Golang enginepb.MVCCStats類代碼示例

// 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.Reader, nowNanos int64,
) (enginepb.MVCCStats, error) {
	iter := e.NewIterator(false)
	defer iter.Close()

	ms := enginepb.MVCCStats{}
	for _, r := range makeReplicatedKeyRanges(d) {
		msDelta, err := iter.ComputeStats(r.start, r.end, nowNanos)
		if err != nil {
			return enginepb.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() (enginepb.MVCCStats, error) {
	var totalStats enginepb.MVCCStats
	var err error

	now := s.Clock().PhysicalNow()
	newStoreReplicaVisitor(s).Visit(func(r *Replica) bool {
		var stats enginepb.MVCCStats
		stats, err = ComputeStatsForRange(r.Desc(), s.Engine(), now)
		if err != nil {
			return false
		}
		totalStats.Add(stats)
		return true
	})
	return totalStats, err
}

func copySeqCache(
	e engine.ReadWriter,
	ms *enginepb.MVCCStats,
	srcID, dstID roachpb.RangeID,
	keyMin, keyMax engine.MVCCKey,
) (int, error) {
	var scratch [64]byte
	var count int
	var meta enginepb.MVCCMetadata
	// TODO(spencer): look into making this an MVCCIteration and writing
	// the values using MVCC so we can avoid the ugliness of updating
	// the MVCCStats by hand below.
	err := e.Iterate(keyMin, keyMax,
		func(kv engine.MVCCKeyValue) (bool, error) {
			// Decode the key, skipping on error. Otherwise, write it to the
			// corresponding key in the new cache.
			txnID, err := decodeAbortCacheMVCCKey(kv.Key, scratch[:0])
			if err != nil {
				return false, errors.Errorf("could not decode an abort cache key %s: %s", kv.Key, err)
			}
			key := keys.AbortCacheKey(dstID, txnID)
			encKey := engine.MakeMVCCMetadataKey(key)
			// Decode the MVCCMetadata value.
			if err := proto.Unmarshal(kv.Value, &meta); err != nil {
				return false, errors.Errorf("could not decode mvcc metadata %s [% x]: %s", kv.Key, kv.Value, err)
			}
			value := engine.MakeValue(meta)
			value.ClearChecksum()
			value.InitChecksum(key)
			meta.RawBytes = value.RawBytes

			keyBytes, valBytes, err := engine.PutProto(e, encKey, &meta)
			if err != nil {
				return false, err
			}
			count++
			if ms != nil {
				ms.SysBytes += keyBytes + valBytes
				ms.SysCount++
			}
			return false, nil
		})
	return count, err
}

func (r *rocksDBIterator) ComputeStats(
	start, end MVCCKey, nowNanos int64,
) (enginepb.MVCCStats, error) {
	result := C.MVCCComputeStats(r.iter, goToCKey(start), goToCKey(end), C.int64_t(nowNanos))
	ms := enginepb.MVCCStats{}
	if err := statusToError(result.status); err != nil {
		return ms, err
	}
	ms.ContainsEstimates = false
	ms.LiveBytes = int64(result.live_bytes)
	ms.KeyBytes = int64(result.key_bytes)
	ms.ValBytes = int64(result.val_bytes)
	ms.IntentBytes = int64(result.intent_bytes)
	ms.LiveCount = int64(result.live_count)
	ms.KeyCount = int64(result.key_count)
	ms.ValCount = int64(result.val_count)
	ms.IntentCount = int64(result.intent_count)
	ms.IntentAge = int64(result.intent_age)
	ms.GCBytesAge = int64(result.gc_bytes_age)
	ms.SysBytes = int64(result.sys_bytes)
	ms.SysCount = int64(result.sys_count)
	ms.LastUpdateNanos = nowNanos
	return ms, nil
}