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

748 lines
18 KiB
Go

// 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"
)
const (
_ uint8 = iota
simpleVdNil = 1
simpleVdFalse = 2
simpleVdTrue = 3
simpleVdFloat32 = 4
simpleVdFloat64 = 5
// each lasts for 4 (ie n, n+1, n+2, n+3)
simpleVdPosInt = 8
simpleVdNegInt = 12
simpleVdTime = 24
// containers: each lasts for 4 (ie n, n+1, n+2, ... n+7)
simpleVdString = 216
simpleVdByteArray = 224
simpleVdArray = 232
simpleVdMap = 240
simpleVdExt = 248
)
var simpledescNames = map[byte]string{
simpleVdNil: "null",
simpleVdFalse: "false",
simpleVdTrue: "true",
simpleVdFloat32: "float32",
simpleVdFloat64: "float64",
simpleVdPosInt: "+int",
simpleVdNegInt: "-int",
simpleVdTime: "time",
simpleVdString: "string",
simpleVdByteArray: "binary",
simpleVdArray: "array",
simpleVdMap: "map",
simpleVdExt: "ext",
}
func simpledesc(bd byte) (s string) {
s = simpledescNames[bd]
if s == "" {
s = "unknown"
}
return
}
type simpleEncDriver struct {
noBuiltInTypes
encDriverNoopContainerWriter
encDriverNoState
h *SimpleHandle
// b [8]byte
e Encoder
}
func (e *simpleEncDriver) encoder() *Encoder {
return &e.e
}
func (e *simpleEncDriver) EncodeNil() {
e.e.encWr.writen1(simpleVdNil)
}
func (e *simpleEncDriver) EncodeBool(b bool) {
if e.h.EncZeroValuesAsNil && e.e.c != containerMapKey && !b {
e.EncodeNil()
return
}
if b {
e.e.encWr.writen1(simpleVdTrue)
} else {
e.e.encWr.writen1(simpleVdFalse)
}
}
func (e *simpleEncDriver) EncodeFloat32(f float32) {
if e.h.EncZeroValuesAsNil && e.e.c != containerMapKey && f == 0.0 {
e.EncodeNil()
return
}
e.e.encWr.writen1(simpleVdFloat32)
bigen.writeUint32(e.e.w(), math.Float32bits(f))
}
func (e *simpleEncDriver) EncodeFloat64(f float64) {
if e.h.EncZeroValuesAsNil && e.e.c != containerMapKey && f == 0.0 {
e.EncodeNil()
return
}
e.e.encWr.writen1(simpleVdFloat64)
bigen.writeUint64(e.e.w(), math.Float64bits(f))
}
func (e *simpleEncDriver) EncodeInt(v int64) {
if v < 0 {
e.encUint(uint64(-v), simpleVdNegInt)
} else {
e.encUint(uint64(v), simpleVdPosInt)
}
}
func (e *simpleEncDriver) EncodeUint(v uint64) {
e.encUint(v, simpleVdPosInt)
}
func (e *simpleEncDriver) encUint(v uint64, bd uint8) {
if e.h.EncZeroValuesAsNil && e.e.c != containerMapKey && v == 0 {
e.EncodeNil()
return
}
if v <= math.MaxUint8 {
e.e.encWr.writen2(bd, uint8(v))
} else if v <= math.MaxUint16 {
e.e.encWr.writen1(bd + 1)
bigen.writeUint16(e.e.w(), uint16(v))
} else if v <= math.MaxUint32 {
e.e.encWr.writen1(bd + 2)
bigen.writeUint32(e.e.w(), uint32(v))
} else { // if v <= math.MaxUint64 {
e.e.encWr.writen1(bd + 3)
bigen.writeUint64(e.e.w(), v)
}
}
func (e *simpleEncDriver) encLen(bd byte, length int) {
if length == 0 {
e.e.encWr.writen1(bd)
} else if length <= math.MaxUint8 {
e.e.encWr.writen1(bd + 1)
e.e.encWr.writen1(uint8(length))
} else if length <= math.MaxUint16 {
e.e.encWr.writen1(bd + 2)
bigen.writeUint16(e.e.w(), uint16(length))
} else if int64(length) <= math.MaxUint32 {
e.e.encWr.writen1(bd + 3)
bigen.writeUint32(e.e.w(), uint32(length))
} else {
e.e.encWr.writen1(bd + 4)
bigen.writeUint64(e.e.w(), uint64(length))
}
}
func (e *simpleEncDriver) 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 *simpleEncDriver) EncodeRawExt(re *RawExt) {
e.encodeExtPreamble(uint8(re.Tag), len(re.Data))
e.e.encWr.writeb(re.Data)
}
func (e *simpleEncDriver) encodeExtPreamble(xtag byte, length int) {
e.encLen(simpleVdExt, length)
e.e.encWr.writen1(xtag)
}
func (e *simpleEncDriver) WriteArrayStart(length int) {
e.encLen(simpleVdArray, length)
}
func (e *simpleEncDriver) WriteMapStart(length int) {
e.encLen(simpleVdMap, length)
}
func (e *simpleEncDriver) EncodeString(v string) {
if e.h.EncZeroValuesAsNil && e.e.c != containerMapKey && v == "" {
e.EncodeNil()
return
}
if e.h.StringToRaw {
e.encLen(simpleVdByteArray, len(v))
} else {
e.encLen(simpleVdString, len(v))
}
e.e.encWr.writestr(v)
}
func (e *simpleEncDriver) EncodeStringBytesRaw(v []byte) {
// if e.h.EncZeroValuesAsNil && e.c != containerMapKey && v == nil {
if v == nil {
e.EncodeNil()
return
}
e.encLen(simpleVdByteArray, len(v))
e.e.encWr.writeb(v)
}
func (e *simpleEncDriver) EncodeTime(t time.Time) {
// if e.h.EncZeroValuesAsNil && e.c != containerMapKey && t.IsZero() {
if t.IsZero() {
e.EncodeNil()
return
}
v, err := t.MarshalBinary()
e.e.onerror(err)
e.e.encWr.writen2(simpleVdTime, uint8(len(v)))
e.e.encWr.writeb(v)
}
//------------------------------------
type simpleDecDriver struct {
h *SimpleHandle
bdAndBdread
_ bool
noBuiltInTypes
decDriverNoopContainerReader
decDriverNoopNumberHelper
d Decoder
}
func (d *simpleDecDriver) decoder() *Decoder {
return &d.d
}
func (d *simpleDecDriver) descBd() string {
return sprintf("%v (%s)", d.bd, simpledesc(d.bd))
}
func (d *simpleDecDriver) readNextBd() {
d.bd = d.d.decRd.readn1()
d.bdRead = true
}
func (d *simpleDecDriver) advanceNil() (null bool) {
if !d.bdRead {
d.readNextBd()
}
if d.bd == simpleVdNil {
d.bdRead = false
return true // null = true
}
return
}
func (d *simpleDecDriver) ContainerType() (vt valueType) {
if !d.bdRead {
d.readNextBd()
}
switch d.bd {
case simpleVdNil:
d.bdRead = false
return valueTypeNil
case simpleVdByteArray, simpleVdByteArray + 1,
simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
return valueTypeBytes
case simpleVdString, simpleVdString + 1,
simpleVdString + 2, simpleVdString + 3, simpleVdString + 4:
return valueTypeString
case simpleVdArray, simpleVdArray + 1,
simpleVdArray + 2, simpleVdArray + 3, simpleVdArray + 4:
return valueTypeArray
case simpleVdMap, simpleVdMap + 1,
simpleVdMap + 2, simpleVdMap + 3, simpleVdMap + 4:
return valueTypeMap
}
return valueTypeUnset
}
func (d *simpleDecDriver) TryNil() bool {
return d.advanceNil()
}
func (d *simpleDecDriver) decFloat() (f float64, ok bool) {
ok = true
switch d.bd {
case simpleVdFloat32:
f = float64(math.Float32frombits(bigen.Uint32(d.d.decRd.readn4())))
case simpleVdFloat64:
f = math.Float64frombits(bigen.Uint64(d.d.decRd.readn8()))
default:
ok = false
}
return
}
func (d *simpleDecDriver) decInteger() (ui uint64, neg, ok bool) {
ok = true
switch d.bd {
case simpleVdPosInt:
ui = uint64(d.d.decRd.readn1())
case simpleVdPosInt + 1:
ui = uint64(bigen.Uint16(d.d.decRd.readn2()))
case simpleVdPosInt + 2:
ui = uint64(bigen.Uint32(d.d.decRd.readn4()))
case simpleVdPosInt + 3:
ui = uint64(bigen.Uint64(d.d.decRd.readn8()))
case simpleVdNegInt:
ui = uint64(d.d.decRd.readn1())
neg = true
case simpleVdNegInt + 1:
ui = uint64(bigen.Uint16(d.d.decRd.readn2()))
neg = true
case simpleVdNegInt + 2:
ui = uint64(bigen.Uint32(d.d.decRd.readn4()))
neg = true
case simpleVdNegInt + 3:
ui = uint64(bigen.Uint64(d.d.decRd.readn8()))
neg = true
default:
ok = false
// d.d.errorf("integer only valid from pos/neg integer1..8. Invalid descriptor: %v", d.bd)
}
// DO NOT do this check below, because callers may only want the unsigned value:
//
// if ui > math.MaxInt64 {
// d.d.errorf("decIntAny: Integer out of range for signed int64: %v", ui)
// return
// }
return
}
func (d *simpleDecDriver) DecodeInt64() (i int64) {
if d.advanceNil() {
return
}
i = decNegintPosintFloatNumberHelper{&d.d}.int64(d.decInteger())
d.bdRead = false
return
}
func (d *simpleDecDriver) DecodeUint64() (ui uint64) {
if d.advanceNil() {
return
}
ui = decNegintPosintFloatNumberHelper{&d.d}.uint64(d.decInteger())
d.bdRead = false
return
}
func (d *simpleDecDriver) DecodeFloat64() (f float64) {
if d.advanceNil() {
return
}
f = decNegintPosintFloatNumberHelper{&d.d}.float64(d.decFloat())
d.bdRead = false
return
}
// bool can be decoded from bool only (single byte).
func (d *simpleDecDriver) DecodeBool() (b bool) {
if d.advanceNil() {
return
}
if d.bd == simpleVdFalse {
} else if d.bd == simpleVdTrue {
b = true
} else {
d.d.errorf("cannot decode bool - %s: %x", msgBadDesc, d.bd)
}
d.bdRead = false
return
}
func (d *simpleDecDriver) ReadMapStart() (length int) {
if d.advanceNil() {
return containerLenNil
}
d.bdRead = false
return d.decLen()
}
func (d *simpleDecDriver) ReadArrayStart() (length int) {
if d.advanceNil() {
return containerLenNil
}
d.bdRead = false
return d.decLen()
}
func (d *simpleDecDriver) uint2Len(ui uint64) int {
if chkOvf.Uint(ui, intBitsize) {
d.d.errorf("overflow integer: %v", ui)
}
return int(ui)
}
func (d *simpleDecDriver) decLen() int {
switch d.bd & 7 { // d.bd % 8 {
case 0:
return 0
case 1:
return int(d.d.decRd.readn1())
case 2:
return int(bigen.Uint16(d.d.decRd.readn2()))
case 3:
return d.uint2Len(uint64(bigen.Uint32(d.d.decRd.readn4())))
case 4:
return d.uint2Len(bigen.Uint64(d.d.decRd.readn8()))
}
d.d.errorf("cannot read length: bd%%8 must be in range 0..4. Got: %d", d.bd%8)
return -1
}
func (d *simpleDecDriver) DecodeStringAsBytes() (s []byte) {
return d.DecodeBytes(nil)
}
func (d *simpleDecDriver) DecodeBytes(bs []byte) (bsOut []byte) {
d.d.decByteState = decByteStateNone
if d.advanceNil() {
return
}
// check if an "array" of uint8's (see ContainerType for how to infer if an array)
if d.bd >= simpleVdArray && d.bd <= simpleVdMap+4 {
if bs == nil {
d.d.decByteState = decByteStateReuseBuf
bs = d.d.b[:]
}
slen := d.ReadArrayStart()
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.d.h.MaxInitLen, bs)
}
func (d *simpleDecDriver) DecodeTime() (t time.Time) {
if d.advanceNil() {
return
}
if d.bd != simpleVdTime {
d.d.errorf("invalid descriptor for time.Time - expect 0x%x, received 0x%x", simpleVdTime, d.bd)
}
d.bdRead = false
clen := uint(d.d.decRd.readn1())
b := d.d.decRd.readx(clen)
d.d.onerror((&t).UnmarshalBinary(b))
return
}
func (d *simpleDecDriver) 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 *simpleDecDriver) decodeExtV(verifyTag bool, tag byte) (xbs []byte, xtag byte, zerocopy bool) {
switch d.bd {
case simpleVdExt, simpleVdExt + 1, simpleVdExt + 2, simpleVdExt + 3, simpleVdExt + 4:
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[:])
}
case simpleVdByteArray, simpleVdByteArray + 1,
simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
xbs = d.DecodeBytes(nil)
default:
d.d.errorf("ext - %s - expecting extensions/bytearray, got: 0x%x", msgBadDesc, d.bd)
}
d.bdRead = false
return
}
func (d *simpleDecDriver) DecodeNaked() {
if !d.bdRead {
d.readNextBd()
}
n := d.d.naked()
var decodeFurther bool
switch d.bd {
case simpleVdNil:
n.v = valueTypeNil
case simpleVdFalse:
n.v = valueTypeBool
n.b = false
case simpleVdTrue:
n.v = valueTypeBool
n.b = true
case simpleVdPosInt, simpleVdPosInt + 1, simpleVdPosInt + 2, simpleVdPosInt + 3:
if d.h.SignedInteger {
n.v = valueTypeInt
n.i = d.DecodeInt64()
} else {
n.v = valueTypeUint
n.u = d.DecodeUint64()
}
case simpleVdNegInt, simpleVdNegInt + 1, simpleVdNegInt + 2, simpleVdNegInt + 3:
n.v = valueTypeInt
n.i = d.DecodeInt64()
case simpleVdFloat32:
n.v = valueTypeFloat
n.f = d.DecodeFloat64()
case simpleVdFloat64:
n.v = valueTypeFloat
n.f = d.DecodeFloat64()
case simpleVdTime:
n.v = valueTypeTime
n.t = d.DecodeTime()
case simpleVdString, simpleVdString + 1,
simpleVdString + 2, simpleVdString + 3, simpleVdString + 4:
n.v = valueTypeString
n.s = d.d.stringZC(d.DecodeStringAsBytes())
case simpleVdByteArray, simpleVdByteArray + 1,
simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
d.d.fauxUnionReadRawBytes(false)
case simpleVdExt, simpleVdExt + 1, simpleVdExt + 2, simpleVdExt + 3, simpleVdExt + 4:
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 simpleVdArray, simpleVdArray + 1, simpleVdArray + 2,
simpleVdArray + 3, simpleVdArray + 4:
n.v = valueTypeArray
decodeFurther = true
case simpleVdMap, simpleVdMap + 1, simpleVdMap + 2, simpleVdMap + 3, simpleVdMap + 4:
n.v = valueTypeMap
decodeFurther = true
default:
d.d.errorf("cannot infer value - %s 0x%x", msgBadDesc, d.bd)
}
if !decodeFurther {
d.bdRead = false
}
}
func (d *simpleDecDriver) 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 *simpleDecDriver) 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 *simpleDecDriver) nextValueBytesBdReadR(v0 []byte) (v []byte) {
v = v0
var h = decNextValueBytesHelper{d: &d.d}
c := d.bd
var length uint
switch c {
case simpleVdNil, simpleVdFalse, simpleVdTrue, simpleVdString, simpleVdByteArray:
// pass
case simpleVdPosInt, simpleVdNegInt:
h.append1(&v, d.d.decRd.readn1())
case simpleVdPosInt + 1, simpleVdNegInt + 1:
h.appendN(&v, d.d.decRd.readx(2)...)
case simpleVdPosInt + 2, simpleVdNegInt + 2, simpleVdFloat32:
h.appendN(&v, d.d.decRd.readx(4)...)
case simpleVdPosInt + 3, simpleVdNegInt + 3, simpleVdFloat64:
h.appendN(&v, d.d.decRd.readx(8)...)
case simpleVdTime:
c = d.d.decRd.readn1()
h.append1(&v, c)
h.appendN(&v, d.d.decRd.readx(uint(c))...)
default:
switch c & 7 { // c % 8 {
case 0:
length = 0
case 1:
b := d.d.decRd.readn1()
length = uint(b)
h.append1(&v, b)
case 2:
x := d.d.decRd.readn2()
length = uint(bigen.Uint16(x))
h.appendN(&v, x[:]...)
case 3:
x := d.d.decRd.readn4()
length = uint(bigen.Uint32(x))
h.appendN(&v, x[:]...)
case 4:
x := d.d.decRd.readn8()
length = uint(bigen.Uint64(x))
h.appendN(&v, x[:]...)
}
bExt := c >= simpleVdExt && c <= simpleVdExt+7
bStr := c >= simpleVdString && c <= simpleVdString+7
bByteArray := c >= simpleVdByteArray && c <= simpleVdByteArray+7
bArray := c >= simpleVdArray && c <= simpleVdArray+7
bMap := c >= simpleVdMap && c <= simpleVdMap+7
if !(bExt || bStr || bByteArray || bArray || bMap) {
d.d.errorf("cannot infer value - %s 0x%x", msgBadDesc, c)
}
if bExt {
h.append1(&v, d.d.decRd.readn1()) // tag
}
if length == 0 {
break
}
if bArray {
for i := uint(0); i < length; i++ {
v = d.nextValueBytesR(v)
}
} else if bMap {
for i := uint(0); i < length; i++ {
v = d.nextValueBytesR(v)
v = d.nextValueBytesR(v)
}
} else {
h.appendN(&v, d.d.decRd.readx(length)...)
}
}
return
}
//------------------------------------
// SimpleHandle is a Handle for a very simple encoding format.
//
// simple is a simplistic codec similar to binc, but not as compact.
// - Encoding of a value is always preceded by the descriptor byte (bd)
// - True, false, nil are encoded fully in 1 byte (the descriptor)
// - Integers (intXXX, uintXXX) are encoded in 1, 2, 4 or 8 bytes (plus a descriptor byte).
// There are positive (uintXXX and intXXX >= 0) and negative (intXXX < 0) integers.
// - Floats are encoded in 4 or 8 bytes (plus a descriptor byte)
// - Length of containers (strings, bytes, array, map, extensions)
// are encoded in 0, 1, 2, 4 or 8 bytes.
// Zero-length containers have no length encoded.
// For others, the number of bytes is given by pow(2, bd%3)
// - maps are encoded as [bd] [length] [[key][value]]...
// - arrays are encoded as [bd] [length] [value]...
// - extensions are encoded as [bd] [length] [tag] [byte]...
// - strings/bytearrays are encoded as [bd] [length] [byte]...
// - time.Time are encoded as [bd] [length] [byte]...
//
// The full spec will be published soon.
type SimpleHandle struct {
binaryEncodingType
BasicHandle
// EncZeroValuesAsNil says to encode zero values for numbers, bool, string, etc as nil
EncZeroValuesAsNil bool
}
// Name returns the name of the handle: simple
func (h *SimpleHandle) Name() string { return "simple" }
func (h *SimpleHandle) desc(bd byte) string { return simpledesc(bd) }
func (h *SimpleHandle) newEncDriver() encDriver {
var e = &simpleEncDriver{h: h}
e.e.e = e
e.e.init(h)
e.reset()
return e
}
func (h *SimpleHandle) newDecDriver() decDriver {
d := &simpleDecDriver{h: h}
d.d.d = d
d.d.init(h)
d.reset()
return d
}
var _ decDriver = (*simpleDecDriver)(nil)
var _ encDriver = (*simpleEncDriver)(nil)