diff options
| -rw-r--r-- | rlp/decode.go | 109 |
1 files changed, 61 insertions, 48 deletions
diff --git a/rlp/decode.go b/rlp/decode.go index 31485ee70..66830b89c 100644 --- a/rlp/decode.go +++ b/rlp/decode.go @@ -154,8 +154,6 @@ func decodeBigInt(s *Stream, val reflect.Value) error { return nil } -const maxInt = int(^uint(0) >> 1) - func makeListDecoder(typ reflect.Type) (decoder, error) { etype := typ.Elem() if etype.Kind() == reflect.Uint8 && !reflect.PtrTo(etype).Implements(decoderInterface) { @@ -169,55 +167,41 @@ func makeListDecoder(typ reflect.Type) (decoder, error) { if err != nil { return nil, err } - var maxLen = maxInt + if typ.Kind() == reflect.Array { - maxLen = typ.Len() - } - dec := func(s *Stream, val reflect.Value) error { - return decodeList(s, val, etypeinfo.decoder, maxLen) + return func(s *Stream, val reflect.Value) error { + return decodeListArray(s, val, etypeinfo.decoder) + }, nil } - return dec, nil + return func(s *Stream, val reflect.Value) error { + return decodeListSlice(s, val, etypeinfo.decoder) + }, nil } -// decodeList decodes RLP list elements into slices and arrays. -// -// The approach here is stolen from package json, although we differ -// in the semantics for arrays. package json discards remaining -// elements that would not fit into the array. We generate an error in -// this case because we'd be losing information. -func decodeList(s *Stream, val reflect.Value, elemdec decoder, maxelem int) error { +func decodeListSlice(s *Stream, val reflect.Value, elemdec decoder) error { size, err := s.List() if err != nil { return err } if size == 0 { - if val.Kind() == reflect.Slice { - val.Set(reflect.MakeSlice(val.Type(), 0, 0)) - } else { - zero(val, 0) - } + val.Set(reflect.MakeSlice(val.Type(), 0, 0)) return s.ListEnd() } i := 0 - for { - if i > maxelem { - return decodeError{"input list has too many elements", val.Type()} - } - if val.Kind() == reflect.Slice { - // grow slice if necessary - if i >= val.Cap() { - newcap := val.Cap() + val.Cap()/2 - if newcap < 4 { - newcap = 4 - } - newv := reflect.MakeSlice(val.Type(), val.Len(), newcap) - reflect.Copy(newv, val) - val.Set(newv) - } - if i >= val.Len() { - val.SetLen(i + 1) + for ; ; i++ { + // grow slice if necessary + if i >= val.Cap() { + newcap := val.Cap() + val.Cap()/2 + if newcap < 4 { + newcap = 4 } + newv := reflect.MakeSlice(val.Type(), val.Len(), newcap) + reflect.Copy(newv, val) + val.Set(newv) + } + if i >= val.Len() { + val.SetLen(i + 1) } // decode into element if err := elemdec(s, val.Index(i)); err == EOL { @@ -225,26 +209,54 @@ func decodeList(s *Stream, val reflect.Value, elemdec decoder, maxelem int) erro } else if err != nil { return err } - i++ } if i < val.Len() { - if val.Kind() == reflect.Array { - // zero the rest of the array. - zero(val, i) - } else { - val.SetLen(i) - } + val.SetLen(i) } return s.ListEnd() } +func decodeListArray(s *Stream, val reflect.Value, elemdec decoder) error { + size, err := s.List() + if err != nil { + return err + } + if size == 0 { + zero(val, 0) + return s.ListEnd() + } + + // The approach here is stolen from package json, although we differ + // in the semantics for arrays. package json discards remaining + // elements that would not fit into the array. We generate an error in + // this case because we'd be losing information. + vlen := val.Len() + i := 0 + for ; i < vlen; i++ { + if err := elemdec(s, val.Index(i)); err == EOL { + break + } else if err != nil { + return err + } + if i == vlen { + } + } + if i < vlen { + zero(val, i) + } + if err = s.ListEnd(); err == errNotAtEOL { + return decodeError{"input list has too many elements", val.Type()} + } + return err +} + func decodeByteSlice(s *Stream, val reflect.Value) error { kind, _, err := s.Kind() if err != nil { return err } if kind == List { - return decodeList(s, val, decodeUint, maxInt) + return decodeListSlice(s, val, decodeUint) } b, err := s.Bytes() if err == nil { @@ -276,14 +288,15 @@ func decodeByteArray(s *Stream, val reflect.Value) error { } zero(val, int(size)) case List: - return decodeList(s, val, decodeUint, val.Len()) + return decodeListArray(s, val, decodeUint) } return nil } func zero(val reflect.Value, start int) { z := reflect.Zero(val.Type().Elem()) - for i := start; i < val.Len(); i++ { + end := val.Len() + for i := start; i < end; i++ { val.Index(i).Set(z) } } @@ -358,7 +371,7 @@ func decodeInterface(s *Stream, val reflect.Value) error { } if kind == List { slice := reflect.New(ifsliceType).Elem() - if err := decodeList(s, slice, decodeInterface, maxInt); err != nil { + if err := decodeListSlice(s, slice, decodeInterface); err != nil { return err } val.Set(slice) |