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

   1 #include "disk_space_estimator.h"
   2
   3 #include <stdio.h>
   4 #include <sys/stat.h>
   5 #include <sys/statfs.h>
   6 #include <memory>
   7
   8 #include "timebase.h"
   9
  10 DiskSpaceEstimator::DiskSpaceEstimator(DiskSpaceEstimator::callback_t callback)
  11         : callback(callback)
  12 {
  13 }
  14
  15 void DiskSpaceEstimator::report_write(const std::string &filename, uint64_t pts)
  16 {
  17         if (filename != last_filename) {
  18                 last_filename = filename;
  19                 measure_points.clear();
  20         }
  21
  22         // Reject points that are out-of-order (happens with B-frames).
  23         if (!measure_points.empty() && pts < measure_points.back().pts) {
  24                 return;
  25         }
  26
  27         // Remove too old points.
  28         while (measure_points.size() > 1 && measure_points.front().pts + window_length < pts) {
  29                 measure_points.pop_front();
  30         }
  31
  32         struct stat st;
  33         if (stat(filename.c_str(), &st) == -1) {
  34                 perror(filename.c_str());
  35                 return;
  36         }
  37
  38         struct statfs fst;
  39         if (statfs(filename.c_str(), &fst) == -1) {
  40                 perror(filename.c_str());
  41                 return;
  42         }
  43
  44         if (!measure_points.empty()) {
  45                 off_t free_bytes = off_t(fst.f_bavail) * fst.f_frsize;
  46                 double bytes_per_second = double(st.st_size - measure_points.front().size) /
  47                         (pts - measure_points.front().pts) * TIMEBASE;
  48                 double seconds_left = free_bytes / bytes_per_second;
  49                 callback(free_bytes, seconds_left);
  50         }
  51
  52         measure_points.push_back({ pts, st.st_size });
  53 }
  54
  55 DiskSpaceEstimator *global_disk_space_estimator = nullptr;  // Created in MainWindow::MainWindow().