gotosocial/vendor/github.com/ugorji/go/codec/json.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
// By default, this json support uses base64 encoding for bytes, because you cannot
// store and read any arbitrary string in json (only unicode).
// However, the user can configre how to encode/decode bytes.
//
// This library specifically supports UTF-8 for encoding and decoding only.
//
// Note that the library will happily encode/decode things which are not valid
// json e.g. a map[int64]string. We do it for consistency. With valid json,
// we will encode and decode appropriately.
// Users can specify their map type if necessary to force it.
//
// We cannot use strconv.(Q|Unq)uote because json quotes/unquotes differently.
import (
"encoding/base64"
"math"
"reflect"
"strconv"
"time"
"unicode"
"unicode/utf16"
"unicode/utf8"
)
//--------------------------------
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// jsonLits and jsonLitb are defined at the package level,
// so they are guaranteed to be stored efficiently, making
// for better append/string comparison/etc.
//
// (anecdotal evidence from some benchmarking on go 1.20 devel in 20220104)
const jsonLits = `"true"false"null"`
var jsonLitb = []byte(jsonLits)
const (
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jsonLitT = 1
jsonLitF = 6
jsonLitN = 12
)
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const jsonEncodeUintSmallsString = "" +
"00010203040506070809" +
"10111213141516171819" +
"20212223242526272829" +
"30313233343536373839" +
"40414243444546474849" +
"50515253545556575859" +
"60616263646566676869" +
"70717273747576777879" +
"80818283848586878889" +
"90919293949596979899"
var jsonEncodeUintSmallsStringBytes = []byte(jsonEncodeUintSmallsString)
const (
jsonU4Chk2 = '0'
jsonU4Chk1 = 'a' - 10
jsonU4Chk0 = 'A' - 10
)
const (
// If !jsonValidateSymbols, decoding will be faster, by skipping some checks:
// - If we see first character of null, false or true,
// do not validate subsequent characters.
// - e.g. if we see a n, assume null and skip next 3 characters,
// and do not validate they are ull.
// P.S. Do not expect a significant decoding boost from this.
jsonValidateSymbols = true
// jsonEscapeMultiByteUnicodeSep controls whether some unicode characters
// that are valid json but may bomb in some contexts are escaped during encoeing.
//
// U+2028 is LINE SEPARATOR. U+2029 is PARAGRAPH SEPARATOR.
// Both technically valid JSON, but bomb on JSONP, so fix here unconditionally.
jsonEscapeMultiByteUnicodeSep = true
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// jsonRecognizeBoolNullInQuotedStr is used during decoding into a blank interface{}
// to control whether we detect quoted values of bools and null where a map key is expected,
// and treat as nil, true or false.
jsonNakedBoolNullInQuotedStr = true
// jsonManualInlineDecRdInHotZones controls whether we manually inline some decReader calls.
//
// encode performance is at par with libraries that just iterate over bytes directly,
// because encWr (with inlined bytesEncAppender calls) is inlined.
// Conversely, decode performance suffers because decRd (with inlined bytesDecReader calls)
// isn't inlinable.
//
// To improve decode performamnce from json:
// - readn1 is only called for \u
// - consequently, to optimize json decoding, we specifically need inlining
// for bytes use-case of some other decReader methods:
// - jsonReadAsisChars, skipWhitespace (advance) and jsonReadNum
// - AND THEN readn3, readn4 (for ull, rue and alse).
// - (readn1 is only called when a char is escaped).
// - without inlining, we still pay the cost of a method invocationK, and this dominates time
// - To mitigate, we manually inline in hot zones
// *excluding places where used sparingly (e.g. nextValueBytes, and other atypical cases)*.
// - jsonReadAsisChars *only* called in: appendStringAsBytes
// - advance called: everywhere
// - jsonReadNum: decNumBytes, DecodeNaked
// - From running go test (our anecdotal findings):
// - calling jsonReadAsisChars in appendStringAsBytes: 23431
// - calling jsonReadNum in decNumBytes: 15251
// - calling jsonReadNum in DecodeNaked: 612
// Consequently, we manually inline jsonReadAsisChars (in appendStringAsBytes)
// and jsonReadNum (in decNumbytes)
jsonManualInlineDecRdInHotZones = true
jsonSpacesOrTabsLen = 128
// jsonAlwaysReturnInternString = false
)
var (
// jsonTabs and jsonSpaces are used as caches for indents
jsonTabs, jsonSpaces [jsonSpacesOrTabsLen]byte
jsonCharHtmlSafeSet bitset256
jsonCharSafeSet bitset256
)
func init() {
var i byte
for i = 0; i < jsonSpacesOrTabsLen; i++ {
jsonSpaces[i] = ' '
jsonTabs[i] = '\t'
}
// populate the safe values as true: note: ASCII control characters are (0-31)
// jsonCharSafeSet: all true except (0-31) " \
// jsonCharHtmlSafeSet: all true except (0-31) " \ < > &
for i = 32; i < utf8.RuneSelf; i++ {
switch i {
case '"', '\\':
case '<', '>', '&':
jsonCharSafeSet.set(i) // = true
default:
jsonCharSafeSet.set(i)
jsonCharHtmlSafeSet.set(i)
}
}
}
// ----------------
type jsonEncState struct {
di int8 // indent per: if negative, use tabs
d bool // indenting?
dl uint16 // indent level
}
func (x jsonEncState) captureState() interface{} { return x }
func (x *jsonEncState) restoreState(v interface{}) { *x = v.(jsonEncState) }
type jsonEncDriver struct {
noBuiltInTypes
h *JsonHandle
// se interfaceExtWrapper
// ---- cpu cache line boundary?
jsonEncState
ks bool // map key as string
is byte // integer as string
typical bool
rawext bool // rawext configured on the handle
s *bitset256 // safe set for characters (taking h.HTMLAsIs into consideration)
// buf *[]byte // used mostly for encoding []byte
// scratch buffer for: encode time, numbers, etc
//
// RFC3339Nano uses 35 chars: 2006-01-02T15:04:05.999999999Z07:00
// MaxUint64 uses 20 chars: 18446744073709551615
// floats are encoded using: f/e fmt, and -1 precision, or 1 if no fractions.
// This means we are limited by the number of characters for the
// mantissa (up to 17), exponent (up to 3), signs (up to 3), dot (up to 1), E (up to 1)
// for a total of 24 characters.
// -xxx.yyyyyyyyyyyye-zzz
// Consequently, 35 characters should be sufficient for encoding time, integers or floats.
// We use up all the remaining bytes to make this use full cache lines.
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b [48]byte
e Encoder
}
func (e *jsonEncDriver) encoder() *Encoder { return &e.e }
func (e *jsonEncDriver) writeIndent() {
e.e.encWr.writen1('\n')
x := int(e.di) * int(e.dl)
if e.di < 0 {
x = -x
for x > jsonSpacesOrTabsLen {
e.e.encWr.writeb(jsonTabs[:])
x -= jsonSpacesOrTabsLen
}
e.e.encWr.writeb(jsonTabs[:x])
} else {
for x > jsonSpacesOrTabsLen {
e.e.encWr.writeb(jsonSpaces[:])
x -= jsonSpacesOrTabsLen
}
e.e.encWr.writeb(jsonSpaces[:x])
}
}
func (e *jsonEncDriver) WriteArrayElem() {
if e.e.c != containerArrayStart {
e.e.encWr.writen1(',')
}
if e.d {
e.writeIndent()
}
}
func (e *jsonEncDriver) WriteMapElemKey() {
if e.e.c != containerMapStart {
e.e.encWr.writen1(',')
}
if e.d {
e.writeIndent()
}
}
func (e *jsonEncDriver) WriteMapElemValue() {
if e.d {
e.e.encWr.writen2(':', ' ')
} else {
e.e.encWr.writen1(':')
}
}
func (e *jsonEncDriver) EncodeNil() {
// We always encode nil as just null (never in quotes)
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// so we can easily decode if a nil in the json stream ie if initial token is n.
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e.e.encWr.writestr(jsonLits[jsonLitN : jsonLitN+4])
}
func (e *jsonEncDriver) EncodeTime(t time.Time) {
// Do NOT use MarshalJSON, as it allocates internally.
// instead, we call AppendFormat directly, using our scratch buffer (e.b)
if t.IsZero() {
e.EncodeNil()
} else {
e.b[0] = '"'
b := fmtTime(t, time.RFC3339Nano, e.b[1:1])
e.b[len(b)+1] = '"'
e.e.encWr.writeb(e.b[:len(b)+2])
}
}
func (e *jsonEncDriver) EncodeExt(rv interface{}, basetype reflect.Type, xtag uint64, ext Ext) {
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 *jsonEncDriver) EncodeRawExt(re *RawExt) {
// only encodes re.Value (never re.Data)
if re.Value == nil {
e.EncodeNil()
} else {
e.e.encode(re.Value)
}
}
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var jsonEncBoolStrs = [2][2]string{
{jsonLits[jsonLitF : jsonLitF+5], jsonLits[jsonLitT : jsonLitT+4]},
{jsonLits[jsonLitF-1 : jsonLitF+6], jsonLits[jsonLitT-1 : jsonLitT+5]},
}
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func (e *jsonEncDriver) EncodeBool(b bool) {
e.e.encWr.writestr(
jsonEncBoolStrs[bool2int(e.ks && e.e.c == containerMapKey)%2][bool2int(b)%2])
}
// func (e *jsonEncDriver) EncodeBool(b bool) {
// if e.ks && e.e.c == containerMapKey {
// if b {
// e.e.encWr.writestr(jsonLits[jsonLitT-1 : jsonLitT+5])
// } else {
// e.e.encWr.writestr(jsonLits[jsonLitF-1 : jsonLitF+6])
// }
// } else {
// if b {
// e.e.encWr.writestr(jsonLits[jsonLitT : jsonLitT+4])
// } else {
// e.e.encWr.writestr(jsonLits[jsonLitF : jsonLitF+5])
// }
// }
// }
func (e *jsonEncDriver) encodeFloat(f float64, bitsize, fmt byte, prec int8) {
var blen uint
if e.ks && e.e.c == containerMapKey {
blen = 2 + uint(len(strconv.AppendFloat(e.b[1:1], f, fmt, int(prec), int(bitsize))))
// _ = e.b[:blen]
e.b[0] = '"'
e.b[blen-1] = '"'
e.e.encWr.writeb(e.b[:blen])
} else {
e.e.encWr.writeb(strconv.AppendFloat(e.b[:0], f, fmt, int(prec), int(bitsize)))
}
}
func (e *jsonEncDriver) EncodeFloat64(f float64) {
if math.IsNaN(f) || math.IsInf(f, 0) {
e.EncodeNil()
return
}
fmt, prec := jsonFloatStrconvFmtPrec64(f)
e.encodeFloat(f, 64, fmt, prec)
}
func (e *jsonEncDriver) EncodeFloat32(f float32) {
if math.IsNaN(float64(f)) || math.IsInf(float64(f), 0) {
e.EncodeNil()
return
}
fmt, prec := jsonFloatStrconvFmtPrec32(f)
e.encodeFloat(float64(f), 32, fmt, prec)
}
func (e *jsonEncDriver) encodeUint(neg bool, quotes bool, u uint64) {
// copied mostly from std library: strconv
// this should only be called on 64bit OS.
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// const smallsString = jsonEncodeUintSmallsString
var ss = jsonEncodeUintSmallsStringBytes
// typically, 19 or 20 bytes sufficient for decimal encoding a uint64
// var a [24]byte
var a = e.b[0:24]
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var i = uint(len(a))
if quotes {
i--
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setByteAt(a, i, '"')
// a[i] = '"'
}
// u guaranteed to fit into a uint (as we are not 32bit OS)
var is uint
var us = uint(u)
for us >= 100 {
is = us % 100 * 2
us /= 100
i -= 2
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setByteAt(a, i+1, byteAt(ss, is+1))
setByteAt(a, i, byteAt(ss, is))
// a[i+1] = smallsString[is+1]
// a[i+0] = smallsString[is+0]
}
// us < 100
is = us * 2
i--
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setByteAt(a, i, byteAt(ss, is+1))
// a[i] = smallsString[is+1]
if us >= 10 {
i--
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setByteAt(a, i, byteAt(ss, is))
// a[i] = smallsString[is]
}
if neg {
i--
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setByteAt(a, i, '-')
// a[i] = '-'
}
if quotes {
i--
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setByteAt(a, i, '"')
// a[i] = '"'
}
e.e.encWr.writeb(a[i:])
}
func (e *jsonEncDriver) EncodeInt(v int64) {
quotes := e.is == 'A' || e.is == 'L' && (v > 1<<53 || v < -(1<<53)) ||
(e.ks && e.e.c == containerMapKey)
if cpu32Bit {
if quotes {
blen := 2 + len(strconv.AppendInt(e.b[1:1], v, 10))
e.b[0] = '"'
e.b[blen-1] = '"'
e.e.encWr.writeb(e.b[:blen])
} else {
e.e.encWr.writeb(strconv.AppendInt(e.b[:0], v, 10))
}
return
}
if v < 0 {
e.encodeUint(true, quotes, uint64(-v))
} else {
e.encodeUint(false, quotes, uint64(v))
}
}
func (e *jsonEncDriver) EncodeUint(v uint64) {
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quotes := e.is == 'A' || e.is == 'L' && v > 1<<53 ||
(e.ks && e.e.c == containerMapKey)
if cpu32Bit {
// use strconv directly, as optimized encodeUint only works on 64-bit alone
if quotes {
blen := 2 + len(strconv.AppendUint(e.b[1:1], v, 10))
e.b[0] = '"'
e.b[blen-1] = '"'
e.e.encWr.writeb(e.b[:blen])
} else {
e.e.encWr.writeb(strconv.AppendUint(e.b[:0], v, 10))
}
return
}
e.encodeUint(false, quotes, v)
}
func (e *jsonEncDriver) EncodeString(v string) {
if e.h.StringToRaw {
e.EncodeStringBytesRaw(bytesView(v))
return
}
e.quoteStr(v)
}
func (e *jsonEncDriver) EncodeStringBytesRaw(v []byte) {
// if encoding raw bytes and RawBytesExt is configured, use it to encode
if v == nil {
e.EncodeNil()
return
}
if e.rawext {
iv := e.h.RawBytesExt.ConvertExt(v)
if iv == nil {
e.EncodeNil()
} else {
e.e.encode(iv)
}
return
}
slen := base64.StdEncoding.EncodedLen(len(v)) + 2
// bs := e.e.blist.check(*e.buf, n)[:slen]
// *e.buf = bs
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bs := e.e.blist.peek(slen, false)
bs = bs[:slen]
base64.StdEncoding.Encode(bs[1:], v)
bs[len(bs)-1] = '"'
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bs[0] = '"'
e.e.encWr.writeb(bs)
}
// indent is done as below:
// - newline and indent are added before each mapKey or arrayElem
// - newline and indent are added before each ending,
// except there was no entry (so we can have {} or [])
func (e *jsonEncDriver) WriteArrayStart(length int) {
if e.d {
e.dl++
}
e.e.encWr.writen1('[')
}
func (e *jsonEncDriver) WriteArrayEnd() {
if e.d {
e.dl--
e.writeIndent()
}
e.e.encWr.writen1(']')
}
func (e *jsonEncDriver) WriteMapStart(length int) {
if e.d {
e.dl++
}
e.e.encWr.writen1('{')
}
func (e *jsonEncDriver) WriteMapEnd() {
if e.d {
e.dl--
if e.e.c != containerMapStart {
e.writeIndent()
}
}
e.e.encWr.writen1('}')
}
func (e *jsonEncDriver) quoteStr(s string) {
// adapted from std pkg encoding/json
const hex = "0123456789abcdef"
w := e.e.w()
w.writen1('"')
var i, start uint
for i < uint(len(s)) {
// encode all bytes < 0x20 (except \r, \n).
// also encode < > & to prevent security holes when served to some browsers.
// We optimize for ascii, by assumining that most characters are in the BMP
// and natively consumed by json without much computation.
// if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && b != '&' {
// if (htmlasis && jsonCharSafeSet.isset(b)) || jsonCharHtmlSafeSet.isset(b) {
if e.s.isset(s[i]) {
i++
continue
}
// b := s[i]
if s[i] < utf8.RuneSelf {
if start < i {
w.writestr(s[start:i])
}
switch s[i] {
case '\\', '"':
w.writen2('\\', s[i])
case '\n':
w.writen2('\\', 'n')
case '\r':
w.writen2('\\', 'r')
case '\b':
w.writen2('\\', 'b')
case '\f':
w.writen2('\\', 'f')
case '\t':
w.writen2('\\', 't')
default:
w.writestr(`\u00`)
w.writen2(hex[s[i]>>4], hex[s[i]&0xF])
}
i++
start = i
continue
}
c, size := utf8.DecodeRuneInString(s[i:])
if c == utf8.RuneError && size == 1 { // meaning invalid encoding (so output as-is)
if start < i {
w.writestr(s[start:i])
}
w.writestr(`\uFFFD`)
i++
start = i
continue
}
// U+2028 is LINE SEPARATOR. U+2029 is PARAGRAPH SEPARATOR.
// Both technically valid JSON, but bomb on JSONP, so fix here *unconditionally*.
if jsonEscapeMultiByteUnicodeSep && (c == '\u2028' || c == '\u2029') {
if start < i {
w.writestr(s[start:i])
}
w.writestr(`\u202`)
w.writen1(hex[c&0xF])
i += uint(size)
start = i
continue
}
i += uint(size)
}
if start < uint(len(s)) {
w.writestr(s[start:])
}
w.writen1('"')
}
func (e *jsonEncDriver) atEndOfEncode() {
if e.h.TermWhitespace {
var c byte = ' ' // default is that scalar is written, so output space
if e.e.c != 0 {
c = '\n' // for containers (map/list), output a newline
}
e.e.encWr.writen1(c)
}
}
// ----------
type jsonDecState struct {
rawext bool // rawext configured on the handle
tok uint8 // used to store the token read right after skipWhiteSpace
_ bool // found null
_ byte // padding
bstr [4]byte // scratch used for string \UXXX parsing
// scratch buffer used for base64 decoding (DecodeBytes in reuseBuf mode),
// or reading doubleQuoted string (DecodeStringAsBytes, DecodeNaked)
buf *[]byte
}
func (x jsonDecState) captureState() interface{} { return x }
func (x *jsonDecState) restoreState(v interface{}) { *x = v.(jsonDecState) }
type jsonDecDriver struct {
noBuiltInTypes
decDriverNoopNumberHelper
h *JsonHandle
jsonDecState
// se interfaceExtWrapper
// ---- cpu cache line boundary?
d Decoder
}
func (d *jsonDecDriver) descBd() (s string) { panic("descBd unsupported") }
func (d *jsonDecDriver) decoder() *Decoder {
return &d.d
}
func (d *jsonDecDriver) ReadMapStart() int {
d.advance()
if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return containerLenNil
}
if d.tok != '{' {
d.d.errorf("read map - expect char '%c' but got char '%c'", '{', d.tok)
}
d.tok = 0
return containerLenUnknown
}
func (d *jsonDecDriver) ReadArrayStart() int {
d.advance()
if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return containerLenNil
}
if d.tok != '[' {
d.d.errorf("read array - expect char '%c' but got char '%c'", '[', d.tok)
}
d.tok = 0
return containerLenUnknown
}
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// MARKER:
// We attempted making sure CheckBreak can be inlined, by moving the skipWhitespace
// call to an explicit (noinline) function call.
// However, this forces CheckBreak to always incur a function call if there was whitespace,
// with no clear benefit.
func (d *jsonDecDriver) CheckBreak() bool {
d.advance()
return d.tok == '}' || d.tok == ']'
}
func (d *jsonDecDriver) ReadArrayElem() {
const xc uint8 = ','
if d.d.c != containerArrayStart {
d.advance()
if d.tok != xc {
d.readDelimError(xc)
}
d.tok = 0
}
}
func (d *jsonDecDriver) ReadArrayEnd() {
const xc uint8 = ']'
d.advance()
if d.tok != xc {
d.readDelimError(xc)
}
d.tok = 0
}
func (d *jsonDecDriver) ReadMapElemKey() {
const xc uint8 = ','
if d.d.c != containerMapStart {
d.advance()
if d.tok != xc {
d.readDelimError(xc)
}
d.tok = 0
}
}
func (d *jsonDecDriver) ReadMapElemValue() {
const xc uint8 = ':'
d.advance()
if d.tok != xc {
d.readDelimError(xc)
}
d.tok = 0
}
func (d *jsonDecDriver) ReadMapEnd() {
const xc uint8 = '}'
d.advance()
if d.tok != xc {
d.readDelimError(xc)
}
d.tok = 0
}
func (d *jsonDecDriver) readDelimError(xc uint8) {
d.d.errorf("read json delimiter - expect char '%c' but got char '%c'", xc, d.tok)
}
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// MARKER: checkLit takes the readn(3|4) result as a parameter so they can be inlined.
// We pass the array directly to errorf, as passing slice pushes past inlining threshold,
// and passing slice also might cause allocation of the bs array on the heap.
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func (d *jsonDecDriver) checkLit3(got, expect [3]byte) {
d.tok = 0
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if jsonValidateSymbols && got != expect {
d.d.errorf("expecting %s: got %s", expect, got)
}
}
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func (d *jsonDecDriver) checkLit4(got, expect [4]byte) {
d.tok = 0
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if jsonValidateSymbols && got != expect {
d.d.errorf("expecting %s: got %s", expect, got)
}
}
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func (d *jsonDecDriver) skipWhitespace() {
d.tok = d.d.decRd.skipWhitespace()
}
func (d *jsonDecDriver) advance() {
if d.tok == 0 {
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d.skipWhitespace()
}
}
func (d *jsonDecDriver) nextValueBytes(v []byte) []byte {
v, cursor := d.nextValueBytesR(v)
decNextValueBytesHelper{d: &d.d}.bytesRdV(&v, cursor)
return v
}
func (d *jsonDecDriver) nextValueBytesR(v0 []byte) (v []byte, cursor uint) {
v = v0
var h = decNextValueBytesHelper{d: &d.d}
dr := &d.d.decRd
consumeString := func() {
TOP:
bs := dr.jsonReadAsisChars()
h.appendN(&v, bs...)
if bs[len(bs)-1] != '"' {
// last char is '\', so consume next one and try again
h.append1(&v, dr.readn1())
goto TOP
}
}
d.advance() // ignore leading whitespace
cursor = d.d.rb.c - 1 // cursor starts just before non-whitespace token
switch d.tok {
default:
h.appendN(&v, dr.jsonReadNum()...)
case 'n':
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
h.appendS(&v, jsonLits[jsonLitN:jsonLitN+4])
case 'f':
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d.checkLit4([4]byte{'a', 'l', 's', 'e'}, d.d.decRd.readn4())
h.appendS(&v, jsonLits[jsonLitF:jsonLitF+5])
case 't':
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d.checkLit3([3]byte{'r', 'u', 'e'}, d.d.decRd.readn3())
h.appendS(&v, jsonLits[jsonLitT:jsonLitT+4])
case '"':
h.append1(&v, '"')
consumeString()
case '{', '[':
var elem struct{}
var stack []struct{}
stack = append(stack, elem)
h.append1(&v, d.tok)
for len(stack) != 0 {
c := dr.readn1()
h.append1(&v, c)
switch c {
case '"':
consumeString()
case '{', '[':
stack = append(stack, elem)
case '}', ']':
stack = stack[:len(stack)-1]
}
}
}
d.tok = 0
return
}
func (d *jsonDecDriver) TryNil() bool {
d.advance()
// we shouldn't try to see if quoted "null" was here, right?
// only the plain string: `null` denotes a nil (ie not quotes)
if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return true
}
return false
}
func (d *jsonDecDriver) DecodeBool() (v bool) {
d.advance()
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// bool can be in quotes if and only if it's a map key
fquot := d.d.c == containerMapKey && d.tok == '"'
if fquot {
d.tok = d.d.decRd.readn1()
}
switch d.tok {
case 'f':
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d.checkLit4([4]byte{'a', 'l', 's', 'e'}, d.d.decRd.readn4())
// v = false
case 't':
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d.checkLit3([3]byte{'r', 'u', 'e'}, d.d.decRd.readn3())
v = true
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case 'n':
d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
// v = false
default:
d.d.errorf("decode bool: got first char %c", d.tok)
// v = false // "unreachable"
}
if fquot {
d.d.decRd.readn1()
}
return
}
func (d *jsonDecDriver) DecodeTime() (t time.Time) {
// read string, and pass the string into json.unmarshal
d.advance()
if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return
}
d.ensureReadingString()
bs := d.readUnescapedString()
t, err := time.Parse(time.RFC3339, stringView(bs))
d.d.onerror(err)
return
}
func (d *jsonDecDriver) ContainerType() (vt valueType) {
// check container type by checking the first char
d.advance()
// optimize this, so we don't do 4 checks but do one computation.
// return jsonContainerSet[d.tok]
// ContainerType is mostly called for Map and Array,
// so this conditional is good enough (max 2 checks typically)
if d.tok == '{' {
return valueTypeMap
} else if d.tok == '[' {
return valueTypeArray
} else if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return valueTypeNil
} else if d.tok == '"' {
return valueTypeString
}
return valueTypeUnset
}
func (d *jsonDecDriver) decNumBytes() (bs []byte) {
d.advance()
dr := &d.d.decRd
if d.tok == '"' {
bs = dr.readUntil('"')
} else if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, dr.readn3())
} else {
if jsonManualInlineDecRdInHotZones {
if dr.bytes {
bs = dr.rb.jsonReadNum()
} else {
bs = dr.ri.jsonReadNum()
}
} else {
bs = dr.jsonReadNum()
}
}
d.tok = 0
return
}
func (d *jsonDecDriver) DecodeUint64() (u uint64) {
b := d.decNumBytes()
u, neg, ok := parseInteger_bytes(b)
if neg {
d.d.errorf("negative number cannot be decoded as uint64")
}
if !ok {
d.d.onerror(strconvParseErr(b, "ParseUint"))
}
return
}
func (d *jsonDecDriver) DecodeInt64() (v int64) {
b := d.decNumBytes()
u, neg, ok := parseInteger_bytes(b)
if !ok {
d.d.onerror(strconvParseErr(b, "ParseInt"))
}
if chkOvf.Uint2Int(u, neg) {
d.d.errorf("overflow decoding number from %s", b)
}
if neg {
v = -int64(u)
} else {
v = int64(u)
}
return
}
func (d *jsonDecDriver) DecodeFloat64() (f float64) {
var err error
bs := d.decNumBytes()
if len(bs) == 0 {
return
}
f, err = parseFloat64(bs)
d.d.onerror(err)
return
}
func (d *jsonDecDriver) DecodeFloat32() (f float32) {
var err error
bs := d.decNumBytes()
if len(bs) == 0 {
return
}
f, err = parseFloat32(bs)
d.d.onerror(err)
return
}
func (d *jsonDecDriver) DecodeExt(rv interface{}, basetype reflect.Type, xtag uint64, ext Ext) {
d.advance()
if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return
}
if ext == nil {
re := rv.(*RawExt)
re.Tag = xtag
d.d.decode(&re.Value)
} else if ext == SelfExt {
d.d.decodeValue(baseRV(rv), d.h.fnNoExt(basetype))
} else {
d.d.interfaceExtConvertAndDecode(rv, ext)
}
}
func (d *jsonDecDriver) decBytesFromArray(bs []byte) []byte {
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if bs != nil {
bs = bs[:0]
}
d.tok = 0
bs = append(bs, uint8(d.DecodeUint64()))
d.tok = d.d.decRd.skipWhitespace() // skip(&whitespaceCharBitset)
for d.tok != ']' {
if d.tok != ',' {
d.d.errorf("read array element - expect char '%c' but got char '%c'", ',', d.tok)
}
d.tok = 0
bs = append(bs, uint8(chkOvf.UintV(d.DecodeUint64(), 8)))
d.tok = d.d.decRd.skipWhitespace() // skip(&whitespaceCharBitset)
}
d.tok = 0
return bs
}
func (d *jsonDecDriver) DecodeBytes(bs []byte) (bsOut []byte) {
d.d.decByteState = decByteStateNone
d.advance()
if d.tok == 'n' {
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return nil
}
// if decoding into raw bytes, and the RawBytesExt is configured, use it to decode.
if d.rawext {
bsOut = bs
d.d.interfaceExtConvertAndDecode(&bsOut, d.h.RawBytesExt)
return
}
// check if an "array" of uint8's (see ContainerType for how to infer if an array)
if d.tok == '[' {
// bsOut, _ = fastpathTV.DecSliceUint8V(bs, true, d.d)
if bs == nil {
d.d.decByteState = decByteStateReuseBuf
bs = d.d.b[:]
}
return d.decBytesFromArray(bs)
}
// base64 encodes []byte{} as "", and we encode nil []byte as null.
// Consequently, base64 should decode null as a nil []byte, and "" as an empty []byte{}.
d.ensureReadingString()
bs1 := d.readUnescapedString()
slen := base64.StdEncoding.DecodedLen(len(bs1))
if slen == 0 {
bsOut = []byte{}
} else if slen <= cap(bs) {
bsOut = bs[:slen]
} else if bs == nil {
d.d.decByteState = decByteStateReuseBuf
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bsOut = d.d.blist.check(*d.buf, slen)
bsOut = bsOut[:slen]
*d.buf = bsOut
} else {
bsOut = make([]byte, slen)
}
slen2, err := base64.StdEncoding.Decode(bsOut, bs1)
if err != nil {
d.d.errorf("error decoding base64 binary '%s': %v", bs1, err)
}
if slen != slen2 {
bsOut = bsOut[:slen2]
}
return
}
func (d *jsonDecDriver) DecodeStringAsBytes() (s []byte) {
d.d.decByteState = decByteStateNone
d.advance()
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// common case - hoist outside the switch statement
if d.tok == '"' {
return d.dblQuoteStringAsBytes()
}
// handle non-string scalar: null, true, false or a number
switch d.tok {
case 'n':
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
return nil // []byte{}
case 'f':
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d.checkLit4([4]byte{'a', 'l', 's', 'e'}, d.d.decRd.readn4())
return jsonLitb[jsonLitF : jsonLitF+5]
case 't':
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d.checkLit3([3]byte{'r', 'u', 'e'}, d.d.decRd.readn3())
return jsonLitb[jsonLitT : jsonLitT+4]
default:
// try to parse a valid number
d.tok = 0
return d.d.decRd.jsonReadNum()
}
}
func (d *jsonDecDriver) ensureReadingString() {
if d.tok != '"' {
d.d.errorf("expecting string starting with '\"'; got '%c'", d.tok)
}
}
func (d *jsonDecDriver) readUnescapedString() (bs []byte) {
// d.ensureReadingString()
bs = d.d.decRd.readUntil('"')
d.tok = 0
return
}
func (d *jsonDecDriver) dblQuoteStringAsBytes() (buf []byte) {
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checkUtf8 := d.h.ValidateUnicode
d.d.decByteState = decByteStateNone
// use a local buf variable, so we don't do pointer chasing within loop
buf = (*d.buf)[:0]
dr := &d.d.decRd
d.tok = 0
var bs []byte
var c byte
var firstTime bool = true
for {
if firstTime {
firstTime = false
if dr.bytes {
bs = dr.rb.jsonReadAsisChars()
if bs[len(bs)-1] == '"' {
d.d.decByteState = decByteStateZerocopy
return bs[:len(bs)-1]
}
goto APPEND
}
}
if jsonManualInlineDecRdInHotZones {
if dr.bytes {
bs = dr.rb.jsonReadAsisChars()
} else {
bs = dr.ri.jsonReadAsisChars()
}
} else {
bs = dr.jsonReadAsisChars()
}
APPEND:
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_ = bs[0] // bounds check hint - slice must be > 0 elements
buf = append(buf, bs[:len(bs)-1]...)
c = bs[len(bs)-1]
if c == '"' {
break
}
// c is now '\'
c = dr.readn1()
switch c {
case '"', '\\', '/', '\'':
buf = append(buf, c)
case 'b':
buf = append(buf, '\b')
case 'f':
buf = append(buf, '\f')
case 'n':
buf = append(buf, '\n')
case 'r':
buf = append(buf, '\r')
case 't':
buf = append(buf, '\t')
case 'u':
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rr := d.appendStringAsBytesSlashU()
if checkUtf8 && rr == unicode.ReplacementChar {
d.d.errorf("invalid UTF-8 character found after: %s", buf)
}
buf = append(buf, d.bstr[:utf8.EncodeRune(d.bstr[:], rr)]...)
default:
*d.buf = buf
d.d.errorf("unsupported escaped value: %c", c)
}
}
*d.buf = buf
d.d.decByteState = decByteStateReuseBuf
return
}
func (d *jsonDecDriver) appendStringAsBytesSlashU() (r rune) {
var rr uint32
var csu [2]byte
var cs [4]byte = d.d.decRd.readn4()
if rr = jsonSlashURune(cs); rr == unicode.ReplacementChar {
return unicode.ReplacementChar
}
r = rune(rr)
if utf16.IsSurrogate(r) {
csu = d.d.decRd.readn2()
cs = d.d.decRd.readn4()
if csu[0] == '\\' && csu[1] == 'u' {
if rr = jsonSlashURune(cs); rr == unicode.ReplacementChar {
return unicode.ReplacementChar
}
return utf16.DecodeRune(r, rune(rr))
}
return unicode.ReplacementChar
}
return
}
func jsonSlashURune(cs [4]byte) (rr uint32) {
for _, c := range cs {
// best to use explicit if-else
// - not a table, etc which involve memory loads, array lookup with bounds checks, etc
if c >= '0' && c <= '9' {
rr = rr*16 + uint32(c-jsonU4Chk2)
} else if c >= 'a' && c <= 'f' {
rr = rr*16 + uint32(c-jsonU4Chk1)
} else if c >= 'A' && c <= 'F' {
rr = rr*16 + uint32(c-jsonU4Chk0)
} else {
return unicode.ReplacementChar
}
}
return
}
func (d *jsonDecDriver) nakedNum(z *fauxUnion, bs []byte) (err error) {
// Note: nakedNum is NEVER called with a zero-length []byte
if d.h.PreferFloat {
z.v = valueTypeFloat
z.f, err = parseFloat64(bs)
} else {
err = parseNumber(bs, z, d.h.SignedInteger)
}
return
}
func (d *jsonDecDriver) DecodeNaked() {
z := d.d.naked()
d.advance()
var bs []byte
switch d.tok {
case 'n':
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d.checkLit3([3]byte{'u', 'l', 'l'}, d.d.decRd.readn3())
z.v = valueTypeNil
case 'f':
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d.checkLit4([4]byte{'a', 'l', 's', 'e'}, d.d.decRd.readn4())
z.v = valueTypeBool
z.b = false
case 't':
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d.checkLit3([3]byte{'r', 'u', 'e'}, d.d.decRd.readn3())
z.v = valueTypeBool
z.b = true
case '{':
z.v = valueTypeMap // don't consume. kInterfaceNaked will call ReadMapStart
case '[':
z.v = valueTypeArray // don't consume. kInterfaceNaked will call ReadArrayStart
case '"':
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// if a string, and MapKeyAsString, then try to decode it as a bool or number first
bs = d.dblQuoteStringAsBytes()
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if jsonNakedBoolNullInQuotedStr &&
d.h.MapKeyAsString && len(bs) > 0 && d.d.c == containerMapKey {
switch string(bs) {
// case "null": // nil is never quoted
// z.v = valueTypeNil
case "true":
z.v = valueTypeBool
z.b = true
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case "false":
z.v = valueTypeBool
z.b = false
2023-02-25 12:12:40 +00:00
default:
// check if a number: float, int or uint
if err := d.nakedNum(z, bs); err != nil {
z.v = valueTypeString
z.s = d.d.stringZC(bs)
}
}
} else {
z.v = valueTypeString
z.s = d.d.stringZC(bs)
}
default: // number
bs = d.d.decRd.jsonReadNum()
d.tok = 0
if len(bs) == 0 {
d.d.errorf("decode number from empty string")
}
if err := d.nakedNum(z, bs); err != nil {
d.d.errorf("decode number from %s: %v", bs, err)
}
}
}
//----------------------
// JsonHandle is a handle for JSON encoding format.
//
// Json is comprehensively supported:
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// - decodes numbers into interface{} as int, uint or float64
// based on how the number looks and some config parameters e.g. PreferFloat, SignedInt, etc.
// - decode integers from float formatted numbers e.g. 1.27e+8
// - decode any json value (numbers, bool, etc) from quoted strings
// - configurable way to encode/decode []byte .
// by default, encodes and decodes []byte using base64 Std Encoding
// - UTF-8 support for encoding and decoding
//
// It has better performance than the json library in the standard library,
// by leveraging the performance improvements of the codec library.
//
// In addition, it doesn't read more bytes than necessary during a decode, which allows
// reading multiple values from a stream containing json and non-json content.
// For example, a user can read a json value, then a cbor value, then a msgpack value,
// all from the same stream in sequence.
//
// Note that, when decoding quoted strings, invalid UTF-8 or invalid UTF-16 surrogate pairs are
// not treated as an error. Instead, they are replaced by the Unicode replacement character U+FFFD.
//
// Note also that the float values for NaN, +Inf or -Inf are encoded as null,
// as suggested by NOTE 4 of the ECMA-262 ECMAScript Language Specification 5.1 edition.
// see http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf .
type JsonHandle struct {
textEncodingType
BasicHandle
// Indent indicates how a value is encoded.
// - If positive, indent by that number of spaces.
// - If negative, indent by that number of tabs.
Indent int8
// IntegerAsString controls how integers (signed and unsigned) are encoded.
//
// Per the JSON Spec, JSON numbers are 64-bit floating point numbers.
// Consequently, integers > 2^53 cannot be represented as a JSON number without losing precision.
// This can be mitigated by configuring how to encode integers.
//
// IntegerAsString interpretes the following values:
// - if 'L', then encode integers > 2^53 as a json string.
// - if 'A', then encode all integers as a json string
// containing the exact integer representation as a decimal.
// - else encode all integers as a json number (default)
IntegerAsString byte
// HTMLCharsAsIs controls how to encode some special characters to html: < > &
//
// By default, we encode them as \uXXX
// to prevent security holes when served from some browsers.
HTMLCharsAsIs bool
// PreferFloat says that we will default to decoding a number as a float.
// If not set, we will examine the characters of the number and decode as an
// integer type if it doesn't have any of the characters [.eE].
PreferFloat bool
// TermWhitespace says that we add a whitespace character
// at the end of an encoding.
//
// The whitespace is important, especially if using numbers in a context
// where multiple items are written to a stream.
TermWhitespace bool
// MapKeyAsString says to encode all map keys as strings.
//
// Use this to enforce strict json output.
// The only caveat is that nil value is ALWAYS written as null (never as "null")
MapKeyAsString bool
// _ uint64 // padding (cache line)
// Note: below, we store hardly-used items e.g. RawBytesExt.
// These values below may straddle a cache line, but they are hardly-used,
// so shouldn't contribute to false-sharing except in rare cases.
// RawBytesExt, if configured, is used to encode and decode raw bytes in a custom way.
// If not configured, raw bytes are encoded to/from base64 text.
RawBytesExt InterfaceExt
}
func (h *JsonHandle) isJson() bool { return true }
// Name returns the name of the handle: json
func (h *JsonHandle) Name() string { return "json" }
func (h *JsonHandle) desc(bd byte) string { return string(bd) }
func (h *JsonHandle) typical() bool {
return h.Indent == 0 && !h.MapKeyAsString && h.IntegerAsString != 'A' && h.IntegerAsString != 'L'
}
func (h *JsonHandle) newEncDriver() encDriver {
var e = &jsonEncDriver{h: h}
// var x []byte
// e.buf = &x
e.e.e = e
e.e.js = true
e.e.init(h)
e.reset()
return e
}
func (h *JsonHandle) newDecDriver() decDriver {
var d = &jsonDecDriver{h: h}
var x []byte
d.buf = &x
d.d.d = d
d.d.js = true
d.d.jsms = h.MapKeyAsString
d.d.init(h)
d.reset()
return d
}
func (e *jsonEncDriver) resetState() {
e.dl = 0
}
func (e *jsonEncDriver) reset() {
e.resetState()
// (htmlasis && jsonCharSafeSet.isset(b)) || jsonCharHtmlSafeSet.isset(b)
// cache values from the handle
e.typical = e.h.typical()
if e.h.HTMLCharsAsIs {
e.s = &jsonCharSafeSet
} else {
e.s = &jsonCharHtmlSafeSet
}
e.rawext = e.h.RawBytesExt != nil
e.di = int8(e.h.Indent)
e.d = e.h.Indent != 0
e.ks = e.h.MapKeyAsString
e.is = e.h.IntegerAsString
}
func (d *jsonDecDriver) resetState() {
*d.buf = d.d.blist.check(*d.buf, 256)
d.tok = 0
}
func (d *jsonDecDriver) reset() {
d.resetState()
d.rawext = d.h.RawBytesExt != nil
}
func jsonFloatStrconvFmtPrec64(f float64) (fmt byte, prec int8) {
fmt = 'f'
prec = -1
fbits := math.Float64bits(f)
abs := math.Float64frombits(fbits &^ (1 << 63))
if abs == 0 || abs == 1 {
prec = 1
} else if abs < 1e-6 || abs >= 1e21 {
fmt = 'e'
} else if noFrac64(fbits) {
prec = 1
}
return
}
func jsonFloatStrconvFmtPrec32(f float32) (fmt byte, prec int8) {
fmt = 'f'
prec = -1
// directly handle Modf (to get fractions) and Abs (to get absolute)
fbits := math.Float32bits(f)
abs := math.Float32frombits(fbits &^ (1 << 31))
if abs == 0 || abs == 1 {
prec = 1
} else if abs < 1e-6 || abs >= 1e21 {
fmt = 'e'
} else if noFrac32(fbits) {
prec = 1
}
return
}
var _ decDriverContainerTracker = (*jsonDecDriver)(nil)
var _ encDriverContainerTracker = (*jsonEncDriver)(nil)
var _ decDriver = (*jsonDecDriver)(nil)
var _ encDriver = (*jsonEncDriver)(nil)