          details.emplace_back(*detail);
        }
      }
  
      int max_cnt_len = 1;
      for (auto& [name, detail] : details) {
        max_cnt_len =
            max(max_cnt_len, static_cast<int>(to_string(detail.cnt_).length()));
      }
  
      for (auto& [name, detail] : details) {
        LOG_STAT(" %6.3f / %*d %s", detail.elapsed_, max_cnt_len, detail.cnt_,
                 name.c_str());
      }
    }
  }
  
  string Stats::String() const {
    unique_lock<mutex> lock(mu_);
    if (!detailed_.empty())
      return StringPrintf("%s: %f / %d (%d unique)", name_, elapsed_, cnt_,
                          detailed_.size());
    return StringPrintf("%s: %f / %d", name_, elapsed_, cnt_);
  }
  
  double Stats::Start() {
    double start = GetTime();
    unique_lock<mutex> lock(mu_);
    cnt_++;
    return start;
  }
  
  double Stats::End(double start, const char* msg) {
    double e = GetTime() - start;
    unique_lock<mutex> lock(mu_);
    elapsed_ += e;
    if (msg != 0) {
      StatsDetails& details = detailed_[string(msg)];
      details.elapsed_ += e;
      details.cnt_++;
    }
    return e;
  }
  
  void Stats::MarkInteresting(const string& msg) {
    unique_lock<mutex> lock(mu_);
    interesting_.emplace(msg);
  }
  
  ScopedStatsRecorder::ScopedStatsRecorder(Stats* st, const char* msg)
      : st_(st), msg_(msg), start_time_(0) {
    if (!g_flags.enable_stat_logs)
      return;
    start_time_ = st_->Start();
  }
  
  ScopedStatsRecorder::~ScopedStatsRecorder() {
    if (!g_flags.enable_stat_logs)
      return;
    double e = st_->End(start_time_, msg_);
    if (msg_ && e > 3.0) {
      LOG_STAT("slow %s (%f): %s", st_->name_, e, msg_);
    }
  }
  
  void ReportAllStats() {
    if (!g_stats)
      return;
    for (Stats* st : *g_stats) {
      LOG_STAT("%s", st->String().c_str());
      st->DumpTop();
    }
    delete g_stats;
  
    LOG_STAT("%u find nodes", FindEmulator::GetNodeCount());
  }
  