gotosocial/vendor/github.com/ugorji/go/codec/binc.go

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// 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"
)
// Symbol management:
// - symbols are stored in a symbol map during encoding and decoding.
// - the symbols persist until the (En|De)coder ResetXXX method is called.
const bincDoPrune = true
// vd as low 4 bits (there are 16 slots)
const (
bincVdSpecial byte = iota
bincVdPosInt
bincVdNegInt
bincVdFloat
bincVdString
bincVdByteArray
bincVdArray
bincVdMap
bincVdTimestamp
bincVdSmallInt
_ // bincVdUnicodeOther
bincVdSymbol
_ // bincVdDecimal
_ // open slot
_ // open slot
bincVdCustomExt = 0x0f
)
const (
bincSpNil byte = iota
bincSpFalse
bincSpTrue
bincSpNan
bincSpPosInf
bincSpNegInf
bincSpZeroFloat
bincSpZero
bincSpNegOne
)
const (
_ byte = iota // bincFlBin16
bincFlBin32
_ // bincFlBin32e
bincFlBin64
_ // bincFlBin64e
// others not currently supported
)
const bincBdNil = 0 // bincVdSpecial<<4 | bincSpNil // staticcheck barfs on this (SA4016)
var (
bincdescSpecialVsNames = map[byte]string{
bincSpNil: "nil",
bincSpFalse: "false",
bincSpTrue: "true",
bincSpNan: "float",
bincSpPosInf: "float",
bincSpNegInf: "float",
bincSpZeroFloat: "float",
bincSpZero: "uint",
bincSpNegOne: "int",
}
bincdescVdNames = map[byte]string{
bincVdSpecial: "special",
bincVdSmallInt: "uint",
bincVdPosInt: "uint",
bincVdFloat: "float",
bincVdSymbol: "string",
bincVdString: "string",
bincVdByteArray: "bytes",
bincVdTimestamp: "time",
bincVdCustomExt: "ext",
bincVdArray: "array",
bincVdMap: "map",
}
)
func bincdescbd(bd byte) (s string) {
return bincdesc(bd>>4, bd&0x0f)
}
func bincdesc(vd, vs byte) (s string) {
if vd == bincVdSpecial {
s = bincdescSpecialVsNames[vs]
} else {
s = bincdescVdNames[vd]
}
if s == "" {
s = "unknown"
}
return
}
type bincEncState struct {
m map[string]uint16 // symbols
}
func (e bincEncState) captureState() interface{} { return e.m }
func (e *bincEncState) resetState() { e.m = nil }
func (e *bincEncState) reset() { e.resetState() }
func (e *bincEncState) restoreState(v interface{}) { e.m = v.(map[string]uint16) }
type bincEncDriver struct {
noBuiltInTypes
encDriverNoopContainerWriter
h *BincHandle
bincEncState
e Encoder
}
func (e *bincEncDriver) encoder() *Encoder {
return &e.e
}
func (e *bincEncDriver) EncodeNil() {
e.e.encWr.writen1(bincBdNil)
}
func (e *bincEncDriver) EncodeTime(t time.Time) {
if t.IsZero() {
e.EncodeNil()
} else {
bs := bincEncodeTime(t)
e.e.encWr.writen1(bincVdTimestamp<<4 | uint8(len(bs)))
e.e.encWr.writeb(bs)
}
}
func (e *bincEncDriver) EncodeBool(b bool) {
if b {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpTrue)
} else {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpFalse)
}
}
func (e *bincEncDriver) encSpFloat(f float64) (done bool) {
if f == 0 {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpZeroFloat)
} else if math.IsNaN(float64(f)) {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpNan)
} else if math.IsInf(float64(f), +1) {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpPosInf)
} else if math.IsInf(float64(f), -1) {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpNegInf)
} else {
return
}
return true
}
func (e *bincEncDriver) EncodeFloat32(f float32) {
if !e.encSpFloat(float64(f)) {
e.e.encWr.writen1(bincVdFloat<<4 | bincFlBin32)
bigen.writeUint32(e.e.w(), math.Float32bits(f))
}
}
func (e *bincEncDriver) EncodeFloat64(f float64) {
if e.encSpFloat(f) {
return
}
b := bigen.PutUint64(math.Float64bits(f))
if bincDoPrune {
i := 7
for ; i >= 0 && (b[i] == 0); i-- {
}
i++
if i <= 6 {
e.e.encWr.writen1(bincVdFloat<<4 | 0x8 | bincFlBin64)
e.e.encWr.writen1(byte(i))
e.e.encWr.writeb(b[:i])
return
}
}
e.e.encWr.writen1(bincVdFloat<<4 | bincFlBin64)
e.e.encWr.writen8(b)
}
func (e *bincEncDriver) encIntegerPrune32(bd byte, pos bool, v uint64) {
b := bigen.PutUint32(uint32(v))
if bincDoPrune {
i := byte(pruneSignExt(b[:], pos))
e.e.encWr.writen1(bd | 3 - i)
e.e.encWr.writeb(b[i:])
} else {
e.e.encWr.writen1(bd | 3)
e.e.encWr.writen4(b)
}
}
func (e *bincEncDriver) encIntegerPrune64(bd byte, pos bool, v uint64) {
b := bigen.PutUint64(v)
if bincDoPrune {
i := byte(pruneSignExt(b[:], pos))
e.e.encWr.writen1(bd | 7 - i)
e.e.encWr.writeb(b[i:])
} else {
e.e.encWr.writen1(bd | 7)
e.e.encWr.writen8(b)
}
}
func (e *bincEncDriver) EncodeInt(v int64) {
if v >= 0 {
e.encUint(bincVdPosInt<<4, true, uint64(v))
} else if v == -1 {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpNegOne)
} else {
e.encUint(bincVdNegInt<<4, false, uint64(-v))
}
}
func (e *bincEncDriver) EncodeUint(v uint64) {
e.encUint(bincVdPosInt<<4, true, v)
}
func (e *bincEncDriver) encUint(bd byte, pos bool, v uint64) {
if v == 0 {
e.e.encWr.writen1(bincVdSpecial<<4 | bincSpZero)
} else if pos && v >= 1 && v <= 16 {
e.e.encWr.writen1(bincVdSmallInt<<4 | byte(v-1))
} else if v <= math.MaxUint8 {
e.e.encWr.writen2(bd|0x0, byte(v))
} else if v <= math.MaxUint16 {
e.e.encWr.writen1(bd | 0x01)
bigen.writeUint16(e.e.w(), uint16(v))
} else if v <= math.MaxUint32 {
e.encIntegerPrune32(bd, pos, v)
} else {
e.encIntegerPrune64(bd, pos, v)
}
}
func (e *bincEncDriver) EncodeExt(v interface{}, basetype reflect.Type, xtag uint64, ext Ext) {
var bs0, bs []byte
if ext == SelfExt {
bs0 = e.e.blist.get(1024)
bs = bs0
e.e.sideEncode(v, basetype, &bs)
} else {
bs = ext.WriteExt(v)
}
if bs == nil {
e.EncodeNil()
goto END
}
e.encodeExtPreamble(uint8(xtag), len(bs))
e.e.encWr.writeb(bs)
END:
if ext == SelfExt {
e.e.blist.put(bs)
if !byteSliceSameData(bs0, bs) {
e.e.blist.put(bs0)
}
}
}
func (e *bincEncDriver) EncodeRawExt(re *RawExt) {
e.encodeExtPreamble(uint8(re.Tag), len(re.Data))
e.e.encWr.writeb(re.Data)
}
func (e *bincEncDriver) encodeExtPreamble(xtag byte, length int) {
e.encLen(bincVdCustomExt<<4, uint64(length))
e.e.encWr.writen1(xtag)
}
func (e *bincEncDriver) WriteArrayStart(length int) {
e.encLen(bincVdArray<<4, uint64(length))
}
func (e *bincEncDriver) WriteMapStart(length int) {
e.encLen(bincVdMap<<4, uint64(length))
}
func (e *bincEncDriver) EncodeSymbol(v string) {
//symbols only offer benefit when string length > 1.
//This is because strings with length 1 take only 2 bytes to store
//(bd with embedded length, and single byte for string val).
l := len(v)
if l == 0 {
e.encBytesLen(cUTF8, 0)
return
} else if l == 1 {
e.encBytesLen(cUTF8, 1)
e.e.encWr.writen1(v[0])
return
}
if e.m == nil {
e.m = make(map[string]uint16, 16)
}
ui, ok := e.m[v]
if ok {
if ui <= math.MaxUint8 {
e.e.encWr.writen2(bincVdSymbol<<4, byte(ui))
} else {
e.e.encWr.writen1(bincVdSymbol<<4 | 0x8)
bigen.writeUint16(e.e.w(), ui)
}
} else {
e.e.seq++
ui = e.e.seq
e.m[v] = ui
var lenprec uint8
if l <= math.MaxUint8 {
// lenprec = 0
} else if l <= math.MaxUint16 {
lenprec = 1
} else if int64(l) <= math.MaxUint32 {
lenprec = 2
} else {
lenprec = 3
}
if ui <= math.MaxUint8 {
e.e.encWr.writen2(bincVdSymbol<<4|0x0|0x4|lenprec, byte(ui))
} else {
e.e.encWr.writen1(bincVdSymbol<<4 | 0x8 | 0x4 | lenprec)
bigen.writeUint16(e.e.w(), ui)
}
if lenprec == 0 {
e.e.encWr.writen1(byte(l))
} else if lenprec == 1 {
bigen.writeUint16(e.e.w(), uint16(l))
} else if lenprec == 2 {
bigen.writeUint32(e.e.w(), uint32(l))
} else {
bigen.writeUint64(e.e.w(), uint64(l))
}
e.e.encWr.writestr(v)
}
}
func (e *bincEncDriver) EncodeString(v string) {
if e.h.StringToRaw {
e.encLen(bincVdByteArray<<4, uint64(len(v)))
if len(v) > 0 {
e.e.encWr.writestr(v)
}
return
}
e.EncodeStringEnc(cUTF8, v)
}
func (e *bincEncDriver) EncodeStringEnc(c charEncoding, v string) {
if e.e.c == containerMapKey && c == cUTF8 && (e.h.AsSymbols == 1) {
e.EncodeSymbol(v)
return
}
e.encLen(bincVdString<<4, uint64(len(v)))
if len(v) > 0 {
e.e.encWr.writestr(v)
}
}
func (e *bincEncDriver) EncodeStringBytesRaw(v []byte) {
if v == nil {
e.EncodeNil()
return
}
e.encLen(bincVdByteArray<<4, uint64(len(v)))
if len(v) > 0 {
e.e.encWr.writeb(v)
}
}
func (e *bincEncDriver) encBytesLen(c charEncoding, length uint64) {
// MARKER: we currently only support UTF-8 (string) and RAW (bytearray).
// We should consider supporting bincUnicodeOther.
if c == cRAW {
e.encLen(bincVdByteArray<<4, length)
} else {
e.encLen(bincVdString<<4, length)
}
}
func (e *bincEncDriver) encLen(bd byte, l uint64) {
if l < 12 {
e.e.encWr.writen1(bd | uint8(l+4))
} else {
e.encLenNumber(bd, l)
}
}
func (e *bincEncDriver) encLenNumber(bd byte, v uint64) {
if v <= math.MaxUint8 {
e.e.encWr.writen2(bd, byte(v))
} else if v <= math.MaxUint16 {
e.e.encWr.writen1(bd | 0x01)
bigen.writeUint16(e.e.w(), uint16(v))
} else if v <= math.MaxUint32 {
e.e.encWr.writen1(bd | 0x02)
bigen.writeUint32(e.e.w(), uint32(v))
} else {
e.e.encWr.writen1(bd | 0x03)
bigen.writeUint64(e.e.w(), uint64(v))
}
}
//------------------------------------
type bincDecState struct {
bdRead bool
bd byte
vd byte
vs byte
_ bool
// MARKER: consider using binary search here instead of a map (ie bincDecSymbol)
s map[uint16][]byte
}
func (x bincDecState) captureState() interface{} { return x }
func (x *bincDecState) resetState() { *x = bincDecState{} }
func (x *bincDecState) reset() { x.resetState() }
func (x *bincDecState) restoreState(v interface{}) { *x = v.(bincDecState) }
type bincDecDriver struct {
decDriverNoopContainerReader
decDriverNoopNumberHelper
noBuiltInTypes
h *BincHandle
bincDecState
d Decoder
}
func (d *bincDecDriver) decoder() *Decoder {
return &d.d
}
func (d *bincDecDriver) descBd() string {
return sprintf("%v (%s)", d.bd, bincdescbd(d.bd))
}
func (d *bincDecDriver) readNextBd() {
d.bd = d.d.decRd.readn1()
d.vd = d.bd >> 4
d.vs = d.bd & 0x0f
d.bdRead = true
}
func (d *bincDecDriver) advanceNil() (null bool) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == bincBdNil {
d.bdRead = false
return true // null = true
}
return
}
func (d *bincDecDriver) TryNil() bool {
return d.advanceNil()
}
func (d *bincDecDriver) ContainerType() (vt valueType) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == bincBdNil {
d.bdRead = false
return valueTypeNil
} else if d.vd == bincVdByteArray {
return valueTypeBytes
} else if d.vd == bincVdString {
return valueTypeString
} else if d.vd == bincVdArray {
return valueTypeArray
} else if d.vd == bincVdMap {
return valueTypeMap
}
return valueTypeUnset
}
func (d *bincDecDriver) DecodeTime() (t time.Time) {
if d.advanceNil() {
return
}
if d.vd != bincVdTimestamp {
d.d.errorf("cannot decode time - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
t, err := bincDecodeTime(d.d.decRd.readx(uint(d.vs)))
halt.onerror(err)
d.bdRead = false
return
}
func (d *bincDecDriver) decFloatPruned(maxlen uint8) {
l := d.d.decRd.readn1()
if l > maxlen {
d.d.errorf("cannot read float - at most %v bytes used to represent float - received %v bytes", maxlen, l)
}
for i := l; i < maxlen; i++ {
d.d.b[i] = 0
}
d.d.decRd.readb(d.d.b[0:l])
}
func (d *bincDecDriver) decFloatPre32() (b [4]byte) {
if d.vs&0x8 == 0 {
b = d.d.decRd.readn4()
} else {
d.decFloatPruned(4)
copy(b[:], d.d.b[:])
}
return
}
func (d *bincDecDriver) decFloatPre64() (b [8]byte) {
if d.vs&0x8 == 0 {
b = d.d.decRd.readn8()
} else {
d.decFloatPruned(8)
copy(b[:], d.d.b[:])
}
return
}
func (d *bincDecDriver) decFloatVal() (f float64) {
switch d.vs & 0x7 {
case bincFlBin32:
f = float64(math.Float32frombits(bigen.Uint32(d.decFloatPre32())))
case bincFlBin64:
f = math.Float64frombits(bigen.Uint64(d.decFloatPre64()))
default:
// ok = false
d.d.errorf("read float supports only float32/64 - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
return
}
func (d *bincDecDriver) decUint() (v uint64) {
switch d.vs {
case 0:
v = uint64(d.d.decRd.readn1())
case 1:
v = uint64(bigen.Uint16(d.d.decRd.readn2()))
case 2:
v = uint64(bigen.Uint32(d.d.decRd.readn3()))
case 3:
v = uint64(bigen.Uint32(d.d.decRd.readn4()))
case 4, 5, 6:
var b [8]byte
lim := 7 - d.vs
bs := d.d.b[lim:8]
d.d.decRd.readb(bs)
copy(b[lim:], bs)
v = bigen.Uint64(b)
case 7:
v = bigen.Uint64(d.d.decRd.readn8())
default:
d.d.errorf("unsigned integers with greater than 64 bits of precision not supported: d.vs: %v %x", d.vs, d.vs)
}
return
}
func (d *bincDecDriver) uintBytes() (bs []byte) {
switch d.vs {
case 0:
bs = d.d.b[:1]
bs[0] = d.d.decRd.readn1()
case 1:
bs = d.d.b[:2]
d.d.decRd.readb(bs)
case 2:
bs = d.d.b[:3]
d.d.decRd.readb(bs)
case 3:
bs = d.d.b[:4]
d.d.decRd.readb(bs)
case 4, 5, 6:
lim := 7 - d.vs
bs = d.d.b[lim:8]
d.d.decRd.readb(bs)
case 7:
bs = d.d.b[:8]
d.d.decRd.readb(bs)
default:
d.d.errorf("unsigned integers with greater than 64 bits of precision not supported: d.vs: %v %x", d.vs, d.vs)
}
return
}
func (d *bincDecDriver) decInteger() (ui uint64, neg, ok bool) {
ok = true
vd, vs := d.vd, d.vs
if vd == bincVdPosInt {
ui = d.decUint()
} else if vd == bincVdNegInt {
ui = d.decUint()
neg = true
} else if vd == bincVdSmallInt {
ui = uint64(d.vs) + 1
} else if vd == bincVdSpecial {
if vs == bincSpZero {
// i = 0
} else if vs == bincSpNegOne {
neg = true
ui = 1
} else {
ok = false
// d.d.errorf("integer decode has invalid special value %x-%x/%s", d.vd, d.vs, bincdesc(d.vd, d.vs))
}
} else {
ok = false
// d.d.errorf("integer can only be decoded from int/uint. d.bd: 0x%x, d.vd: 0x%x", d.bd, d.vd)
}
return
}
func (d *bincDecDriver) decFloat() (f float64, ok bool) {
ok = true
vd, vs := d.vd, d.vs
if vd == bincVdSpecial {
if vs == bincSpNan {
f = math.NaN()
} else if vs == bincSpPosInf {
f = math.Inf(1)
} else if vs == bincSpZeroFloat || vs == bincSpZero {
} else if vs == bincSpNegInf {
f = math.Inf(-1)
} else {
ok = false
// d.d.errorf("float - invalid special value %x-%x/%s", d.vd, d.vs, bincdesc(d.vd, d.vs))
}
} else if vd == bincVdFloat {
f = d.decFloatVal()
} else {
ok = false
}
return
}
func (d *bincDecDriver) DecodeInt64() (i int64) {
if d.advanceNil() {
return
}
i = decNegintPosintFloatNumberHelper{&d.d}.int64(d.decInteger())
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeUint64() (ui uint64) {
if d.advanceNil() {
return
}
ui = decNegintPosintFloatNumberHelper{&d.d}.uint64(d.decInteger())
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeFloat64() (f float64) {
if d.advanceNil() {
return
}
f = decNegintPosintFloatNumberHelper{&d.d}.float64(d.decFloat())
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeBool() (b bool) {
if d.advanceNil() {
return
}
if d.bd == (bincVdSpecial | bincSpFalse) {
// b = false
} else if d.bd == (bincVdSpecial | bincSpTrue) {
b = true
} else {
d.d.errorf("bool - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
d.bdRead = false
return
}
func (d *bincDecDriver) ReadMapStart() (length int) {
if d.advanceNil() {
return containerLenNil
}
if d.vd != bincVdMap {
d.d.errorf("map - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
length = d.decLen()
d.bdRead = false
return
}
func (d *bincDecDriver) ReadArrayStart() (length int) {
if d.advanceNil() {
return containerLenNil
}
if d.vd != bincVdArray {
d.d.errorf("array - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
length = d.decLen()
d.bdRead = false
return
}
func (d *bincDecDriver) decLen() int {
if d.vs > 3 {
return int(d.vs - 4)
}
return int(d.decLenNumber())
}
func (d *bincDecDriver) decLenNumber() (v uint64) {
if x := d.vs; x == 0 {
v = uint64(d.d.decRd.readn1())
} else if x == 1 {
v = uint64(bigen.Uint16(d.d.decRd.readn2()))
} else if x == 2 {
v = uint64(bigen.Uint32(d.d.decRd.readn4()))
} else {
v = bigen.Uint64(d.d.decRd.readn8())
}
return
}
// func (d *bincDecDriver) decStringBytes(bs []byte, zerocopy bool) (bs2 []byte) {
func (d *bincDecDriver) DecodeStringAsBytes() (bs2 []byte) {
d.d.decByteState = decByteStateNone
if d.advanceNil() {
return
}
var slen = -1
switch d.vd {
case bincVdString, bincVdByteArray:
slen = d.decLen()
if d.d.bytes {
d.d.decByteState = decByteStateZerocopy
bs2 = d.d.decRd.rb.readx(uint(slen))
} else {
d.d.decByteState = decByteStateReuseBuf
bs2 = decByteSlice(d.d.r(), slen, d.d.h.MaxInitLen, d.d.b[:])
}
case bincVdSymbol:
// zerocopy doesn't apply for symbols,
// as the values must be stored in a table for later use.
var symbol uint16
vs := d.vs
if vs&0x8 == 0 {
symbol = uint16(d.d.decRd.readn1())
} else {
symbol = uint16(bigen.Uint16(d.d.decRd.readn2()))
}
if d.s == nil {
d.s = make(map[uint16][]byte, 16)
}
if vs&0x4 == 0 {
bs2 = d.s[symbol]
} else {
switch vs & 0x3 {
case 0:
slen = int(d.d.decRd.readn1())
case 1:
slen = int(bigen.Uint16(d.d.decRd.readn2()))
case 2:
slen = int(bigen.Uint32(d.d.decRd.readn4()))
case 3:
slen = int(bigen.Uint64(d.d.decRd.readn8()))
}
// As we are using symbols, do not store any part of
// the parameter bs in the map, as it might be a shared buffer.
bs2 = decByteSlice(d.d.r(), slen, d.d.h.MaxInitLen, nil)
d.s[symbol] = bs2
}
default:
d.d.errorf("string/bytes - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeBytes(bs []byte) (bsOut []byte) {
d.d.decByteState = decByteStateNone
if d.advanceNil() {
return
}
if d.vd == bincVdArray {
if bs == nil {
bs = d.d.b[:]
d.d.decByteState = decByteStateReuseBuf
}
slen := d.ReadArrayStart()
var changed bool
if bs, changed = usableByteSlice(bs, slen); changed {
d.d.decByteState = decByteStateNone
}
for i := 0; i < slen; i++ {
bs[i] = uint8(chkOvf.UintV(d.DecodeUint64(), 8))
}
for i := len(bs); i < slen; i++ {
bs = append(bs, uint8(chkOvf.UintV(d.DecodeUint64(), 8)))
}
return bs
}
var clen int
if d.vd == bincVdString || d.vd == bincVdByteArray {
clen = d.decLen()
} else {
d.d.errorf("bytes - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
d.bdRead = false
if d.d.zerocopy() {
d.d.decByteState = decByteStateZerocopy
return d.d.decRd.rb.readx(uint(clen))
}
if bs == nil {
bs = d.d.b[:]
d.d.decByteState = decByteStateReuseBuf
}
return decByteSlice(d.d.r(), clen, d.d.h.MaxInitLen, bs)
}
func (d *bincDecDriver) DecodeExt(rv interface{}, basetype reflect.Type, xtag uint64, ext Ext) {
if xtag > 0xff {
d.d.errorf("ext: tag must be <= 0xff; got: %v", xtag)
}
if d.advanceNil() {
return
}
xbs, realxtag1, zerocopy := d.decodeExtV(ext != nil, uint8(xtag))
realxtag := uint64(realxtag1)
if ext == nil {
re := rv.(*RawExt)
re.Tag = realxtag
re.setData(xbs, zerocopy)
} else if ext == SelfExt {
d.d.sideDecode(rv, basetype, xbs)
} else {
ext.ReadExt(rv, xbs)
}
}
func (d *bincDecDriver) decodeExtV(verifyTag bool, tag byte) (xbs []byte, xtag byte, zerocopy bool) {
if d.vd == bincVdCustomExt {
l := d.decLen()
xtag = d.d.decRd.readn1()
if verifyTag && xtag != tag {
d.d.errorf("wrong extension tag - got %b, expecting: %v", xtag, tag)
}
if d.d.bytes {
xbs = d.d.decRd.rb.readx(uint(l))
zerocopy = true
} else {
xbs = decByteSlice(d.d.r(), l, d.d.h.MaxInitLen, d.d.b[:])
}
} else if d.vd == bincVdByteArray {
xbs = d.DecodeBytes(nil)
} else {
d.d.errorf("ext expects extensions or byte array - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeNaked() {
if !d.bdRead {
d.readNextBd()
}
n := d.d.naked()
var decodeFurther bool
switch d.vd {
case bincVdSpecial:
switch d.vs {
case bincSpNil:
n.v = valueTypeNil
case bincSpFalse:
n.v = valueTypeBool
n.b = false
case bincSpTrue:
n.v = valueTypeBool
n.b = true
case bincSpNan:
n.v = valueTypeFloat
n.f = math.NaN()
case bincSpPosInf:
n.v = valueTypeFloat
n.f = math.Inf(1)
case bincSpNegInf:
n.v = valueTypeFloat
n.f = math.Inf(-1)
case bincSpZeroFloat:
n.v = valueTypeFloat
n.f = float64(0)
case bincSpZero:
n.v = valueTypeUint
n.u = uint64(0) // int8(0)
case bincSpNegOne:
n.v = valueTypeInt
n.i = int64(-1) // int8(-1)
default:
d.d.errorf("cannot infer value - unrecognized special value %x-%x/%s", d.vd, d.vs, bincdesc(d.vd, d.vs))
}
case bincVdSmallInt:
n.v = valueTypeUint
n.u = uint64(int8(d.vs)) + 1 // int8(d.vs) + 1
case bincVdPosInt:
n.v = valueTypeUint
n.u = d.decUint()
case bincVdNegInt:
n.v = valueTypeInt
n.i = -(int64(d.decUint()))
case bincVdFloat:
n.v = valueTypeFloat
n.f = d.decFloatVal()
case bincVdString:
n.v = valueTypeString
n.s = d.d.stringZC(d.DecodeStringAsBytes())
case bincVdByteArray:
d.d.fauxUnionReadRawBytes(false)
case bincVdSymbol:
n.v = valueTypeSymbol
n.s = d.d.stringZC(d.DecodeStringAsBytes())
case bincVdTimestamp:
n.v = valueTypeTime
tt, err := bincDecodeTime(d.d.decRd.readx(uint(d.vs)))
halt.onerror(err)
n.t = tt
case bincVdCustomExt:
n.v = valueTypeExt
l := d.decLen()
n.u = uint64(d.d.decRd.readn1())
if d.d.bytes {
n.l = d.d.decRd.rb.readx(uint(l))
} else {
n.l = decByteSlice(d.d.r(), l, d.d.h.MaxInitLen, d.d.b[:])
}
case bincVdArray:
n.v = valueTypeArray
decodeFurther = true
case bincVdMap:
n.v = valueTypeMap
decodeFurther = true
default:
d.d.errorf("cannot infer value - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
if !decodeFurther {
d.bdRead = false
}
if n.v == valueTypeUint && d.h.SignedInteger {
n.v = valueTypeInt
n.i = int64(n.u)
}
}
func (d *bincDecDriver) 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 *bincDecDriver) 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 *bincDecDriver) nextValueBytesBdReadR(v0 []byte) (v []byte) {
v = v0
var h = decNextValueBytesHelper{d: &d.d}
fnLen := func(vs byte) uint {
switch vs {
case 0:
x := d.d.decRd.readn1()
h.append1(&v, x)
return uint(x)
case 1:
x := d.d.decRd.readn2()
h.appendN(&v, x[:]...)
return uint(bigen.Uint16(x))
case 2:
x := d.d.decRd.readn4()
h.appendN(&v, x[:]...)
return uint(bigen.Uint32(x))
case 3:
x := d.d.decRd.readn8()
h.appendN(&v, x[:]...)
return uint(bigen.Uint64(x))
default:
return uint(vs - 4)
}
}
var clen uint
switch d.vd {
case bincVdSpecial:
switch d.vs {
case bincSpNil, bincSpFalse, bincSpTrue, bincSpNan, bincSpPosInf: // pass
case bincSpNegInf, bincSpZeroFloat, bincSpZero, bincSpNegOne: // pass
default:
d.d.errorf("cannot infer value - unrecognized special value %x-%x/%s", d.vd, d.vs, bincdesc(d.vd, d.vs))
}
case bincVdSmallInt: // pass
case bincVdPosInt, bincVdNegInt:
bs := d.uintBytes()
h.appendN(&v, bs...)
case bincVdFloat:
fn := func(xlen byte) {
if d.vs&0x8 != 0 {
xlen = d.d.decRd.readn1()
h.append1(&v, xlen)
if xlen > 8 {
d.d.errorf("cannot read float - at most 8 bytes used to represent float - received %v bytes", xlen)
}
}
d.d.decRd.readb(d.d.b[:xlen])
h.appendN(&v, d.d.b[:xlen]...)
}
switch d.vs & 0x7 {
case bincFlBin32:
fn(4)
case bincFlBin64:
fn(8)
default:
d.d.errorf("read float supports only float32/64 - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
case bincVdString, bincVdByteArray:
clen = fnLen(d.vs)
h.appendN(&v, d.d.decRd.readx(clen)...)
case bincVdSymbol:
if d.vs&0x8 == 0 {
h.append1(&v, d.d.decRd.readn1())
} else {
h.appendN(&v, d.d.decRd.rb.readx(2)...)
}
if d.vs&0x4 != 0 {
clen = fnLen(d.vs & 0x3)
h.appendN(&v, d.d.decRd.readx(clen)...)
}
case bincVdTimestamp:
h.appendN(&v, d.d.decRd.readx(uint(d.vs))...)
case bincVdCustomExt:
clen = fnLen(d.vs)
h.append1(&v, d.d.decRd.readn1()) // tag
h.appendN(&v, d.d.decRd.readx(clen)...)
case bincVdArray:
clen = fnLen(d.vs)
for i := uint(0); i < clen; i++ {
v = d.nextValueBytesR(v)
}
case bincVdMap:
clen = fnLen(d.vs)
for i := uint(0); i < clen; i++ {
v = d.nextValueBytesR(v)
v = d.nextValueBytesR(v)
}
default:
d.d.errorf("cannot infer value - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
}
return
}
//------------------------------------
//BincHandle is a Handle for the Binc Schema-Free Encoding Format
//defined at https://github.com/ugorji/binc .
//
//BincHandle currently supports all Binc features with the following EXCEPTIONS:
// - only integers up to 64 bits of precision are supported.
// big integers are unsupported.
// - Only IEEE 754 binary32 and binary64 floats are supported (ie Go float32 and float64 types).
// extended precision and decimal IEEE 754 floats are unsupported.
// - Only UTF-8 strings supported.
// Unicode_Other Binc types (UTF16, UTF32) are currently unsupported.
//
//Note that these EXCEPTIONS are temporary and full support is possible and may happen soon.
type BincHandle struct {
BasicHandle
binaryEncodingType
// noElemSeparators
// AsSymbols defines what should be encoded as symbols.
//
// Encoding as symbols can reduce the encoded size significantly.
//
// However, during decoding, each string to be encoded as a symbol must
// be checked to see if it has been seen before. Consequently, encoding time
// will increase if using symbols, because string comparisons has a clear cost.
//
// Values:
// - 0: default: library uses best judgement
// - 1: use symbols
// - 2: do not use symbols
AsSymbols uint8
// AsSymbols: may later on introduce more options ...
// - m: map keys
// - s: struct fields
// - n: none
// - a: all: same as m, s, ...
// _ [7]uint64 // padding (cache-aligned)
}
// Name returns the name of the handle: binc
func (h *BincHandle) Name() string { return "binc" }
func (h *BincHandle) desc(bd byte) string { return bincdesc(bd>>4, bd&0x0f) }
func (h *BincHandle) newEncDriver() encDriver {
var e = &bincEncDriver{h: h}
e.e.e = e
e.e.init(h)
e.reset()
return e
}
func (h *BincHandle) newDecDriver() decDriver {
d := &bincDecDriver{h: h}
d.d.d = d
d.d.init(h)
d.reset()
return d
}
// var timeDigits = [...]byte{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'}
// EncodeTime encodes a time.Time as a []byte, including
// information on the instant in time and UTC offset.
//
// Format Description
//
// A timestamp is composed of 3 components:
//
// - secs: signed integer representing seconds since unix epoch
// - nsces: unsigned integer representing fractional seconds as a
// nanosecond offset within secs, in the range 0 <= nsecs < 1e9
// - tz: signed integer representing timezone offset in minutes east of UTC,
// and a dst (daylight savings time) flag
//
// When encoding a timestamp, the first byte is the descriptor, which
// defines which components are encoded and how many bytes are used to
// encode secs and nsecs components. *If secs/nsecs is 0 or tz is UTC, it
// is not encoded in the byte array explicitly*.
//
// Descriptor 8 bits are of the form `A B C DDD EE`:
// A: Is secs component encoded? 1 = true
// B: Is nsecs component encoded? 1 = true
// C: Is tz component encoded? 1 = true
// DDD: Number of extra bytes for secs (range 0-7).
// If A = 1, secs encoded in DDD+1 bytes.
// If A = 0, secs is not encoded, and is assumed to be 0.
// If A = 1, then we need at least 1 byte to encode secs.
// DDD says the number of extra bytes beyond that 1.
// E.g. if DDD=0, then secs is represented in 1 byte.
// if DDD=2, then secs is represented in 3 bytes.
// EE: Number of extra bytes for nsecs (range 0-3).
// If B = 1, nsecs encoded in EE+1 bytes (similar to secs/DDD above)
//
// Following the descriptor bytes, subsequent bytes are:
//
// secs component encoded in `DDD + 1` bytes (if A == 1)
// nsecs component encoded in `EE + 1` bytes (if B == 1)
// tz component encoded in 2 bytes (if C == 1)
//
// secs and nsecs components are integers encoded in a BigEndian
// 2-complement encoding format.
//
// tz component is encoded as 2 bytes (16 bits). Most significant bit 15 to
// Least significant bit 0 are described below:
//
// Timezone offset has a range of -12:00 to +14:00 (ie -720 to +840 minutes).
// Bit 15 = have\_dst: set to 1 if we set the dst flag.
// Bit 14 = dst\_on: set to 1 if dst is in effect at the time, or 0 if not.
// Bits 13..0 = timezone offset in minutes. It is a signed integer in Big Endian format.
//
func bincEncodeTime(t time.Time) []byte {
// t := rv2i(rv).(time.Time)
tsecs, tnsecs := t.Unix(), t.Nanosecond()
var (
bd byte
bs [16]byte
i int = 1
)
l := t.Location()
if l == time.UTC {
l = nil
}
if tsecs != 0 {
bd = bd | 0x80
btmp := bigen.PutUint64(uint64(tsecs))
f := pruneSignExt(btmp[:], tsecs >= 0)
bd = bd | (byte(7-f) << 2)
copy(bs[i:], btmp[f:])
i = i + (8 - f)
}
if tnsecs != 0 {
bd = bd | 0x40
btmp := bigen.PutUint32(uint32(tnsecs))
f := pruneSignExt(btmp[:4], true)
bd = bd | byte(3-f)
copy(bs[i:], btmp[f:4])
i = i + (4 - f)
}
if l != nil {
bd = bd | 0x20
// Note that Go Libs do not give access to dst flag.
_, zoneOffset := t.Zone()
// zoneName, zoneOffset := t.Zone()
zoneOffset /= 60
z := uint16(zoneOffset)
btmp := bigen.PutUint16(z)
// clear dst flags
bs[i] = btmp[0] & 0x3f
bs[i+1] = btmp[1]
i = i + 2
}
bs[0] = bd
return bs[0:i]
}
// bincDecodeTime decodes a []byte into a time.Time.
func bincDecodeTime(bs []byte) (tt time.Time, err error) {
bd := bs[0]
var (
tsec int64
tnsec uint32
tz uint16
i byte = 1
i2 byte
n byte
)
if bd&(1<<7) != 0 {
var btmp [8]byte
n = ((bd >> 2) & 0x7) + 1
i2 = i + n
copy(btmp[8-n:], bs[i:i2])
// if first bit of bs[i] is set, then fill btmp[0..8-n] with 0xff (ie sign extend it)
if bs[i]&(1<<7) != 0 {
copy(btmp[0:8-n], bsAll0xff)
}
i = i2
tsec = int64(bigen.Uint64(btmp))
}
if bd&(1<<6) != 0 {
var btmp [4]byte
n = (bd & 0x3) + 1
i2 = i + n
copy(btmp[4-n:], bs[i:i2])
i = i2
tnsec = bigen.Uint32(btmp)
}
if bd&(1<<5) == 0 {
tt = time.Unix(tsec, int64(tnsec)).UTC()
return
}
// In stdlib time.Parse, when a date is parsed without a zone name, it uses "" as zone name.
// However, we need name here, so it can be shown when time is printf.d.
// Zone name is in form: UTC-08:00.
// Note that Go Libs do not give access to dst flag, so we ignore dst bits
tz = bigen.Uint16([2]byte{bs[i], bs[i+1]})
// sign extend sign bit into top 2 MSB (which were dst bits):
if tz&(1<<13) == 0 { // positive
tz = tz & 0x3fff //clear 2 MSBs: dst bits
} else { // negative
tz = tz | 0xc000 //set 2 MSBs: dst bits
}
tzint := int16(tz)
if tzint == 0 {
tt = time.Unix(tsec, int64(tnsec)).UTC()
} else {
// For Go Time, do not use a descriptive timezone.
// It's unnecessary, and makes it harder to do a reflect.DeepEqual.
// The Offset already tells what the offset should be, if not on UTC and unknown zone name.
// var zoneName = timeLocUTCName(tzint)
tt = time.Unix(tsec, int64(tnsec)).In(time.FixedZone("", int(tzint)*60))
}
return
}
var _ decDriver = (*bincDecDriver)(nil)
var _ encDriver = (*bincEncDriver)(nil)