Method getCachedShuffledSubring

pkg/ring/ring.go:946–972

(identifier string, size int, zoneStableSharding bool)

}

func (r *Ring) getCachedShuffledSubring(identifier string, size int, zoneStableSharding bool) *Ring {
	if r.cfg.SubringCacheDisabled {
		return nil
	}

	r.mtx.RLock()
	defer r.mtx.RUnlock()

	// if shuffledSubringCache map is nil, reading it returns default value (nil pointer).
	cached := r.shuffledSubringCache[subringCacheKey{identifier: identifier, shardSize: size, zoneStableSharding: zoneStableSharding}]
	if cached == nil {
		return nil
	}

	cached.mtx.Lock()
	defer cached.mtx.Unlock()

	// Update instance states and timestamps. We know that the topology is the same,
	// so zones and tokens are equal.
	for name, cachedIng := range cached.ringDesc.Ingesters {
		ing := r.ringDesc.Ingesters[name]
		cachedIng.State = ing.State
		cachedIng.Timestamp = ing.Timestamp
		cached.ringDesc.Ingesters[name] = cachedIng
	}
	return cached
}

func (r *Ring) setCachedShuffledSubring(identifier string, size int, zoneStableSharding bool, subring *Ring) {
	if subring == nil || r.cfg.SubringCacheDisabled {