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/**
@file      stats.hpp
@brief     collect global statistics - static, partially thread-safe (see below)
@author    Robert van Engelen - engelen@genivia.com
@copyright (c) 2019-2022, Robert van Engelen, Genivia Inc. All rights reserved.
@copyright (c) BSD-3 License - see LICENSE.txt

Thread-safe functions:

Stats::found_file()
Stats::found_part()
Stats::found_files()
Stats::found_parts()
Stats::found_any_file()

*/

#ifndef STATS_HPP
#define STATS_HPP

#include "ugrep.hpp"

// static class to collect global statistics
class Stats {

 public:

  // reset stats
  static void reset()
  {
    files = 0;
    dirs = 0;
    fileno = 0;
    partno = 0;
    ignore.clear();
  }

  // score a file searched
  static void score_file()
  {
    ++files;
  }

  // score a directory searched
  static void score_dir()
  {
    ++dirs;
  }

  // number of files searched
  static size_t searched_files()
  {
    return files;
  }

  // number of directories visited
  static size_t searched_dirs()
  {
    return dirs;
  }

  // atomically update the number of matching files found, excluding files in archives returns true if max file matches (+ number of threads-1 when sorting) is not reached yet
  static bool found_file()
  {
    size_t n = fileno.fetch_add(1, std::memory_order_relaxed);
    return flag_max_files > 0 ? n < flag_max_files : true;
  }

  // atomically update the number of matching files found, including files in archives, returns true if max file matches (+ number of threads-1 when sorting) is not reached yet
  static bool found_part()
  {
    size_t n = partno.fetch_add(1, std::memory_order_relaxed);
    return flag_max_files > 0 ? n < flag_max_files : true;
  }

  // undo found_part
  static void undo_found_part()
  {
    partno.fetch_sub(1, std::memory_order_relaxed);
  }

  // the number of matching files found, excluding files in archives
  static size_t found_files()
  {
    size_t n = fileno.load(std::memory_order_relaxed);
    return flag_max_files > 0 ? std::min(n, flag_max_files) : n;
  }

  // the number of matching files found, including files in archives
  static size_t found_parts()
  {
    size_t n = partno.load(std::memory_order_relaxed);
    return flag_max_files > 0 ? std::min(n, flag_max_files) : n;
  }

  // any matching file was found
  static bool found_any_file()
  {
    return fileno > 0;
  }

  // a .gitignore or similar file was encountered
  static void ignore_file(const std::string& filename)
  {
    ignore.emplace_back(filename);
  }

  // report the statistics
  static void report(FILE *output);

 protected:

  static size_t                   files;  // number of files searched, excluding files in archives
  static size_t                   dirs;   // number of directories searched
  static std::atomic_size_t       fileno; // number of matching files, excluding files in archives, atomic for GrepWorker::search() update
  static std::atomic_size_t       partno; // number of matching files, including files in archives, atomic for GrepWorker::search() update
  static std::vector<std::string> ignore; // the .gitignore files encountered in the recursive search with --ignore-files

};

#endif
