// ComputeStatsForRange computes the stats for a given range by
// iterating over all key ranges for the given range that should
// be accounted for in its stats.
func ComputeStatsForRange(d *roachpb.RangeDescriptor, e engine.Engine, nowNanos int64) (engine.MVCCStats, error) {
iter := e.NewIterator(nil)
defer iter.Close()
ms := engine.MVCCStats{}
for _, r := range makeReplicatedKeyRanges(d) {
msDelta, err := iter.ComputeStats(r.start, r.end, nowNanos)
if err != nil {
return engine.MVCCStats{}, err
}
ms.Add(msDelta)
}
return ms, nil
}
// ComputeMVCCStats immediately computes correct total MVCC usage statistics
// for the store, returning the computed values (but without modifying the
// store).
func (s *Store) ComputeMVCCStats() (engine.MVCCStats, error) {
var totalStats engine.MVCCStats
var err error
visitor := newStoreRangeSet(s)
now := s.Clock().PhysicalNow()
visitor.Visit(func(r *Replica) bool {
var stats engine.MVCCStats
stats, err = ComputeStatsForRange(r.Desc(), s.Engine(), now)
if err != nil {
return false
}
totalStats.Add(stats)
return true
})
return totalStats, err
}