collect method

@override Future<Iterable<MetricFamilySamples>> collect()

collect all metrics and samples that are part of this Collector.

Implementation

@override
Future<Iterable<MetricFamilySamples>> collect() async {
  return [
    MetricFamilySamples('dart_info', MetricType.gauge,
        'Information about the Dart environment.', [
      Sample('dart_info', const ['version'], [Platform.version], 1)
    ]),

    // TODO: Metrics about gc & co would be nice runtime metrics but are
    //  unavailable in the Dart VM.

    // TODO: We can only support a limited set of process metrics, as Dart
    //  doesn't expose more of them.

    MetricFamilySamples('process_resident_memory_bytes', MetricType.gauge,
        'Resident memory size in bytes.', [
      Sample('process_resident_memory_bytes', const [], const [],
          ProcessInfo.currentRss.toDouble())
    ]),

    MetricFamilySamples('process_start_time_seconds', MetricType.gauge,
        'Start time of the process since unix epoch in seconds.', [
      Sample('process_start_time_seconds', const [], const [],
          _startupTime.toDouble())
    ]),
  ];
}