Move everything into a separate futatabi/ subdir, for the upcoming merge with Futatabi.

[nageru] / nageru / disk_space_estimator.cpp

diff --git a/nageru/disk_space_estimator.cpp b/nageru/disk_space_estimator.cpp
new file mode 100644 (file)
index 0000000..86e5e87
--- /dev/null
+++ b/nageru/disk_space_estimator.cpp
@@ -0,0 +1,64 @@
+#include "disk_space_estimator.h"
+
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <memory>
+
+#include "metrics.h"
+#include "timebase.h"
+
+DiskSpaceEstimator::DiskSpaceEstimator(DiskSpaceEstimator::callback_t callback)
+       : callback(callback)
+{
+       global_metrics.add("disk_free_bytes", &metric_disk_free_bytes, Metrics::TYPE_GAUGE);
+}
+
+void DiskSpaceEstimator::report_write(const std::string &filename, uint64_t pts)
+{
+       if (filename != last_filename) {
+               last_filename = filename;
+               measure_points.clear();
+       }
+
+       // Reject points that are out-of-order (happens with B-frames).
+       if (!measure_points.empty() && pts < measure_points.back().pts) {
+               return;
+       }
+
+       // Remove too old points.
+       while (measure_points.size() > 1 && measure_points.front().pts + window_length < pts) {
+               measure_points.pop_front();
+       }
+
+       struct stat st;
+       if (stat(filename.c_str(), &st) == -1) {
+               perror(filename.c_str());
+               return;
+       }
+
+       struct statfs fst;
+       if (statfs(filename.c_str(), &fst) == -1) {
+               perror(filename.c_str());
+               return;
+       }
+
+       off_t free_bytes = off_t(fst.f_bavail) * fst.f_frsize;
+       metric_disk_free_bytes = free_bytes;
+
+       if (!measure_points.empty()) {
+               double bytes_per_second = double(st.st_size - measure_points.front().size) /
+                       (pts - measure_points.front().pts) * TIMEBASE;
+               double seconds_left = free_bytes / bytes_per_second;
+
+               // Only report every second, since updating the UI can be expensive.
+               if (last_pts_reported == 0 || pts - last_pts_reported >= TIMEBASE) {
+                       callback(free_bytes, seconds_left);
+                       last_pts_reported = pts;
+               }
+       }
+
+       measure_points.push_back({ pts, st.st_size });
+}
+
+DiskSpaceEstimator *global_disk_space_estimator = nullptr;  // Created in MainWindow::MainWindow().