status-go/vendor/github.com/anacrolix/dht/v2/krpc/compact_helpers.go

85 lines
1.9 KiB
Go

package krpc
import (
"encoding"
"fmt"
"reflect"
"github.com/anacrolix/missinggo/slices"
"github.com/anacrolix/torrent/bencode"
)
func unmarshalBencodedBinary(u encoding.BinaryUnmarshaler, b []byte) (err error) {
var ub string
err = bencode.Unmarshal(b, &ub)
if err != nil {
return
}
return u.UnmarshalBinary([]byte(ub))
}
type elemSizer interface {
ElemSize() int
}
func unmarshalBinarySlice(slice elemSizer, b []byte) (err error) {
sliceValue := reflect.ValueOf(slice).Elem()
elemType := sliceValue.Type().Elem()
bytesPerElem := slice.ElemSize()
elem := reflect.New(elemType)
for len(b) != 0 {
if len(b) < bytesPerElem {
err = fmt.Errorf("%d trailing bytes < %d required for element", len(b), bytesPerElem)
break
}
if bu, ok := elem.Interface().(encoding.BinaryUnmarshaler); ok {
err = bu.UnmarshalBinary(b[:bytesPerElem])
} else if elem.Elem().Len() == bytesPerElem {
reflect.Copy(elem.Elem(), reflect.ValueOf(b[:bytesPerElem]))
} else {
err = fmt.Errorf("can't unmarshal %v bytes into %v", bytesPerElem, elem.Type())
}
if err != nil {
return
}
sliceValue.Set(reflect.Append(sliceValue, elem.Elem()))
b = b[bytesPerElem:]
}
return
}
func marshalBinarySlice(slice elemSizer) (ret []byte, err error) {
var elems []encoding.BinaryMarshaler
slices.MakeInto(&elems, slice)
for _, e := range elems {
var b []byte
b, err = e.MarshalBinary()
if err != nil {
return
}
if len(b) != slice.ElemSize() {
panic(fmt.Sprintf("marshalled %d bytes, but expected %d", len(b), slice.ElemSize()))
}
ret = append(ret, b...)
}
return
}
func bencodeBytesResult(b []byte, err error) ([]byte, error) {
if err != nil {
return b, err
}
return bencode.Marshal(b)
}
// returns position of x in v, or -1 if not found
func addrIndex(v []NodeAddr, x NodeAddr) int {
for i := 0; i < len(v); i += 1 {
if v[i].Equal(x) {
return i
}
}
return -1
}