func()

in v1storage/storage.go [1603:1670]
54 lines of code
12 McCabe index (conditional complexity)

func (s *MemorySeriesStorage) maintainMemorySeries(
	fp model.Fingerprint, beforeTime model.Time,
) (becameDirty bool) {
	defer func(begin time.Time) {
		s.maintainSeriesDuration.WithLabelValues(maintainInMemory).Observe(
			time.Since(begin).Seconds(),
		)
	}(time.Now())

	s.fpLocker.Lock(fp)
	defer s.fpLocker.Unlock(fp)

	series, ok := s.fpToSeries.get(fp)
	if !ok {
		// Series is actually not in memory, perhaps archived or dropped in the meantime.
		return false
	}

	defer s.seriesOps.WithLabelValues(memoryMaintenance).Inc()

	closed, err := series.maybeCloseHeadChunk(s.headChunkTimeout)
	if err != nil {
		s.quarantineSeries(fp, series.metric, err)
		s.persistErrors.Inc()
	}
	if closed {
		s.incNumChunksToPersist(1)
		s.headChunks.Dec()
	}
	seriesWasDirty := series.dirty

	if s.writeMemorySeries(fp, series, beforeTime) {
		// Series is gone now, we are done.
		return false
	}

	iOldestNotEvicted := -1
	for i, cd := range series.chunkDescs {
		if !cd.IsEvicted() {
			iOldestNotEvicted = i
			break
		}
	}

	// Archive if all chunks are evicted. Also make sure the last sample has
	// an age of at least headChunkTimeout (which is very likely anyway).
	if iOldestNotEvicted == -1 && model.Now().Sub(series.lastTime) > s.headChunkTimeout {
		s.fpToSeries.del(fp)
		s.memorySeries.Dec()
		s.persistence.archiveMetric(fp, series.metric, series.firstTime(), series.lastTime)
		s.seriesOps.WithLabelValues(archive).Inc()
		oldWatermark := atomic.LoadInt64((*int64)(&s.archiveHighWatermark))
		if oldWatermark < int64(series.lastTime) {
			if !atomic.CompareAndSwapInt64(
				(*int64)(&s.archiveHighWatermark),
				oldWatermark, int64(series.lastTime),
			) {
				panic("s.archiveHighWatermark modified outside of maintainMemorySeries")
			}
		}
		return
	}
	// If we are here, the series is not archived, so check for chunk.Desc
	// eviction next.
	series.evictChunkDescs(iOldestNotEvicted)

	return series.dirty && !seriesWasDirty
}