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gitea/vendor/github.com/ugorji/go/codec/cbor.go

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// Copyright (c) 2012-2015 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.
package codec
import (
"math"
"reflect"
)
const (
cborMajorUint byte = iota
cborMajorNegInt
cborMajorBytes
cborMajorText
cborMajorArray
cborMajorMap
cborMajorTag
cborMajorOther
)
const (
cborBdFalse byte = 0xf4 + iota
cborBdTrue
cborBdNil
cborBdUndefined
cborBdExt
cborBdFloat16
cborBdFloat32
cborBdFloat64
)
const (
cborBdIndefiniteBytes byte = 0x5f
cborBdIndefiniteString = 0x7f
cborBdIndefiniteArray = 0x9f
cborBdIndefiniteMap = 0xbf
cborBdBreak = 0xff
)
const (
CborStreamBytes byte = 0x5f
CborStreamString = 0x7f
CborStreamArray = 0x9f
CborStreamMap = 0xbf
CborStreamBreak = 0xff
)
const (
cborBaseUint byte = 0x00
cborBaseNegInt = 0x20
cborBaseBytes = 0x40
cborBaseString = 0x60
cborBaseArray = 0x80
cborBaseMap = 0xa0
cborBaseTag = 0xc0
cborBaseSimple = 0xe0
)
// -------------------
type cborEncDriver struct {
noBuiltInTypes
encNoSeparator
e *Encoder
w encWriter
h *CborHandle
x [8]byte
}
func (e *cborEncDriver) EncodeNil() {
e.w.writen1(cborBdNil)
}
func (e *cborEncDriver) EncodeBool(b bool) {
if b {
e.w.writen1(cborBdTrue)
} else {
e.w.writen1(cborBdFalse)
}
}
func (e *cborEncDriver) EncodeFloat32(f float32) {
e.w.writen1(cborBdFloat32)
bigenHelper{e.x[:4], e.w}.writeUint32(math.Float32bits(f))
}
func (e *cborEncDriver) EncodeFloat64(f float64) {
e.w.writen1(cborBdFloat64)
bigenHelper{e.x[:8], e.w}.writeUint64(math.Float64bits(f))
}
func (e *cborEncDriver) encUint(v uint64, bd byte) {
if v <= 0x17 {
e.w.writen1(byte(v) + bd)
} else if v <= math.MaxUint8 {
e.w.writen2(bd+0x18, uint8(v))
} else if v <= math.MaxUint16 {
e.w.writen1(bd + 0x19)
bigenHelper{e.x[:2], e.w}.writeUint16(uint16(v))
} else if v <= math.MaxUint32 {
e.w.writen1(bd + 0x1a)
bigenHelper{e.x[:4], e.w}.writeUint32(uint32(v))
} else { // if v <= math.MaxUint64 {
e.w.writen1(bd + 0x1b)
bigenHelper{e.x[:8], e.w}.writeUint64(v)
}
}
func (e *cborEncDriver) EncodeInt(v int64) {
if v < 0 {
e.encUint(uint64(-1-v), cborBaseNegInt)
} else {
e.encUint(uint64(v), cborBaseUint)
}
}
func (e *cborEncDriver) EncodeUint(v uint64) {
e.encUint(v, cborBaseUint)
}
func (e *cborEncDriver) encLen(bd byte, length int) {
e.encUint(uint64(length), bd)
}
func (e *cborEncDriver) EncodeExt(rv interface{}, xtag uint64, ext Ext, en *Encoder) {
e.encUint(uint64(xtag), cborBaseTag)
if v := ext.ConvertExt(rv); v == nil {
e.EncodeNil()
} else {
en.encode(v)
}
}
func (e *cborEncDriver) EncodeRawExt(re *RawExt, en *Encoder) {
e.encUint(uint64(re.Tag), cborBaseTag)
if re.Data != nil {
en.encode(re.Data)
} else if re.Value == nil {
e.EncodeNil()
} else {
en.encode(re.Value)
}
}
func (e *cborEncDriver) EncodeArrayStart(length int) {
e.encLen(cborBaseArray, length)
}
func (e *cborEncDriver) EncodeMapStart(length int) {
e.encLen(cborBaseMap, length)
}
func (e *cborEncDriver) EncodeString(c charEncoding, v string) {
e.encLen(cborBaseString, len(v))
e.w.writestr(v)
}
func (e *cborEncDriver) EncodeSymbol(v string) {
e.EncodeString(c_UTF8, v)
}
func (e *cborEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
if c == c_RAW {
e.encLen(cborBaseBytes, len(v))
} else {
e.encLen(cborBaseString, len(v))
}
e.w.writeb(v)
}
// ----------------------
type cborDecDriver struct {
d *Decoder
h *CborHandle
r decReader
b [scratchByteArrayLen]byte
br bool // bytes reader
bdRead bool
bd byte
noBuiltInTypes
decNoSeparator
}
func (d *cborDecDriver) readNextBd() {
d.bd = d.r.readn1()
d.bdRead = true
}
func (d *cborDecDriver) ContainerType() (vt valueType) {
if d.bd == cborBdNil {
return valueTypeNil
} else if d.bd == cborBdIndefiniteBytes || (d.bd >= cborBaseBytes && d.bd < cborBaseString) {
return valueTypeBytes
} else if d.bd == cborBdIndefiniteString || (d.bd >= cborBaseString && d.bd < cborBaseArray) {
return valueTypeString
} else if d.bd == cborBdIndefiniteArray || (d.bd >= cborBaseArray && d.bd < cborBaseMap) {
return valueTypeArray
} else if d.bd == cborBdIndefiniteMap || (d.bd >= cborBaseMap && d.bd < cborBaseTag) {
return valueTypeMap
} else {
// d.d.errorf("isContainerType: unsupported parameter: %v", vt)
}
return valueTypeUnset
}
func (d *cborDecDriver) TryDecodeAsNil() bool {
if !d.bdRead {
d.readNextBd()
}
// treat Nil and Undefined as nil values
if d.bd == cborBdNil || d.bd == cborBdUndefined {
d.bdRead = false
return true
}
return false
}
func (d *cborDecDriver) CheckBreak() bool {
if !d.bdRead {
d.readNextBd()
}
if d.bd == cborBdBreak {
d.bdRead = false
return true
}
return false
}
func (d *cborDecDriver) decUint() (ui uint64) {
v := d.bd & 0x1f
if v <= 0x17 {
ui = uint64(v)
} else {
if v == 0x18 {
ui = uint64(d.r.readn1())
} else if v == 0x19 {
ui = uint64(bigen.Uint16(d.r.readx(2)))
} else if v == 0x1a {
ui = uint64(bigen.Uint32(d.r.readx(4)))
} else if v == 0x1b {
ui = uint64(bigen.Uint64(d.r.readx(8)))
} else {
d.d.errorf("decUint: Invalid descriptor: %v", d.bd)
return
}
}
return
}
func (d *cborDecDriver) decCheckInteger() (neg bool) {
if !d.bdRead {
d.readNextBd()
}
major := d.bd >> 5
if major == cborMajorUint {
} else if major == cborMajorNegInt {
neg = true
} else {
d.d.errorf("invalid major: %v (bd: %v)", major, d.bd)
return
}
return
}
func (d *cborDecDriver) DecodeInt(bitsize uint8) (i int64) {
neg := d.decCheckInteger()
ui := d.decUint()
// check if this number can be converted to an int without overflow
var overflow bool
if neg {
if i, overflow = chkOvf.SignedInt(ui + 1); overflow {
d.d.errorf("cbor: overflow converting %v to signed integer", ui+1)
return
}
i = -i
} else {
if i, overflow = chkOvf.SignedInt(ui); overflow {
d.d.errorf("cbor: overflow converting %v to signed integer", ui)
return
}
}
if chkOvf.Int(i, bitsize) {
d.d.errorf("cbor: overflow integer: %v", i)
return
}
d.bdRead = false
return
}
func (d *cborDecDriver) DecodeUint(bitsize uint8) (ui uint64) {
if d.decCheckInteger() {
d.d.errorf("Assigning negative signed value to unsigned type")
return
}
ui = d.decUint()
if chkOvf.Uint(ui, bitsize) {
d.d.errorf("cbor: overflow integer: %v", ui)
return
}
d.bdRead = false
return
}
func (d *cborDecDriver) DecodeFloat(chkOverflow32 bool) (f float64) {
if !d.bdRead {
d.readNextBd()
}
if bd := d.bd; bd == cborBdFloat16 {
f = float64(math.Float32frombits(halfFloatToFloatBits(bigen.Uint16(d.r.readx(2)))))
} else if bd == cborBdFloat32 {
f = float64(math.Float32frombits(bigen.Uint32(d.r.readx(4))))
} else if bd == cborBdFloat64 {
f = math.Float64frombits(bigen.Uint64(d.r.readx(8)))
} else if bd >= cborBaseUint && bd < cborBaseBytes {
f = float64(d.DecodeInt(64))
} else {
d.d.errorf("Float only valid from float16/32/64: Invalid descriptor: %v", bd)
return
}
if chkOverflow32 && chkOvf.Float32(f) {
d.d.errorf("cbor: float32 overflow: %v", f)
return
}
d.bdRead = false
return
}
// bool can be decoded from bool only (single byte).
func (d *cborDecDriver) DecodeBool() (b bool) {
if !d.bdRead {
d.readNextBd()
}
if bd := d.bd; bd == cborBdTrue {
b = true
} else if bd == cborBdFalse {
} else {
d.d.errorf("Invalid single-byte value for bool: %s: %x", msgBadDesc, d.bd)
return
}
d.bdRead = false
return
}
func (d *cborDecDriver) ReadMapStart() (length int) {
d.bdRead = false
if d.bd == cborBdIndefiniteMap {
return -1
}
return d.decLen()
}
func (d *cborDecDriver) ReadArrayStart() (length int) {
d.bdRead = false
if d.bd == cborBdIndefiniteArray {
return -1
}
return d.decLen()
}
func (d *cborDecDriver) decLen() int {
return int(d.decUint())
}
func (d *cborDecDriver) decAppendIndefiniteBytes(bs []byte) []byte {
d.bdRead = false
for {
if d.CheckBreak() {
break
}
if major := d.bd >> 5; major != cborMajorBytes && major != cborMajorText {
d.d.errorf("cbor: expect bytes or string major type in indefinite string/bytes; got: %v, byte: %v", major, d.bd)
return nil
}
n := d.decLen()
oldLen := len(bs)
newLen := oldLen + n
if newLen > cap(bs) {
bs2 := make([]byte, newLen, 2*cap(bs)+n)
copy(bs2, bs)
bs = bs2
} else {
bs = bs[:newLen]
}
d.r.readb(bs[oldLen:newLen])
// bs = append(bs, d.r.readn()...)
d.bdRead = false
}
d.bdRead = false
return bs
}
func (d *cborDecDriver) DecodeBytes(bs []byte, isstring, zerocopy bool) (bsOut []byte) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == cborBdNil || d.bd == cborBdUndefined {
d.bdRead = false
return nil
}
if d.bd == cborBdIndefiniteBytes || d.bd == cborBdIndefiniteString {
if bs == nil {
return d.decAppendIndefiniteBytes(nil)
}
return d.decAppendIndefiniteBytes(bs[:0])
}
clen := d.decLen()
d.bdRead = false
if zerocopy {
if d.br {
return d.r.readx(clen)
} else if len(bs) == 0 {
bs = d.b[:]
}
}
return decByteSlice(d.r, clen, bs)
}
func (d *cborDecDriver) DecodeString() (s string) {
return string(d.DecodeBytes(d.b[:], true, true))
}
func (d *cborDecDriver) DecodeExt(rv interface{}, xtag uint64, ext Ext) (realxtag uint64) {
if !d.bdRead {
d.readNextBd()
}
u := d.decUint()
d.bdRead = false
realxtag = u
if ext == nil {
re := rv.(*RawExt)
re.Tag = realxtag
d.d.decode(&re.Value)
} else if xtag != realxtag {
d.d.errorf("Wrong extension tag. Got %b. Expecting: %v", realxtag, xtag)
return
} else {
var v interface{}
d.d.decode(&v)
ext.UpdateExt(rv, v)
}
d.bdRead = false
return
}
func (d *cborDecDriver) DecodeNaked() {
if !d.bdRead {
d.readNextBd()
}
n := &d.d.n
var decodeFurther bool
switch d.bd {
case cborBdNil:
n.v = valueTypeNil
case cborBdFalse:
n.v = valueTypeBool
n.b = false
case cborBdTrue:
n.v = valueTypeBool
n.b = true
case cborBdFloat16, cborBdFloat32:
n.v = valueTypeFloat
n.f = d.DecodeFloat(true)
case cborBdFloat64:
n.v = valueTypeFloat
n.f = d.DecodeFloat(false)
case cborBdIndefiniteBytes:
n.v = valueTypeBytes
n.l = d.DecodeBytes(nil, false, false)
case cborBdIndefiniteString:
n.v = valueTypeString
n.s = d.DecodeString()
case cborBdIndefiniteArray:
n.v = valueTypeArray
decodeFurther = true
case cborBdIndefiniteMap:
n.v = valueTypeMap
decodeFurther = true
default:
switch {
case d.bd >= cborBaseUint && d.bd < cborBaseNegInt:
if d.h.SignedInteger {
n.v = valueTypeInt
n.i = d.DecodeInt(64)
} else {
n.v = valueTypeUint
n.u = d.DecodeUint(64)
}
case d.bd >= cborBaseNegInt && d.bd < cborBaseBytes:
n.v = valueTypeInt
n.i = d.DecodeInt(64)
case d.bd >= cborBaseBytes && d.bd < cborBaseString:
n.v = valueTypeBytes
n.l = d.DecodeBytes(nil, false, false)
case d.bd >= cborBaseString && d.bd < cborBaseArray:
n.v = valueTypeString
n.s = d.DecodeString()
case d.bd >= cborBaseArray && d.bd < cborBaseMap:
n.v = valueTypeArray
decodeFurther = true
case d.bd >= cborBaseMap && d.bd < cborBaseTag:
n.v = valueTypeMap
decodeFurther = true
case d.bd >= cborBaseTag && d.bd < cborBaseSimple:
n.v = valueTypeExt
n.u = d.decUint()
n.l = nil
// d.bdRead = false
// d.d.decode(&re.Value) // handled by decode itself.
// decodeFurther = true
default:
d.d.errorf("decodeNaked: Unrecognized d.bd: 0x%x", d.bd)
return
}
}
if !decodeFurther {
d.bdRead = false
}
return
}
// -------------------------
// CborHandle is a Handle for the CBOR encoding format,
// defined at http://tools.ietf.org/html/rfc7049 and documented further at http://cbor.io .
//
// CBOR is comprehensively supported, including support for:
// - indefinite-length arrays/maps/bytes/strings
// - (extension) tags in range 0..0xffff (0 .. 65535)
// - half, single and double-precision floats
// - all numbers (1, 2, 4 and 8-byte signed and unsigned integers)
// - nil, true, false, ...
// - arrays and maps, bytes and text strings
//
// None of the optional extensions (with tags) defined in the spec are supported out-of-the-box.
// Users can implement them as needed (using SetExt), including spec-documented ones:
// - timestamp, BigNum, BigFloat, Decimals, Encoded Text (e.g. URL, regexp, base64, MIME Message), etc.
//
// To encode with indefinite lengths (streaming), users will use
// (Must)Encode methods of *Encoder, along with writing CborStreamXXX constants.
//
// For example, to encode "one-byte" as an indefinite length string:
// var buf bytes.Buffer
// e := NewEncoder(&buf, new(CborHandle))
// buf.WriteByte(CborStreamString)
// e.MustEncode("one-")
// e.MustEncode("byte")
// buf.WriteByte(CborStreamBreak)
// encodedBytes := buf.Bytes()
// var vv interface{}
// NewDecoderBytes(buf.Bytes(), new(CborHandle)).MustDecode(&vv)
// // Now, vv contains the same string "one-byte"
//
type CborHandle struct {
binaryEncodingType
BasicHandle
}
func (h *CborHandle) SetInterfaceExt(rt reflect.Type, tag uint64, ext InterfaceExt) (err error) {
return h.SetExt(rt, tag, &setExtWrapper{i: ext})
}
func (h *CborHandle) newEncDriver(e *Encoder) encDriver {
return &cborEncDriver{e: e, w: e.w, h: h}
}
func (h *CborHandle) newDecDriver(d *Decoder) decDriver {
return &cborDecDriver{d: d, r: d.r, h: h, br: d.bytes}
}
func (e *cborEncDriver) reset() {
e.w = e.e.w
}
func (d *cborDecDriver) reset() {
d.r = d.d.r
d.bd, d.bdRead = 0, false
}
var _ decDriver = (*cborDecDriver)(nil)
var _ encDriver = (*cborEncDriver)(nil)