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

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2023-12-21 18:36:51 +08:00
// Copyright (c) 2012-2020 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"
"time"
)
// major
const (
cborMajorUint byte = iota
cborMajorNegInt
cborMajorBytes
cborMajorString
cborMajorArray
cborMajorMap
cborMajorTag
cborMajorSimpleOrFloat
)
// simple
const (
cborBdFalse byte = 0xf4 + iota
cborBdTrue
cborBdNil
cborBdUndefined
cborBdExt
cborBdFloat16
cborBdFloat32
cborBdFloat64
)
// indefinite
const (
cborBdIndefiniteBytes byte = 0x5f
cborBdIndefiniteString byte = 0x7f
cborBdIndefiniteArray byte = 0x9f
cborBdIndefiniteMap byte = 0xbf
cborBdBreak byte = 0xff
)
// These define some in-stream descriptors for
// manual encoding e.g. when doing explicit indefinite-length
const (
CborStreamBytes byte = 0x5f
CborStreamString byte = 0x7f
CborStreamArray byte = 0x9f
CborStreamMap byte = 0xbf
CborStreamBreak byte = 0xff
)
// base values
const (
cborBaseUint byte = 0x00
cborBaseNegInt byte = 0x20
cborBaseBytes byte = 0x40
cborBaseString byte = 0x60
cborBaseArray byte = 0x80
cborBaseMap byte = 0xa0
cborBaseTag byte = 0xc0
cborBaseSimple byte = 0xe0
)
// const (
// cborSelfDesrTag byte = 0xd9
// cborSelfDesrTag2 byte = 0xd9
// cborSelfDesrTag3 byte = 0xf7
// )
var (
cbordescSimpleNames = map[byte]string{
cborBdNil: "nil",
cborBdFalse: "false",
cborBdTrue: "true",
cborBdFloat16: "float",
cborBdFloat32: "float",
cborBdFloat64: "float",
cborBdBreak: "break",
}
cbordescIndefNames = map[byte]string{
cborBdIndefiniteBytes: "bytes*",
cborBdIndefiniteString: "string*",
cborBdIndefiniteArray: "array*",
cborBdIndefiniteMap: "map*",
}
cbordescMajorNames = map[byte]string{
cborMajorUint: "(u)int",
cborMajorNegInt: "int",
cborMajorBytes: "bytes",
cborMajorString: "string",
cborMajorArray: "array",
cborMajorMap: "map",
cborMajorTag: "tag",
cborMajorSimpleOrFloat: "simple",
}
)
func cbordesc(bd byte) (s string) {
bm := bd >> 5
if bm == cborMajorSimpleOrFloat {
s = cbordescSimpleNames[bd]
} else {
s = cbordescMajorNames[bm]
if s == "" {
s = cbordescIndefNames[bd]
}
}
if s == "" {
s = "unknown"
}
return
}
// -------------------
type cborEncDriver struct {
noBuiltInTypes
encDriverNoState
encDriverNoopContainerWriter
h *CborHandle
e Encoder
}
func (e *cborEncDriver) encoder() *Encoder {
return &e.e
}
func (e *cborEncDriver) EncodeNil() {
e.e.encWr.writen1(cborBdNil)
}
func (e *cborEncDriver) EncodeBool(b bool) {
if b {
e.e.encWr.writen1(cborBdTrue)
} else {
e.e.encWr.writen1(cborBdFalse)
}
}
func (e *cborEncDriver) EncodeFloat32(f float32) {
b := math.Float32bits(f)
if e.h.OptimumSize {
if h := floatToHalfFloatBits(b); halfFloatToFloatBits(h) == b {
e.e.encWr.writen1(cborBdFloat16)
bigen.writeUint16(e.e.w(), h)
return
}
}
e.e.encWr.writen1(cborBdFloat32)
bigen.writeUint32(e.e.w(), b)
}
func (e *cborEncDriver) EncodeFloat64(f float64) {
if e.h.OptimumSize {
if f32 := float32(f); float64(f32) == f {
e.EncodeFloat32(f32)
return
}
}
e.e.encWr.writen1(cborBdFloat64)
bigen.writeUint64(e.e.w(), math.Float64bits(f))
}
func (e *cborEncDriver) encUint(v uint64, bd byte) {
if v <= 0x17 {
e.e.encWr.writen1(byte(v) + bd)
} else if v <= math.MaxUint8 {
e.e.encWr.writen2(bd+0x18, uint8(v))
} else if v <= math.MaxUint16 {
e.e.encWr.writen1(bd + 0x19)
bigen.writeUint16(e.e.w(), uint16(v))
} else if v <= math.MaxUint32 {
e.e.encWr.writen1(bd + 0x1a)
bigen.writeUint32(e.e.w(), uint32(v))
} else { // if v <= math.MaxUint64 {
e.e.encWr.writen1(bd + 0x1b)
bigen.writeUint64(e.e.w(), 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) EncodeTime(t time.Time) {
if t.IsZero() {
e.EncodeNil()
} else if e.h.TimeRFC3339 {
e.encUint(0, cborBaseTag)
e.encStringBytesS(cborBaseString, t.Format(time.RFC3339Nano))
} else {
e.encUint(1, cborBaseTag)
t = t.UTC().Round(time.Microsecond)
sec, nsec := t.Unix(), uint64(t.Nanosecond())
if nsec == 0 {
e.EncodeInt(sec)
} else {
e.EncodeFloat64(float64(sec) + float64(nsec)/1e9)
}
}
}
func (e *cborEncDriver) EncodeExt(rv interface{}, basetype reflect.Type, xtag uint64, ext Ext) {
e.encUint(uint64(xtag), cborBaseTag)
if ext == SelfExt {
e.e.encodeValue(baseRV(rv), e.h.fnNoExt(basetype))
} else if v := ext.ConvertExt(rv); v == nil {
e.EncodeNil()
} else {
e.e.encode(v)
}
}
func (e *cborEncDriver) EncodeRawExt(re *RawExt) {
e.encUint(uint64(re.Tag), cborBaseTag)
// only encodes re.Value (never re.Data)
if re.Value != nil {
e.e.encode(re.Value)
} else {
e.EncodeNil()
}
}
func (e *cborEncDriver) WriteArrayStart(length int) {
if e.h.IndefiniteLength {
e.e.encWr.writen1(cborBdIndefiniteArray)
} else {
e.encLen(cborBaseArray, length)
}
}
func (e *cborEncDriver) WriteMapStart(length int) {
if e.h.IndefiniteLength {
e.e.encWr.writen1(cborBdIndefiniteMap)
} else {
e.encLen(cborBaseMap, length)
}
}
func (e *cborEncDriver) WriteMapEnd() {
if e.h.IndefiniteLength {
e.e.encWr.writen1(cborBdBreak)
}
}
func (e *cborEncDriver) WriteArrayEnd() {
if e.h.IndefiniteLength {
e.e.encWr.writen1(cborBdBreak)
}
}
func (e *cborEncDriver) EncodeString(v string) {
bb := cborBaseString
if e.h.StringToRaw {
bb = cborBaseBytes
}
e.encStringBytesS(bb, v)
}
func (e *cborEncDriver) EncodeStringBytesRaw(v []byte) {
if v == nil {
e.EncodeNil()
} else {
e.encStringBytesS(cborBaseBytes, stringView(v))
}
}
func (e *cborEncDriver) encStringBytesS(bb byte, v string) {
if e.h.IndefiniteLength {
if bb == cborBaseBytes {
e.e.encWr.writen1(cborBdIndefiniteBytes)
} else {
e.e.encWr.writen1(cborBdIndefiniteString)
}
var vlen uint = uint(len(v))
blen := vlen / 4
if blen == 0 {
blen = 64
} else if blen > 1024 {
blen = 1024
}
for i := uint(0); i < vlen; {
var v2 string
i2 := i + blen
if i2 >= i && i2 < vlen {
v2 = v[i:i2]
} else {
v2 = v[i:]
}
e.encLen(bb, len(v2))
e.e.encWr.writestr(v2)
i = i2
}
e.e.encWr.writen1(cborBdBreak)
} else {
e.encLen(bb, len(v))
e.e.encWr.writestr(v)
}
}
// ----------------------
type cborDecDriver struct {
decDriverNoopContainerReader
decDriverNoopNumberHelper
h *CborHandle
bdAndBdread
st bool // skip tags
_ bool // found nil
noBuiltInTypes
d Decoder
}
func (d *cborDecDriver) decoder() *Decoder {
return &d.d
}
func (d *cborDecDriver) descBd() string {
return sprintf("%v (%s)", d.bd, cbordesc(d.bd))
}
func (d *cborDecDriver) readNextBd() {
d.bd = d.d.decRd.readn1()
d.bdRead = true
}
func (d *cborDecDriver) advanceNil() (null bool) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == cborBdNil || d.bd == cborBdUndefined {
d.bdRead = false
return true // null = true
}
return
}
func (d *cborDecDriver) TryNil() bool {
return d.advanceNil()
}
// skipTags is called to skip any tags in the stream.
//
// Since any value can be tagged, then we should call skipTags
// before any value is decoded.
//
// By definition, skipTags should not be called before
// checking for break, or nil or undefined.
func (d *cborDecDriver) skipTags() {
for d.bd>>5 == cborMajorTag {
d.decUint()
d.bd = d.d.decRd.readn1()
}
}
func (d *cborDecDriver) ContainerType() (vt valueType) {
if !d.bdRead {
d.readNextBd()
}
if d.st {
d.skipTags()
}
if d.bd == cborBdNil {
d.bdRead = false // always consume nil after seeing it in container type
return valueTypeNil
}
major := d.bd >> 5
if major == cborMajorBytes {
return valueTypeBytes
} else if major == cborMajorString {
return valueTypeString
} else if major == cborMajorArray {
return valueTypeArray
} else if major == cborMajorMap {
return valueTypeMap
}
return valueTypeUnset
}
func (d *cborDecDriver) CheckBreak() (v bool) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == cborBdBreak {
d.bdRead = false
v = true
}
return
}
func (d *cborDecDriver) decUint() (ui uint64) {
v := d.bd & 0x1f
if v <= 0x17 {
ui = uint64(v)
} else if v == 0x18 {
ui = uint64(d.d.decRd.readn1())
} else if v == 0x19 {
ui = uint64(bigen.Uint16(d.d.decRd.readn2()))
} else if v == 0x1a {
ui = uint64(bigen.Uint32(d.d.decRd.readn4()))
} else if v == 0x1b {
ui = uint64(bigen.Uint64(d.d.decRd.readn8()))
} else {
d.d.errorf("invalid descriptor decoding uint: %x/%s", d.bd, cbordesc(d.bd))
}
return
}
func (d *cborDecDriver) decLen() int {
return int(d.decUint())
}
func (d *cborDecDriver) decAppendIndefiniteBytes(bs []byte) []byte {
d.bdRead = false
for !d.CheckBreak() {
if major := d.bd >> 5; major != cborMajorBytes && major != cborMajorString {
d.d.errorf("invalid indefinite string/bytes %x (%s); got major %v, expected %v or %v",
d.bd, cbordesc(d.bd), major, cborMajorBytes, cborMajorString)
}
n := uint(d.decLen())
oldLen := uint(len(bs))
newLen := oldLen + n
if newLen > uint(cap(bs)) {
bs2 := make([]byte, newLen, 2*uint(cap(bs))+n)
copy(bs2, bs)
bs = bs2
} else {
bs = bs[:newLen]
}
d.d.decRd.readb(bs[oldLen:newLen])
d.bdRead = false
}
d.bdRead = false
return bs
}
func (d *cborDecDriver) decFloat() (f float64, ok bool) {
ok = true
switch d.bd {
case cborBdFloat16:
f = float64(math.Float32frombits(halfFloatToFloatBits(bigen.Uint16(d.d.decRd.readn2()))))
case cborBdFloat32:
f = float64(math.Float32frombits(bigen.Uint32(d.d.decRd.readn4())))
case cborBdFloat64:
f = math.Float64frombits(bigen.Uint64(d.d.decRd.readn8()))
default:
ok = false
}
return
}
func (d *cborDecDriver) decInteger() (ui uint64, neg, ok bool) {
ok = true
switch d.bd >> 5 {
case cborMajorUint:
ui = d.decUint()
case cborMajorNegInt:
ui = d.decUint()
neg = true
default:
ok = false
}
return
}
func (d *cborDecDriver) DecodeInt64() (i int64) {
if d.advanceNil() {
return
}
if d.st {
d.skipTags()
}
i = decNegintPosintFloatNumberHelper{&d.d}.int64(d.decInteger())
d.bdRead = false
return
}
func (d *cborDecDriver) DecodeUint64() (ui uint64) {
if d.advanceNil() {
return
}
if d.st {
d.skipTags()
}
ui = decNegintPosintFloatNumberHelper{&d.d}.uint64(d.decInteger())
d.bdRead = false
return
}
func (d *cborDecDriver) DecodeFloat64() (f float64) {
if d.advanceNil() {
return
}
if d.st {
d.skipTags()
}
f = decNegintPosintFloatNumberHelper{&d.d}.float64(d.decFloat())
d.bdRead = false
return
}
// bool can be decoded from bool only (single byte).
func (d *cborDecDriver) DecodeBool() (b bool) {
if d.advanceNil() {
return
}
if d.st {
d.skipTags()
}
if d.bd == cborBdTrue {
b = true
} else if d.bd == cborBdFalse {
} else {
d.d.errorf("not bool - %s %x/%s", msgBadDesc, d.bd, cbordesc(d.bd))
}
d.bdRead = false
return
}
func (d *cborDecDriver) ReadMapStart() (length int) {
if d.advanceNil() {
return containerLenNil
}
if d.st {
d.skipTags()
}
d.bdRead = false
if d.bd == cborBdIndefiniteMap {
return containerLenUnknown
}
if d.bd>>5 != cborMajorMap {
d.d.errorf("error reading map; got major type: %x, expected %x/%s", d.bd>>5, cborMajorMap, cbordesc(d.bd))
}
return d.decLen()
}
func (d *cborDecDriver) ReadArrayStart() (length int) {
if d.advanceNil() {
return containerLenNil
}
if d.st {
d.skipTags()
}
d.bdRead = false
if d.bd == cborBdIndefiniteArray {
return containerLenUnknown
}
if d.bd>>5 != cborMajorArray {
d.d.errorf("invalid array; got major type: %x, expect: %x/%s", d.bd>>5, cborMajorArray, cbordesc(d.bd))
}
return d.decLen()
}
func (d *cborDecDriver) DecodeBytes(bs []byte) (bsOut []byte) {
d.d.decByteState = decByteStateNone
if d.advanceNil() {
return
}
if d.st {
d.skipTags()
}
if d.bd == cborBdIndefiniteBytes || d.bd == cborBdIndefiniteString {
d.bdRead = false
if bs == nil {
d.d.decByteState = decByteStateReuseBuf
return d.decAppendIndefiniteBytes(d.d.b[:0])
}
return d.decAppendIndefiniteBytes(bs[:0])
}
if d.bd == cborBdIndefiniteArray {
d.bdRead = false
if bs == nil {
d.d.decByteState = decByteStateReuseBuf
bs = d.d.b[:0]
} else {
bs = bs[:0]
}
for !d.CheckBreak() {
bs = append(bs, uint8(chkOvf.UintV(d.DecodeUint64(), 8)))
}
return bs
}
if d.bd>>5 == cborMajorArray {
d.bdRead = false
if bs == nil {
d.d.decByteState = decByteStateReuseBuf
bs = d.d.b[:]
}
slen := d.decLen()
var changed bool
if bs, changed = usableByteSlice(bs, slen); changed {
d.d.decByteState = decByteStateNone
}
for i := 0; i < len(bs); i++ {
bs[i] = uint8(chkOvf.UintV(d.DecodeUint64(), 8))
}
return bs
}
clen := d.decLen()
d.bdRead = false
if d.d.zerocopy() {
d.d.decByteState = decByteStateZerocopy
return d.d.decRd.rb.readx(uint(clen))
}
if bs == nil {
d.d.decByteState = decByteStateReuseBuf
bs = d.d.b[:]
}
return decByteSlice(d.d.r(), clen, d.h.MaxInitLen, bs)
}
func (d *cborDecDriver) DecodeStringAsBytes() (s []byte) {
return d.DecodeBytes(nil)
}
func (d *cborDecDriver) DecodeTime() (t time.Time) {
if d.advanceNil() {
return
}
if d.bd>>5 != cborMajorTag {
d.d.errorf("error reading tag; expected major type: %x, got: %x", cborMajorTag, d.bd>>5)
}
xtag := d.decUint()
d.bdRead = false
return d.decodeTime(xtag)
}
func (d *cborDecDriver) decodeTime(xtag uint64) (t time.Time) {
switch xtag {
case 0:
var err error
t, err = time.Parse(time.RFC3339, stringView(d.DecodeStringAsBytes()))
d.d.onerror(err)
case 1:
f1, f2 := math.Modf(d.DecodeFloat64())
t = time.Unix(int64(f1), int64(f2*1e9))
default:
d.d.errorf("invalid tag for time.Time - expecting 0 or 1, got 0x%x", xtag)
}
t = t.UTC().Round(time.Microsecond)
return
}
func (d *cborDecDriver) DecodeExt(rv interface{}, basetype reflect.Type, xtag uint64, ext Ext) {
if d.advanceNil() {
return
}
if d.bd>>5 != cborMajorTag {
d.d.errorf("error reading tag; expected major type: %x, got: %x", cborMajorTag, d.bd>>5)
}
realxtag := d.decUint()
d.bdRead = false
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)
} else if ext == SelfExt {
d.d.decodeValue(baseRV(rv), d.h.fnNoExt(basetype))
} else {
d.d.interfaceExtConvertAndDecode(rv, ext)
}
d.bdRead = false
}
func (d *cborDecDriver) DecodeNaked() {
if !d.bdRead {
d.readNextBd()
}
n := d.d.naked()
var decodeFurther bool
switch d.bd >> 5 {
case cborMajorUint:
if d.h.SignedInteger {
n.v = valueTypeInt
n.i = d.DecodeInt64()
} else {
n.v = valueTypeUint
n.u = d.DecodeUint64()
}
case cborMajorNegInt:
n.v = valueTypeInt
n.i = d.DecodeInt64()
case cborMajorBytes:
d.d.fauxUnionReadRawBytes(false)
case cborMajorString:
n.v = valueTypeString
n.s = d.d.stringZC(d.DecodeStringAsBytes())
case cborMajorArray:
n.v = valueTypeArray
decodeFurther = true
case cborMajorMap:
n.v = valueTypeMap
decodeFurther = true
case cborMajorTag:
n.v = valueTypeExt
n.u = d.decUint()
n.l = nil
if n.u == 0 || n.u == 1 {
d.bdRead = false
n.v = valueTypeTime
n.t = d.decodeTime(n.u)
} else if d.st && d.h.getExtForTag(n.u) == nil {
// d.skipTags() // no need to call this - tags already skipped
d.bdRead = false
d.DecodeNaked()
return // return when done (as true recursive function)
}
case cborMajorSimpleOrFloat:
switch d.bd {
case cborBdNil, cborBdUndefined:
n.v = valueTypeNil
case cborBdFalse:
n.v = valueTypeBool
n.b = false
case cborBdTrue:
n.v = valueTypeBool
n.b = true
case cborBdFloat16, cborBdFloat32, cborBdFloat64:
n.v = valueTypeFloat
n.f = d.DecodeFloat64()
default:
d.d.errorf("decodeNaked: Unrecognized d.bd: 0x%x", d.bd)
}
default: // should never happen
d.d.errorf("decodeNaked: Unrecognized d.bd: 0x%x", d.bd)
}
if !decodeFurther {
d.bdRead = false
}
}
func (d *cborDecDriver) uintBytes() (v []byte, ui uint64) {
// this is only used by nextValueBytes, so it's ok to
// use readx and bigenstd here.
switch vv := d.bd & 0x1f; vv {
case 0x18:
v = d.d.decRd.readx(1)
ui = uint64(v[0])
case 0x19:
v = d.d.decRd.readx(2)
ui = uint64(bigenstd.Uint16(v))
case 0x1a:
v = d.d.decRd.readx(4)
ui = uint64(bigenstd.Uint32(v))
case 0x1b:
v = d.d.decRd.readx(8)
ui = uint64(bigenstd.Uint64(v))
default:
if vv > 0x1b {
d.d.errorf("invalid descriptor decoding uint: %x/%s", d.bd, cbordesc(d.bd))
}
ui = uint64(vv)
}
return
}
func (d *cborDecDriver) nextValueBytes(v0 []byte) (v []byte) {
if !d.bdRead {
d.readNextBd()
}
v = v0
var h = decNextValueBytesHelper{d: &d.d}
var cursor = d.d.rb.c - 1
h.append1(&v, d.bd)
v = d.nextValueBytesBdReadR(v)
d.bdRead = false
h.bytesRdV(&v, cursor)
return
}
func (d *cborDecDriver) nextValueBytesR(v0 []byte) (v []byte) {
d.readNextBd()
v = v0
var h = decNextValueBytesHelper{d: &d.d}
h.append1(&v, d.bd)
return d.nextValueBytesBdReadR(v)
}
func (d *cborDecDriver) nextValueBytesBdReadR(v0 []byte) (v []byte) {
v = v0
var h = decNextValueBytesHelper{d: &d.d}
var bs []byte
var ui uint64
switch d.bd >> 5 {
case cborMajorUint, cborMajorNegInt:
bs, _ = d.uintBytes()
h.appendN(&v, bs...)
case cborMajorString, cborMajorBytes:
if d.bd == cborBdIndefiniteBytes || d.bd == cborBdIndefiniteString {
for {
d.readNextBd()
h.append1(&v, d.bd)
if d.bd == cborBdBreak {
break
}
bs, ui = d.uintBytes()
h.appendN(&v, bs...)
h.appendN(&v, d.d.decRd.readx(uint(ui))...)
}
} else {
bs, ui = d.uintBytes()
h.appendN(&v, bs...)
h.appendN(&v, d.d.decRd.readx(uint(ui))...)
}
case cborMajorArray:
if d.bd == cborBdIndefiniteArray {
for {
d.readNextBd()
h.append1(&v, d.bd)
if d.bd == cborBdBreak {
break
}
v = d.nextValueBytesBdReadR(v)
}
} else {
bs, ui = d.uintBytes()
h.appendN(&v, bs...)
for i := uint64(0); i < ui; i++ {
v = d.nextValueBytesR(v)
}
}
case cborMajorMap:
if d.bd == cborBdIndefiniteMap {
for {
d.readNextBd()
h.append1(&v, d.bd)
if d.bd == cborBdBreak {
break
}
v = d.nextValueBytesBdReadR(v)
v = d.nextValueBytesR(v)
}
} else {
bs, ui = d.uintBytes()
h.appendN(&v, bs...)
for i := uint64(0); i < ui; i++ {
v = d.nextValueBytesR(v)
v = d.nextValueBytesR(v)
}
}
case cborMajorTag:
bs, _ = d.uintBytes()
h.appendN(&v, bs...)
v = d.nextValueBytesR(v)
case cborMajorSimpleOrFloat:
switch d.bd {
case cborBdNil, cborBdUndefined, cborBdFalse, cborBdTrue: // pass
case cborBdFloat16:
h.appendN(&v, d.d.decRd.readx(2)...)
case cborBdFloat32:
h.appendN(&v, d.d.decRd.readx(4)...)
case cborBdFloat64:
h.appendN(&v, d.d.decRd.readx(8)...)
default:
d.d.errorf("nextValueBytes: Unrecognized d.bd: 0x%x", d.bd)
}
default: // should never happen
d.d.errorf("nextValueBytes: Unrecognized d.bd: 0x%x", d.bd)
}
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.
type CborHandle struct {
binaryEncodingType
// noElemSeparators
BasicHandle
// IndefiniteLength=true, means that we encode using indefinitelength
IndefiniteLength bool
// TimeRFC3339 says to encode time.Time using RFC3339 format.
// If unset, we encode time.Time using seconds past epoch.
TimeRFC3339 bool
// SkipUnexpectedTags says to skip over any tags for which extensions are
// not defined. This is in keeping with the cbor spec on "Optional Tagging of Items".
//
// Furthermore, this allows the skipping over of the Self Describing Tag 0xd9d9f7.
SkipUnexpectedTags bool
}
// Name returns the name of the handle: cbor
func (h *CborHandle) Name() string { return "cbor" }
func (h *CborHandle) desc(bd byte) string { return cbordesc(bd) }
func (h *CborHandle) newEncDriver() encDriver {
var e = &cborEncDriver{h: h}
e.e.e = e
e.e.init(h)
e.reset()
return e
}
func (h *CborHandle) newDecDriver() decDriver {
d := &cborDecDriver{h: h, st: h.SkipUnexpectedTags}
d.d.d = d
d.d.cbor = true
d.d.init(h)
d.reset()
return d
}
func (d *cborDecDriver) reset() {
d.bdAndBdread.reset()
d.st = d.h.SkipUnexpectedTags
}
var _ decDriver = (*cborDecDriver)(nil)
var _ encDriver = (*cborEncDriver)(nil)