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

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