syncthing/vendor/github.com/calmh/xdr/unmarshal.go

140 lines
2.6 KiB
Go
Raw Normal View History

2016-02-02 11:43:33 +00:00
// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
// All rights reserved. Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.
package xdr
import "io"
2016-02-02 11:43:33 +00:00
type Unmarshaller struct {
Error error
Data []byte
}
func (u *Unmarshaller) UnmarshalRaw(l int) []byte {
if u.Error != nil {
return nil
}
if len(u.Data) < l {
u.Error = io.ErrUnexpectedEOF
return nil
}
v := u.Data[:l]
u.Data = u.Data[l:]
return v
}
func (u *Unmarshaller) UnmarshalString() string {
return u.UnmarshalStringMax(0)
}
func (u *Unmarshaller) UnmarshalStringMax(max int) string {
buf := u.UnmarshalBytesMax(max)
if len(buf) == 0 || u.Error != nil {
return ""
}
return string(buf)
2016-02-02 11:43:33 +00:00
}
func (u *Unmarshaller) UnmarshalBytes() []byte {
return u.UnmarshalBytesMax(0)
}
func (u *Unmarshaller) UnmarshalBytesMax(max int) []byte {
if u.Error != nil {
return nil
}
if len(u.Data) < 4 {
u.Error = io.ErrUnexpectedEOF
return nil
}
l := int(u.Data[3]) | int(u.Data[2])<<8 | int(u.Data[1])<<16 | int(u.Data[0])<<24
if l == 0 {
u.Data = u.Data[4:]
return nil
}
if l < 0 || max > 0 && l > max {
// l may be negative on 32 bit builds
u.Error = ElementSizeExceeded("bytes field", l, max)
return nil
}
if len(u.Data) < l+4 {
u.Error = io.ErrUnexpectedEOF
return nil
}
v := u.Data[4 : 4+l]
u.Data = u.Data[4+l+Padding(l):]
return v
}
func (u *Unmarshaller) UnmarshalBool() bool {
return u.UnmarshalUint8() != 0
}
func (u *Unmarshaller) UnmarshalUint8() uint8 {
if u.Error != nil {
return 0
}
if len(u.Data) < 4 {
u.Error = io.ErrUnexpectedEOF
return 0
}
v := uint8(u.Data[3])
u.Data = u.Data[4:]
return v
}
func (u *Unmarshaller) UnmarshalUint16() uint16 {
if u.Error != nil {
return 0
}
if len(u.Data) < 4 {
u.Error = io.ErrUnexpectedEOF
return 0
}
v := uint16(u.Data[3]) | uint16(u.Data[2])<<8
u.Data = u.Data[4:]
return v
}
func (u *Unmarshaller) UnmarshalUint32() uint32 {
if u.Error != nil {
return 0
}
if len(u.Data) < 4 {
u.Error = io.ErrUnexpectedEOF
return 0
}
v := uint32(u.Data[3]) | uint32(u.Data[2])<<8 | uint32(u.Data[1])<<16 | uint32(u.Data[0])<<24
u.Data = u.Data[4:]
return v
}
func (u *Unmarshaller) UnmarshalUint64() uint64 {
if u.Error != nil {
return 0
}
if len(u.Data) < 8 {
u.Error = io.ErrUnexpectedEOF
return 0
}
v := uint64(u.Data[7]) | uint64(u.Data[6])<<8 | uint64(u.Data[5])<<16 | uint64(u.Data[4])<<24 |
uint64(u.Data[3])<<32 | uint64(u.Data[2])<<40 | uint64(u.Data[1])<<48 | uint64(u.Data[0])<<56
u.Data = u.Data[8:]
return v
}