Function GetPredicateValues

testutil/backup.go:137–187

GetPredicateValues reads the specified p directory and returns the values for the given attribute in a map.

(pdir, attr string, readTs uint64)

// GetPredicateValues reads the specified p directory and returns the values for the given
// attribute in a map.
func GetPredicateValues(pdir, attr string, readTs uint64) (map[string]string, error) {
	db, err := openDgraph(pdir)
	if err != nil {
		return nil, err
	}
	defer db.Close()

	values := make(map[string]string)

	txn := db.NewTransactionAt(readTs, false)
	defer txn.Discard()
	itr := txn.NewIterator(badger.DefaultIteratorOptions)
	defer itr.Close()

	for itr.Rewind(); itr.Valid(); itr.Next() {
		item := itr.Item()
		pk, err := x.Parse(item.Key())
		x.Check(err)
		switch {
		case pk.Attr != attr:
			continue
		case !pk.IsData():
			continue
		}

		pl, err := posting.ReadPostingList(item.Key(), itr)
		if err != nil {
			return nil, err
		}

		err = pl.Iterate(readTs, 0, func(p *pb.Posting) error {
			vID := types.TypeID(p.ValType)
			src := types.ValueForType(vID)
			src.Value = p.Value
			str, err := types.Convert(src, types.StringID)
			if err != nil {
				return err
			}
			value := str.Value.(string)
			values[fmt.Sprintf("%#x", pk.Uid)] = value

			return nil
		})

		if err != nil {
			return nil, err
		}
	}

	return values, err
}

type dataType int