1 #include "frame_on_disk.h"
3 #include "shared/metrics.h"
12 using namespace std::chrono;
16 // There can be multiple FrameReader classes, so make all the metrics static.
17 once_flag frame_metrics_inited;
19 atomic<int64_t> metric_frame_opened_files{ 0 };
20 atomic<int64_t> metric_frame_closed_files{ 0 };
21 atomic<int64_t> metric_frame_read_bytes{ 0 };
22 atomic<int64_t> metric_frame_read_frames{ 0 };
24 Summary metric_frame_read_time_seconds;
28 FrameReader::FrameReader()
30 call_once(frame_metrics_inited, [] {
31 global_metrics.add("frame_opened_files", &metric_frame_opened_files);
32 global_metrics.add("frame_closed_files", &metric_frame_closed_files);
33 global_metrics.add("frame_read_bytes", &metric_frame_read_bytes);
34 global_metrics.add("frame_read_frames", &metric_frame_read_frames);
36 vector<double> quantiles{ 0.01, 0.1, 0.25, 0.5, 0.75, 0.9, 0.99 };
37 metric_frame_read_time_seconds.init(quantiles, 60.0);
38 global_metrics.add("frame_read_time_seconds", &metric_frame_read_time_seconds);
42 FrameReader::~FrameReader()
46 ++metric_frame_closed_files;
52 string read_string(int fd, size_t size, off_t offset)
56 size_t str_offset = 0;
57 while (str_offset < size) {
58 int ret = pread(fd, &str[str_offset], size - str_offset, offset + str_offset);
71 FrameReader::Frame FrameReader::read_frame(FrameOnDisk frame, bool read_audio)
73 steady_clock::time_point start = steady_clock::now();
75 if (int(frame.filename_idx) != last_filename_idx) {
77 close(fd); // Ignore errors.
78 ++metric_frame_closed_files;
83 lock_guard<mutex> lock(frame_mu);
84 filename = frame_filenames[frame.filename_idx];
87 fd = open(filename.c_str(), O_RDONLY);
89 perror(filename.c_str());
93 // We want readahead. (Ignore errors.)
94 posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL);
96 last_filename_idx = frame.filename_idx;
97 ++metric_frame_opened_files;
101 ret.video = read_string(fd, frame.size, frame.offset);
103 ret.audio = read_string(fd, frame.audio_size, frame.offset + frame.size);
106 steady_clock::time_point stop = steady_clock::now();
107 metric_frame_read_time_seconds.count_event(duration<double>(stop - start).count());
109 metric_frame_read_bytes += frame.size;
110 ++metric_frame_read_frames;