FileObject MetricFileManager::readBatch()

in cloudwatch_metrics_common/src/utils/metric_file_manager.cpp [33:72]

• 35 lines of code
• 4 McCabe index (conditional complexity)

FileObject<MetricDatumCollection> MetricFileManager::readBatch(
    size_t batch_size) {
  /* We must sort the metric data chronologically because it is not guaranteed
     to be ordered chronologically in the file, but CloudWatch requires all
     puts in a single batch to be sorted chronologically */
  auto metric_comparison = [](const MetricDatum & metric1, const MetricDatum & metric2)
    { return metric1.GetTimestamp() < metric2.GetTimestamp(); };

  std::set<MetricDatum, decltype(metric_comparison)> metrics_set(metric_comparison);
  FileManagement::DataToken data_token;
  std::list<FileManagement::DataToken> data_tokens;
  AWS_LOG_INFO(__func__, "Reading Logbatch");
  size_t actual_batch_size = 0;

  for (size_t i = 0; i < batch_size; ++i) {
    std::string line;
    if (!file_manager_strategy_->isDataAvailable()) {
      AWS_LOG_DEBUG(__func__, "No more metric data available on disk");
      break;
    }
    data_token = read(line);
    Aws::String aws_line(line.c_str());
    MetricDatum metric_datum;
    try {
      metric_datum = Aws::CloudWatchMetrics::Utils::deserializeMetricDatum(aws_line);
    } catch (std::invalid_argument &e) {
      AWS_LOG_ERROR(__func__, e.what());
      continue;
    }
    actual_batch_size++;
    metrics_set.insert(metric_datum);
    data_tokens.push_back(data_token);
  }
  MetricDatumCollection metrics_data(metrics_set.begin(), metrics_set.end());
  FileObject<MetricDatumCollection> file_object;
  file_object.batch_data = metrics_data;
  file_object.batch_size = actual_batch_size;
  file_object.data_tokens = data_tokens;
  return file_object;
}