neo-go/pkg/wire/payload/transaction/Attribute.go
2019-02-25 22:44:14 +00:00

65 lines
1.5 KiB
Go

package transaction
import (
"errors"
"github.com/CityOfZion/neo-go/pkg/wire/util"
)
// Attribute represents a Transaction attribute.
type Attribute struct {
Usage AttrUsage
Data []byte
}
var (
ErrMaxData = errors.New("Max Size of Attribute reached")
)
const (
maxAttrSize = 65535
)
func (a *Attribute) Encode(bw *util.BinWriter) {
if len(a.Data) > maxAttrSize {
bw.Err = ErrMaxData
return
}
bw.Write(uint8(a.Usage))
if a.Usage == DescriptionURL || a.Usage == Vote || (a.Usage >= Hash1 && a.Usage <= Hash15) {
bw.Write(a.Data[:32])
} else if a.Usage == Script {
bw.Write(a.Data[:20])
} else if a.Usage == ECDH02 || a.Usage == ECDH03 {
bw.Write(a.Data[1:33])
} else if a.Usage == CertURL || a.Usage == DescriptionURL || a.Usage == Description || a.Usage >= Remark {
bw.VarUint(uint64(len(a.Data)))
bw.Write(a.Data)
} else {
bw.Write(a.Data)
}
}
func (a *Attribute) Decode(br *util.BinReader) {
br.Read(&a.Usage)
if a.Usage == DescriptionURL || a.Usage == Vote || a.Usage >= Hash1 && a.Usage <= Hash15 {
a.Data = make([]byte, 32)
br.Read(&a.Data)
} else if a.Usage == Script {
a.Data = make([]byte, 20)
br.Read(&a.Data)
} else if a.Usage == ECDH02 || a.Usage == ECDH03 {
a.Data = make([]byte, 32)
br.Read(&a.Data)
} else if a.Usage == CertURL || a.Usage == DescriptionURL || a.Usage == Description || a.Usage >= Remark {
lenData := br.VarUint()
a.Data = make([]byte, lenData)
br.Read(&a.Data)
} else {
br.Read(&a.Data)
}
}