func()

in v1storage/mapper.go [149:184]

• 33 lines of code
• 3 McCabe index (conditional complexity)

func (m *fpMapper) maybeAddMapping(
	fp model.Fingerprint,
	collidingMetric model.Metric,
) model.Fingerprint {
	ms := metricToUniqueString(collidingMetric)
	m.mtx.RLock()
	mappedFPs, ok := m.mappings[fp]
	m.mtx.RUnlock()
	if ok {
		// fp is locked by the caller, so no further locking required.
		mappedFP, ok := mappedFPs[ms]
		if ok {
			return mappedFP // Existing mapping.
		}
		// A new mapping has to be created.
		mappedFP = m.nextMappedFP()
		mappedFPs[ms] = mappedFP
		log.Infof(
			"Collision detected for fingerprint %v, metric %v, mapping to new fingerprint %v.",
			fp, collidingMetric, mappedFP,
		)
		return mappedFP
	}
	// This is the first collision for fp.
	mappedFP := m.nextMappedFP()
	mappedFPs = map[string]model.Fingerprint{ms: mappedFP}
	m.mtx.Lock()
	m.mappings[fp] = mappedFPs
	m.mappingsCounter.Inc()
	m.mtx.Unlock()
	log.Infof(
		"Collision detected for fingerprint %v, metric %v, mapping to new fingerprint %v.",
		fp, collidingMetric, mappedFP,
	)
	return mappedFP
}