git.sesse.net Git - nageru/blob - disk_space_estimator.cpp

   1 #include "disk_space_estimator.h"
   2
   3 #include "timebase.h"
   4
   5 #include <memory>
   6 #include <stdio.h>
   7 #include <sys/stat.h>
   8 #include <sys/statfs.h>
   9
  10 DiskSpaceEstimator::DiskSpaceEstimator(DiskSpaceEstimator::callback_t callback)
  11         : callback(callback)
  12 {
  13 }
  14
  15 void DiskSpaceEstimator::report_write(const std::string &filename, size_t bytes, uint64_t pts)
  16 {
  17         // Reject points that are out-of-order (happens with B-frames).
  18         if (!measure_points.empty() && pts <= measure_points.back().pts) {
  19                 return;
  20         }
  21
  22         // Remove too old points.
  23         while (measure_points.size() > 1 && measure_points.front().pts + window_length < pts) {
  24                 measure_points.pop_front();
  25         }
  26
  27         total_size += bytes;
  28
  29         struct statfs fst;
  30         if (statfs(filename.c_str(), &fst) == -1) {
  31                 perror(filename.c_str());
  32                 return;
  33         }
  34
  35         off_t free_bytes = off_t(fst.f_bavail) * fst.f_frsize;
  36
  37         if (!measure_points.empty()) {
  38                 double bytes_per_second = double(total_size - measure_points.front().size) /
  39                         (pts - measure_points.front().pts) * TIMEBASE;
  40                 double seconds_left = free_bytes / bytes_per_second;
  41
  42                 // Only report every second, since updating the UI can be expensive.
  43                 if (last_pts_reported == 0 || pts - last_pts_reported >= TIMEBASE) {
  44                         callback(free_bytes, seconds_left);
  45                         last_pts_reported = pts;
  46                 }
  47         }
  48
  49         measure_points.push_back({ pts, total_size });
  50 }
  51
  52 DiskSpaceEstimator *global_disk_space_estimator = nullptr;  // Created in MainWindow::MainWindow().