func (r *ReplicationStats) UpdateReplicaStat(bucket string, n int64) {
	if r == nil {
		return
	}

	r.Lock()
	defer r.Unlock()
	bs, ok := r.Cache[bucket]
	if !ok {
		bs = newBucketReplicationStats()
	}
	bs.ReplicaSize += n
	bs.ReplicaCount++
	r.Cache[bucket] = bs
	r.srUpdateReplicaStat(n)
}

func (r *ReplicationStats) srUpdateReplicaStat(sz int64) {
	if r == nil {
		return
	}

	PendingCount int64 `json:"pendingReplicationCount"`
	// Total number of failed operations including metadata updates
	FailedCount int64 `json:"failedReplicationCount"`
}

func newBucketReplicationStats() *BucketReplicationStats {
	return &BucketReplicationStats{
		Stats: make(map[string]*BucketReplicationStat),
	}
}

// Empty returns true if there are no target stats