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

   1 #include "shared/disk_space_estimator.h"
   2
   3 #include <memory>
   4 #include <stdio.h>
   5 #include <sys/stat.h>
   6 #include <sys/statfs.h>
   7
   8 #include "shared/metrics.h"
   9 #include "shared/timebase.h"
  10
  11 using namespace std;
  12
  13 DiskSpaceEstimator::DiskSpaceEstimator(DiskSpaceEstimator::callback_t callback)
  14         : callback(callback)
  15 {
  16         global_metrics.add("disk_free_bytes", &metric_disk_free_bytes, Metrics::TYPE_GAUGE);
  17 }
  18
  19 void DiskSpaceEstimator::report_write(const string &filename, off_t bytes, uint64_t pts)
  20 {
  21         total_size += bytes;
  22         report_write_internal(filename, total_size, pts);
  23 }
  24
  25 void DiskSpaceEstimator::report_append(const string &filename, uint64_t pts)
  26 {
  27         if (filename != last_filename) {
  28                 last_filename = filename;
  29                 measure_points.clear();
  30         }
  31
  32         struct stat st;
  33         if (stat(filename.c_str(), &st) == -1) {
  34                 perror(filename.c_str());
  35                 return;
  36         }
  37
  38         report_write_internal(filename, st.st_size, pts);
  39 }
  40
  41 void DiskSpaceEstimator::report_write_internal(const string &filename, off_t file_size, uint64_t pts)
  42 {
  43         if (measure_points.empty()) {
  44                 first_pts_this_file = pts;
  45         }
  46
  47         // Reject points that are out-of-order (happens with B-frames).
  48         if (!measure_points.empty() && pts <= measure_points.back().pts) {
  49                 return;
  50         }
  51
  52         // Remove too old points.
  53         while (measure_points.size() > 1 && measure_points.front().pts + window_length < pts) {
  54                 measure_points.pop_front();
  55         }
  56
  57         struct statfs fst;
  58         if (statfs(filename.c_str(), &fst) == -1) {
  59                 perror(filename.c_str());
  60                 return;
  61         }
  62
  63         off_t free_bytes = off_t(fst.f_bavail) * fst.f_frsize;
  64         metric_disk_free_bytes = free_bytes;
  65
  66         if (!measure_points.empty()) {
  67                 double bytes_per_second = double(file_size - measure_points.front().size) /
  68                         (pts - measure_points.front().pts) * TIMEBASE;
  69                 double seconds_left = free_bytes / bytes_per_second;
  70
  71                 // Only report every second, since updating the UI can be expensive.
  72                 if (last_pts_reported == 0 || pts - last_pts_reported >= TIMEBASE) {
  73                         callback(free_bytes, seconds_left, double(pts - first_pts_this_file) / TIMEBASE);
  74                         last_pts_reported = pts;
  75                 }
  76         }
  77
  78         measure_points.push_back({ pts, file_size });
  79 }
  80
  81 DiskSpaceEstimator *global_disk_space_estimator = nullptr;  // Created in MainWindow::MainWindow().