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;
50 string FrameReader::read_frame(FrameOnDisk frame)
52 steady_clock::time_point start = steady_clock::now();
54 if (int(frame.filename_idx) != last_filename_idx) {
56 close(fd); // Ignore errors.
57 ++metric_frame_closed_files;
62 lock_guard<mutex> lock(frame_mu);
63 filename = frame_filenames[frame.filename_idx];
66 fd = open(filename.c_str(), O_RDONLY);
68 perror(filename.c_str());
72 // We want readahead. (Ignore errors.)
73 posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL);
75 last_filename_idx = frame.filename_idx;
76 ++metric_frame_opened_files;
80 str.resize(frame.size);
82 while (offset < frame.size) {
83 int ret = pread(fd, &str[offset], frame.size - offset, frame.offset + offset);
92 steady_clock::time_point stop = steady_clock::now();
93 metric_frame_read_time_seconds.count_event(duration<double>(stop - start).count());
95 metric_frame_read_bytes += frame.size;
96 ++metric_frame_read_frames;