2014-12-30 10:40:32 +00:00
|
|
|
package rlp
|
|
|
|
|
|
|
|
import (
|
|
|
|
"fmt"
|
|
|
|
"io"
|
|
|
|
"math/big"
|
|
|
|
"reflect"
|
|
|
|
)
|
|
|
|
|
|
|
|
// TODO: put encbufs in a sync.Pool.
|
|
|
|
// Doing that requires zeroing the buffers after use.
|
|
|
|
// encReader will need to drop it's buffer when done.
|
|
|
|
|
|
|
|
var (
|
|
|
|
// Common encoded values.
|
|
|
|
// These are useful when implementing EncodeRLP.
|
|
|
|
EmptyString = []byte{0x80}
|
|
|
|
EmptyList = []byte{0xC0}
|
|
|
|
)
|
|
|
|
|
|
|
|
// Encoder is implemented by types that require custom
|
|
|
|
// encoding rules or want to encode private fields.
|
|
|
|
type Encoder interface {
|
|
|
|
// EncodeRLP should write the RLP encoding of its receiver to w.
|
|
|
|
// If the implementation is a pointer method, it may also be
|
|
|
|
// called for nil pointers.
|
|
|
|
//
|
|
|
|
// Implementations should generate valid RLP. The data written is
|
|
|
|
// not verified at the moment, but a future version might. It is
|
|
|
|
// recommended to write only a single value but writing multiple
|
|
|
|
// values or no value at all is also permitted.
|
|
|
|
EncodeRLP(io.Writer) error
|
|
|
|
}
|
|
|
|
|
2015-02-11 18:28:56 +00:00
|
|
|
// Flat wraps a value (which must encode as a list) so
|
|
|
|
// it encodes as the list's elements.
|
|
|
|
//
|
|
|
|
// Example: suppose you have defined a type
|
|
|
|
//
|
|
|
|
// type foo struct { A, B uint }
|
|
|
|
//
|
|
|
|
// Under normal encoding rules,
|
|
|
|
//
|
|
|
|
// rlp.Encode(foo{1, 2}) --> 0xC20102
|
|
|
|
//
|
|
|
|
// This function can help you achieve the following encoding:
|
|
|
|
//
|
|
|
|
// rlp.Encode(rlp.Flat(foo{1, 2})) --> 0x0102
|
|
|
|
func Flat(val interface{}) Encoder {
|
|
|
|
return flatenc{val}
|
|
|
|
}
|
|
|
|
|
|
|
|
type flatenc struct{ val interface{} }
|
|
|
|
|
|
|
|
func (e flatenc) EncodeRLP(out io.Writer) error {
|
|
|
|
// record current output position
|
|
|
|
var (
|
|
|
|
eb = out.(*encbuf)
|
|
|
|
prevstrsize = len(eb.str)
|
|
|
|
prevnheads = len(eb.lheads)
|
|
|
|
)
|
|
|
|
if err := eb.encode(e.val); err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
// check that a new list header has appeared
|
|
|
|
if len(eb.lheads) == prevnheads || eb.lheads[prevnheads].offset == prevstrsize-1 {
|
|
|
|
return fmt.Errorf("rlp.Flat: %T did not encode as list", e.val)
|
|
|
|
}
|
|
|
|
// remove the new list header
|
|
|
|
newhead := eb.lheads[prevnheads]
|
|
|
|
copy(eb.lheads[prevnheads:], eb.lheads[prevnheads+1:])
|
|
|
|
eb.lheads = eb.lheads[:len(eb.lheads)-1]
|
|
|
|
eb.lhsize -= newhead.tagsize()
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
2014-12-30 10:40:32 +00:00
|
|
|
// Encode writes the RLP encoding of val to w. Note that Encode may
|
|
|
|
// perform many small writes in some cases. Consider making w
|
|
|
|
// buffered.
|
|
|
|
//
|
|
|
|
// Encode uses the following type-dependent encoding rules:
|
|
|
|
//
|
|
|
|
// If the type implements the Encoder interface, Encode calls
|
|
|
|
// EncodeRLP. This is true even for nil pointers, please see the
|
|
|
|
// documentation for Encoder.
|
|
|
|
//
|
|
|
|
// To encode a pointer, the value being pointed to is encoded. For nil
|
|
|
|
// pointers, Encode will encode the zero value of the type. A nil
|
|
|
|
// pointer to a struct type always encodes as an empty RLP list.
|
|
|
|
//
|
|
|
|
// Struct values are encoded as an RLP list of all their encoded
|
|
|
|
// public fields. Recursive struct types are supported.
|
|
|
|
//
|
|
|
|
// To encode slices and arrays, the elements are encoded as an RLP
|
|
|
|
// list of the value's elements. Note that arrays and slices with
|
|
|
|
// element type uint8 or byte are always encoded as an RLP string.
|
|
|
|
//
|
|
|
|
// A Go string is encoded as an RLP string.
|
|
|
|
//
|
|
|
|
// An unsigned integer value is encoded as an RLP string. Zero always
|
|
|
|
// encodes as an empty RLP string. Encode also supports *big.Int.
|
|
|
|
//
|
|
|
|
// An interface value encodes as the value contained in the interface.
|
|
|
|
//
|
|
|
|
// Boolean values are not supported, nor are signed integers, floating
|
|
|
|
// point numbers, maps, channels and functions.
|
|
|
|
func Encode(w io.Writer, val interface{}) error {
|
|
|
|
if outer, ok := w.(*encbuf); ok {
|
|
|
|
// Encode was called by some type's EncodeRLP.
|
|
|
|
// Avoid copying by writing to the outer encbuf directly.
|
|
|
|
return outer.encode(val)
|
|
|
|
}
|
|
|
|
eb := newencbuf()
|
|
|
|
if err := eb.encode(val); err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
return eb.toWriter(w)
|
|
|
|
}
|
|
|
|
|
|
|
|
// EncodeBytes returns the RLP encoding of val.
|
|
|
|
// Please see the documentation of Encode for the encoding rules.
|
|
|
|
func EncodeToBytes(val interface{}) ([]byte, error) {
|
|
|
|
eb := newencbuf()
|
|
|
|
if err := eb.encode(val); err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
return eb.toBytes(), nil
|
|
|
|
}
|
|
|
|
|
|
|
|
// EncodeReader returns a reader from which the RLP encoding of val
|
|
|
|
// can be read. The returned size is the total size of the encoded
|
|
|
|
// data.
|
|
|
|
//
|
|
|
|
// Please see the documentation of Encode for the encoding rules.
|
|
|
|
func EncodeToReader(val interface{}) (size int, r io.Reader, err error) {
|
|
|
|
eb := newencbuf()
|
|
|
|
if err := eb.encode(val); err != nil {
|
|
|
|
return 0, nil, err
|
|
|
|
}
|
|
|
|
return eb.size(), &encReader{buf: eb}, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
type encbuf struct {
|
|
|
|
str []byte // string data, contains everything except list headers
|
|
|
|
lheads []*listhead // all list headers
|
|
|
|
lhsize int // sum of sizes of all encoded list headers
|
|
|
|
sizebuf []byte // 9-byte auxiliary buffer for uint encoding
|
|
|
|
}
|
|
|
|
|
|
|
|
type listhead struct {
|
|
|
|
offset int // index of this header in string data
|
|
|
|
size int // total size of encoded data (including list headers)
|
|
|
|
}
|
|
|
|
|
|
|
|
// encode writes head to the given buffer, which must be at least
|
|
|
|
// 9 bytes long. It returns the encoded bytes.
|
|
|
|
func (head *listhead) encode(buf []byte) []byte {
|
|
|
|
if head.size < 56 {
|
|
|
|
buf[0] = 0xC0 + byte(head.size)
|
|
|
|
return buf[:1]
|
|
|
|
} else {
|
|
|
|
sizesize := putint(buf[1:], uint64(head.size))
|
|
|
|
buf[0] = 0xF7 + byte(sizesize)
|
|
|
|
return buf[:sizesize+1]
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-02-11 18:28:56 +00:00
|
|
|
func (head *listhead) tagsize() int {
|
|
|
|
if head.size < 56 {
|
|
|
|
return 1
|
|
|
|
}
|
|
|
|
return 1 + intsize(uint64(head.size))
|
|
|
|
}
|
|
|
|
|
2014-12-30 10:40:32 +00:00
|
|
|
func newencbuf() *encbuf {
|
|
|
|
return &encbuf{sizebuf: make([]byte, 9)}
|
|
|
|
}
|
|
|
|
|
|
|
|
// encbuf implements io.Writer so it can be passed it into EncodeRLP.
|
|
|
|
func (w *encbuf) Write(b []byte) (int, error) {
|
|
|
|
w.str = append(w.str, b...)
|
|
|
|
return len(b), nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) encode(val interface{}) error {
|
|
|
|
rval := reflect.ValueOf(val)
|
|
|
|
ti, err := cachedTypeInfo(rval.Type())
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
return ti.writer(rval, w)
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) encodeStringHeader(size int) {
|
|
|
|
if size < 56 {
|
|
|
|
w.str = append(w.str, 0x80+byte(size))
|
|
|
|
} else {
|
|
|
|
// TODO: encode to w.str directly
|
|
|
|
sizesize := putint(w.sizebuf[1:], uint64(size))
|
|
|
|
w.sizebuf[0] = 0xB7 + byte(sizesize)
|
|
|
|
w.str = append(w.str, w.sizebuf[:sizesize+1]...)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) encodeString(b []byte) {
|
2015-03-19 11:15:43 +00:00
|
|
|
if len(b) == 1 && b[0] <= 0x7F {
|
|
|
|
// fits single byte, no string header
|
|
|
|
w.str = append(w.str, b[0])
|
|
|
|
} else {
|
|
|
|
w.encodeStringHeader(len(b))
|
|
|
|
w.str = append(w.str, b...)
|
|
|
|
}
|
2014-12-30 10:40:32 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) list() *listhead {
|
|
|
|
lh := &listhead{offset: len(w.str), size: w.lhsize}
|
|
|
|
w.lheads = append(w.lheads, lh)
|
|
|
|
return lh
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) listEnd(lh *listhead) {
|
|
|
|
lh.size = w.size() - lh.offset - lh.size
|
|
|
|
if lh.size < 56 {
|
|
|
|
w.lhsize += 1 // length encoded into kind tag
|
|
|
|
} else {
|
|
|
|
w.lhsize += 1 + intsize(uint64(lh.size))
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) size() int {
|
|
|
|
return len(w.str) + w.lhsize
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) toBytes() []byte {
|
|
|
|
out := make([]byte, w.size())
|
|
|
|
strpos := 0
|
|
|
|
pos := 0
|
|
|
|
for _, head := range w.lheads {
|
|
|
|
// write string data before header
|
|
|
|
n := copy(out[pos:], w.str[strpos:head.offset])
|
|
|
|
pos += n
|
|
|
|
strpos += n
|
|
|
|
// write the header
|
|
|
|
enc := head.encode(out[pos:])
|
|
|
|
pos += len(enc)
|
|
|
|
}
|
|
|
|
// copy string data after the last list header
|
|
|
|
copy(out[pos:], w.str[strpos:])
|
|
|
|
return out
|
|
|
|
}
|
|
|
|
|
|
|
|
func (w *encbuf) toWriter(out io.Writer) (err error) {
|
|
|
|
strpos := 0
|
|
|
|
for _, head := range w.lheads {
|
|
|
|
// write string data before header
|
|
|
|
if head.offset-strpos > 0 {
|
|
|
|
n, err := out.Write(w.str[strpos:head.offset])
|
|
|
|
strpos += n
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
// write the header
|
|
|
|
enc := head.encode(w.sizebuf)
|
|
|
|
if _, err = out.Write(enc); err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if strpos < len(w.str) {
|
|
|
|
// write string data after the last list header
|
|
|
|
_, err = out.Write(w.str[strpos:])
|
|
|
|
}
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
|
|
|
|
// encReader is the io.Reader returned by EncodeToReader.
|
|
|
|
// It releases its encbuf at EOF.
|
|
|
|
type encReader struct {
|
|
|
|
buf *encbuf // the buffer we're reading from. this is nil when we're at EOF.
|
|
|
|
lhpos int // index of list header that we're reading
|
|
|
|
strpos int // current position in string buffer
|
|
|
|
piece []byte // next piece to be read
|
|
|
|
}
|
|
|
|
|
|
|
|
func (r *encReader) Read(b []byte) (n int, err error) {
|
|
|
|
for {
|
|
|
|
if r.piece = r.next(); r.piece == nil {
|
|
|
|
return n, io.EOF
|
|
|
|
}
|
|
|
|
nn := copy(b[n:], r.piece)
|
|
|
|
n += nn
|
|
|
|
if nn < len(r.piece) {
|
|
|
|
// piece didn't fit, see you next time.
|
|
|
|
r.piece = r.piece[nn:]
|
|
|
|
return n, nil
|
|
|
|
}
|
|
|
|
r.piece = nil
|
|
|
|
}
|
|
|
|
panic("not reached")
|
|
|
|
}
|
|
|
|
|
|
|
|
// next returns the next piece of data to be read.
|
|
|
|
// it returns nil at EOF.
|
|
|
|
func (r *encReader) next() []byte {
|
|
|
|
switch {
|
|
|
|
case r.piece != nil:
|
|
|
|
// There is still data available for reading.
|
|
|
|
return r.piece
|
|
|
|
|
|
|
|
case r.lhpos < len(r.buf.lheads):
|
|
|
|
// We're before the last list header.
|
|
|
|
head := r.buf.lheads[r.lhpos]
|
|
|
|
sizebefore := head.offset - r.strpos
|
|
|
|
if sizebefore > 0 {
|
|
|
|
// String data before header.
|
|
|
|
p := r.buf.str[r.strpos:head.offset]
|
|
|
|
r.strpos += sizebefore
|
|
|
|
return p
|
|
|
|
} else {
|
|
|
|
r.lhpos++
|
|
|
|
return head.encode(r.buf.sizebuf)
|
|
|
|
}
|
|
|
|
|
|
|
|
case r.strpos < len(r.buf.str):
|
|
|
|
// String data at the end, after all list headers.
|
|
|
|
p := r.buf.str[r.strpos:]
|
|
|
|
r.strpos = len(r.buf.str)
|
|
|
|
return p
|
|
|
|
|
|
|
|
default:
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
var (
|
|
|
|
encoderInterface = reflect.TypeOf(new(Encoder)).Elem()
|
|
|
|
big0 = big.NewInt(0)
|
|
|
|
)
|
|
|
|
|
|
|
|
// makeWriter creates a writer function for the given type.
|
|
|
|
func makeWriter(typ reflect.Type) (writer, error) {
|
|
|
|
kind := typ.Kind()
|
|
|
|
switch {
|
|
|
|
case typ.Implements(encoderInterface):
|
|
|
|
return writeEncoder, nil
|
|
|
|
case kind != reflect.Ptr && reflect.PtrTo(typ).Implements(encoderInterface):
|
|
|
|
return writeEncoderNoPtr, nil
|
2015-01-15 22:21:41 +00:00
|
|
|
case kind == reflect.Interface:
|
2014-12-30 10:40:32 +00:00
|
|
|
return writeInterface, nil
|
|
|
|
case typ.AssignableTo(reflect.PtrTo(bigInt)):
|
|
|
|
return writeBigIntPtr, nil
|
|
|
|
case typ.AssignableTo(bigInt):
|
|
|
|
return writeBigIntNoPtr, nil
|
|
|
|
case isUint(kind):
|
|
|
|
return writeUint, nil
|
|
|
|
case kind == reflect.String:
|
|
|
|
return writeString, nil
|
2015-01-30 15:52:48 +00:00
|
|
|
case kind == reflect.Slice && isByte(typ.Elem()):
|
2014-12-30 10:40:32 +00:00
|
|
|
return writeBytes, nil
|
2015-01-30 15:52:48 +00:00
|
|
|
case kind == reflect.Array && isByte(typ.Elem()):
|
|
|
|
return writeByteArray, nil
|
2014-12-30 10:40:32 +00:00
|
|
|
case kind == reflect.Slice || kind == reflect.Array:
|
|
|
|
return makeSliceWriter(typ)
|
|
|
|
case kind == reflect.Struct:
|
|
|
|
return makeStructWriter(typ)
|
|
|
|
case kind == reflect.Ptr:
|
|
|
|
return makePtrWriter(typ)
|
|
|
|
default:
|
|
|
|
return nil, fmt.Errorf("rlp: type %v is not RLP-serializable", typ)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-01-30 15:52:48 +00:00
|
|
|
func isByte(typ reflect.Type) bool {
|
|
|
|
return typ.Kind() == reflect.Uint8 && !typ.Implements(encoderInterface)
|
|
|
|
}
|
|
|
|
|
2014-12-30 10:40:32 +00:00
|
|
|
func writeUint(val reflect.Value, w *encbuf) error {
|
|
|
|
i := val.Uint()
|
|
|
|
if i == 0 {
|
|
|
|
w.str = append(w.str, 0x80)
|
|
|
|
} else if i < 128 {
|
|
|
|
// fits single byte
|
|
|
|
w.str = append(w.str, byte(i))
|
|
|
|
} else {
|
|
|
|
// TODO: encode int to w.str directly
|
|
|
|
s := putint(w.sizebuf[1:], i)
|
|
|
|
w.sizebuf[0] = 0x80 + byte(s)
|
|
|
|
w.str = append(w.str, w.sizebuf[:s+1]...)
|
|
|
|
}
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func writeBigIntPtr(val reflect.Value, w *encbuf) error {
|
2015-03-17 22:49:49 +00:00
|
|
|
ptr := val.Interface().(*big.Int)
|
|
|
|
if ptr == nil {
|
|
|
|
w.str = append(w.str, 0x80)
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
return writeBigInt(ptr, w)
|
2014-12-30 10:40:32 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
func writeBigIntNoPtr(val reflect.Value, w *encbuf) error {
|
|
|
|
i := val.Interface().(big.Int)
|
|
|
|
return writeBigInt(&i, w)
|
|
|
|
}
|
|
|
|
|
|
|
|
func writeBigInt(i *big.Int, w *encbuf) error {
|
|
|
|
if cmp := i.Cmp(big0); cmp == -1 {
|
|
|
|
return fmt.Errorf("rlp: cannot encode negative *big.Int")
|
|
|
|
} else if cmp == 0 {
|
|
|
|
w.str = append(w.str, 0x80)
|
|
|
|
} else {
|
|
|
|
w.encodeString(i.Bytes())
|
|
|
|
}
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func writeBytes(val reflect.Value, w *encbuf) error {
|
|
|
|
w.encodeString(val.Bytes())
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
2015-01-30 15:52:48 +00:00
|
|
|
func writeByteArray(val reflect.Value, w *encbuf) error {
|
|
|
|
if !val.CanAddr() {
|
|
|
|
// Slice requires the value to be addressable.
|
|
|
|
// Make it addressable by copying.
|
|
|
|
copy := reflect.New(val.Type()).Elem()
|
|
|
|
copy.Set(val)
|
|
|
|
val = copy
|
|
|
|
}
|
|
|
|
size := val.Len()
|
|
|
|
slice := val.Slice(0, size).Bytes()
|
|
|
|
w.encodeString(slice)
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
2014-12-30 10:40:32 +00:00
|
|
|
func writeString(val reflect.Value, w *encbuf) error {
|
|
|
|
s := val.String()
|
2015-03-19 11:15:43 +00:00
|
|
|
if len(s) == 1 && s[0] <= 0x7f {
|
|
|
|
// fits single byte, no string header
|
|
|
|
w.str = append(w.str, s[0])
|
|
|
|
} else {
|
|
|
|
w.encodeStringHeader(len(s))
|
|
|
|
w.str = append(w.str, s...)
|
|
|
|
}
|
2014-12-30 10:40:32 +00:00
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func writeEncoder(val reflect.Value, w *encbuf) error {
|
|
|
|
return val.Interface().(Encoder).EncodeRLP(w)
|
|
|
|
}
|
|
|
|
|
|
|
|
// writeEncoderNoPtr handles non-pointer values that implement Encoder
|
|
|
|
// with a pointer receiver.
|
|
|
|
func writeEncoderNoPtr(val reflect.Value, w *encbuf) error {
|
|
|
|
if !val.CanAddr() {
|
|
|
|
// We can't get the address. It would be possible make the
|
|
|
|
// value addressable by creating a shallow copy, but this
|
|
|
|
// creates other problems so we're not doing it (yet).
|
|
|
|
//
|
|
|
|
// package json simply doesn't call MarshalJSON for cases like
|
|
|
|
// this, but encodes the value as if it didn't implement the
|
|
|
|
// interface. We don't want to handle it that way.
|
|
|
|
return fmt.Errorf("rlp: game over: unadressable value of type %v, EncodeRLP is pointer method", val.Type())
|
|
|
|
}
|
|
|
|
return val.Addr().Interface().(Encoder).EncodeRLP(w)
|
|
|
|
}
|
|
|
|
|
|
|
|
func writeInterface(val reflect.Value, w *encbuf) error {
|
|
|
|
if val.IsNil() {
|
|
|
|
// Write empty list. This is consistent with the previous RLP
|
|
|
|
// encoder that we had and should therefore avoid any
|
|
|
|
// problems.
|
|
|
|
w.str = append(w.str, 0xC0)
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
eval := val.Elem()
|
|
|
|
ti, err := cachedTypeInfo(eval.Type())
|
|
|
|
if err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
return ti.writer(eval, w)
|
|
|
|
}
|
|
|
|
|
|
|
|
func makeSliceWriter(typ reflect.Type) (writer, error) {
|
|
|
|
etypeinfo, err := cachedTypeInfo1(typ.Elem())
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
writer := func(val reflect.Value, w *encbuf) error {
|
|
|
|
lh := w.list()
|
|
|
|
vlen := val.Len()
|
|
|
|
for i := 0; i < vlen; i++ {
|
|
|
|
if err := etypeinfo.writer(val.Index(i), w); err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
w.listEnd(lh)
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
return writer, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func makeStructWriter(typ reflect.Type) (writer, error) {
|
|
|
|
fields, err := structFields(typ)
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
writer := func(val reflect.Value, w *encbuf) error {
|
|
|
|
lh := w.list()
|
|
|
|
for _, f := range fields {
|
|
|
|
if err := f.info.writer(val.Field(f.index), w); err != nil {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
w.listEnd(lh)
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
return writer, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func makePtrWriter(typ reflect.Type) (writer, error) {
|
|
|
|
etypeinfo, err := cachedTypeInfo1(typ.Elem())
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
zero := reflect.Zero(typ.Elem())
|
|
|
|
kind := typ.Elem().Kind()
|
|
|
|
writer := func(val reflect.Value, w *encbuf) error {
|
|
|
|
switch {
|
|
|
|
case !val.IsNil():
|
|
|
|
return etypeinfo.writer(val.Elem(), w)
|
|
|
|
case kind == reflect.Struct:
|
|
|
|
// encoding the zero value of a struct could trigger
|
|
|
|
// infinite recursion, avoid that.
|
|
|
|
w.listEnd(w.list())
|
|
|
|
return nil
|
|
|
|
default:
|
|
|
|
return etypeinfo.writer(zero, w)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return writer, err
|
|
|
|
}
|
|
|
|
|
|
|
|
// putint writes i to the beginning of b in with big endian byte
|
|
|
|
// order, using the least number of bytes needed to represent i.
|
|
|
|
func putint(b []byte, i uint64) (size int) {
|
|
|
|
switch {
|
|
|
|
case i < (1 << 8):
|
|
|
|
b[0] = byte(i)
|
|
|
|
return 1
|
|
|
|
case i < (1 << 16):
|
|
|
|
b[0] = byte(i >> 8)
|
|
|
|
b[1] = byte(i)
|
|
|
|
return 2
|
|
|
|
case i < (1 << 24):
|
|
|
|
b[0] = byte(i >> 16)
|
|
|
|
b[1] = byte(i >> 8)
|
|
|
|
b[2] = byte(i)
|
|
|
|
return 3
|
|
|
|
case i < (1 << 32):
|
|
|
|
b[0] = byte(i >> 24)
|
|
|
|
b[1] = byte(i >> 16)
|
|
|
|
b[2] = byte(i >> 8)
|
|
|
|
b[3] = byte(i)
|
|
|
|
return 4
|
|
|
|
case i < (1 << 40):
|
|
|
|
b[0] = byte(i >> 32)
|
|
|
|
b[1] = byte(i >> 24)
|
|
|
|
b[2] = byte(i >> 16)
|
|
|
|
b[3] = byte(i >> 8)
|
|
|
|
b[4] = byte(i)
|
|
|
|
return 5
|
|
|
|
case i < (1 << 48):
|
|
|
|
b[0] = byte(i >> 40)
|
|
|
|
b[1] = byte(i >> 32)
|
|
|
|
b[2] = byte(i >> 24)
|
|
|
|
b[3] = byte(i >> 16)
|
|
|
|
b[4] = byte(i >> 8)
|
|
|
|
b[5] = byte(i)
|
|
|
|
return 6
|
|
|
|
case i < (1 << 56):
|
|
|
|
b[0] = byte(i >> 48)
|
|
|
|
b[1] = byte(i >> 40)
|
|
|
|
b[2] = byte(i >> 32)
|
|
|
|
b[3] = byte(i >> 24)
|
|
|
|
b[4] = byte(i >> 16)
|
|
|
|
b[5] = byte(i >> 8)
|
|
|
|
b[6] = byte(i)
|
|
|
|
return 7
|
|
|
|
default:
|
|
|
|
b[0] = byte(i >> 56)
|
|
|
|
b[1] = byte(i >> 48)
|
|
|
|
b[2] = byte(i >> 40)
|
|
|
|
b[3] = byte(i >> 32)
|
|
|
|
b[4] = byte(i >> 24)
|
|
|
|
b[5] = byte(i >> 16)
|
|
|
|
b[6] = byte(i >> 8)
|
|
|
|
b[7] = byte(i)
|
|
|
|
return 8
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// intsize computes the minimum number of bytes required to store i.
|
|
|
|
func intsize(i uint64) (size int) {
|
|
|
|
for size = 1; ; size++ {
|
|
|
|
if i >>= 8; i == 0 {
|
|
|
|
return size
|
|
|
|
}
|
|
|
|
}
|
|
|
|
panic("not reached")
|
|
|
|
}
|