in v1storage/storage.go [851:887]
func (s *MemorySeriesStorage) metricForRange(
fp model.Fingerprint,
from, through model.Time,
) (model.Metric, *memorySeries, bool) {
series, ok := s.fpToSeries.get(fp)
if ok {
if series.lastTime.Before(from) || series.firstTime().After(through) {
return nil, nil, false
}
return series.metric, series, true
}
// From here on, we are only concerned with archived metrics.
// If the high watermark of archived series is before 'from', we are done.
watermark := model.Time(atomic.LoadInt64((*int64)(&s.archiveHighWatermark)))
if watermark < from {
return nil, nil, false
}
if from.After(model.Earliest) || through.Before(model.Latest) {
// The range lookup is relatively cheap, so let's do it first if
// we have a chance the archived metric is not in the range.
has, first, last := s.persistence.hasArchivedMetric(fp)
if !has {
s.nonExistentSeriesMatches.Inc()
return nil, nil, false
}
if first.After(through) || last.Before(from) {
return nil, nil, false
}
}
metric, err := s.persistence.archivedMetric(fp)
if err != nil {
// archivedMetric has already flagged the storage as dirty in this case.
return nil, nil, false
}
return metric, nil, true
}