frostfs-node/pkg/local_object_storage/pilorama/meta.go

91 lines
1.8 KiB
Go
Raw Normal View History

package pilorama
import "github.com/nspcc-dev/neo-go/pkg/io"
func (x *Meta) FromBytes(data []byte) error {
if len(data) == 0 {
x.Items = nil
x.Time = 0
return nil
}
r := io.NewBinReaderFromBuf(data)
x.DecodeBinary(r)
return r.Err
}
func (x Meta) Bytes() []byte {
w := io.NewBufBinWriter()
x.EncodeBinary(w.BinWriter)
return w.Bytes()
}
func (x Meta) GetAttr(name string) []byte {
return findAttr(x.Items, name)
}
func findAttr(ms []KeyValue, name string) []byte {
for _, kv := range ms {
if kv.Key == name {
return kv.Value
}
}
return nil
}
// DecodeBinary implements the io.Serializable interface.
func (x *Meta) DecodeBinary(r *io.BinReader) {
ts := r.ReadVarUint()
size := r.ReadVarUint()
m := make([]KeyValue, size)
for i := range m {
m[i].Key = r.ReadString()
m[i].Value = r.ReadVarBytes()
}
if r.Err != nil {
return
}
x.Time = ts
x.Items = m
}
// EncodeBinary implements the io.Serializable interface.
func (x Meta) EncodeBinary(w *io.BinWriter) {
w.WriteVarUint(x.Time)
w.WriteVarUint(uint64(len(x.Items)))
for _, e := range x.Items {
w.WriteString(e.Key)
w.WriteVarBytes(e.Value)
}
}
// Size returns size of x in bytes.
func (x Meta) Size() int {
size := getVarIntSize(x.Time)
size += getVarIntSize(uint64(len(x.Items)))
for i := range x.Items {
ln := len(x.Items[i].Key)
size += getVarIntSize(uint64(ln)) + ln
ln = len(x.Items[i].Value)
size += getVarIntSize(uint64(ln)) + ln
}
return size
}
// getVarIntSize returns the size in number of bytes of a variable integer.
// (reference: GetVarSize(int value), https://github.com/neo-project/neo/blob/master/neo/IO/Helper.cs)
func getVarIntSize(value uint64) int {
var size int
if value < 0xFD {
size = 1 // unit8
} else if value <= 0xFFFF {
size = 3 // byte + uint16
} else {
size = 5 // byte + uint32
}
return size
}