From 74266d5bbd95ac07882b09230aec876bf7704f69 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Thu, 13 Nov 2014 20:31:48 +0100
Subject: rlp: new package for streaming RLP decoder

---
 rlp/decode.go | 666 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 666 insertions(+)
 create mode 100644 rlp/decode.go

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
new file mode 100644
index 000000000..1a51e7130
--- /dev/null
+++ b/rlp/decode.go
@@ -0,0 +1,666 @@
+package rlp
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"reflect"
+)
+
+var (
+	errNoPointer     = errors.New("rlp: interface given to Decode must be a pointer")
+	errDecodeIntoNil = errors.New("rlp: pointer given to Decode must not be nil")
+)
+
+// Decoder is implemented by types that require custom RLP
+// decoding rules or need to decode into private fields.
+//
+// The DecodeRLP method should read one value from the given
+// Stream. It is not forbidden to read less or more, but it might
+// be confusing.
+type Decoder interface {
+	DecodeRLP(*Stream) error
+}
+
+// Decode parses RLP-encoded data from r and stores the result
+// in the value pointed to by val. Val must be a non-nil pointer.
+//
+// Decode uses the following type-dependent decoding rules:
+//
+// If the type implements the Decoder interface, decode calls
+// DecodeRLP.
+//
+// To decode into a pointer, Decode will set the pointer to nil if the
+// input has size zero or the input is a single byte with value zero.
+// If the input has nonzero size, Decode will allocate a new value of
+// the type being pointed to.
+//
+// To decode into a struct, Decode expects the input to be an RLP
+// list. The decoded elements of the list are assigned to each public
+// field in the order given by the struct's definition. If the input
+// list has too few elements, no error is returned and the remaining
+// fields will have the zero value.
+// Recursive struct types are supported.
+//
+// To decode into a slice, the input must be a list and the resulting
+// slice will contain the input elements in order.
+// As a special case, if the slice has a byte-size element type, the input
+// can also be an RLP string.
+//
+// To decode into a Go string, the input must be an RLP string. The
+// bytes are taken as-is and will not necessarily be valid UTF-8.
+//
+// To decode into an integer type, the input must also be an RLP
+// string. The bytes are interpreted as a big endian representation of
+// the integer. If the RLP string is larger than the bit size of the
+// type, Decode will return an error. Decode also supports *big.Int.
+// There is no size limit for big integers.
+//
+// To decode into an interface value, Decode stores one of these
+// in the value:
+//
+//	[]interface{}, for RLP lists
+//	[]byte, for RLP strings
+//
+// Non-empty interface types are not supported, nor are bool, float32,
+// float64, maps, channel types and functions.
+func Decode(r ByteReader, val interface{}) error {
+	return NewStream(r).Decode(val)
+}
+
+func makeNumDecoder(typ reflect.Type) decoder {
+	kind := typ.Kind()
+	switch {
+	case kind <= reflect.Int64:
+		return decodeInt
+	case kind <= reflect.Uint64:
+		return decodeUint
+	default:
+		panic("fallthrough")
+	}
+}
+
+func decodeInt(s *Stream, val reflect.Value) error {
+	num, err := s.uint(val.Type().Bits())
+	if err != nil {
+		return err
+	}
+	val.SetInt(int64(num))
+	return nil
+}
+
+func decodeUint(s *Stream, val reflect.Value) error {
+	num, err := s.uint(val.Type().Bits())
+	if err != nil {
+		return err
+	}
+	val.SetUint(num)
+	return nil
+}
+
+func decodeString(s *Stream, val reflect.Value) error {
+	b, err := s.Bytes()
+	if err != nil {
+		return err
+	}
+	val.SetString(string(b))
+	return nil
+}
+
+func decodeBigIntNoPtr(s *Stream, val reflect.Value) error {
+	return decodeBigInt(s, val.Addr())
+}
+
+func decodeBigInt(s *Stream, val reflect.Value) error {
+	b, err := s.Bytes()
+	if err != nil {
+		return err
+	}
+	i := val.Interface().(*big.Int)
+	if i == nil {
+		i = new(big.Int)
+		val.Set(reflect.ValueOf(i))
+	}
+	i.SetBytes(b)
+	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) {
+		if typ.Kind() == reflect.Array {
+			return decodeByteArray, nil
+		} else {
+			return decodeByteSlice, nil
+		}
+	}
+	etypeinfo, err := cachedTypeInfo1(etype)
+	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 dec, 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 {
+	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)
+		}
+		return s.ListEnd()
+	}
+
+	i := 0
+	for {
+		if i > maxelem {
+			return fmt.Errorf("rlp: input List has more than %d elements", maxelem)
+		}
+		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)
+			}
+		}
+		// decode into element
+		if err := elemdec(s, val.Index(i)); err == EOL {
+			break
+		} 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)
+		}
+	}
+	return s.ListEnd()
+}
+
+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)
+	}
+	b, err := s.Bytes()
+	if err == nil {
+		val.SetBytes(b)
+	}
+	return err
+}
+
+var errStringDoesntFitArray = errors.New("rlp: string value doesn't fit into target array")
+
+func decodeByteArray(s *Stream, val reflect.Value) error {
+	kind, size, err := s.Kind()
+	if err != nil {
+		return err
+	}
+	switch kind {
+	case Byte:
+		if val.Len() == 0 {
+			return errStringDoesntFitArray
+		}
+		bv, _ := s.Uint()
+		val.Index(0).SetUint(bv)
+		zero(val, 1)
+	case String:
+		if uint64(val.Len()) < size {
+			return errStringDoesntFitArray
+		}
+		slice := val.Slice(0, int(size)).Interface().([]byte)
+		if err := s.readFull(slice); err != nil {
+			return err
+		}
+		zero(val, int(size))
+	case List:
+		return decodeList(s, val, decodeUint, val.Len())
+	}
+	return nil
+}
+
+func zero(val reflect.Value, start int) {
+	z := reflect.Zero(val.Type().Elem())
+	for i := start; i < val.Len(); i++ {
+		val.Index(i).Set(z)
+	}
+}
+
+type field struct {
+	index int
+	info  *typeinfo
+}
+
+func makeStructDecoder(typ reflect.Type) (decoder, error) {
+	var fields []field
+	for i := 0; i < typ.NumField(); i++ {
+		if f := typ.Field(i); f.PkgPath == "" { // exported
+			info, err := cachedTypeInfo1(f.Type)
+			if err != nil {
+				return nil, err
+			}
+			fields = append(fields, field{i, info})
+		}
+	}
+	dec := func(s *Stream, val reflect.Value) (err error) {
+		if _, err = s.List(); err != nil {
+			return err
+		}
+		for _, f := range fields {
+			err = f.info.decoder(s, val.Field(f.index))
+			if err == EOL {
+				// too few elements. leave the rest at their zero value.
+				break
+			} else if err != nil {
+				return err
+			}
+		}
+		if err = s.ListEnd(); err == errNotAtEOL {
+			err = errors.New("rlp: input List has too many elements")
+		}
+		return err
+	}
+	return dec, nil
+}
+
+func makePtrDecoder(typ reflect.Type) (decoder, error) {
+	etype := typ.Elem()
+	etypeinfo, err := cachedTypeInfo1(etype)
+	if err != nil {
+		return nil, err
+	}
+	dec := func(s *Stream, val reflect.Value) (err error) {
+		_, size, err := s.Kind()
+		if err != nil || size == 0 && s.byteval == 0 {
+			return err
+		}
+		newval := val
+		if val.IsNil() {
+			newval = reflect.New(etype)
+		}
+		if err = etypeinfo.decoder(s, newval.Elem()); err == nil {
+			val.Set(newval)
+		}
+		return err
+	}
+	return dec, nil
+}
+
+var ifsliceType = reflect.TypeOf([]interface{}{})
+
+func decodeInterface(s *Stream, val reflect.Value) error {
+	kind, _, err := s.Kind()
+	if err != nil {
+		return err
+	}
+	if kind == List {
+		slice := reflect.New(ifsliceType).Elem()
+		if err := decodeList(s, slice, decodeInterface, maxInt); err != nil {
+			return err
+		}
+		val.Set(slice)
+	} else {
+		b, err := s.Bytes()
+		if err != nil {
+			return err
+		}
+		val.Set(reflect.ValueOf(b))
+	}
+	return nil
+}
+
+// This decoder is used for non-pointer values of types
+// that implement the Decoder interface using a pointer receiver.
+func decodeDecoderNoPtr(s *Stream, val reflect.Value) error {
+	return val.Addr().Interface().(Decoder).DecodeRLP(s)
+}
+
+func decodeDecoder(s *Stream, val reflect.Value) error {
+	// Decoder instances are not handled using the pointer rule if the type
+	// implements Decoder with pointer receiver (i.e. always)
+	// because it might handle empty values specially.
+	// We need to allocate one here in this case, like makePtrDecoder does.
+	if val.Kind() == reflect.Ptr && val.IsNil() {
+		val.Set(reflect.New(val.Type().Elem()))
+	}
+	return val.Interface().(Decoder).DecodeRLP(s)
+}
+
+// Kind represents the kind of value contained in an RLP stream.
+type Kind int
+
+const (
+	Byte Kind = iota
+	String
+	List
+)
+
+func (k Kind) String() string {
+	switch k {
+	case Byte:
+		return "Byte"
+	case String:
+		return "String"
+	case List:
+		return "List"
+	default:
+		return fmt.Sprintf("Unknown(%d)", k)
+	}
+}
+
+var (
+	// EOL is returned when the end of the current list
+	// has been reached during streaming.
+	EOL = errors.New("rlp: end of list")
+
+	// Other errors
+	ErrExpectedString = errors.New("rlp: expected String or Byte")
+	ErrExpectedList   = errors.New("rlp: expected List")
+	ErrElemTooLarge   = errors.New("rlp: element is larger than containing list")
+
+	// internal errors
+	errNotInList = errors.New("rlp: call of ListEnd outside of any list")
+	errNotAtEOL  = errors.New("rlp: call of ListEnd not positioned at EOL")
+)
+
+// ByteReader must be implemented by any input reader for a Stream. It
+// is implemented by e.g. bufio.Reader and bytes.Reader.
+type ByteReader interface {
+	io.Reader
+	io.ByteReader
+}
+
+// Stream can be used for piecemeal decoding of an input stream. This
+// is useful if the input is very large or if the decoding rules for a
+// type depend on the input structure. Stream does not keep an
+// internal buffer. After decoding a value, the input reader will be
+// positioned just before the type information for the next value.
+//
+// When decoding a list and the input position reaches the declared
+// length of the list, all operations will return error EOL.
+// The end of the list must be acknowledged using ListEnd to continue
+// reading the enclosing list.
+//
+// Stream is not safe for concurrent use.
+type Stream struct {
+	r       ByteReader
+	uintbuf []byte
+
+	kind    Kind   // kind of value ahead
+	size    uint64 // size of value ahead
+	byteval byte   // value of single byte in type tag
+	stack   []listpos
+}
+
+type listpos struct{ pos, size uint64 }
+
+func NewStream(r ByteReader) *Stream {
+	return &Stream{r: r, uintbuf: make([]byte, 8), kind: -1}
+}
+
+// Bytes reads an RLP string and returns its contents as a byte slice.
+// If the input does not contain an RLP string, the returned
+// error will be ErrExpectedString.
+func (s *Stream) Bytes() ([]byte, error) {
+	kind, size, err := s.Kind()
+	if err != nil {
+		return nil, err
+	}
+	switch kind {
+	case Byte:
+		s.kind = -1 // rearm Kind
+		return []byte{s.byteval}, nil
+	case String:
+		b := make([]byte, size)
+		if err = s.readFull(b); err != nil {
+			return nil, err
+		}
+		return b, nil
+	default:
+		return nil, ErrExpectedString
+	}
+}
+
+// Uint reads an RLP string of up to 8 bytes and returns its contents
+// as an unsigned integer. If the input does not contain an RLP string, the
+// returned error will be ErrExpectedString.
+func (s *Stream) Uint() (uint64, error) {
+	return s.uint(64)
+}
+
+func (s *Stream) uint(maxbits int) (uint64, error) {
+	kind, size, err := s.Kind()
+	if err != nil {
+		return 0, err
+	}
+	switch kind {
+	case Byte:
+		s.kind = -1 // rearm Kind
+		return uint64(s.byteval), nil
+	case String:
+		if size > uint64(maxbits/8) {
+			return 0, fmt.Errorf("rlp: string is larger than %d bits", maxbits)
+		}
+		return s.readUint(byte(size))
+	default:
+		return 0, ErrExpectedString
+	}
+}
+
+// List starts decoding an RLP list. If the input does not contain a
+// list, the returned error will be ErrExpectedList. When the list's
+// end has been reached, any Stream operation will return EOL.
+func (s *Stream) List() (size uint64, err error) {
+	kind, size, err := s.Kind()
+	if err != nil {
+		return 0, err
+	}
+	if kind != List {
+		return 0, ErrExpectedList
+	}
+	s.stack = append(s.stack, listpos{0, size})
+	s.kind = -1
+	s.size = 0
+	return size, nil
+}
+
+// ListEnd returns to the enclosing list.
+// The input reader must be positioned at the end of a list.
+func (s *Stream) ListEnd() error {
+	if len(s.stack) == 0 {
+		return errNotInList
+	}
+	tos := s.stack[len(s.stack)-1]
+	if tos.pos != tos.size {
+		return errNotAtEOL
+	}
+	s.stack = s.stack[:len(s.stack)-1] // pop
+	if len(s.stack) > 0 {
+		s.stack[len(s.stack)-1].pos += tos.size
+	}
+	s.kind = -1
+	s.size = 0
+	return nil
+}
+
+// Decode decodes a value and stores the result in the value pointed
+// to by val. Please see the documentation for the Decode function
+// to learn about the decoding rules.
+func (s *Stream) Decode(val interface{}) error {
+	if val == nil {
+		return errDecodeIntoNil
+	}
+	rval := reflect.ValueOf(val)
+	rtyp := rval.Type()
+	if rtyp.Kind() != reflect.Ptr {
+		return errNoPointer
+	}
+	if rval.IsNil() {
+		return errDecodeIntoNil
+	}
+	info, err := cachedTypeInfo(rtyp.Elem())
+	if err != nil {
+		return err
+	}
+	return info.decoder(s, rval.Elem())
+}
+
+// Kind returns the kind and size of the next value in the
+// input stream.
+//
+// The returned size is the number of bytes that make up the value.
+// For kind == Byte, the size is zero because the value is
+// contained in the type tag.
+//
+// The first call to Kind will read size information from the input
+// reader and leave it positioned at the start of the actual bytes of
+// the value. Subsequent calls to Kind (until the value is decoded)
+// will not advance the input reader and return cached information.
+func (s *Stream) Kind() (kind Kind, size uint64, err error) {
+	var tos *listpos
+	if len(s.stack) > 0 {
+		tos = &s.stack[len(s.stack)-1]
+	}
+	if s.kind < 0 {
+		if tos != nil && tos.pos == tos.size {
+			return 0, 0, EOL
+		}
+		kind, size, err = s.readKind()
+		if err != nil {
+			return 0, 0, err
+		}
+		s.kind, s.size = kind, size
+	}
+	if tos != nil && tos.pos+s.size > tos.size {
+		return 0, 0, ErrElemTooLarge
+	}
+	return s.kind, s.size, nil
+}
+
+func (s *Stream) readKind() (kind Kind, size uint64, err error) {
+	b, err := s.readByte()
+	if err != nil {
+		return 0, 0, err
+	}
+	s.byteval = 0
+	switch {
+	case b < 0x80:
+		// For a single byte whose value is in the [0x00, 0x7F] range, that byte
+		// is its own RLP encoding.
+		s.byteval = b
+		return Byte, 0, nil
+	case b < 0xB8:
+		// Otherwise, if a string is 0-55 bytes long,
+		// the RLP encoding consists of a single byte with value 0x80 plus the
+		// length of the string followed by the string. The range of the first
+		// byte is thus [0x80, 0xB7].
+		return String, uint64(b - 0x80), nil
+	case b < 0xC0:
+		// If a string is more than 55 bytes long, the
+		// RLP encoding consists of a single byte with value 0xB7 plus the length
+		// of the length of the string in binary form, followed by the length of
+		// the string, followed by the string. For example, a length-1024 string
+		// would be encoded as 0xB90400 followed by the string. The range of
+		// the first byte is thus [0xB8, 0xBF].
+		size, err = s.readUint(b - 0xB7)
+		return String, size, err
+	case b < 0xF8:
+		// If the total payload of a list
+		// (i.e. the combined length of all its items) is 0-55 bytes long, the
+		// RLP encoding consists of a single byte with value 0xC0 plus the length
+		// of the list followed by the concatenation of the RLP encodings of the
+		// items. The range of the first byte is thus [0xC0, 0xF7].
+		return List, uint64(b - 0xC0), nil
+	default:
+		// If the total payload of a list is more than 55 bytes long,
+		// the RLP encoding consists of a single byte with value 0xF7
+		// plus the length of the length of the payload in binary
+		// form, followed by the length of the payload, followed by
+		// the concatenation of the RLP encodings of the items. The
+		// range of the first byte is thus [0xF8, 0xFF].
+		size, err = s.readUint(b - 0xF7)
+		return List, size, err
+	}
+}
+
+func (s *Stream) readUint(size byte) (uint64, error) {
+	if size == 1 {
+		b, err := s.readByte()
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return uint64(b), err
+	}
+	start := int(8 - size)
+	for i := 0; i < start; i++ {
+		s.uintbuf[i] = 0
+	}
+	err := s.readFull(s.uintbuf[start:])
+	return binary.BigEndian.Uint64(s.uintbuf), err
+}
+
+func (s *Stream) readFull(buf []byte) (err error) {
+	s.willRead(uint64(len(buf)))
+	var nn, n int
+	for n < len(buf) && err == nil {
+		nn, err = s.r.Read(buf[n:])
+		n += nn
+	}
+	if err == io.EOF {
+		err = io.ErrUnexpectedEOF
+	}
+	return err
+}
+
+func (s *Stream) readByte() (byte, error) {
+	s.willRead(1)
+	b, err := s.r.ReadByte()
+	if len(s.stack) > 0 && err == io.EOF {
+		err = io.ErrUnexpectedEOF
+	}
+	return b, err
+}
+
+func (s *Stream) willRead(n uint64) {
+	s.kind = -1 // rearm Kind
+	if len(s.stack) > 0 {
+		s.stack[len(s.stack)-1].pos += n
+	}
+}
-- 
cgit v1.2.3


From bd0a50fdc3550eba979b132a92960f1e08110033 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Mon, 17 Nov 2014 12:02:08 +0100
Subject: rlp: fix pointer reuse

---
 rlp/decode.go | 1 +
 1 file changed, 1 insertion(+)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 1a51e7130..96d912f56 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -309,6 +309,7 @@ func makePtrDecoder(typ reflect.Type) (decoder, error) {
 	dec := func(s *Stream, val reflect.Value) (err error) {
 		_, size, err := s.Kind()
 		if err != nil || size == 0 && s.byteval == 0 {
+			val.Set(reflect.Zero(typ)) // set to nil
 			return err
 		}
 		newval := val
-- 
cgit v1.2.3


From 5a5560f1051b51fae34e799ee8d2dfd8d1094e09 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Mon, 24 Nov 2014 19:01:25 +0100
Subject: rlp: add Stream.Reset and accept any reader (for p2p)

---
 rlp/decode.go | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 96d912f56..565c84790 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -1,6 +1,7 @@
 package rlp
 
 import (
+	"bufio"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -24,8 +25,9 @@ type Decoder interface {
 	DecodeRLP(*Stream) error
 }
 
-// Decode parses RLP-encoded data from r and stores the result
-// in the value pointed to by val. Val must be a non-nil pointer.
+// Decode parses RLP-encoded data from r and stores the result in the
+// value pointed to by val. Val must be a non-nil pointer. If r does
+// not implement ByteReader, Decode will do its own buffering.
 //
 // Decode uses the following type-dependent decoding rules:
 //
@@ -66,7 +68,7 @@ type Decoder interface {
 //
 // Non-empty interface types are not supported, nor are bool, float32,
 // float64, maps, channel types and functions.
-func Decode(r ByteReader, val interface{}) error {
+func Decode(r io.Reader, val interface{}) error {
 	return NewStream(r).Decode(val)
 }
 
@@ -432,8 +434,14 @@ type Stream struct {
 
 type listpos struct{ pos, size uint64 }
 
-func NewStream(r ByteReader) *Stream {
-	return &Stream{r: r, uintbuf: make([]byte, 8), kind: -1}
+// NewStream creates a new stream reading from r.
+// If r does not implement ByteReader, the Stream will
+// introduce its own buffering.
+func NewStream(r io.Reader) *Stream {
+	s := new(Stream)
+	s.Reset(r)
+	return s
+}
 }
 
 // Bytes reads an RLP string and returns its contents as a byte slice.
@@ -543,6 +551,23 @@ func (s *Stream) Decode(val interface{}) error {
 	return info.decoder(s, rval.Elem())
 }
 
+// Reset discards any information about the current decoding context
+// and starts reading from r. If r does not also implement ByteReader,
+// Stream will do its own buffering.
+func (s *Stream) Reset(r io.Reader) {
+	bufr, ok := r.(ByteReader)
+	if !ok {
+		bufr = bufio.NewReader(r)
+	}
+	s.r = bufr
+	s.stack = s.stack[:0]
+	s.size = 0
+	s.kind = -1
+	if s.uintbuf == nil {
+		s.uintbuf = make([]byte, 8)
+	}
+}
+
 // Kind returns the kind and size of the next value in the
 // input stream.
 //
-- 
cgit v1.2.3


From 205af02a1f13f6712a8f30538ddf31cf0544c8d9 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Mon, 24 Nov 2014 19:02:04 +0100
Subject: rlp: add NewListStream (for p2p)

---
 rlp/decode.go | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'rlp/decode.go')

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.
-- 
cgit v1.2.3


From f816fdcb692d64cd5196b08c678550060e7e7df7 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 25 Nov 2014 16:00:48 +0100
Subject: rlp: include target type in decoder error messages

---
 rlp/decode.go | 37 ++++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 11 deletions(-)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 3546f6106..7d95af02b 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -72,6 +72,15 @@ func Decode(r io.Reader, val interface{}) error {
 	return NewStream(r).Decode(val)
 }
 
+type decodeError struct {
+	msg string
+	typ reflect.Type
+}
+
+func (err decodeError) Error() string {
+	return fmt.Sprintf("rlp: %s for %v", err.msg, err.typ)
+}
+
 func makeNumDecoder(typ reflect.Type) decoder {
 	kind := typ.Kind()
 	switch {
@@ -85,8 +94,11 @@ func makeNumDecoder(typ reflect.Type) decoder {
 }
 
 func decodeInt(s *Stream, val reflect.Value) error {
-	num, err := s.uint(val.Type().Bits())
-	if err != nil {
+	typ := val.Type()
+	num, err := s.uint(typ.Bits())
+	if err == errUintOverflow {
+		return decodeError{"input string too long", typ}
+	} else if err != nil {
 		return err
 	}
 	val.SetInt(int64(num))
@@ -94,8 +106,11 @@ func decodeInt(s *Stream, val reflect.Value) error {
 }
 
 func decodeUint(s *Stream, val reflect.Value) error {
-	num, err := s.uint(val.Type().Bits())
-	if err != nil {
+	typ := val.Type()
+	num, err := s.uint(typ.Bits())
+	if err == errUintOverflow {
+		return decodeError{"input string too big", typ}
+	} else if err != nil {
 		return err
 	}
 	val.SetUint(num)
@@ -177,7 +192,7 @@ func decodeList(s *Stream, val reflect.Value, elemdec decoder, maxelem int) erro
 	i := 0
 	for {
 		if i > maxelem {
-			return fmt.Errorf("rlp: input List has more than %d elements", maxelem)
+			return decodeError{"input list has too many elements", val.Type()}
 		}
 		if val.Kind() == reflect.Slice {
 			// grow slice if necessary
@@ -228,8 +243,6 @@ func decodeByteSlice(s *Stream, val reflect.Value) error {
 	return err
 }
 
-var errStringDoesntFitArray = errors.New("rlp: string value doesn't fit into target array")
-
 func decodeByteArray(s *Stream, val reflect.Value) error {
 	kind, size, err := s.Kind()
 	if err != nil {
@@ -238,14 +251,14 @@ func decodeByteArray(s *Stream, val reflect.Value) error {
 	switch kind {
 	case Byte:
 		if val.Len() == 0 {
-			return errStringDoesntFitArray
+			return decodeError{"input string too big", val.Type()}
 		}
 		bv, _ := s.Uint()
 		val.Index(0).SetUint(bv)
 		zero(val, 1)
 	case String:
 		if uint64(val.Len()) < size {
-			return errStringDoesntFitArray
+			return decodeError{"input string too big", val.Type()}
 		}
 		slice := val.Slice(0, int(size)).Interface().([]byte)
 		if err := s.readFull(slice); err != nil {
@@ -295,7 +308,7 @@ func makeStructDecoder(typ reflect.Type) (decoder, error) {
 			}
 		}
 		if err = s.ListEnd(); err == errNotAtEOL {
-			err = errors.New("rlp: input List has too many elements")
+			err = decodeError{"input list has too many elements", typ}
 		}
 		return err
 	}
@@ -476,6 +489,8 @@ func (s *Stream) Bytes() ([]byte, error) {
 	}
 }
 
+var errUintOverflow = errors.New("rlp: uint overflow")
+
 // Uint reads an RLP string of up to 8 bytes and returns its contents
 // as an unsigned integer. If the input does not contain an RLP string, the
 // returned error will be ErrExpectedString.
@@ -494,7 +509,7 @@ func (s *Stream) uint(maxbits int) (uint64, error) {
 		return uint64(s.byteval), nil
 	case String:
 		if size > uint64(maxbits/8) {
-			return 0, fmt.Errorf("rlp: string is larger than %d bits", maxbits)
+			return 0, errUintOverflow
 		}
 		return s.readUint(byte(size))
 	default:
-- 
cgit v1.2.3


From 4f12f0697e645a567fac9f13ed8cdb25e1218b84 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 9 Dec 2014 10:39:39 +0100
Subject: rlp: move decoder type switch to decode.go

---
 rlp/decode.go | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 7d95af02b..7acbbfa0d 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -81,6 +81,39 @@ func (err decodeError) Error() string {
 	return fmt.Sprintf("rlp: %s for %v", err.msg, err.typ)
 }
 
+var (
+	decoderInterface = reflect.TypeOf(new(Decoder)).Elem()
+	bigInt           = reflect.TypeOf(big.Int{})
+)
+
+func makeDecoder(typ reflect.Type) (dec decoder, err error) {
+	kind := typ.Kind()
+	switch {
+	case typ.Implements(decoderInterface):
+		return decodeDecoder, nil
+	case kind != reflect.Ptr && reflect.PtrTo(typ).Implements(decoderInterface):
+		return decodeDecoderNoPtr, nil
+	case typ.AssignableTo(reflect.PtrTo(bigInt)):
+		return decodeBigInt, nil
+	case typ.AssignableTo(bigInt):
+		return decodeBigIntNoPtr, nil
+	case isInteger(kind):
+		return makeNumDecoder(typ), nil
+	case kind == reflect.String:
+		return decodeString, nil
+	case kind == reflect.Slice || kind == reflect.Array:
+		return makeListDecoder(typ)
+	case kind == reflect.Struct:
+		return makeStructDecoder(typ)
+	case kind == reflect.Ptr:
+		return makePtrDecoder(typ)
+	case kind == reflect.Interface && typ.NumMethod() == 0:
+		return decodeInterface, nil
+	default:
+		return nil, fmt.Errorf("rlp: type %v is not RLP-serializable", typ)
+	}
+}
+
 func makeNumDecoder(typ reflect.Type) decoder {
 	kind := typ.Kind()
 	switch {
-- 
cgit v1.2.3


From 93e858f88ef9a9a572c2dabd4aef8bbbd678dd97 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 9 Dec 2014 10:41:47 +0100
Subject: rlp: remove support for signed integer types

There is no agreement on how to encode negative integers
across implementations. cpp-ethereum doesn't support them either.
---
 rlp/decode.go | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 7acbbfa0d..31485ee70 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -54,7 +54,7 @@ type Decoder interface {
 // To decode into a Go string, the input must be an RLP string. The
 // bytes are taken as-is and will not necessarily be valid UTF-8.
 //
-// To decode into an integer type, the input must also be an RLP
+// To decode into an unsigned integer type, the input must also be an RLP
 // string. The bytes are interpreted as a big endian representation of
 // the integer. If the RLP string is larger than the bit size of the
 // type, Decode will return an error. Decode also supports *big.Int.
@@ -66,8 +66,9 @@ type Decoder interface {
 //	[]interface{}, for RLP lists
 //	[]byte, for RLP strings
 //
-// Non-empty interface types are not supported, nor are bool, float32,
-// float64, maps, channel types and functions.
+// Non-empty interface types are not supported, nor are booleans,
+// signed integers, floating point numbers, maps, channels and
+// functions.
 func Decode(r io.Reader, val interface{}) error {
 	return NewStream(r).Decode(val)
 }
@@ -97,8 +98,8 @@ func makeDecoder(typ reflect.Type) (dec decoder, err error) {
 		return decodeBigInt, nil
 	case typ.AssignableTo(bigInt):
 		return decodeBigIntNoPtr, nil
-	case isInteger(kind):
-		return makeNumDecoder(typ), nil
+	case isUint(kind):
+		return decodeUint, nil
 	case kind == reflect.String:
 		return decodeString, nil
 	case kind == reflect.Slice || kind == reflect.Array:
@@ -114,30 +115,6 @@ func makeDecoder(typ reflect.Type) (dec decoder, err error) {
 	}
 }
 
-func makeNumDecoder(typ reflect.Type) decoder {
-	kind := typ.Kind()
-	switch {
-	case kind <= reflect.Int64:
-		return decodeInt
-	case kind <= reflect.Uint64:
-		return decodeUint
-	default:
-		panic("fallthrough")
-	}
-}
-
-func decodeInt(s *Stream, val reflect.Value) error {
-	typ := val.Type()
-	num, err := s.uint(typ.Bits())
-	if err == errUintOverflow {
-		return decodeError{"input string too long", typ}
-	} else if err != nil {
-		return err
-	}
-	val.SetInt(int64(num))
-	return nil
-}
-
 func decodeUint(s *Stream, val reflect.Value) error {
 	typ := val.Type()
 	num, err := s.uint(typ.Bits())
-- 
cgit v1.2.3


From c084a7daa58117f1864eac5130ccf3290372fd4c Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 9 Dec 2014 10:44:48 +0100
Subject: rlp: fix panic in decodeList on go 1.4+

The documentation for reflect.Value.Index states that it will
panic for out-of-bounds indices. Since go 1.4, it actually panics.
---
 rlp/decode.go | 109 ++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 61 insertions(+), 48 deletions(-)

(limited to 'rlp/decode.go')

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)
-- 
cgit v1.2.3


From 829730dec419112a8e870e1bf0ea20736ab0d02a Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 9 Dec 2014 12:49:20 +0100
Subject: rlp: remove dead code

---
 rlp/decode.go | 2 --
 1 file changed, 2 deletions(-)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 66830b89c..06786eae7 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -238,8 +238,6 @@ func decodeListArray(s *Stream, val reflect.Value, elemdec decoder) error {
 		} else if err != nil {
 			return err
 		}
-		if i == vlen {
-		}
 	}
 	if i < vlen {
 		zero(val, i)
-- 
cgit v1.2.3


From 6cf4e0329c05174da7450f38dcba457c9ffea417 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 9 Dec 2014 13:55:47 +0100
Subject: rlp: display decoder target type in more error messages

Decode error messages now say "expected input list for foo.MyStruct"
instead of just "expected List".
---
 rlp/decode.go | 42 ++++++++++++++++++++++++------------------
 1 file changed, 24 insertions(+), 18 deletions(-)

(limited to 'rlp/decode.go')

diff --git a/rlp/decode.go b/rlp/decode.go
index 06786eae7..712d9fcf1 100644
--- a/rlp/decode.go
+++ b/rlp/decode.go
@@ -82,6 +82,20 @@ func (err decodeError) Error() string {
 	return fmt.Sprintf("rlp: %s for %v", err.msg, err.typ)
 }
 
+func wrapStreamError(err error, typ reflect.Type) error {
+	switch err {
+	case ErrExpectedList:
+		return decodeError{"expected input list", typ}
+	case ErrExpectedString:
+		return decodeError{"expected input string or byte", typ}
+	case errUintOverflow:
+		return decodeError{"input string too long", typ}
+	case errNotAtEOL:
+		return decodeError{"input list has too many elements", typ}
+	}
+	return err
+}
+
 var (
 	decoderInterface = reflect.TypeOf(new(Decoder)).Elem()
 	bigInt           = reflect.TypeOf(big.Int{})
@@ -118,10 +132,8 @@ func makeDecoder(typ reflect.Type) (dec decoder, err error) {
 func decodeUint(s *Stream, val reflect.Value) error {
 	typ := val.Type()
 	num, err := s.uint(typ.Bits())
-	if err == errUintOverflow {
-		return decodeError{"input string too big", typ}
-	} else if err != nil {
-		return err
+	if err != nil {
+		return wrapStreamError(err, val.Type())
 	}
 	val.SetUint(num)
 	return nil
@@ -130,7 +142,7 @@ func decodeUint(s *Stream, val reflect.Value) error {
 func decodeString(s *Stream, val reflect.Value) error {
 	b, err := s.Bytes()
 	if err != nil {
-		return err
+		return wrapStreamError(err, val.Type())
 	}
 	val.SetString(string(b))
 	return nil
@@ -143,7 +155,7 @@ func decodeBigIntNoPtr(s *Stream, val reflect.Value) error {
 func decodeBigInt(s *Stream, val reflect.Value) error {
 	b, err := s.Bytes()
 	if err != nil {
-		return err
+		return wrapStreamError(err, val.Type())
 	}
 	i := val.Interface().(*big.Int)
 	if i == nil {
@@ -181,7 +193,7 @@ func makeListDecoder(typ reflect.Type) (decoder, error) {
 func decodeListSlice(s *Stream, val reflect.Value, elemdec decoder) error {
 	size, err := s.List()
 	if err != nil {
-		return err
+		return wrapStreamError(err, val.Type())
 	}
 	if size == 0 {
 		val.Set(reflect.MakeSlice(val.Type(), 0, 0))
@@ -242,10 +254,7 @@ func decodeListArray(s *Stream, val reflect.Value, elemdec decoder) error {
 	if i < vlen {
 		zero(val, i)
 	}
-	if err = s.ListEnd(); err == errNotAtEOL {
-		return decodeError{"input list has too many elements", val.Type()}
-	}
-	return err
+	return wrapStreamError(s.ListEnd(), val.Type())
 }
 
 func decodeByteSlice(s *Stream, val reflect.Value) error {
@@ -271,14 +280,14 @@ func decodeByteArray(s *Stream, val reflect.Value) error {
 	switch kind {
 	case Byte:
 		if val.Len() == 0 {
-			return decodeError{"input string too big", val.Type()}
+			return decodeError{"input string too long", val.Type()}
 		}
 		bv, _ := s.Uint()
 		val.Index(0).SetUint(bv)
 		zero(val, 1)
 	case String:
 		if uint64(val.Len()) < size {
-			return decodeError{"input string too big", val.Type()}
+			return decodeError{"input string too long", val.Type()}
 		}
 		slice := val.Slice(0, int(size)).Interface().([]byte)
 		if err := s.readFull(slice); err != nil {
@@ -317,7 +326,7 @@ func makeStructDecoder(typ reflect.Type) (decoder, error) {
 	}
 	dec := func(s *Stream, val reflect.Value) (err error) {
 		if _, err = s.List(); err != nil {
-			return err
+			return wrapStreamError(err, typ)
 		}
 		for _, f := range fields {
 			err = f.info.decoder(s, val.Field(f.index))
@@ -328,10 +337,7 @@ func makeStructDecoder(typ reflect.Type) (decoder, error) {
 				return err
 			}
 		}
-		if err = s.ListEnd(); err == errNotAtEOL {
-			err = decodeError{"input list has too many elements", typ}
-		}
-		return err
+		return wrapStreamError(s.ListEnd(), typ)
 	}
 	return dec, nil
 }
-- 
cgit v1.2.3