Merge pull request #184 from fjl/feature/rlp
rlp: new package for streaming RLP decoder
This commit is contained in:
Jeffrey Wilcke
commit
b4e47a094c
|
|
@ -0,0 +1,667 @@
|
|||
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 {
|
||||
val.Set(reflect.Zero(typ)) // set to nil
|
||||
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
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,476 @@
|
|||
package rlp
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"encoding/hex"
|
||||
"errors"
|
||||
"fmt"
|
||||
"io"
|
||||
"math/big"
|
||||
"reflect"
|
||||
"testing"
|
||||
|
||||
"github.com/ethereum/go-ethereum/ethutil"
|
||||
)
|
||||
|
||||
func TestStreamKind(t *testing.T) {
|
||||
tests := []struct {
|
||||
input string
|
||||
wantKind Kind
|
||||
wantLen uint64
|
||||
}{
|
||||
{"00", Byte, 0},
|
||||
{"01", Byte, 0},
|
||||
{"7F", Byte, 0},
|
||||
{"80", String, 0},
|
||||
{"B7", String, 55},
|
||||
{"B800", String, 0},
|
||||
{"B90400", String, 1024},
|
||||
{"BA000400", String, 1024},
|
||||
{"BB00000400", String, 1024},
|
||||
{"BFFFFFFFFFFFFFFFFF", String, ^uint64(0)},
|
||||
{"C0", List, 0},
|
||||
{"C8", List, 8},
|
||||
{"F7", List, 55},
|
||||
{"F800", List, 0},
|
||||
{"F804", List, 4},
|
||||
{"F90400", List, 1024},
|
||||
{"FFFFFFFFFFFFFFFFFF", List, ^uint64(0)},
|
||||
}
|
||||
|
||||
for i, test := range tests {
|
||||
s := NewStream(bytes.NewReader(unhex(test.input)))
|
||||
kind, len, err := s.Kind()
|
||||
if err != nil {
|
||||
t.Errorf("test %d: Type returned error: %v", i, err)
|
||||
continue
|
||||
}
|
||||
if kind != test.wantKind {
|
||||
t.Errorf("test %d: kind mismatch: got %d, want %d", i, kind, test.wantKind)
|
||||
}
|
||||
if len != test.wantLen {
|
||||
t.Errorf("test %d: len mismatch: got %d, want %d", i, len, test.wantLen)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestStreamErrors(t *testing.T) {
|
||||
type calls []string
|
||||
tests := []struct {
|
||||
string
|
||||
calls
|
||||
error
|
||||
}{
|
||||
{"", calls{"Kind"}, io.EOF},
|
||||
{"", calls{"List"}, io.EOF},
|
||||
{"", calls{"Uint"}, io.EOF},
|
||||
{"C0", calls{"Bytes"}, ErrExpectedString},
|
||||
{"C0", calls{"Uint"}, ErrExpectedString},
|
||||
{"81", calls{"Bytes"}, io.ErrUnexpectedEOF},
|
||||
{"81", calls{"Uint"}, io.ErrUnexpectedEOF},
|
||||
{"BFFFFFFFFFFFFFFF", calls{"Bytes"}, io.ErrUnexpectedEOF},
|
||||
{"89000000000000000001", calls{"Uint"}, errors.New("rlp: string is larger than 64 bits")},
|
||||
{"00", calls{"List"}, ErrExpectedList},
|
||||
{"80", calls{"List"}, ErrExpectedList},
|
||||
{"C0", calls{"List", "Uint"}, EOL},
|
||||
{"C801", calls{"List", "Uint", "Uint"}, io.ErrUnexpectedEOF},
|
||||
{"C8C9", calls{"List", "Kind"}, ErrElemTooLarge},
|
||||
{"C3C2010201", calls{"List", "List", "Uint", "Uint", "ListEnd", "Uint"}, EOL},
|
||||
{"00", calls{"ListEnd"}, errNotInList},
|
||||
{"C40102", calls{"List", "Uint", "ListEnd"}, errNotAtEOL},
|
||||
}
|
||||
|
||||
testfor:
|
||||
for i, test := range tests {
|
||||
s := NewStream(bytes.NewReader(unhex(test.string)))
|
||||
rs := reflect.ValueOf(s)
|
||||
for j, call := range test.calls {
|
||||
fval := rs.MethodByName(call)
|
||||
ret := fval.Call(nil)
|
||||
err := "<nil>"
|
||||
if lastret := ret[len(ret)-1].Interface(); lastret != nil {
|
||||
err = lastret.(error).Error()
|
||||
}
|
||||
if j == len(test.calls)-1 {
|
||||
if err != test.error.Error() {
|
||||
t.Errorf("test %d: last call (%s) error mismatch\ngot: %s\nwant: %v",
|
||||
i, call, err, test.error)
|
||||
}
|
||||
} else if err != "<nil>" {
|
||||
t.Errorf("test %d: call %d (%s) unexpected error: %q", i, j, call, err)
|
||||
continue testfor
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestStreamList(t *testing.T) {
|
||||
s := NewStream(bytes.NewReader(unhex("C80102030405060708")))
|
||||
|
||||
len, err := s.List()
|
||||
if err != nil {
|
||||
t.Fatalf("List error: %v", err)
|
||||
}
|
||||
if len != 8 {
|
||||
t.Fatalf("List returned invalid length, got %d, want 8", len)
|
||||
}
|
||||
|
||||
for i := uint64(1); i <= 8; i++ {
|
||||
v, err := s.Uint()
|
||||
if err != nil {
|
||||
t.Fatalf("Uint error: %v", err)
|
||||
}
|
||||
if i != v {
|
||||
t.Errorf("Uint returned wrong value, got %d, want %d", v, i)
|
||||
}
|
||||
}
|
||||
|
||||
if _, err := s.Uint(); err != EOL {
|
||||
t.Errorf("Uint error mismatch, got %v, want %v", err, EOL)
|
||||
}
|
||||
if err = s.ListEnd(); err != nil {
|
||||
t.Fatalf("ListEnd error: %v", err)
|
||||
}
|
||||
}
|
||||
|
||||
func TestDecodeErrors(t *testing.T) {
|
||||
r := bytes.NewReader(nil)
|
||||
|
||||
if err := Decode(r, nil); err != errDecodeIntoNil {
|
||||
t.Errorf("Decode(r, nil) error mismatch, got %q, want %q", err, errDecodeIntoNil)
|
||||
}
|
||||
|
||||
var nilptr *struct{}
|
||||
if err := Decode(r, nilptr); err != errDecodeIntoNil {
|
||||
t.Errorf("Decode(r, nilptr) error mismatch, got %q, want %q", err, errDecodeIntoNil)
|
||||
}
|
||||
|
||||
if err := Decode(r, struct{}{}); err != errNoPointer {
|
||||
t.Errorf("Decode(r, struct{}{}) error mismatch, got %q, want %q", err, errNoPointer)
|
||||
}
|
||||
|
||||
expectErr := "rlp: type chan bool is not RLP-serializable"
|
||||
if err := Decode(r, new(chan bool)); err == nil || err.Error() != expectErr {
|
||||
t.Errorf("Decode(r, new(chan bool)) error mismatch, got %q, want %q", err, expectErr)
|
||||
}
|
||||
|
||||
if err := Decode(r, new(int)); err != io.EOF {
|
||||
t.Errorf("Decode(r, new(int)) error mismatch, got %q, want %q", err, io.EOF)
|
||||
}
|
||||
}
|
||||
|
||||
type decodeTest struct {
|
||||
input string
|
||||
ptr interface{}
|
||||
value interface{}
|
||||
error error
|
||||
}
|
||||
|
||||
type simplestruct struct {
|
||||
A int
|
||||
B string
|
||||
}
|
||||
|
||||
type recstruct struct {
|
||||
I int
|
||||
Child *recstruct
|
||||
}
|
||||
|
||||
var (
|
||||
veryBigInt = big.NewInt(0).Add(
|
||||
big.NewInt(0).Lsh(big.NewInt(0xFFFFFFFFFFFFFF), 16),
|
||||
big.NewInt(0xFFFF),
|
||||
)
|
||||
)
|
||||
|
||||
var (
|
||||
sharedByteArray [5]byte
|
||||
sharedPtr = new(*int)
|
||||
)
|
||||
|
||||
var decodeTests = []decodeTest{
|
||||
// integers
|
||||
{input: "05", ptr: new(uint32), value: uint32(5)},
|
||||
{input: "80", ptr: new(uint32), value: uint32(0)},
|
||||
{input: "8105", ptr: new(uint32), value: uint32(5)},
|
||||
{input: "820505", ptr: new(uint32), value: uint32(0x0505)},
|
||||
{input: "83050505", ptr: new(uint32), value: uint32(0x050505)},
|
||||
{input: "8405050505", ptr: new(uint32), value: uint32(0x05050505)},
|
||||
{input: "850505050505", ptr: new(uint32), error: errors.New("rlp: string is larger than 32 bits")},
|
||||
{input: "C0", ptr: new(uint32), error: ErrExpectedString},
|
||||
|
||||
// slices
|
||||
{input: "C0", ptr: new([]int), value: []int{}},
|
||||
{input: "C80102030405060708", ptr: new([]int), value: []int{1, 2, 3, 4, 5, 6, 7, 8}},
|
||||
|
||||
// arrays
|
||||
{input: "C0", ptr: new([5]int), value: [5]int{}},
|
||||
{input: "C50102030405", ptr: new([5]int), value: [5]int{1, 2, 3, 4, 5}},
|
||||
{input: "C6010203040506", ptr: new([5]int), error: errors.New("rlp: input List has more than 5 elements")},
|
||||
|
||||
// byte slices
|
||||
{input: "01", ptr: new([]byte), value: []byte{1}},
|
||||
{input: "80", ptr: new([]byte), value: []byte{}},
|
||||
{input: "8D6162636465666768696A6B6C6D", ptr: new([]byte), value: []byte("abcdefghijklm")},
|
||||
{input: "C0", ptr: new([]byte), value: []byte{}},
|
||||
{input: "C3010203", ptr: new([]byte), value: []byte{1, 2, 3}},
|
||||
{input: "C3820102", ptr: new([]byte), error: errors.New("rlp: string is larger than 8 bits")},
|
||||
|
||||
// byte arrays
|
||||
{input: "01", ptr: new([5]byte), value: [5]byte{1}},
|
||||
{input: "80", ptr: new([5]byte), value: [5]byte{}},
|
||||
{input: "850102030405", ptr: new([5]byte), value: [5]byte{1, 2, 3, 4, 5}},
|
||||
{input: "C0", ptr: new([5]byte), value: [5]byte{}},
|
||||
{input: "C3010203", ptr: new([5]byte), value: [5]byte{1, 2, 3, 0, 0}},
|
||||
{input: "C3820102", ptr: new([5]byte), error: errors.New("rlp: string is larger than 8 bits")},
|
||||
{input: "86010203040506", ptr: new([5]byte), error: errStringDoesntFitArray},
|
||||
{input: "850101", ptr: new([5]byte), error: io.ErrUnexpectedEOF},
|
||||
|
||||
// byte array reuse (should be zeroed)
|
||||
{input: "850102030405", ptr: &sharedByteArray, value: [5]byte{1, 2, 3, 4, 5}},
|
||||
{input: "8101", ptr: &sharedByteArray, value: [5]byte{1}}, // kind: String
|
||||
{input: "850102030405", ptr: &sharedByteArray, value: [5]byte{1, 2, 3, 4, 5}},
|
||||
{input: "01", ptr: &sharedByteArray, value: [5]byte{1}}, // kind: Byte
|
||||
{input: "C3010203", ptr: &sharedByteArray, value: [5]byte{1, 2, 3, 0, 0}},
|
||||
{input: "C101", ptr: &sharedByteArray, value: [5]byte{1}}, // kind: List
|
||||
|
||||
// zero sized byte arrays
|
||||
{input: "80", ptr: new([0]byte), value: [0]byte{}},
|
||||
{input: "C0", ptr: new([0]byte), value: [0]byte{}},
|
||||
{input: "01", ptr: new([0]byte), error: errStringDoesntFitArray},
|
||||
{input: "8101", ptr: new([0]byte), error: errStringDoesntFitArray},
|
||||
|
||||
// strings
|
||||
{input: "00", ptr: new(string), value: "\000"},
|
||||
{input: "8D6162636465666768696A6B6C6D", ptr: new(string), value: "abcdefghijklm"},
|
||||
{input: "C0", ptr: new(string), error: ErrExpectedString},
|
||||
|
||||
// big ints
|
||||
{input: "01", ptr: new(*big.Int), value: big.NewInt(1)},
|
||||
{input: "89FFFFFFFFFFFFFFFFFF", ptr: new(*big.Int), value: veryBigInt},
|
||||
{input: "10", ptr: new(big.Int), value: *big.NewInt(16)}, // non-pointer also works
|
||||
{input: "C0", ptr: new(*big.Int), error: ErrExpectedString},
|
||||
|
||||
// structs
|
||||
{input: "C0", ptr: new(simplestruct), value: simplestruct{0, ""}},
|
||||
{input: "C105", ptr: new(simplestruct), value: simplestruct{5, ""}},
|
||||
{input: "C50583343434", ptr: new(simplestruct), value: simplestruct{5, "444"}},
|
||||
{input: "C3010101", ptr: new(simplestruct), error: errors.New("rlp: input List has too many elements")},
|
||||
{
|
||||
input: "C501C302C103",
|
||||
ptr: new(recstruct),
|
||||
value: recstruct{1, &recstruct{2, &recstruct{3, nil}}},
|
||||
},
|
||||
|
||||
// pointers
|
||||
{input: "00", ptr: new(*int), value: (*int)(nil)},
|
||||
{input: "80", ptr: new(*int), value: (*int)(nil)},
|
||||
{input: "C0", ptr: new(*int), value: (*int)(nil)},
|
||||
{input: "07", ptr: new(*int), value: intp(7)},
|
||||
{input: "8108", ptr: new(*int), value: intp(8)},
|
||||
{input: "C109", ptr: new(*[]int), value: &[]int{9}},
|
||||
{input: "C58403030303", ptr: new(*[][]byte), value: &[][]byte{{3, 3, 3, 3}}},
|
||||
|
||||
// pointer should be reset to nil
|
||||
{input: "05", ptr: sharedPtr, value: intp(5)},
|
||||
{input: "80", ptr: sharedPtr, value: (*int)(nil)},
|
||||
|
||||
// interface{}
|
||||
{input: "00", ptr: new(interface{}), value: []byte{0}},
|
||||
{input: "01", ptr: new(interface{}), value: []byte{1}},
|
||||
{input: "80", ptr: new(interface{}), value: []byte{}},
|
||||
{input: "850505050505", ptr: new(interface{}), value: []byte{5, 5, 5, 5, 5}},
|
||||
{input: "C0", ptr: new(interface{}), value: []interface{}{}},
|
||||
{input: "C50183040404", ptr: new(interface{}), value: []interface{}{[]byte{1}, []byte{4, 4, 4}}},
|
||||
}
|
||||
|
||||
func intp(i int) *int { return &i }
|
||||
|
||||
func TestDecode(t *testing.T) {
|
||||
for i, test := range decodeTests {
|
||||
input, err := hex.DecodeString(test.input)
|
||||
if err != nil {
|
||||
t.Errorf("test %d: invalid hex input %q", i, test.input)
|
||||
continue
|
||||
}
|
||||
err = Decode(bytes.NewReader(input), test.ptr)
|
||||
if err != nil && test.error == nil {
|
||||
t.Errorf("test %d: unexpected Decode error: %v\ndecoding into %T\ninput %q",
|
||||
i, err, test.ptr, test.input)
|
||||
continue
|
||||
}
|
||||
if test.error != nil && fmt.Sprint(err) != fmt.Sprint(test.error) {
|
||||
t.Errorf("test %d: Decode error mismatch\ngot %v\nwant %v\ndecoding into %T\ninput %q",
|
||||
i, err, test.error, test.ptr, test.input)
|
||||
continue
|
||||
}
|
||||
deref := reflect.ValueOf(test.ptr).Elem().Interface()
|
||||
if err == nil && !reflect.DeepEqual(deref, test.value) {
|
||||
t.Errorf("test %d: value mismatch\ngot %#v\nwant %#v\ndecoding into %T\ninput %q",
|
||||
i, deref, test.value, test.ptr, test.input)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
type testDecoder struct{ called bool }
|
||||
|
||||
func (t *testDecoder) DecodeRLP(s *Stream) error {
|
||||
if _, err := s.Uint(); err != nil {
|
||||
return err
|
||||
}
|
||||
t.called = true
|
||||
return nil
|
||||
}
|
||||
|
||||
func TestDecodeDecoder(t *testing.T) {
|
||||
var s struct {
|
||||
T1 testDecoder
|
||||
T2 *testDecoder
|
||||
T3 **testDecoder
|
||||
}
|
||||
if err := Decode(bytes.NewReader(unhex("C3010203")), &s); err != nil {
|
||||
t.Fatalf("Decode error: %v", err)
|
||||
}
|
||||
|
||||
if !s.T1.called {
|
||||
t.Errorf("DecodeRLP was not called for (non-pointer) testDecoder")
|
||||
}
|
||||
|
||||
if s.T2 == nil {
|
||||
t.Errorf("*testDecoder has not been allocated")
|
||||
} else if !s.T2.called {
|
||||
t.Errorf("DecodeRLP was not called for *testDecoder")
|
||||
}
|
||||
|
||||
if s.T3 == nil || *s.T3 == nil {
|
||||
t.Errorf("**testDecoder has not been allocated")
|
||||
} else if !(*s.T3).called {
|
||||
t.Errorf("DecodeRLP was not called for **testDecoder")
|
||||
}
|
||||
}
|
||||
|
||||
type byteDecoder byte
|
||||
|
||||
func (bd *byteDecoder) DecodeRLP(s *Stream) error {
|
||||
_, err := s.Uint()
|
||||
*bd = 255
|
||||
return err
|
||||
}
|
||||
|
||||
func (bd byteDecoder) called() bool {
|
||||
return bd == 255
|
||||
}
|
||||
|
||||
// This test verifies that the byte slice/byte array logic
|
||||
// does not kick in for element types implementing Decoder.
|
||||
func TestDecoderInByteSlice(t *testing.T) {
|
||||
var slice []byteDecoder
|
||||
if err := Decode(bytes.NewReader(unhex("C101")), &slice); err != nil {
|
||||
t.Errorf("unexpected Decode error %v", err)
|
||||
} else if !slice[0].called() {
|
||||
t.Errorf("DecodeRLP not called for slice element")
|
||||
}
|
||||
|
||||
var array [1]byteDecoder
|
||||
if err := Decode(bytes.NewReader(unhex("C101")), &array); err != nil {
|
||||
t.Errorf("unexpected Decode error %v", err)
|
||||
} else if !array[0].called() {
|
||||
t.Errorf("DecodeRLP not called for array element")
|
||||
}
|
||||
}
|
||||
|
||||
func ExampleDecode() {
|
||||
input, _ := hex.DecodeString("C90A1486666F6F626172")
|
||||
|
||||
type example struct {
|
||||
A, B int
|
||||
private int // private fields are ignored
|
||||
String string
|
||||
}
|
||||
|
||||
var s example
|
||||
err := Decode(bytes.NewReader(input), &s)
|
||||
if err != nil {
|
||||
fmt.Printf("Error: %v\n", err)
|
||||
} else {
|
||||
fmt.Printf("Decoded value: %#v\n", s)
|
||||
}
|
||||
// Output:
|
||||
// Decoded value: rlp.example{A:10, B:20, private:0, String:"foobar"}
|
||||
}
|
||||
|
||||
func ExampleStream() {
|
||||
input, _ := hex.DecodeString("C90A1486666F6F626172")
|
||||
s := NewStream(bytes.NewReader(input))
|
||||
|
||||
// Check what kind of value lies ahead
|
||||
kind, size, _ := s.Kind()
|
||||
fmt.Printf("Kind: %v size:%d\n", kind, size)
|
||||
|
||||
// Enter the list
|
||||
if _, err := s.List(); err != nil {
|
||||
fmt.Printf("List error: %v\n", err)
|
||||
return
|
||||
}
|
||||
|
||||
// Decode elements
|
||||
fmt.Println(s.Uint())
|
||||
fmt.Println(s.Uint())
|
||||
fmt.Println(s.Bytes())
|
||||
|
||||
// Acknowledge end of list
|
||||
if err := s.ListEnd(); err != nil {
|
||||
fmt.Printf("ListEnd error: %v\n", err)
|
||||
}
|
||||
// Output:
|
||||
// Kind: List size:9
|
||||
// 10 <nil>
|
||||
// 20 <nil>
|
||||
// [102 111 111 98 97 114] <nil>
|
||||
}
|
||||
|
||||
func BenchmarkDecode(b *testing.B) {
|
||||
enc := encTest(90000)
|
||||
b.SetBytes(int64(len(enc)))
|
||||
b.ReportAllocs()
|
||||
b.ResetTimer()
|
||||
|
||||
for i := 0; i < b.N; i++ {
|
||||
var s []int
|
||||
r := bytes.NewReader(enc)
|
||||
if err := Decode(r, &s); err != nil {
|
||||
b.Fatalf("Decode error: %v", err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkDecodeIntSliceReuse(b *testing.B) {
|
||||
enc := encTest(100000)
|
||||
b.SetBytes(int64(len(enc)))
|
||||
b.ReportAllocs()
|
||||
b.ResetTimer()
|
||||
|
||||
var s []int
|
||||
for i := 0; i < b.N; i++ {
|
||||
r := bytes.NewReader(enc)
|
||||
if err := Decode(r, &s); err != nil {
|
||||
b.Fatalf("Decode error: %v", err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func encTest(n int) []byte {
|
||||
s := make([]interface{}, n)
|
||||
for i := 0; i < n; i++ {
|
||||
s[i] = i
|
||||
}
|
||||
return ethutil.Encode(s)
|
||||
}
|
||||
|
||||
func unhex(str string) []byte {
|
||||
b, err := hex.DecodeString(str)
|
||||
if err != nil {
|
||||
panic(fmt.Sprintf("invalid hex string: %q", str))
|
||||
}
|
||||
return b
|
||||
}
|
||||
|
|
@ -0,0 +1,17 @@
|
|||
/*
|
||||
Package rlp implements the RLP serialization format.
|
||||
|
||||
The purpose of RLP (Recursive Linear Prefix) qis to encode arbitrarily
|
||||
nested arrays of binary data, and RLP is the main encoding method used
|
||||
to serialize objects in Ethereum. The only purpose of RLP is to encode
|
||||
structure; encoding specific atomic data types (eg. strings, ints,
|
||||
floats) is left up to higher-order protocols; in Ethereum integers
|
||||
must be represented in big endian binary form with no leading zeroes
|
||||
(thus making the integer value zero be equivalent to the empty byte
|
||||
array).
|
||||
|
||||
RLP values are distinguished by a type tag. The type tag precedes the
|
||||
value in the input stream and defines the size and kind of the bytes
|
||||
that follow.
|
||||
*/
|
||||
package rlp
|
||||
|
|
@ -0,0 +1,91 @@
|
|||
package rlp
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"math/big"
|
||||
"reflect"
|
||||
"sync"
|
||||
)
|
||||
|
||||
type decoder func(*Stream, reflect.Value) error
|
||||
|
||||
type typeinfo struct {
|
||||
decoder
|
||||
}
|
||||
|
||||
var (
|
||||
typeCacheMutex sync.RWMutex
|
||||
typeCache = make(map[reflect.Type]*typeinfo)
|
||||
)
|
||||
|
||||
func cachedTypeInfo(typ reflect.Type) (*typeinfo, error) {
|
||||
typeCacheMutex.RLock()
|
||||
info := typeCache[typ]
|
||||
typeCacheMutex.RUnlock()
|
||||
if info != nil {
|
||||
return info, nil
|
||||
}
|
||||
// not in the cache, need to generate info for this type.
|
||||
typeCacheMutex.Lock()
|
||||
defer typeCacheMutex.Unlock()
|
||||
return cachedTypeInfo1(typ)
|
||||
}
|
||||
|
||||
func cachedTypeInfo1(typ reflect.Type) (*typeinfo, error) {
|
||||
info := typeCache[typ]
|
||||
if info != nil {
|
||||
// another goroutine got the write lock first
|
||||
return info, nil
|
||||
}
|
||||
// put a dummmy value into the cache before generating.
|
||||
// if the generator tries to lookup itself, it will get
|
||||
// the dummy value and won't call itself recursively.
|
||||
typeCache[typ] = new(typeinfo)
|
||||
info, err := genTypeInfo(typ)
|
||||
if err != nil {
|
||||
// remove the dummy value if the generator fails
|
||||
delete(typeCache, typ)
|
||||
return nil, err
|
||||
}
|
||||
*typeCache[typ] = *info
|
||||
return typeCache[typ], err
|
||||
}
|
||||
|
||||
var (
|
||||
decoderInterface = reflect.TypeOf(new(Decoder)).Elem()
|
||||
bigInt = reflect.TypeOf(big.Int{})
|
||||
)
|
||||
|
||||
func genTypeInfo(typ reflect.Type) (info *typeinfo, err error) {
|
||||
info = new(typeinfo)
|
||||
kind := typ.Kind()
|
||||
switch {
|
||||
case typ.Implements(decoderInterface):
|
||||
info.decoder = decodeDecoder
|
||||
case kind != reflect.Ptr && reflect.PtrTo(typ).Implements(decoderInterface):
|
||||
info.decoder = decodeDecoderNoPtr
|
||||
case typ.AssignableTo(reflect.PtrTo(bigInt)):
|
||||
info.decoder = decodeBigInt
|
||||
case typ.AssignableTo(bigInt):
|
||||
info.decoder = decodeBigIntNoPtr
|
||||
case isInteger(kind):
|
||||
info.decoder = makeNumDecoder(typ)
|
||||
case kind == reflect.String:
|
||||
info.decoder = decodeString
|
||||
case kind == reflect.Slice || kind == reflect.Array:
|
||||
info.decoder, err = makeListDecoder(typ)
|
||||
case kind == reflect.Struct:
|
||||
info.decoder, err = makeStructDecoder(typ)
|
||||
case kind == reflect.Ptr:
|
||||
info.decoder, err = makePtrDecoder(typ)
|
||||
case kind == reflect.Interface && typ.NumMethod() == 0:
|
||||
info.decoder = decodeInterface
|
||||
default:
|
||||
err = fmt.Errorf("rlp: type %v is not RLP-serializable", typ)
|
||||
}
|
||||
return info, err
|
||||
}
|
||||
|
||||
func isInteger(k reflect.Kind) bool {
|
||||
return k >= reflect.Int && k <= reflect.Uintptr
|
||||
}
|
||||
Loading…
Reference in New Issue