diff --git a/rlp/decode.go b/rlp/decode.go index 565c84790..3546f6106 100644 --- a/rlp/decode.go +++ b/rlp/decode.go @@ -442,6 +442,15 @@ func NewStream(r io.Reader) *Stream { s.Reset(r) return s } + +// NewListStream creates a new stream that pretends to be positioned +// at an encoded list of the given length. +func NewListStream(r io.Reader, len uint64) *Stream { + s := new(Stream) + s.Reset(r) + s.kind = List + s.size = len + return s } // Bytes reads an RLP string and returns its contents as a byte slice. diff --git a/rlp/decode_test.go b/rlp/decode_test.go index 9d320564b..d82ccbd6a 100644 --- a/rlp/decode_test.go +++ b/rlp/decode_test.go @@ -54,6 +54,24 @@ func TestStreamKind(t *testing.T) { } } +func TestNewListStream(t *testing.T) { + ls := NewListStream(bytes.NewReader(unhex("0101010101")), 3) + if k, size, err := ls.Kind(); k != List || size != 3 || err != nil { + t.Errorf("Kind() returned (%v, %d, %v), expected (List, 3, nil)", k, size, err) + } + if size, err := ls.List(); size != 3 || err != nil { + t.Errorf("List() returned (%d, %v), expected (3, nil)", size, err) + } + for i := 0; i < 3; i++ { + if val, err := ls.Uint(); val != 1 || err != nil { + t.Errorf("Uint() returned (%d, %v), expected (1, nil)", val, err) + } + } + if err := ls.ListEnd(); err != nil { + t.Errorf("ListEnd() returned %v, expected (3, nil)", err) + } +} + func TestStreamErrors(t *testing.T) { type calls []string tests := []struct {