frostfs-node/pkg/util/attributes/parser.go

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package attributes
import (
"errors"
"fmt"
"strings"
"github.com/nspcc-dev/neofs-api-go/v2/netmap"
)
const (
pairSeparator = "/"
keyValueSeparator = ":"
)
var (
errEmptyChain = errors.New("empty attribute chain")
errNonUniqueBucket = errors.New("attributes must contain unique keys")
errUnexpectedKey = errors.New("attributes contain unexpected key")
)
// ParseV2Attributes parses strings like "K1:V1/K2:V2/K3:V3" into netmap
// attributes.
func ParseV2Attributes(attrs []string, excl []string) ([]*netmap.Attribute, error) {
restricted := make(map[string]struct{}, len(excl))
for i := range excl {
restricted[excl[i]] = struct{}{}
}
cache := make(map[string]*netmap.Attribute, len(attrs))
for i := range attrs {
line := strings.Trim(attrs[i], pairSeparator)
chain := strings.Split(line, pairSeparator)
if len(chain) == 0 {
return nil, errEmptyChain
}
var parentKey string // backtrack parents in next pairs
for j := range chain {
pair := strings.Split(chain[j], keyValueSeparator)
if len(pair) != 2 {
return nil, fmt.Errorf("incorrect attribute pair %s", chain[j])
}
key := pair[0]
value := pair[1]
if at, ok := cache[key]; ok && at.GetValue() != value {
return nil, errNonUniqueBucket
}
if _, ok := restricted[key]; ok {
return nil, errUnexpectedKey
}
attribute := new(netmap.Attribute)
attribute.SetKey(key)
attribute.SetValue(value)
if parentKey != "" {
attribute.SetParents([]string{parentKey})
}
parentKey = key
cache[key] = attribute
}
}
result := make([]*netmap.Attribute, 0, len(cache))
for _, v := range cache {
result = append(result, v)
}
return result, nil
}