Permalink
Switch branches/tags
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
1452 lines (1319 sloc) 34.4 KB
// 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
// 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.
//
// Note:
// - we cannot use strconv.Quote and strconv.Unquote because json quotes/unquotes differently.
// We implement it here.
// Top-level methods of json(End|Dec)Driver (which are implementations of (en|de)cDriver
// MUST not call one-another.
import (
"bytes"
"encoding/base64"
"math"
"reflect"
"strconv"
"time"
"unicode"
"unicode/utf16"
"unicode/utf8"
)
//--------------------------------
var jsonLiterals = [...]byte{
'"', 't', 'r', 'u', 'e', '"',
'"', 'f', 'a', 'l', 's', 'e', '"',
'"', 'n', 'u', 'l', 'l', '"',
}
const (
jsonLitTrueQ = 0
jsonLitTrue = 1
jsonLitFalseQ = 6
jsonLitFalse = 7
jsonLitNullQ = 13
jsonLitNull = 14
)
const (
jsonU4Chk2 = '0'
jsonU4Chk1 = 'a' - 10
jsonU4Chk0 = 'A' - 10
jsonScratchArrayLen = 64
)
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
jsonSpacesOrTabsLen = 128
jsonAlwaysReturnInternString = false
)
var (
// jsonTabs and jsonSpaces are used as caches for indents
jsonTabs, jsonSpaces [jsonSpacesOrTabsLen]byte
jsonCharHtmlSafeSet bitset128
jsonCharSafeSet bitset128
jsonCharWhitespaceSet bitset256
jsonNumSet bitset256
)
func init() {
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) " \ < > &
var i byte
for i = 32; i < utf8.RuneSelf; i++ {
switch i {
case '"', '\\':
case '<', '>', '&':
jsonCharSafeSet.set(i) // = true
default:
jsonCharSafeSet.set(i)
jsonCharHtmlSafeSet.set(i)
}
}
for i = 0; i <= utf8.RuneSelf; i++ {
switch i {
case ' ', '\t', '\r', '\n':
jsonCharWhitespaceSet.set(i)
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'e', 'E', '.', '+', '-':
jsonNumSet.set(i)
}
}
}
// ----------------
type jsonEncDriverTypical struct {
w encWriter
b *[jsonScratchArrayLen]byte
tw bool // term white space
c containerState
}
func (e *jsonEncDriverTypical) typical() {}
func (e *jsonEncDriverTypical) reset(ee *jsonEncDriver) {
e.w = ee.ew
e.b = &ee.b
e.tw = ee.h.TermWhitespace
e.c = 0
}
func (e *jsonEncDriverTypical) WriteArrayStart(length int) {
e.w.writen1('[')
e.c = containerArrayStart
}
func (e *jsonEncDriverTypical) WriteArrayElem() {
if e.c != containerArrayStart {
e.w.writen1(',')
}
e.c = containerArrayElem
}
func (e *jsonEncDriverTypical) WriteArrayEnd() {
e.w.writen1(']')
e.c = containerArrayEnd
}
func (e *jsonEncDriverTypical) WriteMapStart(length int) {
e.w.writen1('{')
e.c = containerMapStart
}
func (e *jsonEncDriverTypical) WriteMapElemKey() {
if e.c != containerMapStart {
e.w.writen1(',')
}
e.c = containerMapKey
}
func (e *jsonEncDriverTypical) WriteMapElemValue() {
e.w.writen1(':')
e.c = containerMapValue
}
func (e *jsonEncDriverTypical) WriteMapEnd() {
e.w.writen1('}')
e.c = containerMapEnd
}
func (e *jsonEncDriverTypical) EncodeBool(b bool) {
if b {
e.w.writeb(jsonLiterals[jsonLitTrue : jsonLitTrue+4])
} else {
e.w.writeb(jsonLiterals[jsonLitFalse : jsonLitFalse+5])
}
}
func (e *jsonEncDriverTypical) EncodeFloat64(f float64) {
fmt, prec := jsonFloatStrconvFmtPrec(f)
e.w.writeb(strconv.AppendFloat(e.b[:0], f, fmt, prec, 64))
}
func (e *jsonEncDriverTypical) EncodeInt(v int64) {
e.w.writeb(strconv.AppendInt(e.b[:0], v, 10))
}
func (e *jsonEncDriverTypical) EncodeUint(v uint64) {
e.w.writeb(strconv.AppendUint(e.b[:0], v, 10))
}
func (e *jsonEncDriverTypical) EncodeFloat32(f float32) {
e.EncodeFloat64(float64(f))
}
func (e *jsonEncDriverTypical) atEndOfEncode() {
if e.tw {
e.w.writen1(' ')
}
}
// ----------------
type jsonEncDriverGeneric struct {
w encWriter
b *[jsonScratchArrayLen]byte
c containerState
// ds string // indent string
di int8 // indent per
d bool // indenting?
dt bool // indent using tabs
dl uint16 // indent level
ks bool // map key as string
is byte // integer as string
tw bool // term white space
_ [7]byte // padding
}
// 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 *jsonEncDriverGeneric) reset(ee *jsonEncDriver) {
e.w = ee.ew
e.b = &ee.b
e.tw = ee.h.TermWhitespace
e.c = 0
e.d, e.dt, e.dl, e.di = false, false, 0, 0
h := ee.h
if h.Indent > 0 {
e.d = true
e.di = int8(h.Indent)
} else if h.Indent < 0 {
e.d = true
e.dt = true
e.di = int8(-h.Indent)
}
e.ks = h.MapKeyAsString
e.is = h.IntegerAsString
}
func (e *jsonEncDriverGeneric) WriteArrayStart(length int) {
if e.d {
e.dl++
}
e.w.writen1('[')
e.c = containerArrayStart
}
func (e *jsonEncDriverGeneric) WriteArrayElem() {
if e.c != containerArrayStart {
e.w.writen1(',')
}
if e.d {
e.writeIndent()
}
e.c = containerArrayElem
}
func (e *jsonEncDriverGeneric) WriteArrayEnd() {
if e.d {
e.dl--
if e.c != containerArrayStart {
e.writeIndent()
}
}
e.w.writen1(']')
e.c = containerArrayEnd
}
func (e *jsonEncDriverGeneric) WriteMapStart(length int) {
if e.d {
e.dl++
}
e.w.writen1('{')
e.c = containerMapStart
}
func (e *jsonEncDriverGeneric) WriteMapElemKey() {
if e.c != containerMapStart {
e.w.writen1(',')
}
if e.d {
e.writeIndent()
}
e.c = containerMapKey
}
func (e *jsonEncDriverGeneric) WriteMapElemValue() {
if e.d {
e.w.writen2(':', ' ')
} else {
e.w.writen1(':')
}
e.c = containerMapValue
}
func (e *jsonEncDriverGeneric) WriteMapEnd() {
if e.d {
e.dl--
if e.c != containerMapStart {
e.writeIndent()
}
}
e.w.writen1('}')
e.c = containerMapEnd
}
func (e *jsonEncDriverGeneric) writeIndent() {
e.w.writen1('\n')
x := int(e.di) * int(e.dl)
if e.dt {
for x > jsonSpacesOrTabsLen {
e.w.writeb(jsonTabs[:])
x -= jsonSpacesOrTabsLen
}
e.w.writeb(jsonTabs[:x])
} else {
for x > jsonSpacesOrTabsLen {
e.w.writeb(jsonSpaces[:])
x -= jsonSpacesOrTabsLen
}
e.w.writeb(jsonSpaces[:x])
}
}
func (e *jsonEncDriverGeneric) EncodeBool(b bool) {
if e.ks && e.c == containerMapKey {
if b {
e.w.writeb(jsonLiterals[jsonLitTrueQ : jsonLitTrueQ+6])
} else {
e.w.writeb(jsonLiterals[jsonLitFalseQ : jsonLitFalseQ+7])
}
} else {
if b {
e.w.writeb(jsonLiterals[jsonLitTrue : jsonLitTrue+4])
} else {
e.w.writeb(jsonLiterals[jsonLitFalse : jsonLitFalse+5])
}
}
}
func (e *jsonEncDriverGeneric) EncodeFloat64(f float64) {
// instead of using 'g', specify whether to use 'e' or 'f'
fmt, prec := jsonFloatStrconvFmtPrec(f)
var blen int
if e.ks && e.c == containerMapKey {
blen = 2 + len(strconv.AppendFloat(e.b[1:1], f, fmt, prec, 64))
e.b[0] = '"'
e.b[blen-1] = '"'
} else {
blen = len(strconv.AppendFloat(e.b[:0], f, fmt, prec, 64))
}
e.w.writeb(e.b[:blen])
}
func (e *jsonEncDriverGeneric) EncodeInt(v int64) {
x := e.is
if x == 'A' || x == 'L' && (v > 1<<53 || v < -(1<<53)) || (e.ks && e.c == containerMapKey) {
blen := 2 + len(strconv.AppendInt(e.b[1:1], v, 10))
e.b[0] = '"'
e.b[blen-1] = '"'
e.w.writeb(e.b[:blen])
return
}
e.w.writeb(strconv.AppendInt(e.b[:0], v, 10))
}
func (e *jsonEncDriverGeneric) EncodeUint(v uint64) {
x := e.is
if x == 'A' || x == 'L' && v > 1<<53 || (e.ks && e.c == containerMapKey) {
blen := 2 + len(strconv.AppendUint(e.b[1:1], v, 10))
e.b[0] = '"'
e.b[blen-1] = '"'
e.w.writeb(e.b[:blen])
return
}
e.w.writeb(strconv.AppendUint(e.b[:0], v, 10))
}
func (e *jsonEncDriverGeneric) EncodeFloat32(f float32) {
// e.encodeFloat(float64(f), 32)
// always encode all floats as IEEE 64-bit floating point.
// It also ensures that we can decode in full precision even if into a float32,
// as what is written is always to float64 precision.
e.EncodeFloat64(float64(f))
}
func (e *jsonEncDriverGeneric) atEndOfEncode() {
if e.tw {
if e.d {
e.w.writen1('\n')
} else {
e.w.writen1(' ')
}
}
}
// --------------------
type jsonEncDriver struct {
noBuiltInTypes
e *Encoder
h *JsonHandle
ew encWriter
se extWrapper
// ---- cpu cache line boundary?
bs []byte // scratch
// ---- cpu cache line boundary?
b [jsonScratchArrayLen]byte // scratch (encode time,
_ [2]uint64 // padding
}
func (e *jsonEncDriver) EncodeNil() {
// We always encode nil as just null (never in quotes)
// This allows us to easily decode if a nil in the json stream
// ie if initial token is n.
e.ew.writeb(jsonLiterals[jsonLitNull : jsonLitNull+4])
// if e.h.MapKeyAsString && e.c == containerMapKey {
// e.ew.writeb(jsonLiterals[jsonLitNullQ : jsonLitNullQ+6])
// } else {
// e.ew.writeb(jsonLiterals[jsonLitNull : jsonLitNull+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 := t.AppendFormat(e.b[1:1], time.RFC3339Nano)
e.b[len(b)+1] = '"'
e.ew.writeb(e.b[:len(b)+2])
}
// v, err := t.MarshalJSON(); if err != nil { e.e.error(err) } e.ew.writeb(v)
}
func (e *jsonEncDriver) EncodeExt(rv interface{}, xtag uint64, ext Ext, en *Encoder) {
if v := ext.ConvertExt(rv); v == nil {
e.EncodeNil()
} else {
en.encode(v)
}
}
func (e *jsonEncDriver) EncodeRawExt(re *RawExt, en *Encoder) {
// only encodes re.Value (never re.Data)
if re.Value == nil {
e.EncodeNil()
} else {
en.encode(re.Value)
}
}
func (e *jsonEncDriver) EncodeString(c charEncoding, v string) {
e.quoteStr(v)
}
func (e *jsonEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
// if encoding raw bytes and RawBytesExt is configured, use it to encode
if v == nil {
e.EncodeNil()
return
}
if c == cRAW {
if e.se.InterfaceExt != nil {
e.EncodeExt(v, 0, &e.se, e.e)
return
}
slen := base64.StdEncoding.EncodedLen(len(v))
if cap(e.bs) >= slen+2 {
e.bs = e.bs[:slen+2]
} else {
e.bs = make([]byte, slen+2)
}
e.bs[0] = '"'
base64.StdEncoding.Encode(e.bs[1:], v)
e.bs[slen+1] = '"'
e.ew.writeb(e.bs)
} else {
e.quoteStr(stringView(v))
}
}
func (e *jsonEncDriver) EncodeAsis(v []byte) {
e.ew.writeb(v)
}
func (e *jsonEncDriver) quoteStr(s string) {
// adapted from std pkg encoding/json
const hex = "0123456789abcdef"
w := e.ew
htmlasis := e.h.HTMLCharsAsIs
w.writen1('"')
var start int
for i, slen := 0, len(s); i < slen; {
// encode all bytes < 0x20 (except \r, \n).
// also encode < > & to prevent security holes when served to some browsers.
if b := s[i]; b < utf8.RuneSelf {
// if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && b != '&' {
// if (htmlasis && jsonCharSafeSet.isset(b)) || jsonCharHtmlSafeSet.isset(b) {
if jsonCharHtmlSafeSet.isset(b) || (htmlasis && jsonCharSafeSet.isset(b)) {
i++
continue
}
if start < i {
w.writestr(s[start:i])
}
switch b {
case '\\', '"':
w.writen2('\\', b)
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[b>>4], hex[b&0xF])
}
i++
start = i
continue
}
c, size := utf8.DecodeRuneInString(s[i:])
if c == utf8.RuneError && size == 1 {
if start < i {
w.writestr(s[start:i])
}
w.writestr(`\ufffd`)
i += size
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 c == '\u2028' || c == '\u2029' {
if start < i {
w.writestr(s[start:i])
}
w.writestr(`\u202`)
w.writen1(hex[c&0xF])
i += size
start = i
continue
}
i += size
}
if start < len(s) {
w.writestr(s[start:])
}
w.writen1('"')
}
type jsonDecDriver struct {
noBuiltInTypes
d *Decoder
h *JsonHandle
r decReader
se extWrapper
// ---- writable fields during execution --- *try* to keep in sep cache line
c containerState
// tok is used to store the token read right after skipWhiteSpace.
tok uint8
fnull bool // found null from appendStringAsBytes
bs []byte // scratch. Initialized from b. Used for parsing strings or numbers.
bstr [8]byte // scratch used for string \UXXX parsing
// ---- cpu cache line boundary?
b [jsonScratchArrayLen]byte // scratch 1, used for parsing strings or numbers or time.Time
b2 [jsonScratchArrayLen]byte // scratch 2, used only for readUntil, decNumBytes
_ [3]uint64 // padding
// n jsonNum
}
// func jsonIsWS(b byte) bool {
// // return b == ' ' || b == '\t' || b == '\r' || b == '\n'
// return jsonCharWhitespaceSet.isset(b)
// }
func (d *jsonDecDriver) uncacheRead() {
if d.tok != 0 {
d.r.unreadn1()
d.tok = 0
}
}
func (d *jsonDecDriver) ReadMapStart() int {
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
const xc uint8 = '{'
if d.tok != xc {
d.d.errorf("read map - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
d.c = containerMapStart
return -1
}
func (d *jsonDecDriver) ReadArrayStart() int {
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
const xc uint8 = '['
if d.tok != xc {
d.d.errorf("read array - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
d.c = containerArrayStart
return -1
}
func (d *jsonDecDriver) CheckBreak() bool {
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
return d.tok == '}' || d.tok == ']'
}
// For the ReadXXX methods below, we could just delegate to helper functions
// readContainerState(c containerState, xc uint8, check bool)
// - ReadArrayElem would become:
// readContainerState(containerArrayElem, ',', d.c != containerArrayStart)
//
// However, until mid-stack inlining comes in go1.11 which supports inlining of
// one-liners, we explicitly write them all 5 out to elide the extra func call.
//
// TODO: For Go 1.11, if inlined, consider consolidating these.
func (d *jsonDecDriver) ReadArrayElem() {
const xc uint8 = ','
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
if d.c != containerArrayStart {
if d.tok != xc {
d.d.errorf("read array element - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
}
d.c = containerArrayElem
}
func (d *jsonDecDriver) ReadArrayEnd() {
const xc uint8 = ']'
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
if d.tok != xc {
d.d.errorf("read array end - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
d.c = containerArrayEnd
}
func (d *jsonDecDriver) ReadMapElemKey() {
const xc uint8 = ','
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
if d.c != containerMapStart {
if d.tok != xc {
d.d.errorf("read map key - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
}
d.c = containerMapKey
}
func (d *jsonDecDriver) ReadMapElemValue() {
const xc uint8 = ':'
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
if d.tok != xc {
d.d.errorf("read map value - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
d.c = containerMapValue
}
func (d *jsonDecDriver) ReadMapEnd() {
const xc uint8 = '}'
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
if d.tok != xc {
d.d.errorf("read map end - expect char '%c' but got char '%c'", xc, d.tok)
}
d.tok = 0
d.c = containerMapEnd
}
func (d *jsonDecDriver) readLit(length, fromIdx uint8) {
bs := d.r.readx(int(length))
d.tok = 0
if jsonValidateSymbols && !bytes.Equal(bs, jsonLiterals[fromIdx:fromIdx+length]) {
d.d.errorf("expecting %s: got %s", jsonLiterals[fromIdx:fromIdx+length], bs)
return
}
}
func (d *jsonDecDriver) TryDecodeAsNil() bool {
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
// we shouldn't try to see if "null" was here, right?
// only the plain string: `null` denotes a nil (ie not quotes)
if d.tok == 'n' {
d.readLit(3, jsonLitNull+1) // (n)ull
return true
}
return false
}
func (d *jsonDecDriver) DecodeBool() (v bool) {
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
fquot := d.c == containerMapKey && d.tok == '"'
if fquot {
d.tok = d.r.readn1()
}
switch d.tok {
case 'f':
d.readLit(4, jsonLitFalse+1) // (f)alse
// v = false
case 't':
d.readLit(3, jsonLitTrue+1) // (t)rue
v = true
default:
d.d.errorf("decode bool: got first char %c", d.tok)
// v = false // "unreachable"
}
if fquot {
d.r.readn1()
}
return
}
func (d *jsonDecDriver) DecodeTime() (t time.Time) {
// read string, and pass the string into json.unmarshal
d.appendStringAsBytes()
if d.fnull {
return
}
t, err := time.Parse(time.RFC3339, stringView(d.bs))
if err != nil {
d.d.errorv(err)
}
return
}
func (d *jsonDecDriver) ContainerType() (vt valueType) {
// check container type by checking the first char
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
// 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 b := d.tok; b == '{' {
return valueTypeMap
} else if b == '[' {
return valueTypeArray
} else if b == 'n' {
return valueTypeNil
} else if b == '"' {
return valueTypeString
}
return valueTypeUnset
}
func (d *jsonDecDriver) decNumBytes() (bs []byte) {
// stores num bytes in d.bs
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
if d.tok == '"' {
bs = d.r.readUntil(d.b2[:0], '"')
bs = bs[:len(bs)-1]
} else {
d.r.unreadn1()
bs = d.r.readTo(d.bs[:0], &jsonNumSet)
}
d.tok = 0
return bs
}
func (d *jsonDecDriver) DecodeUint64() (u uint64) {
bs := d.decNumBytes()
if len(bs) == 0 {
return
}
n, neg, badsyntax, overflow := jsonParseInteger(bs)
if overflow {
d.d.errorf("overflow parsing unsigned integer: %s", bs)
} else if neg {
d.d.errorf("minus found parsing unsigned integer: %s", bs)
} else if badsyntax {
// fallback: try to decode as float, and cast
n = d.decUint64ViaFloat(stringView(bs))
}
return n
}
func (d *jsonDecDriver) DecodeInt64() (i int64) {
const cutoff = uint64(1 << uint(64-1))
bs := d.decNumBytes()
if len(bs) == 0 {
return
}
n, neg, badsyntax, overflow := jsonParseInteger(bs)
if overflow {
d.d.errorf("overflow parsing integer: %s", bs)
} else if badsyntax {
// d.d.errorf("invalid syntax for integer: %s", bs)
// fallback: try to decode as float, and cast
if neg {
n = d.decUint64ViaFloat(stringView(bs[1:]))
} else {
n = d.decUint64ViaFloat(stringView(bs))
}
}
if neg {
if n > cutoff {
d.d.errorf("overflow parsing integer: %s", bs)
}
i = -(int64(n))
} else {
if n >= cutoff {
d.d.errorf("overflow parsing integer: %s", bs)
}
i = int64(n)
}
return
}
func (d *jsonDecDriver) decUint64ViaFloat(s string) (u uint64) {
if len(s) == 0 {
return
}
f, err := strconv.ParseFloat(s, 64)
if err != nil {
d.d.errorf("invalid syntax for integer: %s", s)
// d.d.errorv(err)
}
fi, ff := math.Modf(f)
if ff > 0 {
d.d.errorf("fractional part found parsing integer: %s", s)
} else if fi > float64(math.MaxUint64) {
d.d.errorf("overflow parsing integer: %s", s)
}
return uint64(fi)
}
func (d *jsonDecDriver) DecodeFloat64() (f float64) {
bs := d.decNumBytes()
if len(bs) == 0 {
return
}
f, err := strconv.ParseFloat(stringView(bs), 64)
if err != nil {
d.d.errorv(err)
}
return
}
func (d *jsonDecDriver) DecodeExt(rv interface{}, xtag uint64, ext Ext) (realxtag uint64) {
if ext == nil {
re := rv.(*RawExt)
re.Tag = xtag
d.d.decode(&re.Value)
} else {
var v interface{}
d.d.decode(&v)
ext.UpdateExt(rv, v)
}
return
}
func (d *jsonDecDriver) DecodeBytes(bs []byte, zerocopy bool) (bsOut []byte) {
// if decoding into raw bytes, and the RawBytesExt is configured, use it to decode.
if d.se.InterfaceExt != nil {
bsOut = bs
d.DecodeExt(&bsOut, 0, &d.se)
return
}
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
// 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)
return
}
d.appendStringAsBytes()
// 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{}.
// appendStringAsBytes returns a zero-len slice for both, so as not to reset d.bs.
// However, it sets a fnull field to true, so we can check if a null was found.
if len(d.bs) == 0 {
if d.fnull {
return nil
}
return []byte{}
}
bs0 := d.bs
slen := base64.StdEncoding.DecodedLen(len(bs0))
if slen <= cap(bs) {
bsOut = bs[:slen]
} else if zerocopy && slen <= cap(d.b2) {
bsOut = d.b2[:slen]
} else {
bsOut = make([]byte, slen)
}
slen2, err := base64.StdEncoding.Decode(bsOut, bs0)
if err != nil {
d.d.errorf("error decoding base64 binary '%s': %v", bs0, err)
return nil
}
if slen != slen2 {
bsOut = bsOut[:slen2]
}
return
}
func (d *jsonDecDriver) DecodeString() (s string) {
d.appendStringAsBytes()
return d.bsToString()
}
func (d *jsonDecDriver) DecodeStringAsBytes() (s []byte) {
d.appendStringAsBytes()
return d.bs
}
func (d *jsonDecDriver) appendStringAsBytes() {
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
d.fnull = false
if d.tok != '"' {
// d.d.errorf("expect char '%c' but got char '%c'", '"', d.tok)
// handle non-string scalar: null, true, false or a number
switch d.tok {
case 'n':
d.readLit(3, jsonLitNull+1) // (n)ull
d.bs = d.bs[:0]
d.fnull = true
case 'f':
d.readLit(4, jsonLitFalse+1) // (f)alse
d.bs = d.bs[:5]
copy(d.bs, "false")
case 't':
d.readLit(3, jsonLitTrue+1) // (t)rue
d.bs = d.bs[:4]
copy(d.bs, "true")
default:
// try to parse a valid number
bs := d.decNumBytes()
if len(bs) <= cap(d.bs) {
d.bs = d.bs[:len(bs)]
} else {
d.bs = make([]byte, len(bs))
}
copy(d.bs, bs)
}
return
}
d.tok = 0
r := d.r
var cs = r.readUntil(d.b2[:0], '"')
var cslen = len(cs)
var c uint8
v := d.bs[:0]
// append on each byte seen can be expensive, so we just
// keep track of where we last read a contiguous set of
// non-special bytes (using cursor variable),
// and when we see a special byte
// e.g. end-of-slice, " or \,
// we will append the full range into the v slice before proceeding
for i, cursor := 0, 0; ; {
if i == cslen {
v = append(v, cs[cursor:]...)
cs = r.readUntil(d.b2[:0], '"')
cslen = len(cs)
i, cursor = 0, 0
}
c = cs[i]
if c == '"' {
v = append(v, cs[cursor:i]...)
break
}
if c != '\\' {
i++
continue
}
v = append(v, cs[cursor:i]...)
i++
c = cs[i]
switch c {
case '"', '\\', '/', '\'':
v = append(v, c)
case 'b':
v = append(v, '\b')
case 'f':
v = append(v, '\f')
case 'n':
v = append(v, '\n')
case 'r':
v = append(v, '\r')
case 't':
v = append(v, '\t')
case 'u':
var r rune
var rr uint32
if len(cs) < i+4 { // may help reduce bounds-checking
d.d.errorf("need at least 4 more bytes for unicode sequence")
}
// c = cs[i+4] // may help reduce bounds-checking
for j := 1; j < 5; j++ {
// best to use explicit if-else
// - not a table, etc which involve memory loads, array lookup with bounds checks, etc
c = cs[i+j]
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 {
r = unicode.ReplacementChar
i += 4
goto encode_rune
}
}
r = rune(rr)
i += 4
if utf16.IsSurrogate(r) {
if len(cs) >= i+6 && cs[i+2] == 'u' && cs[i+1] == '\\' {
i += 2
// c = cs[i+4] // may help reduce bounds-checking
var rr1 uint32
for j := 1; j < 5; j++ {
c = cs[i+j]
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 {
r = unicode.ReplacementChar
i += 4
goto encode_rune
}
}
r = utf16.DecodeRune(r, rune(rr1))
i += 4
} else {
r = unicode.ReplacementChar
goto encode_rune
}
}
encode_rune:
w2 := utf8.EncodeRune(d.bstr[:], r)
v = append(v, d.bstr[:w2]...)
default:
d.d.errorf("unsupported escaped value: %c", c)
}
i++
cursor = i
}
d.bs = v
}
func (d *jsonDecDriver) nakedNum(z *decNaked, bs []byte) (err error) {
const cutoff = uint64(1 << uint(64-1))
var n uint64
var neg, badsyntax, overflow bool
if len(bs) == 0 {
if d.h.PreferFloat {
z.v = valueTypeFloat
z.f = 0
} else if d.h.SignedInteger {
z.v = valueTypeInt
z.i = 0
} else {
z.v = valueTypeUint
z.u = 0
}
return
}
if d.h.PreferFloat {
goto F
}
n, neg, badsyntax, overflow = jsonParseInteger(bs)
if badsyntax || overflow {
goto F
}
if neg {
if n > cutoff {
goto F
}
z.v = valueTypeInt
z.i = -(int64(n))
} else if d.h.SignedInteger {
if n >= cutoff {
goto F
}
z.v = valueTypeInt
z.i = int64(n)
} else {
z.v = valueTypeUint
z.u = n
}
return
F:
z.v = valueTypeFloat
z.f, err = strconv.ParseFloat(stringView(bs), 64)
return
}
func (d *jsonDecDriver) bsToString() string {
// if x := d.s.sc; x != nil && x.so && x.st == '}' { // map key
if jsonAlwaysReturnInternString || d.c == containerMapKey {
return d.d.string(d.bs)
}
return string(d.bs)
}
func (d *jsonDecDriver) DecodeNaked() {
z := d.d.n
// var decodeFurther bool
if d.tok == 0 {
d.tok = d.r.skip(&jsonCharWhitespaceSet)
}
switch d.tok {
case 'n':
d.readLit(3, jsonLitNull+1) // (n)ull
z.v = valueTypeNil
case 'f':
d.readLit(4, jsonLitFalse+1) // (f)alse
z.v = valueTypeBool
z.b = false
case 't':
d.readLit(3, jsonLitTrue+1) // (t)rue
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 '"':
// if a string, and MapKeyAsString, then try to decode it as a nil, bool or number first
d.appendStringAsBytes()
if len(d.bs) > 0 && d.c == containerMapKey && d.h.MapKeyAsString {
switch stringView(d.bs) {
case "null":
z.v = valueTypeNil
case "true":
z.v = valueTypeBool
z.b = true
case "false":
z.v = valueTypeBool
z.b = false
default:
// check if a number: float, int or uint
if err := d.nakedNum(z, d.bs); err != nil {
z.v = valueTypeString
z.s = d.bsToString()
}
}
} else {
z.v = valueTypeString
z.s = d.bsToString()
}
default: // number
bs := d.decNumBytes()
if len(bs) == 0 {
d.d.errorf("decode number from empty string")
return
}
if err := d.nakedNum(z, bs); err != nil {
d.d.errorf("decode number from %s: %v", bs, err)
return
}
}
// if decodeFurther {
// d.s.sc.retryRead()
// }
return
}
//----------------------
// JsonHandle is a handle for JSON encoding format.
//
// Json is comprehensively supported:
// - 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.
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
// _ [2]byte // padding
// Note: below, we store hardly-used items e.g. RawBytesExt is cached in the (en|de)cDriver.
// 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
_ [2]uint64 // padding
}
// Name returns the name of the handle: json
func (h *JsonHandle) Name() string { return "json" }
func (h *JsonHandle) hasElemSeparators() bool { return true }
func (h *JsonHandle) typical() bool {
return h.Indent == 0 && !h.MapKeyAsString && h.IntegerAsString != 'A' && h.IntegerAsString != 'L'
}
type jsonTypical interface {
typical()
}
func (h *JsonHandle) recreateEncDriver(ed encDriver) (v bool) {
_, v = ed.(jsonTypical)
return v != h.typical()
}
// SetInterfaceExt sets an extension
func (h *JsonHandle) SetInterfaceExt(rt reflect.Type, tag uint64, ext InterfaceExt) (err error) {
return h.SetExt(rt, tag, &extWrapper{bytesExtFailer{}, ext})
}
type jsonEncDriverTypicalImpl struct {
jsonEncDriver
jsonEncDriverTypical
_ [3]uint64 // padding
}
func (x *jsonEncDriverTypicalImpl) reset() {
x.jsonEncDriver.reset()
x.jsonEncDriverTypical.reset(&x.jsonEncDriver)
}
type jsonEncDriverGenericImpl struct {
jsonEncDriver
jsonEncDriverGeneric
_ [2]uint64 // padding
}
func (x *jsonEncDriverGenericImpl) reset() {
x.jsonEncDriver.reset()
x.jsonEncDriverGeneric.reset(&x.jsonEncDriver)
}
func (h *JsonHandle) newEncDriver(e *Encoder) (ee encDriver) {
var hd *jsonEncDriver
if h.typical() {
var v jsonEncDriverTypicalImpl
ee = &v
hd = &v.jsonEncDriver
} else {
var v jsonEncDriverGenericImpl
ee = &v
hd = &v.jsonEncDriver
}
hd.e, hd.h, hd.bs = e, h, hd.b[:0]
hd.se.BytesExt = bytesExtFailer{}
ee.reset()
return
}
func (h *JsonHandle) newDecDriver(d *Decoder) decDriver {
// d := jsonDecDriver{r: r.(*bytesDecReader), h: h}
hd := jsonDecDriver{d: d, h: h}
hd.se.BytesExt = bytesExtFailer{}
hd.bs = hd.b[:0]
hd.reset()
return &hd
}
func (e *jsonEncDriver) reset() {
e.ew = e.e.w
e.se.InterfaceExt = e.h.RawBytesExt
if e.bs != nil {
e.bs = e.bs[:0]
}
}
func (d *jsonDecDriver) reset() {
d.r = d.d.r
d.se.InterfaceExt = d.h.RawBytesExt
if d.bs != nil {
d.bs = d.bs[:0]
}
d.c, d.tok = 0, 0
// d.n.reset()
}
func jsonFloatStrconvFmtPrec(f float64) (fmt byte, prec int) {
prec = -1
var abs = math.Abs(f)
if abs != 0 && (abs < 1e-6 || abs >= 1e21) {
fmt = 'e'
} else {
fmt = 'f'
// set prec to 1 iff mod is 0.
// better than using jsonIsFloatBytesB2 to check if a . or E in the float bytes.
// this ensures that every float has an e or .0 in it.
if abs <= 1 {
if abs == 0 || abs == 1 {
prec = 1
}
} else if _, mod := math.Modf(abs); mod == 0 {
prec = 1
}
}
return
}
// custom-fitted version of strconv.Parse(Ui|I)nt.
// Also ensures we don't have to search for .eE to determine if a float or not.
// Note: s CANNOT be a zero-length slice.
func jsonParseInteger(s []byte) (n uint64, neg, badSyntax, overflow bool) {
const maxUint64 = (1<<64 - 1)
const cutoff = maxUint64/10 + 1
// if len(s) == 0 {
// // treat empty string as zero value
// // badSyntax = true
// return
// }
switch s[0] {
case '+':
s = s[1:]
case '-':
s = s[1:]
neg = true
}
for _, c := range s {
if c < '0' || c > '9' {
badSyntax = true
return
}
// unsigned integers don't overflow well on multiplication, so check cutoff here
// e.g. (maxUint64-5)*10 doesn't overflow well ...
if n >= cutoff {
overflow = true
return
}
n *= 10
n1 := n + uint64(c-'0')
if n1 < n || n1 > maxUint64 {
overflow = true
return
}
n = n1
}
return
}
var _ decDriver = (*jsonDecDriver)(nil)
var _ encDriver = (*jsonEncDriverGenericImpl)(nil)
var _ encDriver = (*jsonEncDriverTypicalImpl)(nil)
var _ jsonTypical = (*jsonEncDriverTypical)(nil)