ProgressBar.cpp

/*
 * Copyright (c) 2018 Trail of Bits, Inc.
 */

#include "mcsema/Util/ProgressBar.h"

#include <algorithm>
#include <cinttypes>
#include <cmath>
#include <cstdio>

namespace mcsema {
namespace {

static const auto kProgressBars = \
    "|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||";

static const double kNumProgressBars = 40;

static int NumDigits(uint64_t val) {
  if (!val) {
    return 1;
  } else {
    int num_digits = 0;
    while (val) {
      val /= 10;
      num_digits++;
    }
    return num_digits;
  }
}

}  // namespace

ProgressBar::ProgressBar(const char *label_, uint64_t max_num_steps_,
                         std::chrono::seconds report_freq_)
    : label(label_),
      max_num_steps(max_num_steps_),
      report_frequency(report_freq_),
      current_step(0),
      progress_reporter([=] (void) {
        do {
          Report();
          std::this_thread::sleep_for(report_frequency);
        } while (current_step.load(std::memory_order_acquire) < max_num_steps);
      }) {
  Report();
}

ProgressBar::~ProgressBar(void) {
  current_step.store(max_num_steps, std::memory_order_seq_cst);
  if (progress_reporter.joinable()) {
    progress_reporter.join();
  }
  Report();
  fprintf(stderr, "\n");
  fflush(stderr);
}

void ProgressBar::Advance(void) {
  current_step.fetch_add(1, std::memory_order_seq_cst);
}

void ProgressBar::Report(void) {
  const auto curr = current_step.load(std::memory_order_acquire);
  const auto steps_done = static_cast<double>(curr);
  const auto steps_total = static_cast<double>(max_num_steps);
  const auto percentage = std::min<double>(1.0, steps_done / steps_total);
  const auto lpad = percentage * kNumProgressBars;
  const auto rpad = kNumProgressBars - lpad;
  const auto num_digits = NumDigits(max_num_steps);
  fprintf(stderr, "\r%s (%*" PRIu64 " / %" PRIu64 ") %3d%% [%.*s%*s]  ",
          label, num_digits, curr, max_num_steps, static_cast<int>(percentage * 100.0),
          static_cast<int>(lpad), kProgressBars, static_cast<int>(rpad), "");
  fflush(stderr);
}

}  // namespace mcsema

ProgressBar.h

/*
 * Copyright (c) 2018 Trail of Bits, Inc.
 */

#pragma once

#include <atomic>
#include <chrono>
#include <cstdint>
#include <thread>

namespace mcsema {

class ProgressBar {
 public:
  ProgressBar(const char *label_, uint64_t max_num_steps_,
              std::chrono::seconds report_freq_);

  ~ProgressBar(void);

  void Advance(void);

 private:
  ProgressBar(void) = delete;

  void Report(void);

  const char * const label;
  const uint64_t max_num_steps;
  const std::chrono::seconds report_frequency;

  std::atomic<uint64_t> current_step;
  std::thread progress_reporter;
};

}  // namespace mcsema