traefik/vendor/github.com/ugorji/go/codec/binc.go
2018-05-23 17:48:04 +02:00

1168 lines
27 KiB
Go

// Copyright (c) 2012-2018 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"
)
const bincDoPrune = true // No longer needed. Needed before as C lib did not support pruning.
// 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 (
bincFlBin16 byte = iota
bincFlBin32
_ // bincFlBin32e
bincFlBin64
_ // bincFlBin64e
// others not currently supported
)
func bincdesc(vd, vs byte) string {
switch vd {
case bincVdSpecial:
switch vs {
case bincSpNil:
return "nil"
case bincSpFalse:
return "false"
case bincSpTrue:
return "true"
case bincSpNan, bincSpPosInf, bincSpNegInf, bincSpZeroFloat:
return "float"
case bincSpZero:
return "uint"
case bincSpNegOne:
return "int"
default:
return "unknown"
}
case bincVdSmallInt, bincVdPosInt:
return "uint"
case bincVdNegInt:
return "int"
case bincVdFloat:
return "float"
case bincVdSymbol:
return "string"
case bincVdString:
return "string"
case bincVdByteArray:
return "bytes"
case bincVdTimestamp:
return "time"
case bincVdCustomExt:
return "ext"
case bincVdArray:
return "array"
case bincVdMap:
return "map"
default:
return "unknown"
}
}
type bincEncDriver struct {
e *Encoder
h *BincHandle
w encWriter
m map[string]uint16 // symbols
b [16]byte // scratch, used for encoding numbers - bigendian style
s uint16 // symbols sequencer
// c containerState
encDriverTrackContainerWriter
noBuiltInTypes
// encNoSeparator
}
func (e *bincEncDriver) EncodeNil() {
e.w.writen1(bincVdSpecial<<4 | bincSpNil)
}
func (e *bincEncDriver) EncodeTime(t time.Time) {
if t.IsZero() {
e.EncodeNil()
} else {
bs := bincEncodeTime(t)
e.w.writen1(bincVdTimestamp<<4 | uint8(len(bs)))
e.w.writeb(bs)
}
}
func (e *bincEncDriver) EncodeBool(b bool) {
if b {
e.w.writen1(bincVdSpecial<<4 | bincSpTrue)
} else {
e.w.writen1(bincVdSpecial<<4 | bincSpFalse)
}
}
func (e *bincEncDriver) EncodeFloat32(f float32) {
if f == 0 {
e.w.writen1(bincVdSpecial<<4 | bincSpZeroFloat)
return
}
e.w.writen1(bincVdFloat<<4 | bincFlBin32)
bigenHelper{e.b[:4], e.w}.writeUint32(math.Float32bits(f))
}
func (e *bincEncDriver) EncodeFloat64(f float64) {
if f == 0 {
e.w.writen1(bincVdSpecial<<4 | bincSpZeroFloat)
return
}
bigen.PutUint64(e.b[:8], math.Float64bits(f))
if bincDoPrune {
i := 7
for ; i >= 0 && (e.b[i] == 0); i-- {
}
i++
if i <= 6 {
e.w.writen1(bincVdFloat<<4 | 0x8 | bincFlBin64)
e.w.writen1(byte(i))
e.w.writeb(e.b[:i])
return
}
}
e.w.writen1(bincVdFloat<<4 | bincFlBin64)
e.w.writeb(e.b[:8])
}
func (e *bincEncDriver) encIntegerPrune(bd byte, pos bool, v uint64, lim uint8) {
if lim == 4 {
bigen.PutUint32(e.b[:lim], uint32(v))
} else {
bigen.PutUint64(e.b[:lim], v)
}
if bincDoPrune {
i := pruneSignExt(e.b[:lim], pos)
e.w.writen1(bd | lim - 1 - byte(i))
e.w.writeb(e.b[i:lim])
} else {
e.w.writen1(bd | lim - 1)
e.w.writeb(e.b[:lim])
}
}
func (e *bincEncDriver) EncodeInt(v int64) {
const nbd byte = bincVdNegInt << 4
if v >= 0 {
e.encUint(bincVdPosInt<<4, true, uint64(v))
} else if v == -1 {
e.w.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.w.writen1(bincVdSpecial<<4 | bincSpZero)
} else if pos && v >= 1 && v <= 16 {
e.w.writen1(bincVdSmallInt<<4 | byte(v-1))
} else if v <= math.MaxUint8 {
e.w.writen2(bd|0x0, byte(v))
} else if v <= math.MaxUint16 {
e.w.writen1(bd | 0x01)
bigenHelper{e.b[:2], e.w}.writeUint16(uint16(v))
} else if v <= math.MaxUint32 {
e.encIntegerPrune(bd, pos, v, 4)
} else {
e.encIntegerPrune(bd, pos, v, 8)
}
}
func (e *bincEncDriver) EncodeExt(rv interface{}, xtag uint64, ext Ext, _ *Encoder) {
bs := ext.WriteExt(rv)
if bs == nil {
e.EncodeNil()
return
}
e.encodeExtPreamble(uint8(xtag), len(bs))
e.w.writeb(bs)
}
func (e *bincEncDriver) EncodeRawExt(re *RawExt, _ *Encoder) {
e.encodeExtPreamble(uint8(re.Tag), len(re.Data))
e.w.writeb(re.Data)
}
func (e *bincEncDriver) encodeExtPreamble(xtag byte, length int) {
e.encLen(bincVdCustomExt<<4, uint64(length))
e.w.writen1(xtag)
}
func (e *bincEncDriver) WriteArrayStart(length int) {
e.encLen(bincVdArray<<4, uint64(length))
e.c = containerArrayStart
}
func (e *bincEncDriver) WriteMapStart(length int) {
e.encLen(bincVdMap<<4, uint64(length))
e.c = containerMapStart
}
func (e *bincEncDriver) EncodeString(c charEncoding, v string) {
if e.c == containerMapKey && c == cUTF8 && (e.h.AsSymbols == 0 || e.h.AsSymbols == 1) {
e.EncodeSymbol(v)
return
}
l := uint64(len(v))
e.encBytesLen(c, l)
if l > 0 {
e.w.writestr(v)
}
}
func (e *bincEncDriver) EncodeSymbol(v string) {
// if WriteSymbolsNoRefs {
// e.encodeString(cUTF8, v)
// return
// }
//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.w.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.w.writen2(bincVdSymbol<<4, byte(ui))
} else {
e.w.writen1(bincVdSymbol<<4 | 0x8)
bigenHelper{e.b[:2], e.w}.writeUint16(ui)
}
} else {
e.s++
ui = e.s
//ui = uint16(atomic.AddUint32(&e.s, 1))
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.w.writen2(bincVdSymbol<<4|0x0|0x4|lenprec, byte(ui))
} else {
e.w.writen1(bincVdSymbol<<4 | 0x8 | 0x4 | lenprec)
bigenHelper{e.b[:2], e.w}.writeUint16(ui)
}
if lenprec == 0 {
e.w.writen1(byte(l))
} else if lenprec == 1 {
bigenHelper{e.b[:2], e.w}.writeUint16(uint16(l))
} else if lenprec == 2 {
bigenHelper{e.b[:4], e.w}.writeUint32(uint32(l))
} else {
bigenHelper{e.b[:8], e.w}.writeUint64(uint64(l))
}
e.w.writestr(v)
}
}
func (e *bincEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
if v == nil {
e.EncodeNil()
return
}
l := uint64(len(v))
e.encBytesLen(c, l)
if l > 0 {
e.w.writeb(v)
}
}
func (e *bincEncDriver) encBytesLen(c charEncoding, length uint64) {
//TODO: support bincUnicodeOther (for now, just use string or bytearray)
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.w.writen1(bd | uint8(l+4))
} else {
e.encLenNumber(bd, l)
}
}
func (e *bincEncDriver) encLenNumber(bd byte, v uint64) {
if v <= math.MaxUint8 {
e.w.writen2(bd, byte(v))
} else if v <= math.MaxUint16 {
e.w.writen1(bd | 0x01)
bigenHelper{e.b[:2], e.w}.writeUint16(uint16(v))
} else if v <= math.MaxUint32 {
e.w.writen1(bd | 0x02)
bigenHelper{e.b[:4], e.w}.writeUint32(uint32(v))
} else {
e.w.writen1(bd | 0x03)
bigenHelper{e.b[:8], e.w}.writeUint64(uint64(v))
}
}
//------------------------------------
type bincDecSymbol struct {
s string
b []byte
i uint16
}
type bincDecDriver struct {
decDriverNoopContainerReader
noBuiltInTypes
d *Decoder
h *BincHandle
r decReader
br bool // bytes reader
bdRead bool
bd byte
vd byte
vs byte
_ [3]byte // padding
// linear searching on this slice is ok,
// because we typically expect < 32 symbols in each stream.
s []bincDecSymbol
// noStreamingCodec
// decNoSeparator
b [8 * 8]byte // scratch
}
func (d *bincDecDriver) readNextBd() {
d.bd = d.r.readn1()
d.vd = d.bd >> 4
d.vs = d.bd & 0x0f
d.bdRead = true
}
func (d *bincDecDriver) uncacheRead() {
if d.bdRead {
d.r.unreadn1()
d.bdRead = false
}
}
func (d *bincDecDriver) ContainerType() (vt valueType) {
if !d.bdRead {
d.readNextBd()
}
if d.vd == bincVdSpecial && d.vs == bincSpNil {
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
}
// else {
// d.d.errorf("isContainerType: unsupported parameter: %v", vt)
// }
return valueTypeUnset
}
func (d *bincDecDriver) TryDecodeAsNil() bool {
if !d.bdRead {
d.readNextBd()
}
if d.bd == bincVdSpecial<<4|bincSpNil {
d.bdRead = false
return true
}
return false
}
func (d *bincDecDriver) DecodeTime() (t time.Time) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == bincVdSpecial<<4|bincSpNil {
d.bdRead = false
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))
return
}
t, err := bincDecodeTime(d.r.readx(int(d.vs)))
if err != nil {
panic(err)
}
d.bdRead = false
return
}
func (d *bincDecDriver) decFloatPre(vs, defaultLen byte) {
if vs&0x8 == 0 {
d.r.readb(d.b[0:defaultLen])
} else {
l := d.r.readn1()
if l > 8 {
d.d.errorf("cannot read float - at most 8 bytes used to represent float - received %v bytes", l)
return
}
for i := l; i < 8; i++ {
d.b[i] = 0
}
d.r.readb(d.b[0:l])
}
}
func (d *bincDecDriver) decFloat() (f float64) {
//if true { f = math.Float64frombits(bigen.Uint64(d.r.readx(8))); break; }
if x := d.vs & 0x7; x == bincFlBin32 {
d.decFloatPre(d.vs, 4)
f = float64(math.Float32frombits(bigen.Uint32(d.b[0:4])))
} else if x == bincFlBin64 {
d.decFloatPre(d.vs, 8)
f = math.Float64frombits(bigen.Uint64(d.b[0:8]))
} else {
d.d.errorf("read float - only float32 and float64 are supported - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
return
}
func (d *bincDecDriver) decUint() (v uint64) {
// need to inline the code (interface conversion and type assertion expensive)
switch d.vs {
case 0:
v = uint64(d.r.readn1())
case 1:
d.r.readb(d.b[6:8])
v = uint64(bigen.Uint16(d.b[6:8]))
case 2:
d.b[4] = 0
d.r.readb(d.b[5:8])
v = uint64(bigen.Uint32(d.b[4:8]))
case 3:
d.r.readb(d.b[4:8])
v = uint64(bigen.Uint32(d.b[4:8]))
case 4, 5, 6:
lim := int(7 - d.vs)
d.r.readb(d.b[lim:8])
for i := 0; i < lim; i++ {
d.b[i] = 0
}
v = uint64(bigen.Uint64(d.b[:8]))
case 7:
d.r.readb(d.b[:8])
v = uint64(bigen.Uint64(d.b[:8]))
default:
d.d.errorf("unsigned integers with greater than 64 bits of precision not supported")
return
}
return
}
func (d *bincDecDriver) decCheckInteger() (ui uint64, neg bool) {
if !d.bdRead {
d.readNextBd()
}
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 {
d.d.errorf("integer decode fails - invalid special value from descriptor %x-%x/%s",
d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
} else {
d.d.errorf("integer can only be decoded from int/uint. d.bd: 0x%x, d.vd: 0x%x", d.bd, d.vd)
return
}
return
}
func (d *bincDecDriver) DecodeInt64() (i int64) {
ui, neg := d.decCheckInteger()
i = chkOvf.SignedIntV(ui)
if neg {
i = -i
}
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeUint64() (ui uint64) {
ui, neg := d.decCheckInteger()
if neg {
d.d.errorf("assigning negative signed value to unsigned integer type")
return
}
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeFloat64() (f float64) {
if !d.bdRead {
d.readNextBd()
}
vd, vs := d.vd, d.vs
if vd == bincVdSpecial {
d.bdRead = false
if vs == bincSpNan {
return math.NaN()
} else if vs == bincSpPosInf {
return math.Inf(1)
} else if vs == bincSpZeroFloat || vs == bincSpZero {
return
} else if vs == bincSpNegInf {
return math.Inf(-1)
} else {
d.d.errorf("float - invalid special value from descriptor %x-%x/%s",
d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
} else if vd == bincVdFloat {
f = d.decFloat()
} else {
f = float64(d.DecodeInt64())
}
d.bdRead = false
return
}
// bool can be decoded from bool only (single byte).
func (d *bincDecDriver) DecodeBool() (b bool) {
if !d.bdRead {
d.readNextBd()
}
if bd := d.bd; bd == (bincVdSpecial | bincSpFalse) {
// b = false
} else if bd == (bincVdSpecial | bincSpTrue) {
b = true
} else {
d.d.errorf("bool - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
d.bdRead = false
return
}
func (d *bincDecDriver) ReadMapStart() (length int) {
if !d.bdRead {
d.readNextBd()
}
if d.vd != bincVdMap {
d.d.errorf("map - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
length = d.decLen()
d.bdRead = false
return
}
func (d *bincDecDriver) ReadArrayStart() (length int) {
if !d.bdRead {
d.readNextBd()
}
if d.vd != bincVdArray {
d.d.errorf("array - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
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.r.readn1())
} else if x == 1 {
d.r.readb(d.b[6:8])
v = uint64(bigen.Uint16(d.b[6:8]))
} else if x == 2 {
d.r.readb(d.b[4:8])
v = uint64(bigen.Uint32(d.b[4:8]))
} else {
d.r.readb(d.b[:8])
v = bigen.Uint64(d.b[:8])
}
return
}
func (d *bincDecDriver) decStringAndBytes(bs []byte, withString, zerocopy bool) (
bs2 []byte, s string) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == bincVdSpecial<<4|bincSpNil {
d.bdRead = false
return
}
var slen = -1
// var ok bool
switch d.vd {
case bincVdString, bincVdByteArray:
slen = d.decLen()
if zerocopy {
if d.br {
bs2 = d.r.readx(slen)
} else if len(bs) == 0 {
bs2 = decByteSlice(d.r, slen, d.d.h.MaxInitLen, d.b[:])
} else {
bs2 = decByteSlice(d.r, slen, d.d.h.MaxInitLen, bs)
}
} else {
bs2 = decByteSlice(d.r, slen, d.d.h.MaxInitLen, bs)
}
if withString {
s = string(bs2)
}
case bincVdSymbol:
// zerocopy doesn't apply for symbols,
// as the values must be stored in a table for later use.
//
//from vs: extract numSymbolBytes, containsStringVal, strLenPrecision,
//extract symbol
//if containsStringVal, read it and put in map
//else look in map for string value
var symbol uint16
vs := d.vs
if vs&0x8 == 0 {
symbol = uint16(d.r.readn1())
} else {
symbol = uint16(bigen.Uint16(d.r.readx(2)))
}
if d.s == nil {
d.s = make([]bincDecSymbol, 0, 16)
}
if vs&0x4 == 0 {
for i := range d.s {
j := &d.s[i]
if j.i == symbol {
bs2 = j.b
if withString {
if j.s == "" && bs2 != nil {
j.s = string(bs2)
}
s = j.s
}
break
}
}
} else {
switch vs & 0x3 {
case 0:
slen = int(d.r.readn1())
case 1:
slen = int(bigen.Uint16(d.r.readx(2)))
case 2:
slen = int(bigen.Uint32(d.r.readx(4)))
case 3:
slen = int(bigen.Uint64(d.r.readx(8)))
}
// since using symbols, do not store any part of
// the parameter bs in the map, as it might be a shared buffer.
// bs2 = decByteSlice(d.r, slen, bs)
bs2 = decByteSlice(d.r, slen, d.d.h.MaxInitLen, nil)
if withString {
s = string(bs2)
}
d.s = append(d.s, bincDecSymbol{i: symbol, s: s, b: bs2})
}
default:
d.d.errorf("string/bytes - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeString() (s string) {
// DecodeBytes does not accommodate symbols, whose impl stores string version in map.
// Use decStringAndBytes directly.
// return string(d.DecodeBytes(d.b[:], true, true))
_, s = d.decStringAndBytes(d.b[:], true, true)
return
}
func (d *bincDecDriver) DecodeStringAsBytes() (s []byte) {
s, _ = d.decStringAndBytes(d.b[:], false, true)
return
}
func (d *bincDecDriver) DecodeBytes(bs []byte, zerocopy bool) (bsOut []byte) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == bincVdSpecial<<4|bincSpNil {
d.bdRead = false
return nil
}
// check if an "array" of uint8's (see ContainerType for how to infer if an array)
if d.vd == bincVdArray {
bsOut, _ = fastpathTV.DecSliceUint8V(bs, true, d.d)
return
}
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))
return
}
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, d.d.h.MaxInitLen, bs)
}
func (d *bincDecDriver) DecodeExt(rv interface{}, xtag uint64, ext Ext) (realxtag uint64) {
if xtag > 0xff {
d.d.errorf("ext: tag must be <= 0xff; got: %v", xtag)
return
}
realxtag1, xbs := d.decodeExtV(ext != nil, uint8(xtag))
realxtag = uint64(realxtag1)
if ext == nil {
re := rv.(*RawExt)
re.Tag = realxtag
re.Data = detachZeroCopyBytes(d.br, re.Data, xbs)
} else {
ext.ReadExt(rv, xbs)
}
return
}
func (d *bincDecDriver) decodeExtV(verifyTag bool, tag byte) (xtag byte, xbs []byte) {
if !d.bdRead {
d.readNextBd()
}
if d.vd == bincVdCustomExt {
l := d.decLen()
xtag = d.r.readn1()
if verifyTag && xtag != tag {
d.d.errorf("wrong extension tag - got %b, expecting: %v", xtag, tag)
return
}
xbs = d.r.readx(l)
} else if d.vd == bincVdByteArray {
xbs = d.DecodeBytes(nil, true)
} else {
d.d.errorf("ext - expecting extensions or byte array - %s %x-%x/%s", msgBadDesc, d.vd, d.vs, bincdesc(d.vd, d.vs))
return
}
d.bdRead = false
return
}
func (d *bincDecDriver) DecodeNaked() {
if !d.bdRead {
d.readNextBd()
}
n := d.d.n
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 from descriptor %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.decFloat()
case bincVdSymbol:
n.v = valueTypeSymbol
n.s = d.DecodeString()
case bincVdString:
n.v = valueTypeString
n.s = d.DecodeString()
case bincVdByteArray:
n.v = valueTypeBytes
n.l = d.DecodeBytes(nil, false)
case bincVdTimestamp:
n.v = valueTypeTime
tt, err := bincDecodeTime(d.r.readx(int(d.vs)))
if err != nil {
panic(err)
}
n.t = tt
case bincVdCustomExt:
n.v = valueTypeExt
l := d.decLen()
n.u = uint64(d.r.readn1())
n.l = d.r.readx(l)
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)
}
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, ...
// _ [1]uint64 // padding
}
// Name returns the name of the handle: binc
func (h *BincHandle) Name() string { return "binc" }
// SetBytesExt sets an extension
func (h *BincHandle) SetBytesExt(rt reflect.Type, tag uint64, ext BytesExt) (err error) {
return h.SetExt(rt, tag, &extWrapper{ext, interfaceExtFailer{}})
}
func (h *BincHandle) newEncDriver(e *Encoder) encDriver {
return &bincEncDriver{e: e, h: h, w: e.w}
}
func (h *BincHandle) newDecDriver(d *Decoder) decDriver {
return &bincDecDriver{d: d, h: h, r: d.r, br: d.bytes}
}
func (e *bincEncDriver) reset() {
e.w = e.e.w
e.s = 0
e.c = 0
e.m = nil
}
func (d *bincDecDriver) reset() {
d.r, d.br = d.d.r, d.d.bytes
d.s = nil
d.bd, d.bdRead, d.vd, d.vs = 0, false, 0, 0
}
// 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 := rv.Interface().(time.Time)
tsecs, tnsecs := t.Unix(), t.Nanosecond()
var (
bd byte
btmp [8]byte
bs [16]byte
i int = 1
)
l := t.Location()
if l == time.UTC {
l = nil
}
if tsecs != 0 {
bd = bd | 0x80
bigen.PutUint64(btmp[:], 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
bigen.PutUint32(btmp[:4], 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)
bigen.PutUint16(btmp[:2], 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)
//for j,k := byte(0), 8-n; j < k; j++ { btmp[j] = 0xff }
}
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 printed.
// Zone name is in form: UTC-08:00.
// Note that Go Libs do not give access to dst flag, so we ignore dst bits
i2 = i + 2
tz = bigen.Uint16(bs[i:i2])
// i = i2
// 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)