Grand test fixup (#138)

* start fixing up tests

* fix up tests + automate with drone

* fiddle with linting

* messing about with drone.yml

* some more fiddling

* hmmm

* add cache

* add vendor directory

* verbose

* ci updates

* update some little things

* update sig

1 files changed, 1457 insertions, 0 deletions

diff --git a/vendor/github.com/ugorji/go/codec/json.go b/vendor/github.com/ugorji/go/codec/json.go
new file mode 100644
index 000000000..8bd151f90
--- /dev/null
+++ b/vendor/github.com/ugorji/go/codec/json.go
@@ -0,0 +1,1457 @@
+// 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 (
+	"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
+)
+
+var (
+	// jsonLiteralTrueQ  = jsonLiterals[jsonLitTrueQ : jsonLitTrueQ+6]
+	// jsonLiteralFalseQ = jsonLiterals[jsonLitFalseQ : jsonLitFalseQ+7]
+	// jsonLiteralNullQ  = jsonLiterals[jsonLitNullQ : jsonLitNullQ+6]
+
+	jsonLiteralTrue  = jsonLiterals[jsonLitTrue : jsonLitTrue+4]
+	jsonLiteralFalse = jsonLiterals[jsonLitFalse : jsonLitFalse+5]
+	jsonLiteralNull  = jsonLiterals[jsonLitNull : jsonLitNull+4]
+
+	// these are used, after consuming the first char
+	jsonLiteral4True  = jsonLiterals[jsonLitTrue+1 : jsonLitTrue+4]
+	jsonLiteral4False = jsonLiterals[jsonLitFalse+1 : jsonLitFalse+5]
+	jsonLiteral4Null  = jsonLiterals[jsonLitNull+1 : jsonLitNull+4]
+)
+
+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
+
+	// 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.
+	b [56]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)
+	// This allows us to easily decode if a nil in the json stream
+	// ie if initial token is n.
+
+	// e.e.encWr.writeb(jsonLiteralNull)
+	e.e.encWr.writen4([4]byte{'n', 'u', 'l', 'l'})
+}
+
+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)
+	}
+}
+
+func (e *jsonEncDriver) EncodeBool(b bool) {
+	// Use writen with an array instead of writeb with a slice
+	// i.e. in place of e.e.encWr.writeb(jsonLiteralTrueQ)
+	//      OR jsonLiteralTrue, jsonLiteralFalse, jsonLiteralFalseQ, etc
+
+	if e.ks && e.e.c == containerMapKey {
+		if b {
+			e.e.encWr.writen4([4]byte{'"', 't', 'r', 'u'})
+			e.e.encWr.writen2('e', '"')
+		} else {
+			e.e.encWr.writen4([4]byte{'"', 'f', 'a', 'l'})
+			e.e.encWr.writen2('s', 'e')
+			e.e.encWr.writen1('"')
+		}
+	} else {
+		if b {
+			e.e.encWr.writen4([4]byte{'t', 'r', 'u', 'e'})
+		} else {
+			e.e.encWr.writen4([4]byte{'f', 'a', 'l', 's'})
+			e.e.encWr.writen1('e')
+		}
+	}
+}
+
+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.
+
+	const smallsString = "00010203040506070809" +
+		"10111213141516171819" +
+		"20212223242526272829" +
+		"30313233343536373839" +
+		"40414243444546474849" +
+		"50515253545556575859" +
+		"60616263646566676869" +
+		"70717273747576777879" +
+		"80818283848586878889" +
+		"90919293949596979899"
+
+	// typically, 19 or 20 bytes sufficient for decimal encoding a uint64
+	// var a [24]byte
+	var a = e.b[0:24]
+	var i = uint8(len(a))
+
+	if quotes {
+		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
+		a[i+1] = smallsString[is+1]
+		a[i+0] = smallsString[is+0]
+	}
+
+	// us < 100
+	is = us * 2
+	i--
+	a[i] = smallsString[is+1]
+	if us >= 10 {
+		i--
+		a[i] = smallsString[is]
+	}
+	if neg {
+		i--
+		a[i] = '-'
+	}
+	if quotes {
+		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) {
+	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
+
+	bs := e.e.blist.peek(slen, false)[:slen]
+
+	bs[0] = '"'
+	base64.StdEncoding.Encode(bs[1:], v)
+	bs[len(bs)-1] = '"'
+	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' {
+		d.readLit4Null(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' {
+		d.readLit4Null(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
+}
+
+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)
+}
+
+// MARKER: readLit4XXX takes the readn(3|4) 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.
+
+func (d *jsonDecDriver) readLit4True(bs [4]byte) {
+	// bs := d.d.decRd.readn3()
+	d.tok = 0
+	if jsonValidateSymbols && bs != [...]byte{0, 'r', 'u', 'e'} { // !Equal jsonLiteral4True
+		// d.d.errorf("expecting %s: got %s", jsonLiteral4True, bs[:])
+		d.d.errorf("expecting true: got t%s", bs)
+	}
+}
+
+func (d *jsonDecDriver) readLit4False(bs [4]byte) {
+	// bs := d.d.decRd.readn4()
+	d.tok = 0
+	if jsonValidateSymbols && bs != [4]byte{'a', 'l', 's', 'e'} { // !Equal jsonLiteral4False
+		// d.d.errorf("expecting %s: got %s", jsonLiteral4False, bs)
+		d.d.errorf("expecting false: got f%s", bs)
+	}
+}
+
+func (d *jsonDecDriver) readLit4Null(bs [4]byte) {
+	// bs := d.d.decRd.readn3() // readx(3)
+	d.tok = 0
+	if jsonValidateSymbols && bs != [...]byte{0, 'u', 'l', 'l'} { // !Equal jsonLiteral4Null
+		// d.d.errorf("expecting %s: got %s", jsonLiteral4Null, bs[:])
+		d.d.errorf("expecting null: got n%s", bs)
+	}
+}
+
+func (d *jsonDecDriver) advance() {
+	if d.tok == 0 {
+		d.tok = d.d.decRd.skipWhitespace() // skip(&whitespaceCharBitset)
+	}
+}
+
+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':
+		d.readLit4Null(d.d.decRd.readn3())
+		h.appendN(&v, jsonLiteralNull...)
+	case 'f':
+		d.readLit4False(d.d.decRd.readn4())
+		h.appendN(&v, jsonLiteralFalse...)
+	case 't':
+		d.readLit4True(d.d.decRd.readn3())
+		h.appendN(&v, jsonLiteralTrue...)
+	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' {
+		d.readLit4Null(d.d.decRd.readn3())
+		return true
+	}
+	return false
+}
+
+func (d *jsonDecDriver) DecodeBool() (v bool) {
+	d.advance()
+	if d.tok == 'n' {
+		d.readLit4Null(d.d.decRd.readn3())
+		return
+	}
+	fquot := d.d.c == containerMapKey && d.tok == '"'
+	if fquot {
+		d.tok = d.d.decRd.readn1()
+	}
+	switch d.tok {
+	case 'f':
+		d.readLit4False(d.d.decRd.readn4())
+		// v = false
+	case 't':
+		d.readLit4True(d.d.decRd.readn3())
+		v = true
+	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' {
+		d.readLit4Null(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' {
+		d.readLit4Null(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' {
+		d.readLit4Null(d.d.decRd.readn3())
+	} else {
+		if jsonManualInlineDecRdInHotZones {
+			if dr.bytes {
+				bs = dr.rb.jsonReadNum()
+			} else if dr.bufio {
+				bs = dr.bi.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' {
+		d.readLit4Null(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 {
+	if bs == nil {
+		bs = []byte{}
+	} else {
+		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' {
+		d.readLit4Null(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
+		bsOut = d.d.blist.check(*d.buf, slen)[: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()
+
+	// common case
+	if d.tok == '"' {
+		return d.dblQuoteStringAsBytes()
+	}
+
+	// handle non-string scalar: null, true, false or a number
+	switch d.tok {
+	case 'n':
+		d.readLit4Null(d.d.decRd.readn3())
+		return nil // []byte{}
+	case 'f':
+		d.readLit4False(d.d.decRd.readn4())
+		return jsonLiteralFalse
+	case 't':
+		d.readLit4True(d.d.decRd.readn3())
+		return jsonLiteralTrue
+	}
+
+	// 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) {
+	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 if dr.bufio {
+				bs = dr.bi.jsonReadAsisChars()
+			} else {
+				bs = dr.ri.jsonReadAsisChars()
+			}
+		} else {
+			bs = dr.jsonReadAsisChars()
+		}
+
+	APPEND:
+		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':
+			buf = append(buf, d.bstr[:utf8.EncodeRune(d.bstr[:], d.appendStringAsBytesSlashU())]...)
+		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':
+		d.readLit4Null(d.d.decRd.readn3())
+		z.v = valueTypeNil
+	case 'f':
+		d.readLit4False(d.d.decRd.readn4())
+		z.v = valueTypeBool
+		z.b = false
+	case 't':
+		d.readLit4True(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 '"':
+		// if a string, and MapKeyAsString, then try to decode it as a nil, bool or number first
+		bs = d.dblQuoteStringAsBytes()
+		if len(bs) > 0 && d.d.c == containerMapKey && d.h.MapKeyAsString {
+			if bytes.Equal(bs, jsonLiteralNull) {
+				z.v = valueTypeNil
+			} else if bytes.Equal(bs, jsonLiteralTrue) {
+				z.v = valueTypeBool
+				z.b = true
+			} else if bytes.Equal(bs, jsonLiteralFalse) {
+				z.v = valueTypeBool
+				z.b = false
+			} else {
+				// 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:
+//    - 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)