diff --git a/vendor/github.com/ugorji/go/codec/decode.go b/vendor/github.com/ugorji/go/codec/decode.go
new file mode 100644
index 0000000..1c0817a
--- /dev/null
+++ b/vendor/github.com/ugorji/go/codec/decode.go
@@ -0,0 +1,2552 @@
+// 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
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"sync"
+	"time"
+)
+
+// Some tagging information for error messages.
+const (
+	msgBadDesc            = "unrecognized descriptor byte"
+	msgDecCannotExpandArr = "cannot expand go array from %v to stream length: %v"
+)
+
+const decDefSliceCap = 8
+const decDefChanCap = 64 // should be large, as cap cannot be expanded
+const decScratchByteArrayLen = cacheLineSize - 8
+
+var (
+	errstrOnlyMapOrArrayCanDecodeIntoStruct = "only encoded map or array can be decoded into a struct"
+	errstrCannotDecodeIntoNil               = "cannot decode into nil"
+
+	errmsgExpandSliceOverflow     = "expand slice: slice overflow"
+	errmsgExpandSliceCannotChange = "expand slice: cannot change"
+
+	errDecoderNotInitialized = errors.New("Decoder not initialized")
+
+	errDecUnreadByteNothingToRead   = errors.New("cannot unread - nothing has been read")
+	errDecUnreadByteLastByteNotRead = errors.New("cannot unread - last byte has not been read")
+	errDecUnreadByteUnknown         = errors.New("cannot unread - reason unknown")
+)
+
+// decReader abstracts the reading source, allowing implementations that can
+// read from an io.Reader or directly off a byte slice with zero-copying.
+type decReader interface {
+	unreadn1()
+
+	// readx will use the implementation scratch buffer if possible i.e. n < len(scratchbuf), OR
+	// just return a view of the []byte being decoded from.
+	// Ensure you call detachZeroCopyBytes later if this needs to be sent outside codec control.
+	readx(n int) []byte
+	readb([]byte)
+	readn1() uint8
+	numread() int // number of bytes read
+	track()
+	stopTrack() []byte
+
+	// skip will skip any byte that matches, and return the first non-matching byte
+	skip(accept *bitset256) (token byte)
+	// readTo will read any byte that matches, stopping once no-longer matching.
+	readTo(in []byte, accept *bitset256) (out []byte)
+	// readUntil will read, only stopping once it matches the 'stop' byte.
+	readUntil(in []byte, stop byte) (out []byte)
+}
+
+type decDriver interface {
+	// this will check if the next token is a break.
+	CheckBreak() bool
+	// Note: TryDecodeAsNil should be careful not to share any temporary []byte with
+	// the rest of the decDriver. This is because sometimes, we optimize by holding onto
+	// a transient []byte, and ensuring the only other call we make to the decDriver
+	// during that time is maybe a TryDecodeAsNil() call.
+	TryDecodeAsNil() bool
+	// vt is one of: Bytes, String, Nil, Slice or Map. Return unSet if not known.
+	ContainerType() (vt valueType)
+	// IsBuiltinType(rt uintptr) bool
+
+	// DecodeNaked will decode primitives (number, bool, string, []byte) and RawExt.
+	// For maps and arrays, it will not do the decoding in-band, but will signal
+	// the decoder, so that is done later, by setting the decNaked.valueType field.
+	//
+	// Note: Numbers are decoded as int64, uint64, float64 only (no smaller sized number types).
+	// for extensions, DecodeNaked must read the tag and the []byte if it exists.
+	// if the []byte is not read, then kInterfaceNaked will treat it as a Handle
+	// that stores the subsequent value in-band, and complete reading the RawExt.
+	//
+	// extensions should also use readx to decode them, for efficiency.
+	// kInterface will extract the detached byte slice if it has to pass it outside its realm.
+	DecodeNaked()
+
+	// Deprecated: use DecodeInt64 and DecodeUint64 instead
+	// DecodeInt(bitsize uint8) (i int64)
+	// DecodeUint(bitsize uint8) (ui uint64)
+
+	DecodeInt64() (i int64)
+	DecodeUint64() (ui uint64)
+
+	DecodeFloat64() (f float64)
+	DecodeBool() (b bool)
+	// DecodeString can also decode symbols.
+	// It looks redundant as DecodeBytes is available.
+	// However, some codecs (e.g. binc) support symbols and can
+	// return a pre-stored string value, meaning that it can bypass
+	// the cost of []byte->string conversion.
+	DecodeString() (s string)
+	DecodeStringAsBytes() (v []byte)
+
+	// DecodeBytes may be called directly, without going through reflection.
+	// Consequently, it must be designed to handle possible nil.
+	DecodeBytes(bs []byte, zerocopy bool) (bsOut []byte)
+	// DecodeBytes(bs []byte, isstring, zerocopy bool) (bsOut []byte)
+
+	// decodeExt will decode into a *RawExt or into an extension.
+	DecodeExt(v interface{}, xtag uint64, ext Ext) (realxtag uint64)
+	// decodeExt(verifyTag bool, tag byte) (xtag byte, xbs []byte)
+
+	DecodeTime() (t time.Time)
+
+	ReadArrayStart() int
+	ReadArrayElem()
+	ReadArrayEnd()
+	ReadMapStart() int
+	ReadMapElemKey()
+	ReadMapElemValue()
+	ReadMapEnd()
+
+	reset()
+	uncacheRead()
+}
+
+type decDriverNoopContainerReader struct{}
+
+func (x decDriverNoopContainerReader) ReadArrayStart() (v int) { return }
+func (x decDriverNoopContainerReader) ReadArrayElem()          {}
+func (x decDriverNoopContainerReader) ReadArrayEnd()           {}
+func (x decDriverNoopContainerReader) ReadMapStart() (v int)   { return }
+func (x decDriverNoopContainerReader) ReadMapElemKey()         {}
+func (x decDriverNoopContainerReader) ReadMapElemValue()       {}
+func (x decDriverNoopContainerReader) ReadMapEnd()             {}
+func (x decDriverNoopContainerReader) CheckBreak() (v bool)    { return }
+
+// func (x decNoSeparator) uncacheRead() {}
+
+// DecodeOptions captures configuration options during decode.
+type DecodeOptions struct {
+	// MapType specifies type to use during schema-less decoding of a map in the stream.
+	// If nil (unset), we default to map[string]interface{} iff json handle and MapStringAsKey=true,
+	// else map[interface{}]interface{}.
+	MapType reflect.Type
+
+	// SliceType specifies type to use during schema-less decoding of an array in the stream.
+	// If nil (unset), we default to []interface{} for all formats.
+	SliceType reflect.Type
+
+	// MaxInitLen defines the maxinum initial length that we "make" a collection
+	// (string, slice, map, chan). If 0 or negative, we default to a sensible value
+	// based on the size of an element in the collection.
+	//
+	// For example, when decoding, a stream may say that it has 2^64 elements.
+	// We should not auto-matically provision a slice of that size, to prevent Out-Of-Memory crash.
+	// Instead, we provision up to MaxInitLen, fill that up, and start appending after that.
+	MaxInitLen int
+
+	// ReaderBufferSize is the size of the buffer used when reading.
+	//
+	// if > 0, we use a smart buffer internally for performance purposes.
+	ReaderBufferSize int
+
+	// If ErrorIfNoField, return an error when decoding a map
+	// from a codec stream into a struct, and no matching struct field is found.
+	ErrorIfNoField bool
+
+	// If ErrorIfNoArrayExpand, return an error when decoding a slice/array that cannot be expanded.
+	// For example, the stream contains an array of 8 items, but you are decoding into a [4]T array,
+	// or you are decoding into a slice of length 4 which is non-addressable (and so cannot be set).
+	ErrorIfNoArrayExpand bool
+
+	// If SignedInteger, use the int64 during schema-less decoding of unsigned values (not uint64).
+	SignedInteger bool
+
+	// MapValueReset controls how we decode into a map value.
+	//
+	// By default, we MAY retrieve the mapping for a key, and then decode into that.
+	// However, especially with big maps, that retrieval may be expensive and unnecessary
+	// if the stream already contains all that is necessary to recreate the value.
+	//
+	// If true, we will never retrieve the previous mapping,
+	// but rather decode into a new value and set that in the map.
+	//
+	// If false, we will retrieve the previous mapping if necessary e.g.
+	// the previous mapping is a pointer, or is a struct or array with pre-set state,
+	// or is an interface.
+	MapValueReset bool
+
+	// SliceElementReset: on decoding a slice, reset the element to a zero value first.
+	//
+	// concern: if the slice already contained some garbage, we will decode into that garbage.
+	SliceElementReset bool
+
+	// InterfaceReset controls how we decode into an interface.
+	//
+	// By default, when we see a field that is an interface{...},
+	// or a map with interface{...} value, we will attempt decoding into the
+	// "contained" value.
+	//
+	// However, this prevents us from reading a string into an interface{}
+	// that formerly contained a number.
+	//
+	// If true, we will decode into a new "blank" value, and set that in the interface.
+	// If false, we will decode into whatever is contained in the interface.
+	InterfaceReset bool
+
+	// InternString controls interning of strings during decoding.
+	//
+	// Some handles, e.g. json, typically will read map keys as strings.
+	// If the set of keys are finite, it may help reduce allocation to
+	// look them up from a map (than to allocate them afresh).
+	//
+	// Note: Handles will be smart when using the intern functionality.
+	// Every string should not be interned.
+	// An excellent use-case for interning is struct field names,
+	// or map keys where key type is string.
+	InternString bool
+
+	// PreferArrayOverSlice controls whether to decode to an array or a slice.
+	//
+	// This only impacts decoding into a nil interface{}.
+	// Consequently, it has no effect on codecgen.
+	//
+	// *Note*: This only applies if using go1.5 and above,
+	// as it requires reflect.ArrayOf support which was absent before go1.5.
+	PreferArrayOverSlice bool
+
+	// DeleteOnNilMapValue controls how to decode a nil value in the stream.
+	//
+	// If true, we will delete the mapping of the key.
+	// Else, just set the mapping to the zero value of the type.
+	DeleteOnNilMapValue bool
+}
+
+// ------------------------------------
+
+type bufioDecReader struct {
+	buf []byte
+	r   io.Reader
+
+	c   int // cursor
+	n   int // num read
+	err error
+
+	tr  []byte
+	trb bool
+	b   [4]byte
+}
+
+func (z *bufioDecReader) reset(r io.Reader) {
+	z.r, z.c, z.n, z.err, z.trb = r, 0, 0, nil, false
+	if z.tr != nil {
+		z.tr = z.tr[:0]
+	}
+}
+
+func (z *bufioDecReader) Read(p []byte) (n int, err error) {
+	if z.err != nil {
+		return 0, z.err
+	}
+	p0 := p
+	n = copy(p, z.buf[z.c:])
+	z.c += n
+	if z.c == len(z.buf) {
+		z.c = 0
+	}
+	z.n += n
+	if len(p) == n {
+		if z.c == 0 {
+			z.buf = z.buf[:1]
+			z.buf[0] = p[len(p)-1]
+			z.c = 1
+		}
+		if z.trb {
+			z.tr = append(z.tr, p0[:n]...)
+		}
+		return
+	}
+	p = p[n:]
+	var n2 int
+	// if we are here, then z.buf is all read
+	if len(p) > len(z.buf) {
+		n2, err = decReadFull(z.r, p)
+		n += n2
+		z.n += n2
+		z.err = err
+		// don't return EOF if some bytes were read. keep for next time.
+		if n > 0 && err == io.EOF {
+			err = nil
+		}
+		// always keep last byte in z.buf
+		z.buf = z.buf[:1]
+		z.buf[0] = p[len(p)-1]
+		z.c = 1
+		if z.trb {
+			z.tr = append(z.tr, p0[:n]...)
+		}
+		return
+	}
+	// z.c is now 0, and len(p) <= len(z.buf)
+	for len(p) > 0 && z.err == nil {
+		// println("len(p) loop starting ... ")
+		z.c = 0
+		z.buf = z.buf[0:cap(z.buf)]
+		n2, err = z.r.Read(z.buf)
+		if n2 > 0 {
+			if err == io.EOF {
+				err = nil
+			}
+			z.buf = z.buf[:n2]
+			n2 = copy(p, z.buf)
+			z.c = n2
+			n += n2
+			z.n += n2
+			p = p[n2:]
+		}
+		z.err = err
+		// println("... len(p) loop done")
+	}
+	if z.c == 0 {
+		z.buf = z.buf[:1]
+		z.buf[0] = p[len(p)-1]
+		z.c = 1
+	}
+	if z.trb {
+		z.tr = append(z.tr, p0[:n]...)
+	}
+	return
+}
+
+func (z *bufioDecReader) ReadByte() (b byte, err error) {
+	z.b[0] = 0
+	_, err = z.Read(z.b[:1])
+	b = z.b[0]
+	return
+}
+
+func (z *bufioDecReader) UnreadByte() (err error) {
+	if z.err != nil {
+		return z.err
+	}
+	if z.c > 0 {
+		z.c--
+		z.n--
+		if z.trb {
+			z.tr = z.tr[:len(z.tr)-1]
+		}
+		return
+	}
+	return errDecUnreadByteNothingToRead
+}
+
+func (z *bufioDecReader) numread() int {
+	return z.n
+}
+
+func (z *bufioDecReader) readx(n int) (bs []byte) {
+	if n <= 0 || z.err != nil {
+		return
+	}
+	if z.c+n <= len(z.buf) {
+		bs = z.buf[z.c : z.c+n]
+		z.n += n
+		z.c += n
+		if z.trb {
+			z.tr = append(z.tr, bs...)
+		}
+		return
+	}
+	bs = make([]byte, n)
+	_, err := z.Read(bs)
+	if err != nil {
+		panic(err)
+	}
+	return
+}
+
+func (z *bufioDecReader) readb(bs []byte) {
+	_, err := z.Read(bs)
+	if err != nil {
+		panic(err)
+	}
+}
+
+// func (z *bufioDecReader) readn1eof() (b uint8, eof bool) {
+// 	b, err := z.ReadByte()
+// 	if err != nil {
+// 		if err == io.EOF {
+// 			eof = true
+// 		} else {
+// 			panic(err)
+// 		}
+// 	}
+// 	return
+// }
+
+func (z *bufioDecReader) readn1() (b uint8) {
+	b, err := z.ReadByte()
+	if err != nil {
+		panic(err)
+	}
+	return
+}
+
+func (z *bufioDecReader) search(in []byte, accept *bitset256, stop, flag uint8) (token byte, out []byte) {
+	// flag: 1 (skip), 2 (readTo), 4 (readUntil)
+	if flag == 4 {
+		for i := z.c; i < len(z.buf); i++ {
+			if z.buf[i] == stop {
+				token = z.buf[i]
+				z.n = z.n + (i - z.c) - 1
+				i++
+				out = z.buf[z.c:i]
+				if z.trb {
+					z.tr = append(z.tr, z.buf[z.c:i]...)
+				}
+				z.c = i
+				return
+			}
+		}
+	} else {
+		for i := z.c; i < len(z.buf); i++ {
+			if !accept.isset(z.buf[i]) {
+				token = z.buf[i]
+				z.n = z.n + (i - z.c) - 1
+				if flag == 1 {
+					i++
+				} else {
+					out = z.buf[z.c:i]
+				}
+				if z.trb {
+					z.tr = append(z.tr, z.buf[z.c:i]...)
+				}
+				z.c = i
+				return
+			}
+		}
+	}
+	z.n += len(z.buf) - z.c
+	if flag != 1 {
+		out = append(in, z.buf[z.c:]...)
+	}
+	if z.trb {
+		z.tr = append(z.tr, z.buf[z.c:]...)
+	}
+	var n2 int
+	if z.err != nil {
+		return
+	}
+	for {
+		z.c = 0
+		z.buf = z.buf[0:cap(z.buf)]
+		n2, z.err = z.r.Read(z.buf)
+		if n2 > 0 && z.err != nil {
+			z.err = nil
+		}
+		z.buf = z.buf[:n2]
+		if flag == 4 {
+			for i := 0; i < n2; i++ {
+				if z.buf[i] == stop {
+					token = z.buf[i]
+					z.n += i - 1
+					i++
+					out = append(out, z.buf[z.c:i]...)
+					if z.trb {
+						z.tr = append(z.tr, z.buf[z.c:i]...)
+					}
+					z.c = i
+					return
+				}
+			}
+		} else {
+			for i := 0; i < n2; i++ {
+				if !accept.isset(z.buf[i]) {
+					token = z.buf[i]
+					z.n += i - 1
+					if flag == 1 {
+						i++
+					}
+					if flag != 1 {
+						out = append(out, z.buf[z.c:i]...)
+					}
+					if z.trb {
+						z.tr = append(z.tr, z.buf[z.c:i]...)
+					}
+					z.c = i
+					return
+				}
+			}
+		}
+		if flag != 1 {
+			out = append(out, z.buf[:n2]...)
+		}
+		z.n += n2
+		if z.err != nil {
+			return
+		}
+		if z.trb {
+			z.tr = append(z.tr, z.buf[:n2]...)
+		}
+	}
+}
+
+func (z *bufioDecReader) skip(accept *bitset256) (token byte) {
+	token, _ = z.search(nil, accept, 0, 1)
+	return
+}
+
+func (z *bufioDecReader) readTo(in []byte, accept *bitset256) (out []byte) {
+	_, out = z.search(in, accept, 0, 2)
+	return
+}
+
+func (z *bufioDecReader) readUntil(in []byte, stop byte) (out []byte) {
+	_, out = z.search(in, nil, stop, 4)
+	return
+}
+
+func (z *bufioDecReader) unreadn1() {
+	err := z.UnreadByte()
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (z *bufioDecReader) track() {
+	if z.tr != nil {
+		z.tr = z.tr[:0]
+	}
+	z.trb = true
+}
+
+func (z *bufioDecReader) stopTrack() (bs []byte) {
+	z.trb = false
+	return z.tr
+}
+
+// ioDecReader is a decReader that reads off an io.Reader.
+//
+// It also has a fallback implementation of ByteScanner if needed.
+type ioDecReader struct {
+	r io.Reader // the reader passed in
+
+	rr io.Reader
+	br io.ByteScanner
+
+	l   byte // last byte
+	ls  byte // last byte status. 0: init-canDoNothing, 1: canRead, 2: canUnread
+	trb bool // tracking bytes turned on
+	_   bool
+	b   [4]byte // tiny buffer for reading single bytes
+
+	x  [scratchByteArrayLen]byte // for: get struct field name, swallow valueTypeBytes, etc
+	n  int                       // num read
+	tr []byte                    // tracking bytes read
+}
+
+func (z *ioDecReader) reset(r io.Reader) {
+	z.r = r
+	z.rr = r
+	z.l, z.ls, z.n, z.trb = 0, 0, 0, false
+	if z.tr != nil {
+		z.tr = z.tr[:0]
+	}
+	var ok bool
+	if z.br, ok = r.(io.ByteScanner); !ok {
+		z.br = z
+		z.rr = z
+	}
+}
+
+func (z *ioDecReader) Read(p []byte) (n int, err error) {
+	if len(p) == 0 {
+		return
+	}
+	var firstByte bool
+	if z.ls == 1 {
+		z.ls = 2
+		p[0] = z.l
+		if len(p) == 1 {
+			n = 1
+			return
+		}
+		firstByte = true
+		p = p[1:]
+	}
+	n, err = z.r.Read(p)
+	if n > 0 {
+		if err == io.EOF && n == len(p) {
+			err = nil // read was successful, so postpone EOF (till next time)
+		}
+		z.l = p[n-1]
+		z.ls = 2
+	}
+	if firstByte {
+		n++
+	}
+	return
+}
+
+func (z *ioDecReader) ReadByte() (c byte, err error) {
+	n, err := z.Read(z.b[:1])
+	if n == 1 {
+		c = z.b[0]
+		if err == io.EOF {
+			err = nil // read was successful, so postpone EOF (till next time)
+		}
+	}
+	return
+}
+
+func (z *ioDecReader) UnreadByte() (err error) {
+	switch z.ls {
+	case 2:
+		z.ls = 1
+	case 0:
+		err = errDecUnreadByteNothingToRead
+	case 1:
+		err = errDecUnreadByteLastByteNotRead
+	default:
+		err = errDecUnreadByteUnknown
+	}
+	return
+}
+
+func (z *ioDecReader) numread() int {
+	return z.n
+}
+
+func (z *ioDecReader) readx(n int) (bs []byte) {
+	if n <= 0 {
+		return
+	}
+	if n < len(z.x) {
+		bs = z.x[:n]
+	} else {
+		bs = make([]byte, n)
+	}
+	if _, err := decReadFull(z.rr, bs); err != nil {
+		panic(err)
+	}
+	z.n += len(bs)
+	if z.trb {
+		z.tr = append(z.tr, bs...)
+	}
+	return
+}
+
+func (z *ioDecReader) readb(bs []byte) {
+	// if len(bs) == 0 {
+	// 	return
+	// }
+	if _, err := decReadFull(z.rr, bs); err != nil {
+		panic(err)
+	}
+	z.n += len(bs)
+	if z.trb {
+		z.tr = append(z.tr, bs...)
+	}
+}
+
+func (z *ioDecReader) readn1eof() (b uint8, eof bool) {
+	b, err := z.br.ReadByte()
+	if err == nil {
+		z.n++
+		if z.trb {
+			z.tr = append(z.tr, b)
+		}
+	} else if err == io.EOF {
+		eof = true
+	} else {
+		panic(err)
+	}
+	return
+}
+
+func (z *ioDecReader) readn1() (b uint8) {
+	var err error
+	if b, err = z.br.ReadByte(); err == nil {
+		z.n++
+		if z.trb {
+			z.tr = append(z.tr, b)
+		}
+		return
+	}
+	panic(err)
+}
+
+func (z *ioDecReader) skip(accept *bitset256) (token byte) {
+	for {
+		var eof bool
+		token, eof = z.readn1eof()
+		if eof {
+			return
+		}
+		if accept.isset(token) {
+			continue
+		}
+		return
+	}
+}
+
+func (z *ioDecReader) readTo(in []byte, accept *bitset256) (out []byte) {
+	out = in
+	for {
+		token, eof := z.readn1eof()
+		if eof {
+			return
+		}
+		if accept.isset(token) {
+			out = append(out, token)
+		} else {
+			z.unreadn1()
+			return
+		}
+	}
+}
+
+func (z *ioDecReader) readUntil(in []byte, stop byte) (out []byte) {
+	out = in
+	for {
+		token, eof := z.readn1eof()
+		if eof {
+			panic(io.EOF)
+		}
+		out = append(out, token)
+		if token == stop {
+			return
+		}
+	}
+}
+
+func (z *ioDecReader) unreadn1() {
+	err := z.br.UnreadByte()
+	if err != nil {
+		panic(err)
+	}
+	z.n--
+	if z.trb {
+		if l := len(z.tr) - 1; l >= 0 {
+			z.tr = z.tr[:l]
+		}
+	}
+}
+
+func (z *ioDecReader) track() {
+	if z.tr != nil {
+		z.tr = z.tr[:0]
+	}
+	z.trb = true
+}
+
+func (z *ioDecReader) stopTrack() (bs []byte) {
+	z.trb = false
+	return z.tr
+}
+
+// ------------------------------------
+
+var errBytesDecReaderCannotUnread = errors.New("cannot unread last byte read")
+
+// bytesDecReader is a decReader that reads off a byte slice with zero copying
+type bytesDecReader struct {
+	b []byte // data
+	c int    // cursor
+	a int    // available
+	t int    // track start
+}
+
+func (z *bytesDecReader) reset(in []byte) {
+	z.b = in
+	z.a = len(in)
+	z.c = 0
+	z.t = 0
+}
+
+func (z *bytesDecReader) numread() int {
+	return z.c
+}
+
+func (z *bytesDecReader) unreadn1() {
+	if z.c == 0 || len(z.b) == 0 {
+		panic(errBytesDecReaderCannotUnread)
+	}
+	z.c--
+	z.a++
+	return
+}
+
+func (z *bytesDecReader) readx(n int) (bs []byte) {
+	// slicing from a non-constant start position is more expensive,
+	// as more computation is required to decipher the pointer start position.
+	// However, we do it only once, and it's better than reslicing both z.b and return value.
+
+	if n <= 0 {
+	} else if z.a == 0 {
+		panic(io.EOF)
+	} else if n > z.a {
+		panic(io.ErrUnexpectedEOF)
+	} else {
+		c0 := z.c
+		z.c = c0 + n
+		z.a = z.a - n
+		bs = z.b[c0:z.c]
+	}
+	return
+}
+
+func (z *bytesDecReader) readb(bs []byte) {
+	copy(bs, z.readx(len(bs)))
+}
+
+func (z *bytesDecReader) readn1() (v uint8) {
+	if z.a == 0 {
+		panic(io.EOF)
+	}
+	v = z.b[z.c]
+	z.c++
+	z.a--
+	return
+}
+
+// func (z *bytesDecReader) readn1eof() (v uint8, eof bool) {
+// 	if z.a == 0 {
+// 		eof = true
+// 		return
+// 	}
+// 	v = z.b[z.c]
+// 	z.c++
+// 	z.a--
+// 	return
+// }
+
+func (z *bytesDecReader) skip(accept *bitset256) (token byte) {
+	if z.a == 0 {
+		return
+	}
+	blen := len(z.b)
+	for i := z.c; i < blen; i++ {
+		if !accept.isset(z.b[i]) {
+			token = z.b[i]
+			i++
+			z.a -= (i - z.c)
+			z.c = i
+			return
+		}
+	}
+	z.a, z.c = 0, blen
+	return
+}
+
+func (z *bytesDecReader) readTo(_ []byte, accept *bitset256) (out []byte) {
+	if z.a == 0 {
+		return
+	}
+	blen := len(z.b)
+	for i := z.c; i < blen; i++ {
+		if !accept.isset(z.b[i]) {
+			out = z.b[z.c:i]
+			z.a -= (i - z.c)
+			z.c = i
+			return
+		}
+	}
+	out = z.b[z.c:]
+	z.a, z.c = 0, blen
+	return
+}
+
+func (z *bytesDecReader) readUntil(_ []byte, stop byte) (out []byte) {
+	if z.a == 0 {
+		panic(io.EOF)
+	}
+	blen := len(z.b)
+	for i := z.c; i < blen; i++ {
+		if z.b[i] == stop {
+			i++
+			out = z.b[z.c:i]
+			z.a -= (i - z.c)
+			z.c = i
+			return
+		}
+	}
+	z.a, z.c = 0, blen
+	panic(io.EOF)
+}
+
+func (z *bytesDecReader) track() {
+	z.t = z.c
+}
+
+func (z *bytesDecReader) stopTrack() (bs []byte) {
+	return z.b[z.t:z.c]
+}
+
+// ----------------------------------------
+
+// func (d *Decoder) builtin(f *codecFnInfo, rv reflect.Value) {
+// 	d.d.DecodeBuiltin(f.ti.rtid, rv2i(rv))
+// }
+
+func (d *Decoder) rawExt(f *codecFnInfo, rv reflect.Value) {
+	d.d.DecodeExt(rv2i(rv), 0, nil)
+}
+
+func (d *Decoder) ext(f *codecFnInfo, rv reflect.Value) {
+	d.d.DecodeExt(rv2i(rv), f.xfTag, f.xfFn)
+}
+
+func (d *Decoder) selferUnmarshal(f *codecFnInfo, rv reflect.Value) {
+	rv2i(rv).(Selfer).CodecDecodeSelf(d)
+}
+
+func (d *Decoder) binaryUnmarshal(f *codecFnInfo, rv reflect.Value) {
+	bm := rv2i(rv).(encoding.BinaryUnmarshaler)
+	xbs := d.d.DecodeBytes(nil, true)
+	if fnerr := bm.UnmarshalBinary(xbs); fnerr != nil {
+		panic(fnerr)
+	}
+}
+
+func (d *Decoder) textUnmarshal(f *codecFnInfo, rv reflect.Value) {
+	tm := rv2i(rv).(encoding.TextUnmarshaler)
+	fnerr := tm.UnmarshalText(d.d.DecodeStringAsBytes())
+	if fnerr != nil {
+		panic(fnerr)
+	}
+}
+
+func (d *Decoder) jsonUnmarshal(f *codecFnInfo, rv reflect.Value) {
+	tm := rv2i(rv).(jsonUnmarshaler)
+	// bs := d.d.DecodeBytes(d.b[:], true, true)
+	// grab the bytes to be read, as UnmarshalJSON needs the full JSON so as to unmarshal it itself.
+	fnerr := tm.UnmarshalJSON(d.nextValueBytes())
+	if fnerr != nil {
+		panic(fnerr)
+	}
+}
+
+func (d *Decoder) kErr(f *codecFnInfo, rv reflect.Value) {
+	d.errorf("no decoding function defined for kind %v", rv.Kind())
+}
+
+// var kIntfCtr uint64
+
+func (d *Decoder) kInterfaceNaked(f *codecFnInfo) (rvn reflect.Value) {
+	// nil interface:
+	// use some hieristics to decode it appropriately
+	// based on the detected next value in the stream.
+	n := d.naked()
+	d.d.DecodeNaked()
+	if n.v == valueTypeNil {
+		return
+	}
+	// We cannot decode non-nil stream value into nil interface with methods (e.g. io.Reader).
+	if f.ti.numMeth > 0 {
+		d.errorf("cannot decode non-nil codec value into nil %v (%v methods)", f.ti.rt, f.ti.numMeth)
+		return
+	}
+	// var useRvn bool
+	switch n.v {
+	case valueTypeMap:
+		// if json, default to a map type with string keys
+		mtid := d.mtid
+		if mtid == 0 {
+			if d.jsms {
+				mtid = mapStrIntfTypId
+			} else {
+				mtid = mapIntfIntfTypId
+			}
+		}
+		if mtid == mapIntfIntfTypId {
+			n.initContainers()
+			if n.lm < arrayCacheLen {
+				n.ma[n.lm] = nil
+				rvn = n.rma[n.lm]
+				n.lm++
+				d.decode(&n.ma[n.lm-1])
+				n.lm--
+			} else {
+				var v2 map[interface{}]interface{}
+				d.decode(&v2)
+				rvn = reflect.ValueOf(&v2).Elem()
+			}
+		} else if mtid == mapStrIntfTypId { // for json performance
+			n.initContainers()
+			if n.ln < arrayCacheLen {
+				n.na[n.ln] = nil
+				rvn = n.rna[n.ln]
+				n.ln++
+				d.decode(&n.na[n.ln-1])
+				n.ln--
+			} else {
+				var v2 map[string]interface{}
+				d.decode(&v2)
+				rvn = reflect.ValueOf(&v2).Elem()
+			}
+		} else {
+			if d.mtr {
+				rvn = reflect.New(d.h.MapType)
+				d.decode(rv2i(rvn))
+				rvn = rvn.Elem()
+			} else {
+				rvn = reflect.New(d.h.MapType).Elem()
+				d.decodeValue(rvn, nil, true)
+			}
+		}
+	case valueTypeArray:
+		if d.stid == 0 || d.stid == intfSliceTypId {
+			n.initContainers()
+			if n.ls < arrayCacheLen {
+				n.sa[n.ls] = nil
+				rvn = n.rsa[n.ls]
+				n.ls++
+				d.decode(&n.sa[n.ls-1])
+				n.ls--
+			} else {
+				var v2 []interface{}
+				d.decode(&v2)
+				rvn = reflect.ValueOf(&v2).Elem()
+			}
+			if reflectArrayOfSupported && d.stid == 0 && d.h.PreferArrayOverSlice {
+				rvn2 := reflect.New(reflectArrayOf(rvn.Len(), intfTyp)).Elem()
+				reflect.Copy(rvn2, rvn)
+				rvn = rvn2
+			}
+		} else {
+			if d.str {
+				rvn = reflect.New(d.h.SliceType)
+				d.decode(rv2i(rvn))
+				rvn = rvn.Elem()
+			} else {
+				rvn = reflect.New(d.h.SliceType).Elem()
+				d.decodeValue(rvn, nil, true)
+			}
+		}
+	case valueTypeExt:
+		var v interface{}
+		tag, bytes := n.u, n.l // calling decode below might taint the values
+		if bytes == nil {
+			n.initContainers()
+			if n.li < arrayCacheLen {
+				n.ia[n.li] = nil
+				n.li++
+				d.decode(&n.ia[n.li-1])
+				// v = *(&n.ia[l])
+				n.li--
+				v = n.ia[n.li]
+				n.ia[n.li] = nil
+			} else {
+				d.decode(&v)
+			}
+		}
+		bfn := d.h.getExtForTag(tag)
+		if bfn == nil {
+			var re RawExt
+			re.Tag = tag
+			re.Data = detachZeroCopyBytes(d.bytes, nil, bytes)
+			re.Value = v
+			rvn = reflect.ValueOf(&re).Elem()
+		} else {
+			rvnA := reflect.New(bfn.rt)
+			if bytes != nil {
+				bfn.ext.ReadExt(rv2i(rvnA), bytes)
+			} else {
+				bfn.ext.UpdateExt(rv2i(rvnA), v)
+			}
+			rvn = rvnA.Elem()
+		}
+	case valueTypeNil:
+		// no-op
+	case valueTypeInt:
+		rvn = n.ri
+	case valueTypeUint:
+		rvn = n.ru
+	case valueTypeFloat:
+		rvn = n.rf
+	case valueTypeBool:
+		rvn = n.rb
+	case valueTypeString, valueTypeSymbol:
+		rvn = n.rs
+	case valueTypeBytes:
+		rvn = n.rl
+	case valueTypeTime:
+		rvn = n.rt
+	default:
+		panicv.errorf("kInterfaceNaked: unexpected valueType: %d", n.v)
+	}
+	return
+}
+
+func (d *Decoder) kInterface(f *codecFnInfo, rv reflect.Value) {
+	// Note:
+	// A consequence of how kInterface works, is that
+	// if an interface already contains something, we try
+	// to decode into what was there before.
+	// We do not replace with a generic value (as got from decodeNaked).
+
+	// every interface passed here MUST be settable.
+	var rvn reflect.Value
+	if rv.IsNil() || d.h.InterfaceReset {
+		// check if mapping to a type: if so, initialize it and move on
+		rvn = d.h.intf2impl(f.ti.rtid)
+		if rvn.IsValid() {
+			rv.Set(rvn)
+		} else {
+			rvn = d.kInterfaceNaked(f)
+			if rvn.IsValid() {
+				rv.Set(rvn)
+			} else if d.h.InterfaceReset {
+				// reset to zero value based on current type in there.
+				rv.Set(reflect.Zero(rv.Elem().Type()))
+			}
+			return
+		}
+	} else {
+		// now we have a non-nil interface value, meaning it contains a type
+		rvn = rv.Elem()
+	}
+	if d.d.TryDecodeAsNil() {
+		rv.Set(reflect.Zero(rvn.Type()))
+		return
+	}
+
+	// Note: interface{} is settable, but underlying type may not be.
+	// Consequently, we MAY have to create a decodable value out of the underlying value,
+	// decode into it, and reset the interface itself.
+	// fmt.Printf(">>>> kInterface: rvn type: %v, rv type: %v\n", rvn.Type(), rv.Type())
+
+	rvn2, canDecode := isDecodeable(rvn)
+	if canDecode {
+		d.decodeValue(rvn2, nil, true)
+		return
+	}
+
+	rvn2 = reflect.New(rvn.Type()).Elem()
+	rvn2.Set(rvn)
+	d.decodeValue(rvn2, nil, true)
+	rv.Set(rvn2)
+}
+
+func decStructFieldKey(dd decDriver, keyType valueType, b *[decScratchByteArrayLen]byte) (rvkencname []byte) {
+	// use if-else-if, not switch (which compiles to binary-search)
+	// since keyType is typically valueTypeString, branch prediction is pretty good.
+
+	if keyType == valueTypeString {
+		rvkencname = dd.DecodeStringAsBytes()
+	} else if keyType == valueTypeInt {
+		rvkencname = strconv.AppendInt(b[:0], dd.DecodeInt64(), 10)
+	} else if keyType == valueTypeUint {
+		rvkencname = strconv.AppendUint(b[:0], dd.DecodeUint64(), 10)
+	} else if keyType == valueTypeFloat {
+		rvkencname = strconv.AppendFloat(b[:0], dd.DecodeFloat64(), 'f', -1, 64)
+	} else {
+		rvkencname = dd.DecodeStringAsBytes()
+	}
+	return rvkencname
+}
+
+func (d *Decoder) kStruct(f *codecFnInfo, rv reflect.Value) {
+	fti := f.ti
+	dd := d.d
+	elemsep := d.esep
+	sfn := structFieldNode{v: rv, update: true}
+	ctyp := dd.ContainerType()
+	if ctyp == valueTypeMap {
+		containerLen := dd.ReadMapStart()
+		if containerLen == 0 {
+			dd.ReadMapEnd()
+			return
+		}
+		tisfi := fti.sfiSort
+		hasLen := containerLen >= 0
+
+		var rvkencname []byte
+		for j := 0; (hasLen && j < containerLen) || !(hasLen || dd.CheckBreak()); j++ {
+			if elemsep {
+				dd.ReadMapElemKey()
+			}
+			rvkencname = decStructFieldKey(dd, fti.keyType, &d.b)
+			if elemsep {
+				dd.ReadMapElemValue()
+			}
+			if k := fti.indexForEncName(rvkencname); k > -1 {
+				si := tisfi[k]
+				if dd.TryDecodeAsNil() {
+					si.setToZeroValue(rv)
+				} else {
+					d.decodeValue(sfn.field(si), nil, true)
+				}
+			} else {
+				d.structFieldNotFound(-1, stringView(rvkencname))
+			}
+			// keepAlive4StringView(rvkencnameB) // not needed, as reference is outside loop
+		}
+		dd.ReadMapEnd()
+	} else if ctyp == valueTypeArray {
+		containerLen := dd.ReadArrayStart()
+		if containerLen == 0 {
+			dd.ReadArrayEnd()
+			return
+		}
+		// Not much gain from doing it two ways for array.
+		// Arrays are not used as much for structs.
+		hasLen := containerLen >= 0
+		for j, si := range fti.sfiSrc {
+			if (hasLen && j == containerLen) || (!hasLen && dd.CheckBreak()) {
+				break
+			}
+			if elemsep {
+				dd.ReadArrayElem()
+			}
+			if dd.TryDecodeAsNil() {
+				si.setToZeroValue(rv)
+			} else {
+				d.decodeValue(sfn.field(si), nil, true)
+			}
+		}
+		if containerLen > len(fti.sfiSrc) {
+			// read remaining values and throw away
+			for j := len(fti.sfiSrc); j < containerLen; j++ {
+				if elemsep {
+					dd.ReadArrayElem()
+				}
+				d.structFieldNotFound(j, "")
+			}
+		}
+		dd.ReadArrayEnd()
+	} else {
+		d.errorstr(errstrOnlyMapOrArrayCanDecodeIntoStruct)
+		return
+	}
+}
+
+func (d *Decoder) kSlice(f *codecFnInfo, rv reflect.Value) {
+	// A slice can be set from a map or array in stream.
+	// This way, the order can be kept (as order is lost with map).
+	ti := f.ti
+	if f.seq == seqTypeChan && ti.chandir&uint8(reflect.SendDir) == 0 {
+		d.errorf("receive-only channel cannot be decoded")
+	}
+	dd := d.d
+	rtelem0 := ti.elem
+	ctyp := dd.ContainerType()
+	if ctyp == valueTypeBytes || ctyp == valueTypeString {
+		// you can only decode bytes or string in the stream into a slice or array of bytes
+		if !(ti.rtid == uint8SliceTypId || rtelem0.Kind() == reflect.Uint8) {
+			d.errorf("bytes/string in stream must decode into slice/array of bytes, not %v", ti.rt)
+		}
+		if f.seq == seqTypeChan {
+			bs2 := dd.DecodeBytes(nil, true)
+			irv := rv2i(rv)
+			ch, ok := irv.(chan<- byte)
+			if !ok {
+				ch = irv.(chan byte)
+			}
+			for _, b := range bs2 {
+				ch <- b
+			}
+		} else {
+			rvbs := rv.Bytes()
+			bs2 := dd.DecodeBytes(rvbs, false)
+			// if rvbs == nil && bs2 != nil || rvbs != nil && bs2 == nil || len(bs2) != len(rvbs) {
+			if !(len(bs2) > 0 && len(bs2) == len(rvbs) && &bs2[0] == &rvbs[0]) {
+				if rv.CanSet() {
+					rv.SetBytes(bs2)
+				} else if len(rvbs) > 0 && len(bs2) > 0 {
+					copy(rvbs, bs2)
+				}
+			}
+		}
+		return
+	}
+
+	// array := f.seq == seqTypeChan
+
+	slh, containerLenS := d.decSliceHelperStart() // only expects valueType(Array|Map)
+
+	// an array can never return a nil slice. so no need to check f.array here.
+	if containerLenS == 0 {
+		if rv.CanSet() {
+			if f.seq == seqTypeSlice {
+				if rv.IsNil() {
+					rv.Set(reflect.MakeSlice(ti.rt, 0, 0))
+				} else {
+					rv.SetLen(0)
+				}
+			} else if f.seq == seqTypeChan {
+				if rv.IsNil() {
+					rv.Set(reflect.MakeChan(ti.rt, 0))
+				}
+			}
+		}
+		slh.End()
+		return
+	}
+
+	rtelem0Size := int(rtelem0.Size())
+	rtElem0Kind := rtelem0.Kind()
+	rtelem0Mut := !isImmutableKind(rtElem0Kind)
+	rtelem := rtelem0
+	rtelemkind := rtelem.Kind()
+	for rtelemkind == reflect.Ptr {
+		rtelem = rtelem.Elem()
+		rtelemkind = rtelem.Kind()
+	}
+
+	var fn *codecFn
+
+	var rvCanset = rv.CanSet()
+	var rvChanged bool
+	var rv0 = rv
+	var rv9 reflect.Value
+
+	rvlen := rv.Len()
+	rvcap := rv.Cap()
+	hasLen := containerLenS > 0
+	if hasLen && f.seq == seqTypeSlice {
+		if containerLenS > rvcap {
+			oldRvlenGtZero := rvlen > 0
+			rvlen = decInferLen(containerLenS, d.h.MaxInitLen, int(rtelem0.Size()))
+			if rvlen <= rvcap {
+				if rvCanset {
+					rv.SetLen(rvlen)
+				}
+			} else if rvCanset {
+				rv = reflect.MakeSlice(ti.rt, rvlen, rvlen)
+				rvcap = rvlen
+				rvChanged = true
+			} else {
+				d.errorf("cannot decode into non-settable slice")
+			}
+			if rvChanged && oldRvlenGtZero && !isImmutableKind(rtelem0.Kind()) {
+				reflect.Copy(rv, rv0) // only copy up to length NOT cap i.e. rv0.Slice(0, rvcap)
+			}
+		} else if containerLenS != rvlen {
+			rvlen = containerLenS
+			if rvCanset {
+				rv.SetLen(rvlen)
+			}
+			// else {
+			// rv = rv.Slice(0, rvlen)
+			// rvChanged = true
+			// d.errorf("cannot decode into non-settable slice")
+			// }
+		}
+	}
+
+	// consider creating new element once, and just decoding into it.
+	var rtelem0Zero reflect.Value
+	var rtelem0ZeroValid bool
+	var decodeAsNil bool
+	var j int
+	d.cfer()
+	for ; (hasLen && j < containerLenS) || !(hasLen || dd.CheckBreak()); j++ {
+		if j == 0 && (f.seq == seqTypeSlice || f.seq == seqTypeChan) && rv.IsNil() {
+			if hasLen {
+				rvlen = decInferLen(containerLenS, d.h.MaxInitLen, rtelem0Size)
+			} else if f.seq == seqTypeSlice {
+				rvlen = decDefSliceCap
+			} else {
+				rvlen = decDefChanCap
+			}
+			if rvCanset {
+				if f.seq == seqTypeSlice {
+					rv = reflect.MakeSlice(ti.rt, rvlen, rvlen)
+					rvChanged = true
+				} else { // chan
+					// xdebugf(">>>>>> haslen = %v, make chan of type '%v' with length: %v", hasLen, ti.rt, rvlen)
+					rv = reflect.MakeChan(ti.rt, rvlen)
+					rvChanged = true
+				}
+			} else {
+				d.errorf("cannot decode into non-settable slice")
+			}
+		}
+		slh.ElemContainerState(j)
+		decodeAsNil = dd.TryDecodeAsNil()
+		if f.seq == seqTypeChan {
+			if decodeAsNil {
+				rv.Send(reflect.Zero(rtelem0))
+				continue
+			}
+			if rtelem0Mut || !rv9.IsValid() { // || (rtElem0Kind == reflect.Ptr && rv9.IsNil()) {
+				rv9 = reflect.New(rtelem0).Elem()
+			}
+			if fn == nil {
+				fn = d.cf.get(rtelem, true, true)
+			}
+			d.decodeValue(rv9, fn, true)
+			// xdebugf(">>>> rv9 sent on %v during decode: %v, with len=%v, cap=%v", rv.Type(), rv9, rv.Len(), rv.Cap())
+			rv.Send(rv9)
+		} else {
+			// if indefinite, etc, then expand the slice if necessary
+			var decodeIntoBlank bool
+			if j >= rvlen {
+				if f.seq == seqTypeArray {
+					d.arrayCannotExpand(rvlen, j+1)
+					decodeIntoBlank = true
+				} else { // if f.seq == seqTypeSlice
+					// rv = reflect.Append(rv, reflect.Zero(rtelem0)) // append logic + varargs
+					var rvcap2 int
+					var rvErrmsg2 string
+					rv9, rvcap2, rvChanged, rvErrmsg2 =
+						expandSliceRV(rv, ti.rt, rvCanset, rtelem0Size, 1, rvlen, rvcap)
+					if rvErrmsg2 != "" {
+						d.errorf(rvErrmsg2)
+					}
+					rvlen++
+					if rvChanged {
+						rv = rv9
+						rvcap = rvcap2
+					}
+				}
+			}
+			if decodeIntoBlank {
+				if !decodeAsNil {
+					d.swallow()
+				}
+			} else {
+				rv9 = rv.Index(j)
+				if d.h.SliceElementReset || decodeAsNil {
+					if !rtelem0ZeroValid {
+						rtelem0ZeroValid = true
+						rtelem0Zero = reflect.Zero(rtelem0)
+					}
+					rv9.Set(rtelem0Zero)
+				}
+				if decodeAsNil {
+					continue
+				}
+
+				if fn == nil {
+					fn = d.cf.get(rtelem, true, true)
+				}
+				d.decodeValue(rv9, fn, true)
+			}
+		}
+	}
+	if f.seq == seqTypeSlice {
+		if j < rvlen {
+			if rv.CanSet() {
+				rv.SetLen(j)
+			} else if rvCanset {
+				rv = rv.Slice(0, j)
+				rvChanged = true
+			} // else { d.errorf("kSlice: cannot change non-settable slice") }
+			rvlen = j
+		} else if j == 0 && rv.IsNil() {
+			if rvCanset {
+				rv = reflect.MakeSlice(ti.rt, 0, 0)
+				rvChanged = true
+			} // else { d.errorf("kSlice: cannot change non-settable slice") }
+		}
+	}
+	slh.End()
+
+	if rvChanged { // infers rvCanset=true, so it can be reset
+		rv0.Set(rv)
+	}
+}
+
+// func (d *Decoder) kArray(f *codecFnInfo, rv reflect.Value) {
+// 	// d.decodeValueFn(rv.Slice(0, rv.Len()))
+// 	f.kSlice(rv.Slice(0, rv.Len()))
+// }
+
+func (d *Decoder) kMap(f *codecFnInfo, rv reflect.Value) {
+	dd := d.d
+	containerLen := dd.ReadMapStart()
+	elemsep := d.esep
+	ti := f.ti
+	if rv.IsNil() {
+		rv.Set(makeMapReflect(ti.rt, containerLen))
+	}
+
+	if containerLen == 0 {
+		dd.ReadMapEnd()
+		return
+	}
+
+	ktype, vtype := ti.key, ti.elem
+	ktypeId := rt2id(ktype)
+	vtypeKind := vtype.Kind()
+
+	var keyFn, valFn *codecFn
+	var ktypeLo, vtypeLo reflect.Type
+
+	for ktypeLo = ktype; ktypeLo.Kind() == reflect.Ptr; ktypeLo = ktypeLo.Elem() {
+	}
+
+	for vtypeLo = vtype; vtypeLo.Kind() == reflect.Ptr; vtypeLo = vtypeLo.Elem() {
+	}
+
+	var mapGet, mapSet bool
+	rvvImmut := isImmutableKind(vtypeKind)
+	if !d.h.MapValueReset {
+		// if pointer, mapGet = true
+		// if interface, mapGet = true if !DecodeNakedAlways (else false)
+		// if builtin, mapGet = false
+		// else mapGet = true
+		if vtypeKind == reflect.Ptr {
+			mapGet = true
+		} else if vtypeKind == reflect.Interface {
+			if !d.h.InterfaceReset {
+				mapGet = true
+			}
+		} else if !rvvImmut {
+			mapGet = true
+		}
+	}
+
+	var rvk, rvkp, rvv, rvz reflect.Value
+	rvkMut := !isImmutableKind(ktype.Kind()) // if ktype is immutable, then re-use the same rvk.
+	ktypeIsString := ktypeId == stringTypId
+	ktypeIsIntf := ktypeId == intfTypId
+	hasLen := containerLen > 0
+	var kstrbs []byte
+	d.cfer()
+	for j := 0; (hasLen && j < containerLen) || !(hasLen || dd.CheckBreak()); j++ {
+		if rvkMut || !rvkp.IsValid() {
+			rvkp = reflect.New(ktype)
+			rvk = rvkp.Elem()
+		}
+		if elemsep {
+			dd.ReadMapElemKey()
+		}
+		if false && dd.TryDecodeAsNil() { // nil cannot be a map key, so disregard this block
+			// Previously, if a nil key, we just ignored the mapped value and continued.
+			// However, that makes the result of encoding and then decoding map[intf]intf{nil:nil}
+			// to be an empty map.
+			// Instead, we treat a nil key as the zero value of the type.
+			rvk.Set(reflect.Zero(ktype))
+		} else if ktypeIsString {
+			kstrbs = dd.DecodeStringAsBytes()
+			rvk.SetString(stringView(kstrbs))
+			// NOTE: if doing an insert, you MUST use a real string (not stringview)
+		} else {
+			if keyFn == nil {
+				keyFn = d.cf.get(ktypeLo, true, true)
+			}
+			d.decodeValue(rvk, keyFn, true)
+		}
+		// special case if a byte array.
+		if ktypeIsIntf {
+			if rvk2 := rvk.Elem(); rvk2.IsValid() {
+				if rvk2.Type() == uint8SliceTyp {
+					rvk = reflect.ValueOf(d.string(rvk2.Bytes()))
+				} else {
+					rvk = rvk2
+				}
+			}
+		}
+
+		if elemsep {
+			dd.ReadMapElemValue()
+		}
+
+		// Brittle, but OK per TryDecodeAsNil() contract.
+		// i.e. TryDecodeAsNil never shares slices with other decDriver procedures
+		if dd.TryDecodeAsNil() {
+			if ktypeIsString {
+				rvk.SetString(d.string(kstrbs))
+			}
+			if d.h.DeleteOnNilMapValue {
+				rv.SetMapIndex(rvk, reflect.Value{})
+			} else {
+				rv.SetMapIndex(rvk, reflect.Zero(vtype))
+			}
+			continue
+		}
+
+		mapSet = true // set to false if u do a get, and its a non-nil pointer
+		if mapGet {
+			// mapGet true only in case where kind=Ptr|Interface or kind is otherwise mutable.
+			rvv = rv.MapIndex(rvk)
+			if !rvv.IsValid() {
+				rvv = reflect.New(vtype).Elem()
+			} else if vtypeKind == reflect.Ptr {
+				if rvv.IsNil() {
+					rvv = reflect.New(vtype).Elem()
+				} else {
+					mapSet = false
+				}
+			} else if vtypeKind == reflect.Interface {
+				// not addressable, and thus not settable.
+				// e MUST create a settable/addressable variant
+				rvv2 := reflect.New(rvv.Type()).Elem()
+				if !rvv.IsNil() {
+					rvv2.Set(rvv)
+				}
+				rvv = rvv2
+			}
+			// else it is ~mutable, and we can just decode into it directly
+		} else if rvvImmut {
+			if !rvz.IsValid() {
+				rvz = reflect.New(vtype).Elem()
+			}
+			rvv = rvz
+		} else {
+			rvv = reflect.New(vtype).Elem()
+		}
+
+		// We MUST be done with the stringview of the key, before decoding the value
+		// so that we don't bastardize the reused byte array.
+		if mapSet && ktypeIsString {
+			rvk.SetString(d.string(kstrbs))
+		}
+		if valFn == nil {
+			valFn = d.cf.get(vtypeLo, true, true)
+		}
+		d.decodeValue(rvv, valFn, true)
+		// d.decodeValueFn(rvv, valFn)
+		if mapSet {
+			rv.SetMapIndex(rvk, rvv)
+		}
+		// if ktypeIsString {
+		// 	// keepAlive4StringView(kstrbs) // not needed, as reference is outside loop
+		// }
+	}
+
+	dd.ReadMapEnd()
+}
+
+// decNaked is used to keep track of the primitives decoded.
+// Without it, we would have to decode each primitive and wrap it
+// in an interface{}, causing an allocation.
+// In this model, the primitives are decoded in a "pseudo-atomic" fashion,
+// so we can rest assured that no other decoding happens while these
+// primitives are being decoded.
+//
+// maps and arrays are not handled by this mechanism.
+// However, RawExt is, and we accommodate for extensions that decode
+// RawExt from DecodeNaked, but need to decode the value subsequently.
+// kInterfaceNaked and swallow, which call DecodeNaked, handle this caveat.
+//
+// However, decNaked also keeps some arrays of default maps and slices
+// used in DecodeNaked. This way, we can get a pointer to it
+// without causing a new heap allocation.
+//
+// kInterfaceNaked will ensure that there is no allocation for the common
+// uses.
+
+type decNakedContainers struct {
+	// array/stacks for reducing allocation
+	// keep arrays at the bottom? Chance is that they are not used much.
+	ia [arrayCacheLen]interface{}
+	ma [arrayCacheLen]map[interface{}]interface{}
+	na [arrayCacheLen]map[string]interface{}
+	sa [arrayCacheLen][]interface{}
+
+	// ria [arrayCacheLen]reflect.Value // not needed, as we decode directly into &ia[n]
+	rma, rna, rsa [arrayCacheLen]reflect.Value // reflect.Value mapping to above
+}
+
+func (n *decNakedContainers) init() {
+	for i := 0; i < arrayCacheLen; i++ {
+		// n.ria[i] = reflect.ValueOf(&(n.ia[i])).Elem()
+		n.rma[i] = reflect.ValueOf(&(n.ma[i])).Elem()
+		n.rna[i] = reflect.ValueOf(&(n.na[i])).Elem()
+		n.rsa[i] = reflect.ValueOf(&(n.sa[i])).Elem()
+	}
+}
+
+type decNaked struct {
+	// r RawExt // used for RawExt, uint, []byte.
+
+	// primitives below
+	u uint64
+	i int64
+	f float64
+	l []byte
+	s string
+
+	// ---- cpu cache line boundary?
+	t time.Time
+	b bool
+
+	// state
+	v              valueType
+	li, lm, ln, ls int8
+	inited         bool
+
+	*decNakedContainers
+
+	ru, ri, rf, rl, rs, rb, rt reflect.Value // mapping to the primitives above
+
+	// _ [6]uint64 // padding // no padding - rt goes into next cache line
+}
+
+func (n *decNaked) init() {
+	if n.inited {
+		return
+	}
+	n.ru = reflect.ValueOf(&n.u).Elem()
+	n.ri = reflect.ValueOf(&n.i).Elem()
+	n.rf = reflect.ValueOf(&n.f).Elem()
+	n.rl = reflect.ValueOf(&n.l).Elem()
+	n.rs = reflect.ValueOf(&n.s).Elem()
+	n.rt = reflect.ValueOf(&n.t).Elem()
+	n.rb = reflect.ValueOf(&n.b).Elem()
+
+	n.inited = true
+	// n.rr[] = reflect.ValueOf(&n.)
+}
+
+func (n *decNaked) initContainers() {
+	if n.decNakedContainers == nil {
+		n.decNakedContainers = new(decNakedContainers)
+		n.decNakedContainers.init()
+	}
+}
+
+func (n *decNaked) reset() {
+	if n == nil {
+		return
+	}
+	n.li, n.lm, n.ln, n.ls = 0, 0, 0, 0
+}
+
+type rtid2rv struct {
+	rtid uintptr
+	rv   reflect.Value
+}
+
+// --------------
+
+type decReaderSwitch struct {
+	rb bytesDecReader
+	// ---- cpu cache line boundary?
+	ri       *ioDecReader
+	mtr, str bool // whether maptype or slicetype are known types
+
+	be    bool // is binary encoding
+	bytes bool // is bytes reader
+	js    bool // is json handle
+	jsms  bool // is json handle, and MapKeyAsString
+	esep  bool // has elem separators
+}
+
+// TODO: Uncomment after mid-stack inlining enabled in go 1.11
+//
+// func (z *decReaderSwitch) unreadn1() {
+// 	if z.bytes {
+// 		z.rb.unreadn1()
+// 	} else {
+// 		z.ri.unreadn1()
+// 	}
+// }
+// func (z *decReaderSwitch) readx(n int) []byte {
+// 	if z.bytes {
+// 		return z.rb.readx(n)
+// 	}
+// 	return z.ri.readx(n)
+// }
+// func (z *decReaderSwitch) readb(s []byte) {
+// 	if z.bytes {
+// 		z.rb.readb(s)
+// 	} else {
+// 		z.ri.readb(s)
+// 	}
+// }
+// func (z *decReaderSwitch) readn1() uint8 {
+// 	if z.bytes {
+// 		return z.rb.readn1()
+// 	}
+// 	return z.ri.readn1()
+// }
+// func (z *decReaderSwitch) numread() int {
+// 	if z.bytes {
+// 		return z.rb.numread()
+// 	}
+// 	return z.ri.numread()
+// }
+// func (z *decReaderSwitch) track() {
+// 	if z.bytes {
+// 		z.rb.track()
+// 	} else {
+// 		z.ri.track()
+// 	}
+// }
+// func (z *decReaderSwitch) stopTrack() []byte {
+// 	if z.bytes {
+// 		return z.rb.stopTrack()
+// 	}
+// 	return z.ri.stopTrack()
+// }
+// func (z *decReaderSwitch) skip(accept *bitset256) (token byte) {
+// 	if z.bytes {
+// 		return z.rb.skip(accept)
+// 	}
+// 	return z.ri.skip(accept)
+// }
+// func (z *decReaderSwitch) readTo(in []byte, accept *bitset256) (out []byte) {
+// 	if z.bytes {
+// 		return z.rb.readTo(in, accept)
+// 	}
+// 	return z.ri.readTo(in, accept)
+// }
+// func (z *decReaderSwitch) readUntil(in []byte, stop byte) (out []byte) {
+// 	if z.bytes {
+// 		return z.rb.readUntil(in, stop)
+// 	}
+// 	return z.ri.readUntil(in, stop)
+// }
+
+// A Decoder reads and decodes an object from an input stream in the codec format.
+type Decoder struct {
+	panicHdl
+	// hopefully, reduce derefencing cost by laying the decReader inside the Decoder.
+	// Try to put things that go together to fit within a cache line (8 words).
+
+	d decDriver
+	// NOTE: Decoder shouldn't call it's read methods,
+	// as the handler MAY need to do some coordination.
+	r  decReader
+	h  *BasicHandle
+	bi *bufioDecReader
+	// cache the mapTypeId and sliceTypeId for faster comparisons
+	mtid uintptr
+	stid uintptr
+
+	// ---- cpu cache line boundary?
+	decReaderSwitch
+
+	// ---- cpu cache line boundary?
+	codecFnPooler
+	// cr containerStateRecv
+	n   *decNaked
+	nsp *sync.Pool
+	err error
+
+	// ---- cpu cache line boundary?
+	b  [decScratchByteArrayLen]byte // scratch buffer, used by Decoder and xxxEncDrivers
+	is map[string]string            // used for interning strings
+
+	// padding - false sharing help // modify 232 if Decoder struct changes.
+	// _ [cacheLineSize - 232%cacheLineSize]byte
+}
+
+// NewDecoder returns a Decoder for decoding a stream of bytes from an io.Reader.
+//
+// For efficiency, Users are encouraged to pass in a memory buffered reader
+// (eg bufio.Reader, bytes.Buffer).
+func NewDecoder(r io.Reader, h Handle) *Decoder {
+	d := newDecoder(h)
+	d.Reset(r)
+	return d
+}
+
+// NewDecoderBytes returns a Decoder which efficiently decodes directly
+// from a byte slice with zero copying.
+func NewDecoderBytes(in []byte, h Handle) *Decoder {
+	d := newDecoder(h)
+	d.ResetBytes(in)
+	return d
+}
+
+var defaultDecNaked decNaked
+
+func newDecoder(h Handle) *Decoder {
+	d := &Decoder{h: h.getBasicHandle(), err: errDecoderNotInitialized}
+	d.hh = h
+	d.be = h.isBinary()
+	// NOTE: do not initialize d.n here. It is lazily initialized in d.naked()
+	var jh *JsonHandle
+	jh, d.js = h.(*JsonHandle)
+	if d.js {
+		d.jsms = jh.MapKeyAsString
+	}
+	d.esep = d.hh.hasElemSeparators()
+	if d.h.InternString {
+		d.is = make(map[string]string, 32)
+	}
+	d.d = h.newDecDriver(d)
+	// d.cr, _ = d.d.(containerStateRecv)
+	return d
+}
+
+func (d *Decoder) resetCommon() {
+	d.n.reset()
+	d.d.reset()
+	d.err = nil
+	// reset all things which were cached from the Handle, but could change
+	d.mtid, d.stid = 0, 0
+	d.mtr, d.str = false, false
+	if d.h.MapType != nil {
+		d.mtid = rt2id(d.h.MapType)
+		d.mtr = fastpathAV.index(d.mtid) != -1
+	}
+	if d.h.SliceType != nil {
+		d.stid = rt2id(d.h.SliceType)
+		d.str = fastpathAV.index(d.stid) != -1
+	}
+}
+
+// Reset the Decoder with a new Reader to decode from,
+// clearing all state from last run(s).
+func (d *Decoder) Reset(r io.Reader) {
+	if r == nil {
+		return
+	}
+	if d.bi == nil {
+		d.bi = new(bufioDecReader)
+	}
+	d.bytes = false
+	if d.h.ReaderBufferSize > 0 {
+		d.bi.buf = make([]byte, 0, d.h.ReaderBufferSize)
+		d.bi.reset(r)
+		d.r = d.bi
+	} else {
+		// d.ri.x = &d.b
+		// d.s = d.sa[:0]
+		if d.ri == nil {
+			d.ri = new(ioDecReader)
+		}
+		d.ri.reset(r)
+		d.r = d.ri
+	}
+	d.resetCommon()
+}
+
+// ResetBytes resets the Decoder with a new []byte to decode from,
+// clearing all state from last run(s).
+func (d *Decoder) ResetBytes(in []byte) {
+	if in == nil {
+		return
+	}
+	d.bytes = true
+	d.rb.reset(in)
+	d.r = &d.rb
+	d.resetCommon()
+}
+
+// naked must be called before each call to .DecodeNaked,
+// as they will use it.
+func (d *Decoder) naked() *decNaked {
+	if d.n == nil {
+		// consider one of:
+		//   - get from sync.Pool  (if GC is frequent, there's no value here)
+		//   - new alloc           (safest. only init'ed if it a naked decode will be done)
+		//   - field in Decoder    (makes the Decoder struct very big)
+		// To support using a decoder where a DecodeNaked is not needed,
+		// we prefer #1 or #2.
+		// d.n = new(decNaked) // &d.nv // new(decNaked) // grab from a sync.Pool
+		// d.n.init()
+		var v interface{}
+		d.nsp, v = pool.decNaked()
+		d.n = v.(*decNaked)
+	}
+	return d.n
+}
+
+// Decode decodes the stream from reader and stores the result in the
+// value pointed to by v. v cannot be a nil pointer. v can also be
+// a reflect.Value of a pointer.
+//
+// Note that a pointer to a nil interface is not a nil pointer.
+// If you do not know what type of stream it is, pass in a pointer to a nil interface.
+// We will decode and store a value in that nil interface.
+//
+// Sample usages:
+//   // Decoding into a non-nil typed value
+//   var f float32
+//   err = codec.NewDecoder(r, handle).Decode(&f)
+//
+//   // Decoding into nil interface
+//   var v interface{}
+//   dec := codec.NewDecoder(r, handle)
+//   err = dec.Decode(&v)
+//
+// When decoding into a nil interface{}, we will decode into an appropriate value based
+// on the contents of the stream:
+//   - Numbers are decoded as float64, int64 or uint64.
+//   - Other values are decoded appropriately depending on the type:
+//     bool, string, []byte, time.Time, etc
+//   - Extensions are decoded as RawExt (if no ext function registered for the tag)
+// Configurations exist on the Handle to override defaults
+// (e.g. for MapType, SliceType and how to decode raw bytes).
+//
+// When decoding into a non-nil interface{} value, the mode of encoding is based on the
+// type of the value. When a value is seen:
+//   - If an extension is registered for it, call that extension function
+//   - If it implements BinaryUnmarshaler, call its UnmarshalBinary(data []byte) error
+//   - Else decode it based on its reflect.Kind
+//
+// There are some special rules when decoding into containers (slice/array/map/struct).
+// Decode will typically use the stream contents to UPDATE the container.
+//   - A map can be decoded from a stream map, by updating matching keys.
+//   - A slice can be decoded from a stream array,
+//     by updating the first n elements, where n is length of the stream.
+//   - A slice can be decoded from a stream map, by decoding as if
+//     it contains a sequence of key-value pairs.
+//   - A struct can be decoded from a stream map, by updating matching fields.
+//   - A struct can be decoded from a stream array,
+//     by updating fields as they occur in the struct (by index).
+//
+// When decoding a stream map or array with length of 0 into a nil map or slice,
+// we reset the destination map or slice to a zero-length value.
+//
+// However, when decoding a stream nil, we reset the destination container
+// to its "zero" value (e.g. nil for slice/map, etc).
+//
+// Note: we allow nil values in the stream anywhere except for map keys.
+// A nil value in the encoded stream where a map key is expected is treated as an error.
+func (d *Decoder) Decode(v interface{}) (err error) {
+	defer d.deferred(&err)
+	d.MustDecode(v)
+	return
+}
+
+// MustDecode is like Decode, but panics if unable to Decode.
+// This provides insight to the code location that triggered the error.
+func (d *Decoder) MustDecode(v interface{}) {
+	// TODO: Top-level: ensure that v is a pointer and not nil.
+	if d.err != nil {
+		panic(d.err)
+	}
+	if d.d.TryDecodeAsNil() {
+		setZero(v)
+	} else {
+		d.decode(v)
+	}
+	d.alwaysAtEnd()
+	// xprintf(">>>>>>>> >>>>>>>> num decFns: %v\n", d.cf.sn)
+}
+
+func (d *Decoder) deferred(err1 *error) {
+	d.alwaysAtEnd()
+	if recoverPanicToErr {
+		if x := recover(); x != nil {
+			panicValToErr(d, x, err1)
+			panicValToErr(d, x, &d.err)
+		}
+	}
+}
+
+func (d *Decoder) alwaysAtEnd() {
+	if d.n != nil {
+		// if n != nil, then nsp != nil (they are always set together)
+		d.nsp.Put(d.n)
+		d.n, d.nsp = nil, nil
+	}
+	d.codecFnPooler.alwaysAtEnd()
+}
+
+// // this is not a smart swallow, as it allocates objects and does unnecessary work.
+// func (d *Decoder) swallowViaHammer() {
+// 	var blank interface{}
+// 	d.decodeValueNoFn(reflect.ValueOf(&blank).Elem())
+// }
+
+func (d *Decoder) swallow() {
+	// smarter decode that just swallows the content
+	dd := d.d
+	if dd.TryDecodeAsNil() {
+		return
+	}
+	elemsep := d.esep
+	switch dd.ContainerType() {
+	case valueTypeMap:
+		containerLen := dd.ReadMapStart()
+		hasLen := containerLen >= 0
+		for j := 0; (hasLen && j < containerLen) || !(hasLen || dd.CheckBreak()); j++ {
+			// if clenGtEqualZero {if j >= containerLen {break} } else if dd.CheckBreak() {break}
+			if elemsep {
+				dd.ReadMapElemKey()
+			}
+			d.swallow()
+			if elemsep {
+				dd.ReadMapElemValue()
+			}
+			d.swallow()
+		}
+		dd.ReadMapEnd()
+	case valueTypeArray:
+		containerLen := dd.ReadArrayStart()
+		hasLen := containerLen >= 0
+		for j := 0; (hasLen && j < containerLen) || !(hasLen || dd.CheckBreak()); j++ {
+			if elemsep {
+				dd.ReadArrayElem()
+			}
+			d.swallow()
+		}
+		dd.ReadArrayEnd()
+	case valueTypeBytes:
+		dd.DecodeBytes(d.b[:], true)
+	case valueTypeString:
+		dd.DecodeStringAsBytes()
+	default:
+		// these are all primitives, which we can get from decodeNaked
+		// if RawExt using Value, complete the processing.
+		n := d.naked()
+		dd.DecodeNaked()
+		if n.v == valueTypeExt && n.l == nil {
+			n.initContainers()
+			if n.li < arrayCacheLen {
+				n.ia[n.li] = nil
+				n.li++
+				d.decode(&n.ia[n.li-1])
+				n.ia[n.li-1] = nil
+				n.li--
+			} else {
+				var v2 interface{}
+				d.decode(&v2)
+			}
+		}
+	}
+}
+
+func setZero(iv interface{}) {
+	if iv == nil || definitelyNil(iv) {
+		return
+	}
+	var canDecode bool
+	switch v := iv.(type) {
+	case *string:
+		*v = ""
+	case *bool:
+		*v = false
+	case *int:
+		*v = 0
+	case *int8:
+		*v = 0
+	case *int16:
+		*v = 0
+	case *int32:
+		*v = 0
+	case *int64:
+		*v = 0
+	case *uint:
+		*v = 0
+	case *uint8:
+		*v = 0
+	case *uint16:
+		*v = 0
+	case *uint32:
+		*v = 0
+	case *uint64:
+		*v = 0
+	case *float32:
+		*v = 0
+	case *float64:
+		*v = 0
+	case *[]uint8:
+		*v = nil
+	case *Raw:
+		*v = nil
+	case *time.Time:
+		*v = time.Time{}
+	case reflect.Value:
+		if v, canDecode = isDecodeable(v); canDecode && v.CanSet() {
+			v.Set(reflect.Zero(v.Type()))
+		} // TODO: else drain if chan, clear if map, set all to nil if slice???
+	default:
+		if !fastpathDecodeSetZeroTypeSwitch(iv) {
+			v := reflect.ValueOf(iv)
+			if v, canDecode = isDecodeable(v); canDecode && v.CanSet() {
+				v.Set(reflect.Zero(v.Type()))
+			} // TODO: else drain if chan, clear if map, set all to nil if slice???
+		}
+	}
+}
+
+func (d *Decoder) decode(iv interface{}) {
+	// check nil and interfaces explicitly,
+	// so that type switches just have a run of constant non-interface types.
+	if iv == nil {
+		d.errorstr(errstrCannotDecodeIntoNil)
+		return
+	}
+	if v, ok := iv.(Selfer); ok {
+		v.CodecDecodeSelf(d)
+		return
+	}
+
+	switch v := iv.(type) {
+	// case nil:
+	// case Selfer:
+
+	case reflect.Value:
+		v = d.ensureDecodeable(v)
+		d.decodeValue(v, nil, true)
+
+	case *string:
+		*v = d.d.DecodeString()
+	case *bool:
+		*v = d.d.DecodeBool()
+	case *int:
+		*v = int(chkOvf.IntV(d.d.DecodeInt64(), intBitsize))
+	case *int8:
+		*v = int8(chkOvf.IntV(d.d.DecodeInt64(), 8))
+	case *int16:
+		*v = int16(chkOvf.IntV(d.d.DecodeInt64(), 16))
+	case *int32:
+		*v = int32(chkOvf.IntV(d.d.DecodeInt64(), 32))
+	case *int64:
+		*v = d.d.DecodeInt64()
+	case *uint:
+		*v = uint(chkOvf.UintV(d.d.DecodeUint64(), uintBitsize))
+	case *uint8:
+		*v = uint8(chkOvf.UintV(d.d.DecodeUint64(), 8))
+	case *uint16:
+		*v = uint16(chkOvf.UintV(d.d.DecodeUint64(), 16))
+	case *uint32:
+		*v = uint32(chkOvf.UintV(d.d.DecodeUint64(), 32))
+	case *uint64:
+		*v = d.d.DecodeUint64()
+	case *float32:
+		f64 := d.d.DecodeFloat64()
+		if chkOvf.Float32(f64) {
+			d.errorf("float32 overflow: %v", f64)
+		}
+		*v = float32(f64)
+	case *float64:
+		*v = d.d.DecodeFloat64()
+	case *[]uint8:
+		*v = d.d.DecodeBytes(*v, false)
+	case []uint8:
+		b := d.d.DecodeBytes(v, false)
+		if !(len(b) > 0 && len(b) == len(v) && &b[0] == &v[0]) {
+			copy(v, b)
+		}
+	case *time.Time:
+		*v = d.d.DecodeTime()
+	case *Raw:
+		*v = d.rawBytes()
+
+	case *interface{}:
+		d.decodeValue(reflect.ValueOf(iv).Elem(), nil, true)
+		// d.decodeValueNotNil(reflect.ValueOf(iv).Elem())
+
+	default:
+		if !fastpathDecodeTypeSwitch(iv, d) {
+			v := reflect.ValueOf(iv)
+			v = d.ensureDecodeable(v)
+			d.decodeValue(v, nil, false)
+			// d.decodeValueFallback(v)
+		}
+	}
+}
+
+func (d *Decoder) decodeValue(rv reflect.Value, fn *codecFn, chkAll bool) {
+	// If stream is not containing a nil value, then we can deref to the base
+	// non-pointer value, and decode into that.
+	var rvp reflect.Value
+	var rvpValid bool
+	if rv.Kind() == reflect.Ptr {
+		rvpValid = true
+		for {
+			if rv.IsNil() {
+				rv.Set(reflect.New(rv.Type().Elem()))
+			}
+			rvp = rv
+			rv = rv.Elem()
+			if rv.Kind() != reflect.Ptr {
+				break
+			}
+		}
+	}
+
+	if fn == nil {
+		// always pass checkCodecSelfer=true, in case T or ****T is passed, where *T is a Selfer
+		fn = d.cfer().get(rv.Type(), chkAll, true) // chkAll, chkAll)
+	}
+	if fn.i.addrD {
+		if rvpValid {
+			fn.fd(d, &fn.i, rvp)
+		} else if rv.CanAddr() {
+			fn.fd(d, &fn.i, rv.Addr())
+		} else if !fn.i.addrF {
+			fn.fd(d, &fn.i, rv)
+		} else {
+			d.errorf("cannot decode into a non-pointer value")
+		}
+	} else {
+		fn.fd(d, &fn.i, rv)
+	}
+	// return rv
+}
+
+func (d *Decoder) structFieldNotFound(index int, rvkencname string) {
+	// NOTE: rvkencname may be a stringView, so don't pass it to another function.
+	if d.h.ErrorIfNoField {
+		if index >= 0 {
+			d.errorf("no matching struct field found when decoding stream array at index %v", index)
+			return
+		} else if rvkencname != "" {
+			d.errorf("no matching struct field found when decoding stream map with key " + rvkencname)
+			return
+		}
+	}
+	d.swallow()
+}
+
+func (d *Decoder) arrayCannotExpand(sliceLen, streamLen int) {
+	if d.h.ErrorIfNoArrayExpand {
+		d.errorf("cannot expand array len during decode from %v to %v", sliceLen, streamLen)
+	}
+}
+
+func isDecodeable(rv reflect.Value) (rv2 reflect.Value, canDecode bool) {
+	switch rv.Kind() {
+	case reflect.Array:
+		return rv, true
+	case reflect.Ptr:
+		if !rv.IsNil() {
+			return rv.Elem(), true
+		}
+	case reflect.Slice, reflect.Chan, reflect.Map:
+		if !rv.IsNil() {
+			return rv, true
+		}
+	}
+	return
+}
+
+func (d *Decoder) ensureDecodeable(rv reflect.Value) (rv2 reflect.Value) {
+	// decode can take any reflect.Value that is a inherently addressable i.e.
+	//   - array
+	//   - non-nil chan    (we will SEND to it)
+	//   - non-nil slice   (we will set its elements)
+	//   - non-nil map     (we will put into it)
+	//   - non-nil pointer (we can "update" it)
+	rv2, canDecode := isDecodeable(rv)
+	if canDecode {
+		return
+	}
+	if !rv.IsValid() {
+		d.errorstr(errstrCannotDecodeIntoNil)
+		return
+	}
+	if !rv.CanInterface() {
+		d.errorf("cannot decode into a value without an interface: %v", rv)
+		return
+	}
+	rvi := rv2i(rv)
+	rvk := rv.Kind()
+	d.errorf("cannot decode into value of kind: %v, type: %T, %v", rvk, rvi, rvi)
+	return
+}
+
+// Possibly get an interned version of a string
+//
+// This should mostly be used for map keys, where the key type is string.
+// This is because keys of a map/struct are typically reused across many objects.
+func (d *Decoder) string(v []byte) (s string) {
+	if d.is == nil {
+		return string(v) // don't return stringView, as we need a real string here.
+	}
+	s, ok := d.is[string(v)] // no allocation here, per go implementation
+	if !ok {
+		s = string(v) // new allocation here
+		d.is[s] = s
+	}
+	return s
+}
+
+// nextValueBytes returns the next value in the stream as a set of bytes.
+func (d *Decoder) nextValueBytes() (bs []byte) {
+	d.d.uncacheRead()
+	d.r.track()
+	d.swallow()
+	bs = d.r.stopTrack()
+	return
+}
+
+func (d *Decoder) rawBytes() []byte {
+	// ensure that this is not a view into the bytes
+	// i.e. make new copy always.
+	bs := d.nextValueBytes()
+	bs2 := make([]byte, len(bs))
+	copy(bs2, bs)
+	return bs2
+}
+
+func (d *Decoder) wrapErrstr(v interface{}, err *error) {
+	*err = fmt.Errorf("%s decode error [pos %d]: %v", d.hh.Name(), d.r.numread(), v)
+}
+
+// --------------------------------------------------
+
+// decSliceHelper assists when decoding into a slice, from a map or an array in the stream.
+// A slice can be set from a map or array in stream. This supports the MapBySlice interface.
+type decSliceHelper struct {
+	d *Decoder
+	// ct valueType
+	array bool
+}
+
+func (d *Decoder) decSliceHelperStart() (x decSliceHelper, clen int) {
+	dd := d.d
+	ctyp := dd.ContainerType()
+	switch ctyp {
+	case valueTypeArray:
+		x.array = true
+		clen = dd.ReadArrayStart()
+	case valueTypeMap:
+		clen = dd.ReadMapStart() * 2
+	default:
+		d.errorf("only encoded map or array can be decoded into a slice (%d)", ctyp)
+	}
+	// x.ct = ctyp
+	x.d = d
+	return
+}
+
+func (x decSliceHelper) End() {
+	if x.array {
+		x.d.d.ReadArrayEnd()
+	} else {
+		x.d.d.ReadMapEnd()
+	}
+}
+
+func (x decSliceHelper) ElemContainerState(index int) {
+	if x.array {
+		x.d.d.ReadArrayElem()
+	} else if index%2 == 0 {
+		x.d.d.ReadMapElemKey()
+	} else {
+		x.d.d.ReadMapElemValue()
+	}
+}
+
+func decByteSlice(r decReader, clen, maxInitLen int, bs []byte) (bsOut []byte) {
+	if clen == 0 {
+		return zeroByteSlice
+	}
+	if len(bs) == clen {
+		bsOut = bs
+		r.readb(bsOut)
+	} else if cap(bs) >= clen {
+		bsOut = bs[:clen]
+		r.readb(bsOut)
+	} else {
+		// bsOut = make([]byte, clen)
+		len2 := decInferLen(clen, maxInitLen, 1)
+		bsOut = make([]byte, len2)
+		r.readb(bsOut)
+		for len2 < clen {
+			len3 := decInferLen(clen-len2, maxInitLen, 1)
+			bs3 := bsOut
+			bsOut = make([]byte, len2+len3)
+			copy(bsOut, bs3)
+			r.readb(bsOut[len2:])
+			len2 += len3
+		}
+	}
+	return
+}
+
+func detachZeroCopyBytes(isBytesReader bool, dest []byte, in []byte) (out []byte) {
+	if xlen := len(in); xlen > 0 {
+		if isBytesReader || xlen <= scratchByteArrayLen {
+			if cap(dest) >= xlen {
+				out = dest[:xlen]
+			} else {
+				out = make([]byte, xlen)
+			}
+			copy(out, in)
+			return
+		}
+	}
+	return in
+}
+
+// decInferLen will infer a sensible length, given the following:
+//    - clen: length wanted.
+//    - maxlen: max length to be returned.
+//      if <= 0, it is unset, and we infer it based on the unit size
+//    - unit: number of bytes for each element of the collection
+func decInferLen(clen, maxlen, unit int) (rvlen int) {
+	// handle when maxlen is not set i.e. <= 0
+	if clen <= 0 {
+		return
+	}
+	if unit == 0 {
+		return clen
+	}
+	if maxlen <= 0 {
+		// no maxlen defined. Use maximum of 256K memory, with a floor of 4K items.
+		// maxlen = 256 * 1024 / unit
+		// if maxlen < (4 * 1024) {
+		// 	maxlen = 4 * 1024
+		// }
+		if unit < (256 / 4) {
+			maxlen = 256 * 1024 / unit
+		} else {
+			maxlen = 4 * 1024
+		}
+	}
+	if clen > maxlen {
+		rvlen = maxlen
+	} else {
+		rvlen = clen
+	}
+	return
+}
+
+func expandSliceRV(s reflect.Value, st reflect.Type, canChange bool, stElemSize, num, slen, scap int) (
+	s2 reflect.Value, scap2 int, changed bool, err string) {
+	l1 := slen + num // new slice length
+	if l1 < slen {
+		err = errmsgExpandSliceOverflow
+		return
+	}
+	if l1 <= scap {
+		if s.CanSet() {
+			s.SetLen(l1)
+		} else if canChange {
+			s2 = s.Slice(0, l1)
+			scap2 = scap
+			changed = true
+		} else {
+			err = errmsgExpandSliceCannotChange
+			return
+		}
+		return
+	}
+	if !canChange {
+		err = errmsgExpandSliceCannotChange
+		return
+	}
+	scap2 = growCap(scap, stElemSize, num)
+	s2 = reflect.MakeSlice(st, l1, scap2)
+	changed = true
+	reflect.Copy(s2, s)
+	return
+}
+
+func decReadFull(r io.Reader, bs []byte) (n int, err error) {
+	var nn int
+	for n < len(bs) && err == nil {
+		nn, err = r.Read(bs[n:])
+		if nn > 0 {
+			if err == io.EOF {
+				// leave EOF for next time
+				err = nil
+			}
+			n += nn
+		}
+	}
+
+	// do not do this - it serves no purpose
+	// if n != len(bs) && err == io.EOF { err = io.ErrUnexpectedEOF }
+	return
+}