// Copyright (c) 2012-2015 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.
package codec
// This json support uses base64 encoding for bytes, because you cannot
// store and read any arbitrary string in json (only unicode).
//
// 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.
// - Also, strconv.ParseXXX for floats and integers
// - only works on strings resulting in unnecessary allocation and []byte-string conversion.
// - it does a lot of redundant checks, because json numbers are simpler that what it supports.
// - We parse numbers (floats and integers) directly here.
// We only delegate parsing floats if it is a hairy float which could cause a loss of precision.
// In that case, we delegate to strconv.ParseFloat.
//
// Note:
// - encode does not beautify. There is no whitespace when encoding.
// - rpc calls which take single integer arguments or write single numeric arguments will need care.
import (
"bytes"
"encoding/base64"
"fmt"
"strconv"
"unicode/utf16"
"unicode/utf8"
)
//--------------------------------
var jsonLiterals = [...]byte{'t', 'r', 'u', 'e', 'f', 'a', 'l', 's', 'e', 'n', 'u', 'l', 'l'}
var jsonFloat64Pow10 = [...]float64{
1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
1e20, 1e21, 1e22,
}
var jsonUint64Pow10 = [...]uint64{
1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
}
const (
// if jsonTrackSkipWhitespace, we track Whitespace and reduce the number of redundant checks.
// Make it a const flag, so that it can be elided during linking if false.
//
// It is not a clear win, because we continually set a flag behind a pointer
// and then check it each time, as opposed to just 4 conditionals on a stack variable.
jsonTrackSkipWhitespace = true
// 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
// if jsonTruncateMantissa, truncate mantissa if trailing 0's.
// This is important because it could allow some floats to be decoded without
// deferring to strconv.ParseFloat.
jsonTruncateMantissa = true
// if mantissa >= jsonNumUintCutoff before multiplying by 10, this is an overflow
jsonNumUintCutoff = (1<<64-1)/uint64(10) + 1 // cutoff64(base)
// if mantissa >= jsonNumUintMaxVal, this is an overflow
jsonNumUintMaxVal = 1<<uint64(64) - 1
// jsonNumDigitsUint64Largest = 19
)
type jsonEncDriver struct {
e *Encoder
w encWriter
h *JsonHandle
b [64]byte // scratch
bs []byte // scratch
noBuiltInTypes
}
func (e *jsonEncDriver) EncodeNil() {
e.w.writeb(jsonLiterals[9:13]) // null
}
func (e *jsonEncDriver) EncodeBool(b bool) {
if b {
e.w.writeb(jsonLiterals[0:4]) // true
} else {
e.w.writeb(jsonLiterals[4:9]) // false
}
}
func (e *jsonEncDriver) EncodeFloat32(f float32) {
e.w.writeb(strconv.AppendFloat(e.b[:0], float64(f), 'E', -1, 32))
}
func (e *jsonEncDriver) EncodeFloat64(f float64) {
// e.w.writestr(strconv.FormatFloat(f, 'E', -1, 64))
e.w.writeb(strconv.AppendFloat(e.b[:0], f, 'E', -1, 64))
}
func (e *jsonEncDriver) EncodeInt(v int64) {
e.w.writeb(strconv.AppendInt(e.b[:0], v, 10))
}
func (e *jsonEncDriver) EncodeUint(v uint64) {
e.w.writeb(strconv.AppendUint(e.b[:0], v, 10))
}
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) EncodeArrayStart(length int) {
e.w.writen1('[')
}
func (e *jsonEncDriver) EncodeArrayEntrySeparator() {
e.w.writen1(',')
}
func (e *jsonEncDriver) EncodeArrayEnd() {
e.w.writen1(']')
}
func (e *jsonEncDriver) EncodeMapStart(length int) {
e.w.writen1('{')
}
func (e *jsonEncDriver) EncodeMapEntrySeparator() {
e.w.writen1(',')
}
func (e *jsonEncDriver) EncodeMapKVSeparator() {
e.w.writen1(':')
}
func (e *jsonEncDriver) EncodeMapEnd() {
e.w.writen1('}')
}
func (e *jsonEncDriver) EncodeString(c charEncoding, v string) {
// e.w.writestr(strconv.Quote(v))
e.quoteStr(v)
}
func (e *jsonEncDriver) EncodeSymbol(v string) {
// e.EncodeString(c_UTF8, v)
e.quoteStr(v)
}
func (e *jsonEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
if c == c_RAW {
slen := base64.StdEncoding.EncodedLen(len(v))
if e.bs == nil {
e.bs = e.b[:]
}
if cap(e.bs) >= slen {
e.bs = e.bs[:slen]
} else {
e.bs = make([]byte, slen)
}
base64.StdEncoding.Encode(e.bs, v)
e.w.writen1('"')
e.w.writeb(e.bs)
e.w.writen1('"')
} else {
// e.EncodeString(c, string(v))
e.quoteStr(stringView(v))
}
}
func (e *jsonEncDriver) quoteStr(s string) {
// adapted from std pkg encoding/json
const hex = "0123456789abcdef"
w := e.w
w.writen1('"')
start := 0
for i := 0; i < len(s); {
if b := s[i]; b < utf8.RuneSelf {
if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && 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:
// encode all bytes < 0x20 (except \r, \n).
// also encode < > & to prevent security holes when served to some browsers.
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.
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 jsonNum struct {
bytes []byte // may have [+-.eE0-9]
mantissa uint64 // where mantissa ends, and maybe dot begins.
exponent int16 // exponent value.
manOverflow bool
neg bool // started with -. No initial sign in the bytes above.
dot bool // has dot
explicitExponent bool // explicit exponent
}
func (x *jsonNum) reset() {
x.bytes = x.bytes[:0]
x.manOverflow = false
x.neg = false
x.dot = false
x.explicitExponent = false
x.mantissa = 0
x.exponent = 0
}
// uintExp is called only if exponent > 0.
func (x *jsonNum) uintExp() (n uint64, overflow bool) {
n = x.mantissa
e := x.exponent
if e >= int16(len(jsonUint64Pow10)) {
overflow = true
return
}
n *= jsonUint64Pow10[e]
if n < x.mantissa || n > jsonNumUintMaxVal {
overflow = true
return
}
return
// for i := int16(0); i < e; i++ {
// if n >= jsonNumUintCutoff {
// overflow = true
// return
// }
// n *= 10
// }
// return
}
func (x *jsonNum) floatVal() (f float64) {
// We do not want to lose precision.
// Consequently, we will delegate to strconv.ParseFloat if any of the following happen:
// - There are more digits than in math.MaxUint64: 18446744073709551615 (20 digits)
// We expect up to 99.... (19 digits)
// - The mantissa cannot fit into a 52 bits of uint64
// - The exponent is beyond our scope ie beyong 22.
const uint64MantissaBits = 52
const maxExponent = int16(len(jsonFloat64Pow10)) - 1
parseUsingStrConv := x.manOverflow ||
x.exponent > maxExponent ||
(x.exponent < 0 && -(x.exponent) > maxExponent) ||
x.mantissa>>uint64MantissaBits != 0
if parseUsingStrConv {
var err error
if f, err = strconv.ParseFloat(stringView(x.bytes), 64); err != nil {
panic(fmt.Errorf("parse float: %s, %v", x.bytes, err))
return
}
if x.neg {
f = -f
}
return
}
// all good. so handle parse here.
f = float64(x.mantissa)
// fmt.Printf(".Float: uint64 value: %v, float: %v\n", m, f)
if x.neg {
f = -f
}
if x.exponent > 0 {
f *= jsonFloat64Pow10[x.exponent]
} else if x.exponent < 0 {
f /= jsonFloat64Pow10[-x.exponent]
}
return
}
type jsonDecDriver struct {
d *Decoder
h *JsonHandle
r decReader // *bytesDecReader decReader
ct valueType // container type. one of unset, array or map.
bstr [8]byte // scratch used for string \UXXX parsing
b [64]byte // scratch
wsSkipped bool // whitespace skipped
n jsonNum
noBuiltInTypes
}
// This will skip whitespace characters and return the next byte to read.
// The next byte determines what the value will be one of.
func (d *jsonDecDriver) skipWhitespace(unread bool) (b byte) {
// as initReadNext is not called all the time, we set ct to unSet whenever
// we skipwhitespace, as this is the signal that something new is about to be read.
d.ct = valueTypeUnset
b = d.r.readn1()
if !jsonTrackSkipWhitespace || !d.wsSkipped {
for ; b == ' ' || b == '\t' || b == '\r' || b == '\n'; b = d.r.readn1() {
}
if jsonTrackSkipWhitespace {
d.wsSkipped = true
}
}
if unread {
d.r.unreadn1()
}
return b
}
func (d *jsonDecDriver) CheckBreak() bool {
b := d.skipWhitespace(true)
return b == '}' || b == ']'
}
func (d *jsonDecDriver) readStrIdx(fromIdx, toIdx uint8) {
bs := d.r.readx(int(toIdx - fromIdx))
if jsonValidateSymbols {
if !bytes.Equal(bs, jsonLiterals[fromIdx:toIdx]) {
d.d.errorf("json: expecting %s: got %s", jsonLiterals[fromIdx:toIdx], bs)
return
}
}
if jsonTrackSkipWhitespace {
d.wsSkipped = false
}
}
func (d *jsonDecDriver) TryDecodeAsNil() bool {
b := d.skipWhitespace(true)
if b == 'n' {
d.readStrIdx(9, 13) // null
d.ct = valueTypeNil
return true
}
return false
}
func (d *jsonDecDriver) DecodeBool() bool {
b := d.skipWhitespace(false)
if b == 'f' {
d.readStrIdx(5, 9) // alse
return false
}
if b == 't' {
d.readStrIdx(1, 4) // rue
return true
}
d.d.errorf("json: decode bool: got first char %c", b)
return false // "unreachable"
}
func (d *jsonDecDriver) ReadMapStart() int {
d.expectChar('{')
d.ct = valueTypeMap
return -1
}
func (d *jsonDecDriver) ReadArrayStart() int {
d.expectChar('[')
d.ct = valueTypeArray
return -1
}
func (d *jsonDecDriver) ReadMapEnd() {
d.expectChar('}')
}
func (d *jsonDecDriver) ReadArrayEnd() {
d.expectChar(']')
}
func (d *jsonDecDriver) ReadArrayEntrySeparator() {
d.expectChar(',')
}
func (d *jsonDecDriver) ReadMapEntrySeparator() {
d.expectChar(',')
}
func (d *jsonDecDriver) ReadMapKVSeparator() {
d.expectChar(':')
}
func (d *jsonDecDriver) expectChar(c uint8) {
b := d.skipWhitespace(false)
if b != c {
d.d.errorf("json: expect char %c but got char %c", c, b)
return
}
if jsonTrackSkipWhitespace {
d.wsSkipped = false
}
}
func (d *jsonDecDriver) IsContainerType(vt valueType) bool {
// check container type by checking the first char
if d.ct == valueTypeUnset {
b := d.skipWhitespace(true)
if b == '{' {
d.ct = valueTypeMap
} else if b == '[' {
d.ct = valueTypeArray
} else if b == 'n' {
d.ct = valueTypeNil
} else if b == '"' {
d.ct = valueTypeString
}
}
if vt == valueTypeNil || vt == valueTypeBytes || vt == valueTypeString ||
vt == valueTypeArray || vt == valueTypeMap {
return d.ct == vt
}
// ugorji: made switch into conditionals, so that IsContainerType can be inlined.
// switch vt {
// case valueTypeNil, valueTypeBytes, valueTypeString, valueTypeArray, valueTypeMap:
// return d.ct == vt
// }
d.d.errorf("isContainerType: unsupported parameter: %v", vt)
return false // "unreachable"
}
func (d *jsonDecDriver) decNum(storeBytes bool) {
// storeBytes = true // TODO: remove.
// If it is has a . or an e|E, decode as a float; else decode as an int.
b := d.skipWhitespace(false)
if !(b == '+' || b == '-' || b == '.' || (b >= '0' && b <= '9')) {
d.d.errorf("json: decNum: got first char '%c'", b)
return
}
const cutoff = (1<<64-1)/uint64(10) + 1 // cutoff64(base)
const jsonNumUintMaxVal = 1<<uint64(64) - 1
// var n jsonNum // create stack-copy jsonNum, and set to pointer at end.
// n.bytes = d.n.bytes[:0]
n := &d.n
n.reset()
// The format of a number is as below:
// parsing: sign? digit* dot? digit* e? sign? digit*
// states: 0 1* 2 3* 4 5* 6 7
// We honor this state so we can break correctly.
var state uint8 = 0
var eNeg bool
var e int16
var eof bool
LOOP:
for !eof {
// fmt.Printf("LOOP: b: %q\n", b)
switch b {
case '+':
switch state {
case 0:
state = 2
// do not add sign to the slice ...
b, eof = d.r.readn1eof()
continue
case 6: // typ = jsonNumFloat
state = 7
default:
break LOOP
}
case '-':
switch state {
case 0:
state = 2
n.neg = true
// do not add sign to the slice ...
b, eof = d.r.readn1eof()
continue
case 6: // typ = jsonNumFloat
eNeg = true
state = 7
default:
break LOOP
}
case '.':
switch state {
case 0, 2: // typ = jsonNumFloat
state = 4
n.dot = true
default:
break LOOP
}
case 'e', 'E':
switch state {
case 0, 2, 4: // typ = jsonNumFloat
state = 6
// n.mantissaEndIndex = int16(len(n.bytes))
n.explicitExponent = true
default:
break LOOP
}
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
switch state {
case 0:
state = 2
fallthrough
case 2:
fallthrough
case 4:
if n.dot {
n.exponent--
}
if n.mantissa >= jsonNumUintCutoff {
n.manOverflow = true
break
}
v := uint64(b - '0')
n.mantissa *= 10
if v != 0 {
n1 := n.mantissa + v
if n1 < n.mantissa || n1 > jsonNumUintMaxVal {
n.manOverflow = true // n+v overflows
break
}
n.mantissa = n1
}
case 6:
state = 7
fallthrough
case 7:
if !(b == '0' && e == 0) {
e = e*10 + int16(b-'0')
}
default:
break LOOP
}
default:
break LOOP
}
if storeBytes {
n.bytes = append(n.bytes, b)
}
b, eof = d.r.readn1eof()
}
if jsonTruncateMantissa && n.mantissa != 0 {
for n.mantissa%10 == 0 {
n.mantissa /= 10
n.exponent++
}
}
if e != 0 {
if eNeg {
n.exponent -= e
} else {
n.exponent += e
}
}
// d.n = n
if !eof {
d.r.unreadn1()
}
if jsonTrackSkipWhitespace {
d.wsSkipped = false
}
// fmt.Printf("1: n: bytes: %s, neg: %v, dot: %v, exponent: %v, mantissaEndIndex: %v\n",
// n.bytes, n.neg, n.dot, n.exponent, n.mantissaEndIndex)
return
}
func (d *jsonDecDriver) DecodeInt(bitsize uint8) (i int64) {
d.decNum(false)
n := &d.n
if n.manOverflow {
d.d.errorf("json: overflow integer after: %v", n.mantissa)
return
}
var u uint64
if n.exponent == 0 {
u = n.mantissa
} else if n.exponent < 0 {
d.d.errorf("json: fractional integer")
return
} else if n.exponent > 0 {
var overflow bool
if u, overflow = n.uintExp(); overflow {
d.d.errorf("json: overflow integer")
return
}
}
i = int64(u)
if n.neg {
i = -i
}
if chkOvf.Int(i, bitsize) {
d.d.errorf("json: overflow %v bits: %s", bitsize, n.bytes)
return
}
// fmt.Printf("DecodeInt: %v\n", i)
return
}
func (d *jsonDecDriver) DecodeUint(bitsize uint8) (u uint64) {
d.decNum(false)
n := &d.n
if n.neg {
d.d.errorf("json: unsigned integer cannot be negative")
return
}
if n.manOverflow {
d.d.errorf("json: overflow integer after: %v", n.mantissa)
return
}
if n.exponent == 0 {
u = n.mantissa
} else if n.exponent < 0 {
d.d.errorf("json: fractional integer")
return
} else if n.exponent > 0 {
var overflow bool
if u, overflow = n.uintExp(); overflow {
d.d.errorf("json: overflow integer")
return
}
}
if chkOvf.Uint(u, bitsize) {
d.d.errorf("json: overflow %v bits: %s", bitsize, n.bytes)
return
}
// fmt.Printf("DecodeUint: %v\n", u)
return
}
func (d *jsonDecDriver) DecodeFloat(chkOverflow32 bool) (f float64) {
d.decNum(true)
n := &d.n
f = n.floatVal()
if chkOverflow32 && chkOvf.Float32(f) {
d.d.errorf("json: overflow float32: %v, %s", f, n.bytes)
return
}
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, isstring, zerocopy bool) (bsOut []byte) {
// zerocopy doesn't matter for json, as the bytes must be parsed.
bs0 := d.appendStringAsBytes(d.b[:0])
if isstring {
return bs0
}
slen := base64.StdEncoding.DecodedLen(len(bs0))
if cap(bs) >= slen {
bsOut = bs[:slen]
} else {
bsOut = make([]byte, slen)
}
slen2, err := base64.StdEncoding.Decode(bsOut, bs0)
if err != nil {
d.d.errorf("json: error decoding base64 binary '%s': %v", bs0, err)
return nil
}
if slen != slen2 {
bsOut = bsOut[:slen2]
}
return
}
func (d *jsonDecDriver) DecodeString() (s string) {
return string(d.appendStringAsBytes(d.b[:0]))
}
func (d *jsonDecDriver) appendStringAsBytes(v []byte) []byte {
d.expectChar('"')
for {
c := d.r.readn1()
if c == '"' {
break
} else if c == '\\' {
c = d.r.readn1()
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':
rr := d.jsonU4(false)
// fmt.Printf("$$$$$$$$$: is surrogate: %v\n", utf16.IsSurrogate(rr))
if utf16.IsSurrogate(rr) {
rr = utf16.DecodeRune(rr, d.jsonU4(true))
}
w2 := utf8.EncodeRune(d.bstr[:], rr)
v = append(v, d.bstr[:w2]...)
default:
d.d.errorf("json: unsupported escaped value: %c", c)
return nil
}
} else {
v = append(v, c)
}
}
if jsonTrackSkipWhitespace {
d.wsSkipped = false
}
return v
}
func (d *jsonDecDriver) jsonU4(checkSlashU bool) rune {
if checkSlashU && !(d.r.readn1() == '\\' && d.r.readn1() == 'u') {
d.d.errorf(`json: unquoteStr: invalid unicode sequence. Expecting \u`)
return 0
}
// u, _ := strconv.ParseUint(string(d.bstr[:4]), 16, 64)
var u uint32
for i := 0; i < 4; i++ {
v := d.r.readn1()
if '0' <= v && v <= '9' {
v = v - '0'
} else if 'a' <= v && v <= 'z' {
v = v - 'a' + 10
} else if 'A' <= v && v <= 'Z' {
v = v - 'A' + 10
} else {
d.d.errorf(`json: unquoteStr: invalid hex char in \u unicode sequence: %q`, v)
return 0
}
u = u*16 + uint32(v)
}
return rune(u)
}
func (d *jsonDecDriver) DecodeNaked() (v interface{}, vt valueType, decodeFurther bool) {
n := d.skipWhitespace(true)
switch n {
case 'n':
d.readStrIdx(9, 13) // null
vt = valueTypeNil
case 'f':
d.readStrIdx(4, 9) // false
vt = valueTypeBool
v = false
case 't':
d.readStrIdx(0, 4) // true
vt = valueTypeBool
v = true
case '{':
vt = valueTypeMap
decodeFurther = true
case '[':
vt = valueTypeArray
decodeFurther = true
case '"':
vt = valueTypeString
v = d.DecodeString()
default: // number
d.decNum(true)
n := &d.n
// if the string had a any of [.eE], then decode as float.
switch {
case n.explicitExponent, n.dot, n.exponent < 0, n.manOverflow:
vt = valueTypeFloat
v = n.floatVal()
case n.exponent == 0:
u := n.mantissa
switch {
case n.neg:
vt = valueTypeInt
v = -int64(u)
case d.h.SignedInteger:
vt = valueTypeInt
v = int64(u)
default:
vt = valueTypeUint
v = u
}
default:
u, overflow := n.uintExp()
switch {
case overflow:
vt = valueTypeFloat
v = n.floatVal()
case n.neg:
vt = valueTypeInt
v = -int64(u)
case d.h.SignedInteger:
vt = valueTypeInt
v = int64(u)
default:
vt = valueTypeUint
v = u
}
}
// fmt.Printf("DecodeNaked: Number: %T, %v\n", v, v)
}
return
}
//----------------------
// JsonHandle is a handle for JSON encoding format.
//
// Json is comprehensively supported:
// - decodes numbers into interface{} as int, uint or float64
// - 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 and
// minimizing allocations.
//
// 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.
type JsonHandle struct {
BasicHandle
textEncodingType
}
func (h *JsonHandle) newEncDriver(e *Encoder) encDriver {
return &jsonEncDriver{e: e, w: e.w, h: h}
}
func (h *JsonHandle) newDecDriver(d *Decoder) decDriver {
// d := jsonDecDriver{r: r.(*bytesDecReader), h: h}
hd := jsonDecDriver{d: d, r: d.r, h: h}
hd.n.bytes = d.b[:]
return &hd
}
var jsonEncodeTerminate = []byte{' '}
func (h *JsonHandle) rpcEncodeTerminate() []byte {
return jsonEncodeTerminate
}
var _ decDriver = (*jsonDecDriver)(nil)
var _ encDriver = (*jsonEncDriver)(nil)