Dependencies for the affinity router and the
affinity routing daemon.

Change-Id: Icda72c3594ef7f8f0bc0c33dc03087a4c25529ca
diff --git a/vendor/github.com/ugorji/go/codec/helper.go b/vendor/github.com/ugorji/go/codec/helper.go
new file mode 100644
index 0000000..bd29895
--- /dev/null
+++ b/vendor/github.com/ugorji/go/codec/helper.go
@@ -0,0 +1,2414 @@
+// 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
+
+// Contains code shared by both encode and decode.
+
+// Some shared ideas around encoding/decoding
+// ------------------------------------------
+//
+// If an interface{} is passed, we first do a type assertion to see if it is
+// a primitive type or a map/slice of primitive types, and use a fastpath to handle it.
+//
+// If we start with a reflect.Value, we are already in reflect.Value land and
+// will try to grab the function for the underlying Type and directly call that function.
+// This is more performant than calling reflect.Value.Interface().
+//
+// This still helps us bypass many layers of reflection, and give best performance.
+//
+// Containers
+// ------------
+// Containers in the stream are either associative arrays (key-value pairs) or
+// regular arrays (indexed by incrementing integers).
+//
+// Some streams support indefinite-length containers, and use a breaking
+// byte-sequence to denote that the container has come to an end.
+//
+// Some streams also are text-based, and use explicit separators to denote the
+// end/beginning of different values.
+//
+// During encode, we use a high-level condition to determine how to iterate through
+// the container. That decision is based on whether the container is text-based (with
+// separators) or binary (without separators). If binary, we do not even call the
+// encoding of separators.
+//
+// During decode, we use a different high-level condition to determine how to iterate
+// through the containers. That decision is based on whether the stream contained
+// a length prefix, or if it used explicit breaks. If length-prefixed, we assume that
+// it has to be binary, and we do not even try to read separators.
+//
+// Philosophy
+// ------------
+// On decode, this codec will update containers appropriately:
+//    - If struct, update fields from stream into fields of struct.
+//      If field in stream not found in struct, handle appropriately (based on option).
+//      If a struct field has no corresponding value in the stream, leave it AS IS.
+//      If nil in stream, set value to nil/zero value.
+//    - If map, update map from stream.
+//      If the stream value is NIL, set the map to nil.
+//    - if slice, try to update up to length of array in stream.
+//      if container len is less than stream array length,
+//      and container cannot be expanded, handled (based on option).
+//      This means you can decode 4-element stream array into 1-element array.
+//
+// ------------------------------------
+// On encode, user can specify omitEmpty. This means that the value will be omitted
+// if the zero value. The problem may occur during decode, where omitted values do not affect
+// the value being decoded into. This means that if decoding into a struct with an
+// int field with current value=5, and the field is omitted in the stream, then after
+// decoding, the value will still be 5 (not 0).
+// omitEmpty only works if you guarantee that you always decode into zero-values.
+//
+// ------------------------------------
+// We could have truncated a map to remove keys not available in the stream,
+// or set values in the struct which are not in the stream to their zero values.
+// We decided against it because there is no efficient way to do it.
+// We may introduce it as an option later.
+// However, that will require enabling it for both runtime and code generation modes.
+//
+// To support truncate, we need to do 2 passes over the container:
+//   map
+//   - first collect all keys (e.g. in k1)
+//   - for each key in stream, mark k1 that the key should not be removed
+//   - after updating map, do second pass and call delete for all keys in k1 which are not marked
+//   struct:
+//   - for each field, track the *typeInfo s1
+//   - iterate through all s1, and for each one not marked, set value to zero
+//   - this involves checking the possible anonymous fields which are nil ptrs.
+//     too much work.
+//
+// ------------------------------------------
+// Error Handling is done within the library using panic.
+//
+// This way, the code doesn't have to keep checking if an error has happened,
+// and we don't have to keep sending the error value along with each call
+// or storing it in the En|Decoder and checking it constantly along the way.
+//
+// The disadvantage is that small functions which use panics cannot be inlined.
+// The code accounts for that by only using panics behind an interface;
+// since interface calls cannot be inlined, this is irrelevant.
+//
+// We considered storing the error is En|Decoder.
+//   - once it has its err field set, it cannot be used again.
+//   - panicing will be optional, controlled by const flag.
+//   - code should always check error first and return early.
+// We eventually decided against it as it makes the code clumsier to always
+// check for these error conditions.
+
+import (
+	"bytes"
+	"encoding"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	scratchByteArrayLen = 32
+	// initCollectionCap   = 16 // 32 is defensive. 16 is preferred.
+
+	// Support encoding.(Binary|Text)(Unm|M)arshaler.
+	// This constant flag will enable or disable it.
+	supportMarshalInterfaces = true
+
+	// for debugging, set this to false, to catch panic traces.
+	// Note that this will always cause rpc tests to fail, since they need io.EOF sent via panic.
+	recoverPanicToErr = true
+
+	// arrayCacheLen is the length of the cache used in encoder or decoder for
+	// allowing zero-alloc initialization.
+	arrayCacheLen = 8
+
+	// size of the cacheline: defaulting to value for archs: amd64, arm64, 386
+	// should use "runtime/internal/sys".CacheLineSize, but that is not exposed.
+	cacheLineSize = 64
+
+	wordSizeBits = 32 << (^uint(0) >> 63) // strconv.IntSize
+	wordSize     = wordSizeBits / 8
+
+	maxLevelsEmbedding = 15 // use this, so structFieldInfo fits into 8 bytes
+)
+
+var (
+	oneByteArr    = [1]byte{0}
+	zeroByteSlice = oneByteArr[:0:0]
+)
+
+var refBitset bitset32
+var pool pooler
+var panicv panicHdl
+
+func init() {
+	pool.init()
+
+	refBitset.set(byte(reflect.Map))
+	refBitset.set(byte(reflect.Ptr))
+	refBitset.set(byte(reflect.Func))
+	refBitset.set(byte(reflect.Chan))
+}
+
+type charEncoding uint8
+
+const (
+	cRAW charEncoding = iota
+	cUTF8
+	cUTF16LE
+	cUTF16BE
+	cUTF32LE
+	cUTF32BE
+)
+
+// valueType is the stream type
+type valueType uint8
+
+const (
+	valueTypeUnset valueType = iota
+	valueTypeNil
+	valueTypeInt
+	valueTypeUint
+	valueTypeFloat
+	valueTypeBool
+	valueTypeString
+	valueTypeSymbol
+	valueTypeBytes
+	valueTypeMap
+	valueTypeArray
+	valueTypeTime
+	valueTypeExt
+
+	// valueTypeInvalid = 0xff
+)
+
+var valueTypeStrings = [...]string{
+	"Unset",
+	"Nil",
+	"Int",
+	"Uint",
+	"Float",
+	"Bool",
+	"String",
+	"Symbol",
+	"Bytes",
+	"Map",
+	"Array",
+	"Timestamp",
+	"Ext",
+}
+
+func (x valueType) String() string {
+	if int(x) < len(valueTypeStrings) {
+		return valueTypeStrings[x]
+	}
+	return strconv.FormatInt(int64(x), 10)
+}
+
+type seqType uint8
+
+const (
+	_ seqType = iota
+	seqTypeArray
+	seqTypeSlice
+	seqTypeChan
+)
+
+// note that containerMapStart and containerArraySend are not sent.
+// This is because the ReadXXXStart and EncodeXXXStart already does these.
+type containerState uint8
+
+const (
+	_ containerState = iota
+
+	containerMapStart // slot left open, since Driver method already covers it
+	containerMapKey
+	containerMapValue
+	containerMapEnd
+	containerArrayStart // slot left open, since Driver methods already cover it
+	containerArrayElem
+	containerArrayEnd
+)
+
+// // sfiIdx used for tracking where a (field/enc)Name is seen in a []*structFieldInfo
+// type sfiIdx struct {
+// 	name  string
+// 	index int
+// }
+
+// do not recurse if a containing type refers to an embedded type
+// which refers back to its containing type (via a pointer).
+// The second time this back-reference happens, break out,
+// so as not to cause an infinite loop.
+const rgetMaxRecursion = 2
+
+// Anecdotally, we believe most types have <= 12 fields.
+// - even Java's PMD rules set TooManyFields threshold to 15.
+// However, go has embedded fields, which should be regarded as
+// top level, allowing structs to possibly double or triple.
+// In addition, we don't want to keep creating transient arrays,
+// especially for the sfi index tracking, and the evtypes tracking.
+//
+// So - try to keep typeInfoLoadArray within 2K bytes
+const (
+	typeInfoLoadArraySfisLen   = 16
+	typeInfoLoadArraySfiidxLen = 8 * 112
+	typeInfoLoadArrayEtypesLen = 12
+	typeInfoLoadArrayBLen      = 8 * 4
+)
+
+type typeInfoLoad struct {
+	// fNames   []string
+	// encNames []string
+	etypes []uintptr
+	sfis   []structFieldInfo
+}
+
+type typeInfoLoadArray struct {
+	// fNames   [typeInfoLoadArrayLen]string
+	// encNames [typeInfoLoadArrayLen]string
+	sfis   [typeInfoLoadArraySfisLen]structFieldInfo
+	sfiidx [typeInfoLoadArraySfiidxLen]byte
+	etypes [typeInfoLoadArrayEtypesLen]uintptr
+	b      [typeInfoLoadArrayBLen]byte // scratch - used for struct field names
+}
+
+// mirror json.Marshaler and json.Unmarshaler here,
+// so we don't import the encoding/json package
+
+type jsonMarshaler interface {
+	MarshalJSON() ([]byte, error)
+}
+type jsonUnmarshaler interface {
+	UnmarshalJSON([]byte) error
+}
+
+type isZeroer interface {
+	IsZero() bool
+}
+
+// type byteAccepter func(byte) bool
+
+var (
+	bigen               = binary.BigEndian
+	structInfoFieldName = "_struct"
+
+	mapStrIntfTyp  = reflect.TypeOf(map[string]interface{}(nil))
+	mapIntfIntfTyp = reflect.TypeOf(map[interface{}]interface{}(nil))
+	intfSliceTyp   = reflect.TypeOf([]interface{}(nil))
+	intfTyp        = intfSliceTyp.Elem()
+
+	reflectValTyp = reflect.TypeOf((*reflect.Value)(nil)).Elem()
+
+	stringTyp     = reflect.TypeOf("")
+	timeTyp       = reflect.TypeOf(time.Time{})
+	rawExtTyp     = reflect.TypeOf(RawExt{})
+	rawTyp        = reflect.TypeOf(Raw{})
+	uintptrTyp    = reflect.TypeOf(uintptr(0))
+	uint8Typ      = reflect.TypeOf(uint8(0))
+	uint8SliceTyp = reflect.TypeOf([]uint8(nil))
+	uintTyp       = reflect.TypeOf(uint(0))
+	intTyp        = reflect.TypeOf(int(0))
+
+	mapBySliceTyp = reflect.TypeOf((*MapBySlice)(nil)).Elem()
+
+	binaryMarshalerTyp   = reflect.TypeOf((*encoding.BinaryMarshaler)(nil)).Elem()
+	binaryUnmarshalerTyp = reflect.TypeOf((*encoding.BinaryUnmarshaler)(nil)).Elem()
+
+	textMarshalerTyp   = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+	textUnmarshalerTyp = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+
+	jsonMarshalerTyp   = reflect.TypeOf((*jsonMarshaler)(nil)).Elem()
+	jsonUnmarshalerTyp = reflect.TypeOf((*jsonUnmarshaler)(nil)).Elem()
+
+	selferTyp = reflect.TypeOf((*Selfer)(nil)).Elem()
+	iszeroTyp = reflect.TypeOf((*isZeroer)(nil)).Elem()
+
+	uint8TypId      = rt2id(uint8Typ)
+	uint8SliceTypId = rt2id(uint8SliceTyp)
+	rawExtTypId     = rt2id(rawExtTyp)
+	rawTypId        = rt2id(rawTyp)
+	intfTypId       = rt2id(intfTyp)
+	timeTypId       = rt2id(timeTyp)
+	stringTypId     = rt2id(stringTyp)
+
+	mapStrIntfTypId  = rt2id(mapStrIntfTyp)
+	mapIntfIntfTypId = rt2id(mapIntfIntfTyp)
+	intfSliceTypId   = rt2id(intfSliceTyp)
+	// mapBySliceTypId  = rt2id(mapBySliceTyp)
+
+	intBitsize  = uint8(intTyp.Bits())
+	uintBitsize = uint8(uintTyp.Bits())
+
+	bsAll0x00 = []byte{0, 0, 0, 0, 0, 0, 0, 0}
+	bsAll0xff = []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
+
+	chkOvf checkOverflow
+
+	errNoFieldNameToStructFieldInfo = errors.New("no field name passed to parseStructFieldInfo")
+)
+
+var defTypeInfos = NewTypeInfos([]string{"codec", "json"})
+
+var immutableKindsSet = [32]bool{
+	// reflect.Invalid:  ,
+	reflect.Bool:       true,
+	reflect.Int:        true,
+	reflect.Int8:       true,
+	reflect.Int16:      true,
+	reflect.Int32:      true,
+	reflect.Int64:      true,
+	reflect.Uint:       true,
+	reflect.Uint8:      true,
+	reflect.Uint16:     true,
+	reflect.Uint32:     true,
+	reflect.Uint64:     true,
+	reflect.Uintptr:    true,
+	reflect.Float32:    true,
+	reflect.Float64:    true,
+	reflect.Complex64:  true,
+	reflect.Complex128: true,
+	// reflect.Array
+	// reflect.Chan
+	// reflect.Func: true,
+	// reflect.Interface
+	// reflect.Map
+	// reflect.Ptr
+	// reflect.Slice
+	reflect.String: true,
+	// reflect.Struct
+	// reflect.UnsafePointer
+}
+
+// Selfer defines methods by which a value can encode or decode itself.
+//
+// Any type which implements Selfer will be able to encode or decode itself.
+// Consequently, during (en|de)code, this takes precedence over
+// (text|binary)(M|Unm)arshal or extension support.
+//
+// Note: *the first set of bytes of any value MUST NOT represent nil in the format*.
+// This is because, during each decode, we first check the the next set of bytes
+// represent nil, and if so, we just set the value to nil.
+type Selfer interface {
+	CodecEncodeSelf(*Encoder)
+	CodecDecodeSelf(*Decoder)
+}
+
+// MapBySlice is a tag interface that denotes wrapped slice should encode as a map in the stream.
+// The slice contains a sequence of key-value pairs.
+// This affords storing a map in a specific sequence in the stream.
+//
+// Example usage:
+//    type T1 []string         // or []int or []Point or any other "slice" type
+//    func (_ T1) MapBySlice{} // T1 now implements MapBySlice, and will be encoded as a map
+//    type T2 struct { KeyValues T1 }
+//
+//    var kvs = []string{"one", "1", "two", "2", "three", "3"}
+//    var v2 = T2{ KeyValues: T1(kvs) }
+//    // v2 will be encoded like the map: {"KeyValues": {"one": "1", "two": "2", "three": "3"} }
+//
+// The support of MapBySlice affords the following:
+//   - A slice type which implements MapBySlice will be encoded as a map
+//   - A slice can be decoded from a map in the stream
+//   - It MUST be a slice type (not a pointer receiver) that implements MapBySlice
+type MapBySlice interface {
+	MapBySlice()
+}
+
+// BasicHandle encapsulates the common options and extension functions.
+//
+// Deprecated: DO NOT USE DIRECTLY. EXPORTED FOR GODOC BENEFIT. WILL BE REMOVED.
+type BasicHandle struct {
+	// BasicHandle is always a part of a different type.
+	// It doesn't have to fit into it own cache lines.
+
+	// TypeInfos is used to get the type info for any type.
+	//
+	// If not configured, the default TypeInfos is used, which uses struct tag keys: codec, json
+	TypeInfos *TypeInfos
+
+	// Note: BasicHandle is not comparable, due to these slices here (extHandle, intf2impls).
+	// If *[]T is used instead, this becomes comparable, at the cost of extra indirection.
+	// Thses slices are used all the time, so keep as slices (not pointers).
+
+	extHandle
+
+	intf2impls
+
+	RPCOptions
+
+	// ---- cache line
+
+	DecodeOptions
+
+	// ---- cache line
+
+	EncodeOptions
+
+	// noBuiltInTypeChecker
+}
+
+func (x *BasicHandle) getBasicHandle() *BasicHandle {
+	return x
+}
+
+func (x *BasicHandle) getTypeInfo(rtid uintptr, rt reflect.Type) (pti *typeInfo) {
+	if x.TypeInfos == nil {
+		return defTypeInfos.get(rtid, rt)
+	}
+	return x.TypeInfos.get(rtid, rt)
+}
+
+// Handle is the interface for a specific encoding format.
+//
+// Typically, a Handle is pre-configured before first time use,
+// and not modified while in use. Such a pre-configured Handle
+// is safe for concurrent access.
+type Handle interface {
+	Name() string
+	getBasicHandle() *BasicHandle
+	recreateEncDriver(encDriver) bool
+	newEncDriver(w *Encoder) encDriver
+	newDecDriver(r *Decoder) decDriver
+	isBinary() bool
+	hasElemSeparators() bool
+	// IsBuiltinType(rtid uintptr) bool
+}
+
+// Raw represents raw formatted bytes.
+// We "blindly" store it during encode and retrieve the raw bytes during decode.
+// Note: it is dangerous during encode, so we may gate the behaviour
+// behind an Encode flag which must be explicitly set.
+type Raw []byte
+
+// RawExt represents raw unprocessed extension data.
+// Some codecs will decode extension data as a *RawExt
+// if there is no registered extension for the tag.
+//
+// Only one of Data or Value is nil.
+// If Data is nil, then the content of the RawExt is in the Value.
+type RawExt struct {
+	Tag uint64
+	// Data is the []byte which represents the raw ext. If nil, ext is exposed in Value.
+	// Data is used by codecs (e.g. binc, msgpack, simple) which do custom serialization of types
+	Data []byte
+	// Value represents the extension, if Data is nil.
+	// Value is used by codecs (e.g. cbor, json) which leverage the format to do
+	// custom serialization of the types.
+	Value interface{}
+}
+
+// BytesExt handles custom (de)serialization of types to/from []byte.
+// It is used by codecs (e.g. binc, msgpack, simple) which do custom serialization of the types.
+type BytesExt interface {
+	// WriteExt converts a value to a []byte.
+	//
+	// Note: v is a pointer iff the registered extension type is a struct or array kind.
+	WriteExt(v interface{}) []byte
+
+	// ReadExt updates a value from a []byte.
+	//
+	// Note: dst is always a pointer kind to the registered extension type.
+	ReadExt(dst interface{}, src []byte)
+}
+
+// InterfaceExt handles custom (de)serialization of types to/from another interface{} value.
+// The Encoder or Decoder will then handle the further (de)serialization of that known type.
+//
+// It is used by codecs (e.g. cbor, json) which use the format to do custom serialization of types.
+type InterfaceExt interface {
+	// ConvertExt converts a value into a simpler interface for easy encoding
+	// e.g. convert time.Time to int64.
+	//
+	// Note: v is a pointer iff the registered extension type is a struct or array kind.
+	ConvertExt(v interface{}) interface{}
+
+	// UpdateExt updates a value from a simpler interface for easy decoding
+	// e.g. convert int64 to time.Time.
+	//
+	// Note: dst is always a pointer kind to the registered extension type.
+	UpdateExt(dst interface{}, src interface{})
+}
+
+// Ext handles custom (de)serialization of custom types / extensions.
+type Ext interface {
+	BytesExt
+	InterfaceExt
+}
+
+// addExtWrapper is a wrapper implementation to support former AddExt exported method.
+type addExtWrapper struct {
+	encFn func(reflect.Value) ([]byte, error)
+	decFn func(reflect.Value, []byte) error
+}
+
+func (x addExtWrapper) WriteExt(v interface{}) []byte {
+	bs, err := x.encFn(reflect.ValueOf(v))
+	if err != nil {
+		panic(err)
+	}
+	return bs
+}
+
+func (x addExtWrapper) ReadExt(v interface{}, bs []byte) {
+	if err := x.decFn(reflect.ValueOf(v), bs); err != nil {
+		panic(err)
+	}
+}
+
+func (x addExtWrapper) ConvertExt(v interface{}) interface{} {
+	return x.WriteExt(v)
+}
+
+func (x addExtWrapper) UpdateExt(dest interface{}, v interface{}) {
+	x.ReadExt(dest, v.([]byte))
+}
+
+type extWrapper struct {
+	BytesExt
+	InterfaceExt
+}
+
+type bytesExtFailer struct{}
+
+func (bytesExtFailer) WriteExt(v interface{}) []byte {
+	panicv.errorstr("BytesExt.WriteExt is not supported")
+	return nil
+}
+func (bytesExtFailer) ReadExt(v interface{}, bs []byte) {
+	panicv.errorstr("BytesExt.ReadExt is not supported")
+}
+
+type interfaceExtFailer struct{}
+
+func (interfaceExtFailer) ConvertExt(v interface{}) interface{} {
+	panicv.errorstr("InterfaceExt.ConvertExt is not supported")
+	return nil
+}
+func (interfaceExtFailer) UpdateExt(dest interface{}, v interface{}) {
+	panicv.errorstr("InterfaceExt.UpdateExt is not supported")
+}
+
+type binaryEncodingType struct{}
+
+func (binaryEncodingType) isBinary() bool { return true }
+
+type textEncodingType struct{}
+
+func (textEncodingType) isBinary() bool { return false }
+
+// noBuiltInTypes is embedded into many types which do not support builtins
+// e.g. msgpack, simple, cbor.
+
+// type noBuiltInTypeChecker struct{}
+// func (noBuiltInTypeChecker) IsBuiltinType(rt uintptr) bool { return false }
+// type noBuiltInTypes struct{ noBuiltInTypeChecker }
+
+type noBuiltInTypes struct{}
+
+func (noBuiltInTypes) EncodeBuiltin(rt uintptr, v interface{}) {}
+func (noBuiltInTypes) DecodeBuiltin(rt uintptr, v interface{}) {}
+
+// type noStreamingCodec struct{}
+// func (noStreamingCodec) CheckBreak() bool { return false }
+// func (noStreamingCodec) hasElemSeparators() bool { return false }
+
+type noElemSeparators struct{}
+
+func (noElemSeparators) hasElemSeparators() (v bool)            { return }
+func (noElemSeparators) recreateEncDriver(e encDriver) (v bool) { return }
+
+// bigenHelper.
+// Users must already slice the x completely, because we will not reslice.
+type bigenHelper struct {
+	x []byte // must be correctly sliced to appropriate len. slicing is a cost.
+	w encWriter
+}
+
+func (z bigenHelper) writeUint16(v uint16) {
+	bigen.PutUint16(z.x, v)
+	z.w.writeb(z.x)
+}
+
+func (z bigenHelper) writeUint32(v uint32) {
+	bigen.PutUint32(z.x, v)
+	z.w.writeb(z.x)
+}
+
+func (z bigenHelper) writeUint64(v uint64) {
+	bigen.PutUint64(z.x, v)
+	z.w.writeb(z.x)
+}
+
+type extTypeTagFn struct {
+	rtid    uintptr
+	rtidptr uintptr
+	rt      reflect.Type
+	tag     uint64
+	ext     Ext
+	_       [1]uint64 // padding
+}
+
+type extHandle []extTypeTagFn
+
+// AddExt registes an encode and decode function for a reflect.Type.
+// To deregister an Ext, call AddExt with nil encfn and/or nil decfn.
+//
+// Deprecated: Use SetBytesExt or SetInterfaceExt on the Handle instead.
+func (o *extHandle) AddExt(rt reflect.Type, tag byte,
+	encfn func(reflect.Value) ([]byte, error),
+	decfn func(reflect.Value, []byte) error) (err error) {
+	if encfn == nil || decfn == nil {
+		return o.SetExt(rt, uint64(tag), nil)
+	}
+	return o.SetExt(rt, uint64(tag), addExtWrapper{encfn, decfn})
+}
+
+// SetExt will set the extension for a tag and reflect.Type.
+// Note that the type must be a named type, and specifically not a pointer or Interface.
+// An error is returned if that is not honored.
+// To Deregister an ext, call SetExt with nil Ext.
+//
+// Deprecated: Use SetBytesExt or SetInterfaceExt on the Handle instead.
+func (o *extHandle) SetExt(rt reflect.Type, tag uint64, ext Ext) (err error) {
+	// o is a pointer, because we may need to initialize it
+	rk := rt.Kind()
+	for rk == reflect.Ptr {
+		rt = rt.Elem()
+		rk = rt.Kind()
+	}
+
+	if rt.PkgPath() == "" || rk == reflect.Interface { // || rk == reflect.Ptr {
+		return fmt.Errorf("codec.Handle.SetExt: Takes named type, not a pointer or interface: %v", rt)
+	}
+
+	rtid := rt2id(rt)
+	switch rtid {
+	case timeTypId, rawTypId, rawExtTypId:
+		// all natively supported type, so cannot have an extension
+		return // TODO: should we silently ignore, or return an error???
+	}
+	// if o == nil {
+	// 	return errors.New("codec.Handle.SetExt: extHandle not initialized")
+	// }
+	o2 := *o
+	// if o2 == nil {
+	// 	return errors.New("codec.Handle.SetExt: extHandle not initialized")
+	// }
+	for i := range o2 {
+		v := &o2[i]
+		if v.rtid == rtid {
+			v.tag, v.ext = tag, ext
+			return
+		}
+	}
+	rtidptr := rt2id(reflect.PtrTo(rt))
+	*o = append(o2, extTypeTagFn{rtid, rtidptr, rt, tag, ext, [1]uint64{}})
+	return
+}
+
+func (o extHandle) getExt(rtid uintptr) (v *extTypeTagFn) {
+	for i := range o {
+		v = &o[i]
+		if v.rtid == rtid || v.rtidptr == rtid {
+			return
+		}
+	}
+	return nil
+}
+
+func (o extHandle) getExtForTag(tag uint64) (v *extTypeTagFn) {
+	for i := range o {
+		v = &o[i]
+		if v.tag == tag {
+			return
+		}
+	}
+	return nil
+}
+
+type intf2impl struct {
+	rtid uintptr // for intf
+	impl reflect.Type
+	// _    [1]uint64 // padding // not-needed, as *intf2impl is never returned.
+}
+
+type intf2impls []intf2impl
+
+// Intf2Impl maps an interface to an implementing type.
+// This allows us support infering the concrete type
+// and populating it when passed an interface.
+// e.g. var v io.Reader can be decoded as a bytes.Buffer, etc.
+//
+// Passing a nil impl will clear the mapping.
+func (o *intf2impls) Intf2Impl(intf, impl reflect.Type) (err error) {
+	if impl != nil && !impl.Implements(intf) {
+		return fmt.Errorf("Intf2Impl: %v does not implement %v", impl, intf)
+	}
+	rtid := rt2id(intf)
+	o2 := *o
+	for i := range o2 {
+		v := &o2[i]
+		if v.rtid == rtid {
+			v.impl = impl
+			return
+		}
+	}
+	*o = append(o2, intf2impl{rtid, impl})
+	return
+}
+
+func (o intf2impls) intf2impl(rtid uintptr) (rv reflect.Value) {
+	for i := range o {
+		v := &o[i]
+		if v.rtid == rtid {
+			if v.impl == nil {
+				return
+			}
+			if v.impl.Kind() == reflect.Ptr {
+				return reflect.New(v.impl.Elem())
+			}
+			return reflect.New(v.impl).Elem()
+		}
+	}
+	return
+}
+
+type structFieldInfoFlag uint8
+
+const (
+	_ structFieldInfoFlag = 1 << iota
+	structFieldInfoFlagReady
+	structFieldInfoFlagOmitEmpty
+)
+
+func (x *structFieldInfoFlag) flagSet(f structFieldInfoFlag) {
+	*x = *x | f
+}
+
+func (x *structFieldInfoFlag) flagClr(f structFieldInfoFlag) {
+	*x = *x &^ f
+}
+
+func (x structFieldInfoFlag) flagGet(f structFieldInfoFlag) bool {
+	return x&f != 0
+}
+
+func (x structFieldInfoFlag) omitEmpty() bool {
+	return x.flagGet(structFieldInfoFlagOmitEmpty)
+}
+
+func (x structFieldInfoFlag) ready() bool {
+	return x.flagGet(structFieldInfoFlagReady)
+}
+
+type structFieldInfo struct {
+	encName   string // encode name
+	fieldName string // field name
+
+	is  [maxLevelsEmbedding]uint16 // (recursive/embedded) field index in struct
+	nis uint8                      // num levels of embedding. if 1, then it's not embedded.
+	structFieldInfoFlag
+}
+
+func (si *structFieldInfo) setToZeroValue(v reflect.Value) {
+	if v, valid := si.field(v, false); valid {
+		v.Set(reflect.Zero(v.Type()))
+	}
+}
+
+// rv returns the field of the struct.
+// If anonymous, it returns an Invalid
+func (si *structFieldInfo) field(v reflect.Value, update bool) (rv2 reflect.Value, valid bool) {
+	// replicate FieldByIndex
+	for i, x := range si.is {
+		if uint8(i) == si.nis {
+			break
+		}
+		if v, valid = baseStructRv(v, update); !valid {
+			return
+		}
+		v = v.Field(int(x))
+	}
+
+	return v, true
+}
+
+// func (si *structFieldInfo) fieldval(v reflect.Value, update bool) reflect.Value {
+// 	v, _ = si.field(v, update)
+// 	return v
+// }
+
+func parseStructInfo(stag string) (toArray, omitEmpty bool, keytype valueType) {
+	keytype = valueTypeString // default
+	if stag == "" {
+		return
+	}
+	for i, s := range strings.Split(stag, ",") {
+		if i == 0 {
+		} else {
+			switch s {
+			case "omitempty":
+				omitEmpty = true
+			case "toarray":
+				toArray = true
+			case "int":
+				keytype = valueTypeInt
+			case "uint":
+				keytype = valueTypeUint
+			case "float":
+				keytype = valueTypeFloat
+				// case "bool":
+				// 	keytype = valueTypeBool
+			case "string":
+				keytype = valueTypeString
+			}
+		}
+	}
+	return
+}
+
+func (si *structFieldInfo) parseTag(stag string) {
+	// if fname == "" {
+	// 	panic(errNoFieldNameToStructFieldInfo)
+	// }
+
+	if stag == "" {
+		return
+	}
+	for i, s := range strings.Split(stag, ",") {
+		if i == 0 {
+			if s != "" {
+				si.encName = s
+			}
+		} else {
+			switch s {
+			case "omitempty":
+				si.flagSet(structFieldInfoFlagOmitEmpty)
+				// si.omitEmpty = true
+				// case "toarray":
+				// 	si.toArray = true
+			}
+		}
+	}
+}
+
+type sfiSortedByEncName []*structFieldInfo
+
+func (p sfiSortedByEncName) Len() int {
+	return len(p)
+}
+
+func (p sfiSortedByEncName) Less(i, j int) bool {
+	return p[i].encName < p[j].encName
+}
+
+func (p sfiSortedByEncName) Swap(i, j int) {
+	p[i], p[j] = p[j], p[i]
+}
+
+const structFieldNodeNumToCache = 4
+
+type structFieldNodeCache struct {
+	rv  [structFieldNodeNumToCache]reflect.Value
+	idx [structFieldNodeNumToCache]uint32
+	num uint8
+}
+
+func (x *structFieldNodeCache) get(key uint32) (fv reflect.Value, valid bool) {
+	for i, k := range &x.idx {
+		if uint8(i) == x.num {
+			return // break
+		}
+		if key == k {
+			return x.rv[i], true
+		}
+	}
+	return
+}
+
+func (x *structFieldNodeCache) tryAdd(fv reflect.Value, key uint32) {
+	if x.num < structFieldNodeNumToCache {
+		x.rv[x.num] = fv
+		x.idx[x.num] = key
+		x.num++
+		return
+	}
+}
+
+type structFieldNode struct {
+	v      reflect.Value
+	cache2 structFieldNodeCache
+	cache3 structFieldNodeCache
+	update bool
+}
+
+func (x *structFieldNode) field(si *structFieldInfo) (fv reflect.Value) {
+	// return si.fieldval(x.v, x.update)
+	// Note: we only cache if nis=2 or nis=3 i.e. up to 2 levels of embedding
+	// This mostly saves us time on the repeated calls to v.Elem, v.Field, etc.
+	var valid bool
+	switch si.nis {
+	case 1:
+		fv = x.v.Field(int(si.is[0]))
+	case 2:
+		if fv, valid = x.cache2.get(uint32(si.is[0])); valid {
+			fv = fv.Field(int(si.is[1]))
+			return
+		}
+		fv = x.v.Field(int(si.is[0]))
+		if fv, valid = baseStructRv(fv, x.update); !valid {
+			return
+		}
+		x.cache2.tryAdd(fv, uint32(si.is[0]))
+		fv = fv.Field(int(si.is[1]))
+	case 3:
+		var key uint32 = uint32(si.is[0])<<16 | uint32(si.is[1])
+		if fv, valid = x.cache3.get(key); valid {
+			fv = fv.Field(int(si.is[2]))
+			return
+		}
+		fv = x.v.Field(int(si.is[0]))
+		if fv, valid = baseStructRv(fv, x.update); !valid {
+			return
+		}
+		fv = fv.Field(int(si.is[1]))
+		if fv, valid = baseStructRv(fv, x.update); !valid {
+			return
+		}
+		x.cache3.tryAdd(fv, key)
+		fv = fv.Field(int(si.is[2]))
+	default:
+		fv, _ = si.field(x.v, x.update)
+	}
+	return
+}
+
+func baseStructRv(v reflect.Value, update bool) (v2 reflect.Value, valid bool) {
+	for v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			if !update {
+				return
+			}
+			v.Set(reflect.New(v.Type().Elem()))
+		}
+		v = v.Elem()
+	}
+	return v, true
+}
+
+type typeInfoFlag uint8
+
+const (
+	typeInfoFlagComparable = 1 << iota
+	typeInfoFlagIsZeroer
+	typeInfoFlagIsZeroerPtr
+)
+
+// typeInfo keeps information about each (non-ptr) type referenced in the encode/decode sequence.
+//
+// During an encode/decode sequence, we work as below:
+//   - If base is a built in type, en/decode base value
+//   - If base is registered as an extension, en/decode base value
+//   - If type is binary(M/Unm)arshaler, call Binary(M/Unm)arshal method
+//   - If type is text(M/Unm)arshaler, call Text(M/Unm)arshal method
+//   - Else decode appropriately based on the reflect.Kind
+type typeInfo struct {
+	rt      reflect.Type
+	elem    reflect.Type
+	pkgpath string
+
+	rtid uintptr
+	// rv0  reflect.Value // saved zero value, used if immutableKind
+
+	numMeth uint16 // number of methods
+	kind    uint8
+	chandir uint8
+
+	anyOmitEmpty bool      // true if a struct, and any of the fields are tagged "omitempty"
+	toArray      bool      // whether this (struct) type should be encoded as an array
+	keyType      valueType // if struct, how is the field name stored in a stream? default is string
+	mbs          bool      // base type (T or *T) is a MapBySlice
+
+	// ---- cpu cache line boundary?
+	sfiSort []*structFieldInfo // sorted. Used when enc/dec struct to map.
+	sfiSrc  []*structFieldInfo // unsorted. Used when enc/dec struct to array.
+
+	key reflect.Type
+
+	// ---- cpu cache line boundary?
+	// sfis         []structFieldInfo // all sfi, in src order, as created.
+	sfiNamesSort []byte // all names, with indexes into the sfiSort
+
+	// format of marshal type fields below: [btj][mu]p? OR csp?
+
+	bm  bool // T is a binaryMarshaler
+	bmp bool // *T is a binaryMarshaler
+	bu  bool // T is a binaryUnmarshaler
+	bup bool // *T is a binaryUnmarshaler
+	tm  bool // T is a textMarshaler
+	tmp bool // *T is a textMarshaler
+	tu  bool // T is a textUnmarshaler
+	tup bool // *T is a textUnmarshaler
+
+	jm  bool // T is a jsonMarshaler
+	jmp bool // *T is a jsonMarshaler
+	ju  bool // T is a jsonUnmarshaler
+	jup bool // *T is a jsonUnmarshaler
+	cs  bool // T is a Selfer
+	csp bool // *T is a Selfer
+
+	// other flags, with individual bits representing if set.
+	flags typeInfoFlag
+
+	// _ [2]byte   // padding
+	_ [3]uint64 // padding
+}
+
+func (ti *typeInfo) isFlag(f typeInfoFlag) bool {
+	return ti.flags&f != 0
+}
+
+func (ti *typeInfo) indexForEncName(name []byte) (index int16) {
+	var sn []byte
+	if len(name)+2 <= 32 {
+		var buf [32]byte // should not escape
+		sn = buf[:len(name)+2]
+	} else {
+		sn = make([]byte, len(name)+2)
+	}
+	copy(sn[1:], name)
+	sn[0], sn[len(sn)-1] = tiSep2(name), 0xff
+	j := bytes.Index(ti.sfiNamesSort, sn)
+	if j < 0 {
+		return -1
+	}
+	index = int16(uint16(ti.sfiNamesSort[j+len(sn)+1]) | uint16(ti.sfiNamesSort[j+len(sn)])<<8)
+	return
+}
+
+type rtid2ti struct {
+	rtid uintptr
+	ti   *typeInfo
+}
+
+// TypeInfos caches typeInfo for each type on first inspection.
+//
+// It is configured with a set of tag keys, which are used to get
+// configuration for the type.
+type TypeInfos struct {
+	// infos: formerly map[uintptr]*typeInfo, now *[]rtid2ti, 2 words expected
+	infos atomicTypeInfoSlice
+	mu    sync.Mutex
+	tags  []string
+	_     [2]uint64 // padding
+}
+
+// NewTypeInfos creates a TypeInfos given a set of struct tags keys.
+//
+// This allows users customize the struct tag keys which contain configuration
+// of their types.
+func NewTypeInfos(tags []string) *TypeInfos {
+	return &TypeInfos{tags: tags}
+}
+
+func (x *TypeInfos) structTag(t reflect.StructTag) (s string) {
+	// check for tags: codec, json, in that order.
+	// this allows seamless support for many configured structs.
+	for _, x := range x.tags {
+		s = t.Get(x)
+		if s != "" {
+			return s
+		}
+	}
+	return
+}
+
+func (x *TypeInfos) find(s []rtid2ti, rtid uintptr) (idx int, ti *typeInfo) {
+	// binary search. adapted from sort/search.go.
+	// if sp == nil {
+	// 	return -1, nil
+	// }
+	// s := *sp
+	h, i, j := 0, 0, len(s)
+	for i < j {
+		h = i + (j-i)/2
+		if s[h].rtid < rtid {
+			i = h + 1
+		} else {
+			j = h
+		}
+	}
+	if i < len(s) && s[i].rtid == rtid {
+		return i, s[i].ti
+	}
+	return i, nil
+}
+
+func (x *TypeInfos) get(rtid uintptr, rt reflect.Type) (pti *typeInfo) {
+	sp := x.infos.load()
+	var idx int
+	if sp != nil {
+		idx, pti = x.find(sp, rtid)
+		if pti != nil {
+			return
+		}
+	}
+
+	rk := rt.Kind()
+
+	if rk == reflect.Ptr { // || (rk == reflect.Interface && rtid != intfTypId) {
+		panicv.errorf("invalid kind passed to TypeInfos.get: %v - %v", rk, rt)
+	}
+
+	// do not hold lock while computing this.
+	// it may lead to duplication, but that's ok.
+	ti := typeInfo{rt: rt, rtid: rtid, kind: uint8(rk), pkgpath: rt.PkgPath()}
+	// ti.rv0 = reflect.Zero(rt)
+
+	// ti.comparable = rt.Comparable()
+	ti.numMeth = uint16(rt.NumMethod())
+
+	ti.bm, ti.bmp = implIntf(rt, binaryMarshalerTyp)
+	ti.bu, ti.bup = implIntf(rt, binaryUnmarshalerTyp)
+	ti.tm, ti.tmp = implIntf(rt, textMarshalerTyp)
+	ti.tu, ti.tup = implIntf(rt, textUnmarshalerTyp)
+	ti.jm, ti.jmp = implIntf(rt, jsonMarshalerTyp)
+	ti.ju, ti.jup = implIntf(rt, jsonUnmarshalerTyp)
+	ti.cs, ti.csp = implIntf(rt, selferTyp)
+
+	b1, b2 := implIntf(rt, iszeroTyp)
+	if b1 {
+		ti.flags |= typeInfoFlagIsZeroer
+	}
+	if b2 {
+		ti.flags |= typeInfoFlagIsZeroerPtr
+	}
+	if rt.Comparable() {
+		ti.flags |= typeInfoFlagComparable
+	}
+
+	switch rk {
+	case reflect.Struct:
+		var omitEmpty bool
+		if f, ok := rt.FieldByName(structInfoFieldName); ok {
+			ti.toArray, omitEmpty, ti.keyType = parseStructInfo(x.structTag(f.Tag))
+		} else {
+			ti.keyType = valueTypeString
+		}
+		pp, pi := pool.tiLoad()
+		pv := pi.(*typeInfoLoadArray)
+		pv.etypes[0] = ti.rtid
+		// vv := typeInfoLoad{pv.fNames[:0], pv.encNames[:0], pv.etypes[:1], pv.sfis[:0]}
+		vv := typeInfoLoad{pv.etypes[:1], pv.sfis[:0]}
+		x.rget(rt, rtid, omitEmpty, nil, &vv)
+		// ti.sfis = vv.sfis
+		ti.sfiSrc, ti.sfiSort, ti.sfiNamesSort, ti.anyOmitEmpty = rgetResolveSFI(rt, vv.sfis, pv)
+		pp.Put(pi)
+	case reflect.Map:
+		ti.elem = rt.Elem()
+		ti.key = rt.Key()
+	case reflect.Slice:
+		ti.mbs, _ = implIntf(rt, mapBySliceTyp)
+		ti.elem = rt.Elem()
+	case reflect.Chan:
+		ti.elem = rt.Elem()
+		ti.chandir = uint8(rt.ChanDir())
+	case reflect.Array, reflect.Ptr:
+		ti.elem = rt.Elem()
+	}
+	// sfi = sfiSrc
+
+	x.mu.Lock()
+	sp = x.infos.load()
+	if sp == nil {
+		pti = &ti
+		vs := []rtid2ti{{rtid, pti}}
+		x.infos.store(vs)
+	} else {
+		idx, pti = x.find(sp, rtid)
+		if pti == nil {
+			pti = &ti
+			vs := make([]rtid2ti, len(sp)+1)
+			copy(vs, sp[:idx])
+			copy(vs[idx+1:], sp[idx:])
+			vs[idx] = rtid2ti{rtid, pti}
+			x.infos.store(vs)
+		}
+	}
+	x.mu.Unlock()
+	return
+}
+
+func (x *TypeInfos) rget(rt reflect.Type, rtid uintptr, omitEmpty bool,
+	indexstack []uint16, pv *typeInfoLoad) {
+	// Read up fields and store how to access the value.
+	//
+	// It uses go's rules for message selectors,
+	// which say that the field with the shallowest depth is selected.
+	//
+	// Note: we consciously use slices, not a map, to simulate a set.
+	//       Typically, types have < 16 fields,
+	//       and iteration using equals is faster than maps there
+	flen := rt.NumField()
+	if flen > (1<<maxLevelsEmbedding - 1) {
+		panicv.errorf("codec: types with > %v fields are not supported - has %v fields",
+			(1<<maxLevelsEmbedding - 1), flen)
+	}
+	// pv.sfis = make([]structFieldInfo, flen)
+LOOP:
+	for j, jlen := uint16(0), uint16(flen); j < jlen; j++ {
+		f := rt.Field(int(j))
+		fkind := f.Type.Kind()
+		// skip if a func type, or is unexported, or structTag value == "-"
+		switch fkind {
+		case reflect.Func, reflect.Complex64, reflect.Complex128, reflect.UnsafePointer:
+			continue LOOP
+		}
+
+		isUnexported := f.PkgPath != ""
+		if isUnexported && !f.Anonymous {
+			continue
+		}
+		stag := x.structTag(f.Tag)
+		if stag == "-" {
+			continue
+		}
+		var si structFieldInfo
+		var parsed bool
+		// if anonymous and no struct tag (or it's blank),
+		// and a struct (or pointer to struct), inline it.
+		if f.Anonymous && fkind != reflect.Interface {
+			// ^^ redundant but ok: per go spec, an embedded pointer type cannot be to an interface
+			ft := f.Type
+			isPtr := ft.Kind() == reflect.Ptr
+			for ft.Kind() == reflect.Ptr {
+				ft = ft.Elem()
+			}
+			isStruct := ft.Kind() == reflect.Struct
+
+			// Ignore embedded fields of unexported non-struct types.
+			// Also, from go1.10, ignore pointers to unexported struct types
+			// because unmarshal cannot assign a new struct to an unexported field.
+			// See https://golang.org/issue/21357
+			if (isUnexported && !isStruct) || (!allowSetUnexportedEmbeddedPtr && isUnexported && isPtr) {
+				continue
+			}
+			doInline := stag == ""
+			if !doInline {
+				si.parseTag(stag)
+				parsed = true
+				doInline = si.encName == ""
+				// doInline = si.isZero()
+			}
+			if doInline && isStruct {
+				// if etypes contains this, don't call rget again (as fields are already seen here)
+				ftid := rt2id(ft)
+				// We cannot recurse forever, but we need to track other field depths.
+				// So - we break if we see a type twice (not the first time).
+				// This should be sufficient to handle an embedded type that refers to its
+				// owning type, which then refers to its embedded type.
+				processIt := true
+				numk := 0
+				for _, k := range pv.etypes {
+					if k == ftid {
+						numk++
+						if numk == rgetMaxRecursion {
+							processIt = false
+							break
+						}
+					}
+				}
+				if processIt {
+					pv.etypes = append(pv.etypes, ftid)
+					indexstack2 := make([]uint16, len(indexstack)+1)
+					copy(indexstack2, indexstack)
+					indexstack2[len(indexstack)] = j
+					// indexstack2 := append(append(make([]int, 0, len(indexstack)+4), indexstack...), j)
+					x.rget(ft, ftid, omitEmpty, indexstack2, pv)
+				}
+				continue
+			}
+		}
+
+		// after the anonymous dance: if an unexported field, skip
+		if isUnexported {
+			continue
+		}
+
+		if f.Name == "" {
+			panic(errNoFieldNameToStructFieldInfo)
+		}
+
+		// pv.fNames = append(pv.fNames, f.Name)
+		// if si.encName == "" {
+
+		if !parsed {
+			si.encName = f.Name
+			si.parseTag(stag)
+			parsed = true
+		} else if si.encName == "" {
+			si.encName = f.Name
+		}
+		si.fieldName = f.Name
+		si.flagSet(structFieldInfoFlagReady)
+
+		// pv.encNames = append(pv.encNames, si.encName)
+
+		// si.ikind = int(f.Type.Kind())
+		if len(indexstack) > maxLevelsEmbedding-1 {
+			panicv.errorf("codec: only supports up to %v depth of embedding - type has %v depth",
+				maxLevelsEmbedding-1, len(indexstack))
+		}
+		si.nis = uint8(len(indexstack)) + 1
+		copy(si.is[:], indexstack)
+		si.is[len(indexstack)] = j
+
+		if omitEmpty {
+			si.flagSet(structFieldInfoFlagOmitEmpty)
+		}
+		pv.sfis = append(pv.sfis, si)
+	}
+}
+
+func tiSep(name string) uint8 {
+	// (xn[0]%64) // (between 192-255 - outside ascii BMP)
+	// return 0xfe - (name[0] & 63)
+	// return 0xfe - (name[0] & 63) - uint8(len(name))
+	// return 0xfe - (name[0] & 63) - uint8(len(name)&63)
+	// return ((0xfe - (name[0] & 63)) & 0xf8) | (uint8(len(name) & 0x07))
+	return 0xfe - (name[0] & 63) - uint8(len(name)&63)
+}
+
+func tiSep2(name []byte) uint8 {
+	return 0xfe - (name[0] & 63) - uint8(len(name)&63)
+}
+
+// resolves the struct field info got from a call to rget.
+// Returns a trimmed, unsorted and sorted []*structFieldInfo.
+func rgetResolveSFI(rt reflect.Type, x []structFieldInfo, pv *typeInfoLoadArray) (
+	y, z []*structFieldInfo, ss []byte, anyOmitEmpty bool) {
+	sa := pv.sfiidx[:0]
+	sn := pv.b[:]
+	n := len(x)
+
+	var xn string
+	var ui uint16
+	var sep byte
+
+	for i := range x {
+		ui = uint16(i)
+		xn = x[i].encName // fieldName or encName? use encName for now.
+		if len(xn)+2 > cap(pv.b) {
+			sn = make([]byte, len(xn)+2)
+		} else {
+			sn = sn[:len(xn)+2]
+		}
+		// use a custom sep, so that misses are less frequent,
+		// since the sep (first char in search) is as unique as first char in field name.
+		sep = tiSep(xn)
+		sn[0], sn[len(sn)-1] = sep, 0xff
+		copy(sn[1:], xn)
+		j := bytes.Index(sa, sn)
+		if j == -1 {
+			sa = append(sa, sep)
+			sa = append(sa, xn...)
+			sa = append(sa, 0xff, byte(ui>>8), byte(ui))
+		} else {
+			index := uint16(sa[j+len(sn)+1]) | uint16(sa[j+len(sn)])<<8
+			// one of them must be reset to nil,
+			// and the index updated appropriately to the other one
+			if x[i].nis == x[index].nis {
+			} else if x[i].nis < x[index].nis {
+				sa[j+len(sn)], sa[j+len(sn)+1] = byte(ui>>8), byte(ui)
+				if x[index].ready() {
+					x[index].flagClr(structFieldInfoFlagReady)
+					n--
+				}
+			} else {
+				if x[i].ready() {
+					x[i].flagClr(structFieldInfoFlagReady)
+					n--
+				}
+			}
+		}
+
+	}
+	var w []structFieldInfo
+	sharingArray := len(x) <= typeInfoLoadArraySfisLen // sharing array with typeInfoLoadArray
+	if sharingArray {
+		w = make([]structFieldInfo, n)
+	}
+
+	// remove all the nils (non-ready)
+	y = make([]*structFieldInfo, n)
+	n = 0
+	var sslen int
+	for i := range x {
+		if !x[i].ready() {
+			continue
+		}
+		if !anyOmitEmpty && x[i].omitEmpty() {
+			anyOmitEmpty = true
+		}
+		if sharingArray {
+			w[n] = x[i]
+			y[n] = &w[n]
+		} else {
+			y[n] = &x[i]
+		}
+		sslen = sslen + len(x[i].encName) + 4
+		n++
+	}
+	if n != len(y) {
+		panicv.errorf("failure reading struct %v - expecting %d of %d valid fields, got %d",
+			rt, len(y), len(x), n)
+	}
+
+	z = make([]*structFieldInfo, len(y))
+	copy(z, y)
+	sort.Sort(sfiSortedByEncName(z))
+
+	sharingArray = len(sa) <= typeInfoLoadArraySfiidxLen
+	if sharingArray {
+		ss = make([]byte, 0, sslen)
+	} else {
+		ss = sa[:0] // reuse the newly made sa array if necessary
+	}
+	for i := range z {
+		xn = z[i].encName
+		sep = tiSep(xn)
+		ui = uint16(i)
+		ss = append(ss, sep)
+		ss = append(ss, xn...)
+		ss = append(ss, 0xff, byte(ui>>8), byte(ui))
+	}
+	return
+}
+
+func implIntf(rt, iTyp reflect.Type) (base bool, indir bool) {
+	return rt.Implements(iTyp), reflect.PtrTo(rt).Implements(iTyp)
+}
+
+// isEmptyStruct is only called from isEmptyValue, and checks if a struct is empty:
+//    - does it implement IsZero() bool
+//    - is it comparable, and can i compare directly using ==
+//    - if checkStruct, then walk through the encodable fields
+//      and check if they are empty or not.
+func isEmptyStruct(v reflect.Value, tinfos *TypeInfos, deref, checkStruct bool) bool {
+	// v is a struct kind - no need to check again.
+	// We only check isZero on a struct kind, to reduce the amount of times
+	// that we lookup the rtid and typeInfo for each type as we walk the tree.
+
+	vt := v.Type()
+	rtid := rt2id(vt)
+	if tinfos == nil {
+		tinfos = defTypeInfos
+	}
+	ti := tinfos.get(rtid, vt)
+	if ti.rtid == timeTypId {
+		return rv2i(v).(time.Time).IsZero()
+	}
+	if ti.isFlag(typeInfoFlagIsZeroerPtr) && v.CanAddr() {
+		return rv2i(v.Addr()).(isZeroer).IsZero()
+	}
+	if ti.isFlag(typeInfoFlagIsZeroer) {
+		return rv2i(v).(isZeroer).IsZero()
+	}
+	if ti.isFlag(typeInfoFlagComparable) {
+		return rv2i(v) == rv2i(reflect.Zero(vt))
+	}
+	if !checkStruct {
+		return false
+	}
+	// We only care about what we can encode/decode,
+	// so that is what we use to check omitEmpty.
+	for _, si := range ti.sfiSrc {
+		sfv, valid := si.field(v, false)
+		if valid && !isEmptyValue(sfv, tinfos, deref, checkStruct) {
+			return false
+		}
+	}
+	return true
+}
+
+// func roundFloat(x float64) float64 {
+// 	t := math.Trunc(x)
+// 	if math.Abs(x-t) >= 0.5 {
+// 		return t + math.Copysign(1, x)
+// 	}
+// 	return t
+// }
+
+func panicToErr(h errstrDecorator, err *error) {
+	// Note: This method MUST be called directly from defer i.e. defer panicToErr ...
+	// else it seems the recover is not fully handled
+	if recoverPanicToErr {
+		if x := recover(); x != nil {
+			// fmt.Printf("panic'ing with: %v\n", x)
+			// debug.PrintStack()
+			panicValToErr(h, x, err)
+		}
+	}
+}
+
+func panicValToErr(h errstrDecorator, v interface{}, err *error) {
+	switch xerr := v.(type) {
+	case nil:
+	case error:
+		switch xerr {
+		case nil:
+		case io.EOF, io.ErrUnexpectedEOF, errEncoderNotInitialized, errDecoderNotInitialized:
+			// treat as special (bubble up)
+			*err = xerr
+		default:
+			h.wrapErrstr(xerr.Error(), err)
+		}
+	case string:
+		if xerr != "" {
+			h.wrapErrstr(xerr, err)
+		}
+	case fmt.Stringer:
+		if xerr != nil {
+			h.wrapErrstr(xerr.String(), err)
+		}
+	default:
+		h.wrapErrstr(v, err)
+	}
+}
+
+func isImmutableKind(k reflect.Kind) (v bool) {
+	return immutableKindsSet[k]
+}
+
+// ----
+
+type codecFnInfo struct {
+	ti    *typeInfo
+	xfFn  Ext
+	xfTag uint64
+	seq   seqType
+	addrD bool
+	addrF bool // if addrD, this says whether decode function can take a value or a ptr
+	addrE bool
+	ready bool // ready to use
+}
+
+// codecFn encapsulates the captured variables and the encode function.
+// This way, we only do some calculations one times, and pass to the
+// code block that should be called (encapsulated in a function)
+// instead of executing the checks every time.
+type codecFn struct {
+	i  codecFnInfo
+	fe func(*Encoder, *codecFnInfo, reflect.Value)
+	fd func(*Decoder, *codecFnInfo, reflect.Value)
+	_  [1]uint64 // padding
+}
+
+type codecRtidFn struct {
+	rtid uintptr
+	fn   *codecFn
+}
+
+type codecFner struct {
+	// hh Handle
+	h  *BasicHandle
+	s  []codecRtidFn
+	be bool
+	js bool
+	_  [6]byte   // padding
+	_  [3]uint64 // padding
+}
+
+func (c *codecFner) reset(hh Handle) {
+	bh := hh.getBasicHandle()
+	// only reset iff extensions changed or *TypeInfos changed
+	var hhSame = true &&
+		c.h == bh && c.h.TypeInfos == bh.TypeInfos &&
+		len(c.h.extHandle) == len(bh.extHandle) &&
+		(len(c.h.extHandle) == 0 || &c.h.extHandle[0] == &bh.extHandle[0])
+	if !hhSame {
+		// c.hh = hh
+		c.h, bh = bh, c.h // swap both
+		_, c.js = hh.(*JsonHandle)
+		c.be = hh.isBinary()
+		for i := range c.s {
+			c.s[i].fn.i.ready = false
+		}
+	}
+}
+
+func (c *codecFner) get(rt reflect.Type, checkFastpath, checkCodecSelfer bool) (fn *codecFn) {
+	rtid := rt2id(rt)
+
+	for _, x := range c.s {
+		if x.rtid == rtid {
+			// if rtid exists, then there's a *codenFn attached (non-nil)
+			fn = x.fn
+			if fn.i.ready {
+				return
+			}
+			break
+		}
+	}
+	var ti *typeInfo
+	if fn == nil {
+		fn = new(codecFn)
+		if c.s == nil {
+			c.s = make([]codecRtidFn, 0, 8)
+		}
+		c.s = append(c.s, codecRtidFn{rtid, fn})
+	} else {
+		ti = fn.i.ti
+		*fn = codecFn{}
+		fn.i.ti = ti
+		// fn.fe, fn.fd = nil, nil
+	}
+	fi := &(fn.i)
+	fi.ready = true
+	if ti == nil {
+		ti = c.h.getTypeInfo(rtid, rt)
+		fi.ti = ti
+	}
+
+	rk := reflect.Kind(ti.kind)
+
+	if checkCodecSelfer && (ti.cs || ti.csp) {
+		fn.fe = (*Encoder).selferMarshal
+		fn.fd = (*Decoder).selferUnmarshal
+		fi.addrF = true
+		fi.addrD = ti.csp
+		fi.addrE = ti.csp
+	} else if rtid == timeTypId {
+		fn.fe = (*Encoder).kTime
+		fn.fd = (*Decoder).kTime
+	} else if rtid == rawTypId {
+		fn.fe = (*Encoder).raw
+		fn.fd = (*Decoder).raw
+	} else if rtid == rawExtTypId {
+		fn.fe = (*Encoder).rawExt
+		fn.fd = (*Decoder).rawExt
+		fi.addrF = true
+		fi.addrD = true
+		fi.addrE = true
+	} else if xfFn := c.h.getExt(rtid); xfFn != nil {
+		fi.xfTag, fi.xfFn = xfFn.tag, xfFn.ext
+		fn.fe = (*Encoder).ext
+		fn.fd = (*Decoder).ext
+		fi.addrF = true
+		fi.addrD = true
+		if rk == reflect.Struct || rk == reflect.Array {
+			fi.addrE = true
+		}
+	} else if supportMarshalInterfaces && c.be && (ti.bm || ti.bmp) && (ti.bu || ti.bup) {
+		fn.fe = (*Encoder).binaryMarshal
+		fn.fd = (*Decoder).binaryUnmarshal
+		fi.addrF = true
+		fi.addrD = ti.bup
+		fi.addrE = ti.bmp
+	} else if supportMarshalInterfaces && !c.be && c.js && (ti.jm || ti.jmp) && (ti.ju || ti.jup) {
+		//If JSON, we should check JSONMarshal before textMarshal
+		fn.fe = (*Encoder).jsonMarshal
+		fn.fd = (*Decoder).jsonUnmarshal
+		fi.addrF = true
+		fi.addrD = ti.jup
+		fi.addrE = ti.jmp
+	} else if supportMarshalInterfaces && !c.be && (ti.tm || ti.tmp) && (ti.tu || ti.tup) {
+		fn.fe = (*Encoder).textMarshal
+		fn.fd = (*Decoder).textUnmarshal
+		fi.addrF = true
+		fi.addrD = ti.tup
+		fi.addrE = ti.tmp
+	} else {
+		if fastpathEnabled && checkFastpath && (rk == reflect.Map || rk == reflect.Slice) {
+			if ti.pkgpath == "" { // un-named slice or map
+				if idx := fastpathAV.index(rtid); idx != -1 {
+					fn.fe = fastpathAV[idx].encfn
+					fn.fd = fastpathAV[idx].decfn
+					fi.addrD = true
+					fi.addrF = false
+				}
+			} else {
+				// use mapping for underlying type if there
+				var rtu reflect.Type
+				if rk == reflect.Map {
+					rtu = reflect.MapOf(ti.key, ti.elem)
+				} else {
+					rtu = reflect.SliceOf(ti.elem)
+				}
+				rtuid := rt2id(rtu)
+				if idx := fastpathAV.index(rtuid); idx != -1 {
+					xfnf := fastpathAV[idx].encfn
+					xrt := fastpathAV[idx].rt
+					fn.fe = func(e *Encoder, xf *codecFnInfo, xrv reflect.Value) {
+						xfnf(e, xf, xrv.Convert(xrt))
+					}
+					fi.addrD = true
+					fi.addrF = false // meaning it can be an address(ptr) or a value
+					xfnf2 := fastpathAV[idx].decfn
+					fn.fd = func(d *Decoder, xf *codecFnInfo, xrv reflect.Value) {
+						if xrv.Kind() == reflect.Ptr {
+							xfnf2(d, xf, xrv.Convert(reflect.PtrTo(xrt)))
+						} else {
+							xfnf2(d, xf, xrv.Convert(xrt))
+						}
+					}
+				}
+			}
+		}
+		if fn.fe == nil && fn.fd == nil {
+			switch rk {
+			case reflect.Bool:
+				fn.fe = (*Encoder).kBool
+				fn.fd = (*Decoder).kBool
+			case reflect.String:
+				fn.fe = (*Encoder).kString
+				fn.fd = (*Decoder).kString
+			case reflect.Int:
+				fn.fd = (*Decoder).kInt
+				fn.fe = (*Encoder).kInt
+			case reflect.Int8:
+				fn.fe = (*Encoder).kInt8
+				fn.fd = (*Decoder).kInt8
+			case reflect.Int16:
+				fn.fe = (*Encoder).kInt16
+				fn.fd = (*Decoder).kInt16
+			case reflect.Int32:
+				fn.fe = (*Encoder).kInt32
+				fn.fd = (*Decoder).kInt32
+			case reflect.Int64:
+				fn.fe = (*Encoder).kInt64
+				fn.fd = (*Decoder).kInt64
+			case reflect.Uint:
+				fn.fd = (*Decoder).kUint
+				fn.fe = (*Encoder).kUint
+			case reflect.Uint8:
+				fn.fe = (*Encoder).kUint8
+				fn.fd = (*Decoder).kUint8
+			case reflect.Uint16:
+				fn.fe = (*Encoder).kUint16
+				fn.fd = (*Decoder).kUint16
+			case reflect.Uint32:
+				fn.fe = (*Encoder).kUint32
+				fn.fd = (*Decoder).kUint32
+			case reflect.Uint64:
+				fn.fe = (*Encoder).kUint64
+				fn.fd = (*Decoder).kUint64
+			case reflect.Uintptr:
+				fn.fe = (*Encoder).kUintptr
+				fn.fd = (*Decoder).kUintptr
+			case reflect.Float32:
+				fn.fe = (*Encoder).kFloat32
+				fn.fd = (*Decoder).kFloat32
+			case reflect.Float64:
+				fn.fe = (*Encoder).kFloat64
+				fn.fd = (*Decoder).kFloat64
+			case reflect.Invalid:
+				fn.fe = (*Encoder).kInvalid
+				fn.fd = (*Decoder).kErr
+			case reflect.Chan:
+				fi.seq = seqTypeChan
+				fn.fe = (*Encoder).kSlice
+				fn.fd = (*Decoder).kSlice
+			case reflect.Slice:
+				fi.seq = seqTypeSlice
+				fn.fe = (*Encoder).kSlice
+				fn.fd = (*Decoder).kSlice
+			case reflect.Array:
+				fi.seq = seqTypeArray
+				fn.fe = (*Encoder).kSlice
+				fi.addrF = false
+				fi.addrD = false
+				rt2 := reflect.SliceOf(ti.elem)
+				fn.fd = func(d *Decoder, xf *codecFnInfo, xrv reflect.Value) {
+					d.cfer().get(rt2, true, false).fd(d, xf, xrv.Slice(0, xrv.Len()))
+				}
+				// fn.fd = (*Decoder).kArray
+			case reflect.Struct:
+				if ti.anyOmitEmpty {
+					fn.fe = (*Encoder).kStruct
+				} else {
+					fn.fe = (*Encoder).kStructNoOmitempty
+				}
+				fn.fd = (*Decoder).kStruct
+			case reflect.Map:
+				fn.fe = (*Encoder).kMap
+				fn.fd = (*Decoder).kMap
+			case reflect.Interface:
+				// encode: reflect.Interface are handled already by preEncodeValue
+				fn.fd = (*Decoder).kInterface
+				fn.fe = (*Encoder).kErr
+			default:
+				// reflect.Ptr and reflect.Interface are handled already by preEncodeValue
+				fn.fe = (*Encoder).kErr
+				fn.fd = (*Decoder).kErr
+			}
+		}
+	}
+	return
+}
+
+type codecFnPooler struct {
+	cf  *codecFner
+	cfp *sync.Pool
+	hh  Handle
+}
+
+func (d *codecFnPooler) cfer() *codecFner {
+	if d.cf == nil {
+		var v interface{}
+		d.cfp, v = pool.codecFner()
+		d.cf = v.(*codecFner)
+		d.cf.reset(d.hh)
+	}
+	return d.cf
+}
+
+func (d *codecFnPooler) alwaysAtEnd() {
+	if d.cf != nil {
+		d.cfp.Put(d.cf)
+		d.cf, d.cfp = nil, nil
+	}
+}
+
+// ----
+
+// these "checkOverflow" functions must be inlinable, and not call anybody.
+// Overflow means that the value cannot be represented without wrapping/overflow.
+// Overflow=false does not mean that the value can be represented without losing precision
+// (especially for floating point).
+
+type checkOverflow struct{}
+
+// func (checkOverflow) Float16(f float64) (overflow bool) {
+// 	panicv.errorf("unimplemented")
+// 	if f < 0 {
+// 		f = -f
+// 	}
+// 	return math.MaxFloat32 < f && f <= math.MaxFloat64
+// }
+
+func (checkOverflow) Float32(v float64) (overflow bool) {
+	if v < 0 {
+		v = -v
+	}
+	return math.MaxFloat32 < v && v <= math.MaxFloat64
+}
+func (checkOverflow) Uint(v uint64, bitsize uint8) (overflow bool) {
+	if bitsize == 0 || bitsize >= 64 || v == 0 {
+		return
+	}
+	if trunc := (v << (64 - bitsize)) >> (64 - bitsize); v != trunc {
+		overflow = true
+	}
+	return
+}
+func (checkOverflow) Int(v int64, bitsize uint8) (overflow bool) {
+	if bitsize == 0 || bitsize >= 64 || v == 0 {
+		return
+	}
+	if trunc := (v << (64 - bitsize)) >> (64 - bitsize); v != trunc {
+		overflow = true
+	}
+	return
+}
+func (checkOverflow) SignedInt(v uint64) (overflow bool) {
+	//e.g. -127 to 128 for int8
+	pos := (v >> 63) == 0
+	ui2 := v & 0x7fffffffffffffff
+	if pos {
+		if ui2 > math.MaxInt64 {
+			overflow = true
+		}
+	} else {
+		if ui2 > math.MaxInt64-1 {
+			overflow = true
+		}
+	}
+	return
+}
+
+func (x checkOverflow) Float32V(v float64) float64 {
+	if x.Float32(v) {
+		panicv.errorf("float32 overflow: %v", v)
+	}
+	return v
+}
+func (x checkOverflow) UintV(v uint64, bitsize uint8) uint64 {
+	if x.Uint(v, bitsize) {
+		panicv.errorf("uint64 overflow: %v", v)
+	}
+	return v
+}
+func (x checkOverflow) IntV(v int64, bitsize uint8) int64 {
+	if x.Int(v, bitsize) {
+		panicv.errorf("int64 overflow: %v", v)
+	}
+	return v
+}
+func (x checkOverflow) SignedIntV(v uint64) int64 {
+	if x.SignedInt(v) {
+		panicv.errorf("uint64 to int64 overflow: %v", v)
+	}
+	return int64(v)
+}
+
+// ------------------ SORT -----------------
+
+func isNaN(f float64) bool { return f != f }
+
+// -----------------------
+
+type ioFlusher interface {
+	Flush() error
+}
+
+type ioPeeker interface {
+	Peek(int) ([]byte, error)
+}
+
+type ioBuffered interface {
+	Buffered() int
+}
+
+// -----------------------
+
+type intSlice []int64
+type uintSlice []uint64
+
+// type uintptrSlice []uintptr
+type floatSlice []float64
+type boolSlice []bool
+type stringSlice []string
+
+// type bytesSlice [][]byte
+
+func (p intSlice) Len() int           { return len(p) }
+func (p intSlice) Less(i, j int) bool { return p[i] < p[j] }
+func (p intSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p uintSlice) Len() int           { return len(p) }
+func (p uintSlice) Less(i, j int) bool { return p[i] < p[j] }
+func (p uintSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// func (p uintptrSlice) Len() int           { return len(p) }
+// func (p uintptrSlice) Less(i, j int) bool { return p[i] < p[j] }
+// func (p uintptrSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p floatSlice) Len() int { return len(p) }
+func (p floatSlice) Less(i, j int) bool {
+	return p[i] < p[j] || isNaN(p[i]) && !isNaN(p[j])
+}
+func (p floatSlice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
+
+func (p stringSlice) Len() int           { return len(p) }
+func (p stringSlice) Less(i, j int) bool { return p[i] < p[j] }
+func (p stringSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// func (p bytesSlice) Len() int           { return len(p) }
+// func (p bytesSlice) Less(i, j int) bool { return bytes.Compare(p[i], p[j]) == -1 }
+// func (p bytesSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p boolSlice) Len() int           { return len(p) }
+func (p boolSlice) Less(i, j int) bool { return !p[i] && p[j] }
+func (p boolSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// ---------------------
+
+type intRv struct {
+	v int64
+	r reflect.Value
+}
+type intRvSlice []intRv
+type uintRv struct {
+	v uint64
+	r reflect.Value
+}
+type uintRvSlice []uintRv
+type floatRv struct {
+	v float64
+	r reflect.Value
+}
+type floatRvSlice []floatRv
+type boolRv struct {
+	v bool
+	r reflect.Value
+}
+type boolRvSlice []boolRv
+type stringRv struct {
+	v string
+	r reflect.Value
+}
+type stringRvSlice []stringRv
+type bytesRv struct {
+	v []byte
+	r reflect.Value
+}
+type bytesRvSlice []bytesRv
+type timeRv struct {
+	v time.Time
+	r reflect.Value
+}
+type timeRvSlice []timeRv
+
+func (p intRvSlice) Len() int           { return len(p) }
+func (p intRvSlice) Less(i, j int) bool { return p[i].v < p[j].v }
+func (p intRvSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p uintRvSlice) Len() int           { return len(p) }
+func (p uintRvSlice) Less(i, j int) bool { return p[i].v < p[j].v }
+func (p uintRvSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p floatRvSlice) Len() int { return len(p) }
+func (p floatRvSlice) Less(i, j int) bool {
+	return p[i].v < p[j].v || isNaN(p[i].v) && !isNaN(p[j].v)
+}
+func (p floatRvSlice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
+
+func (p stringRvSlice) Len() int           { return len(p) }
+func (p stringRvSlice) Less(i, j int) bool { return p[i].v < p[j].v }
+func (p stringRvSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p bytesRvSlice) Len() int           { return len(p) }
+func (p bytesRvSlice) Less(i, j int) bool { return bytes.Compare(p[i].v, p[j].v) == -1 }
+func (p bytesRvSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p boolRvSlice) Len() int           { return len(p) }
+func (p boolRvSlice) Less(i, j int) bool { return !p[i].v && p[j].v }
+func (p boolRvSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+func (p timeRvSlice) Len() int           { return len(p) }
+func (p timeRvSlice) Less(i, j int) bool { return p[i].v.Before(p[j].v) }
+func (p timeRvSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// -----------------
+
+type bytesI struct {
+	v []byte
+	i interface{}
+}
+
+type bytesISlice []bytesI
+
+func (p bytesISlice) Len() int           { return len(p) }
+func (p bytesISlice) Less(i, j int) bool { return bytes.Compare(p[i].v, p[j].v) == -1 }
+func (p bytesISlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// -----------------
+
+type set []uintptr
+
+func (s *set) add(v uintptr) (exists bool) {
+	// e.ci is always nil, or len >= 1
+	x := *s
+	if x == nil {
+		x = make([]uintptr, 1, 8)
+		x[0] = v
+		*s = x
+		return
+	}
+	// typically, length will be 1. make this perform.
+	if len(x) == 1 {
+		if j := x[0]; j == 0 {
+			x[0] = v
+		} else if j == v {
+			exists = true
+		} else {
+			x = append(x, v)
+			*s = x
+		}
+		return
+	}
+	// check if it exists
+	for _, j := range x {
+		if j == v {
+			exists = true
+			return
+		}
+	}
+	// try to replace a "deleted" slot
+	for i, j := range x {
+		if j == 0 {
+			x[i] = v
+			return
+		}
+	}
+	// if unable to replace deleted slot, just append it.
+	x = append(x, v)
+	*s = x
+	return
+}
+
+func (s *set) remove(v uintptr) (exists bool) {
+	x := *s
+	if len(x) == 0 {
+		return
+	}
+	if len(x) == 1 {
+		if x[0] == v {
+			x[0] = 0
+		}
+		return
+	}
+	for i, j := range x {
+		if j == v {
+			exists = true
+			x[i] = 0 // set it to 0, as way to delete it.
+			// copy(x[i:], x[i+1:])
+			// x = x[:len(x)-1]
+			return
+		}
+	}
+	return
+}
+
+// ------
+
+// bitset types are better than [256]bool, because they permit the whole
+// bitset array being on a single cache line and use less memory.
+
+// given x > 0 and n > 0 and x is exactly 2^n, then pos/x === pos>>n AND pos%x === pos&(x-1).
+// consequently, pos/32 === pos>>5, pos/16 === pos>>4, pos/8 === pos>>3, pos%8 == pos&7
+
+type bitset256 [32]byte
+
+func (x *bitset256) isset(pos byte) bool {
+	return x[pos>>3]&(1<<(pos&7)) != 0
+}
+func (x *bitset256) issetv(pos byte) byte {
+	return x[pos>>3] & (1 << (pos & 7))
+}
+func (x *bitset256) set(pos byte) {
+	x[pos>>3] |= (1 << (pos & 7))
+}
+
+// func (x *bitset256) unset(pos byte) {
+// 	x[pos>>3] &^= (1 << (pos & 7))
+// }
+
+type bitset128 [16]byte
+
+func (x *bitset128) isset(pos byte) bool {
+	return x[pos>>3]&(1<<(pos&7)) != 0
+}
+func (x *bitset128) set(pos byte) {
+	x[pos>>3] |= (1 << (pos & 7))
+}
+
+// func (x *bitset128) unset(pos byte) {
+// 	x[pos>>3] &^= (1 << (pos & 7))
+// }
+
+type bitset32 [4]byte
+
+func (x *bitset32) isset(pos byte) bool {
+	return x[pos>>3]&(1<<(pos&7)) != 0
+}
+func (x *bitset32) set(pos byte) {
+	x[pos>>3] |= (1 << (pos & 7))
+}
+
+// func (x *bitset32) unset(pos byte) {
+// 	x[pos>>3] &^= (1 << (pos & 7))
+// }
+
+// type bit2set256 [64]byte
+
+// func (x *bit2set256) set(pos byte, v1, v2 bool) {
+// 	var pos2 uint8 = (pos & 3) << 1 // returning 0, 2, 4 or 6
+// 	if v1 {
+// 		x[pos>>2] |= 1 << (pos2 + 1)
+// 	}
+// 	if v2 {
+// 		x[pos>>2] |= 1 << pos2
+// 	}
+// }
+// func (x *bit2set256) get(pos byte) uint8 {
+// 	var pos2 uint8 = (pos & 3) << 1     // returning 0, 2, 4 or 6
+// 	return x[pos>>2] << (6 - pos2) >> 6 // 11000000 -> 00000011
+// }
+
+// ------------
+
+type pooler struct {
+	dn                                          sync.Pool // for decNaked
+	cfn                                         sync.Pool // for codecFner
+	tiload                                      sync.Pool
+	strRv8, strRv16, strRv32, strRv64, strRv128 sync.Pool // for stringRV
+}
+
+func (p *pooler) init() {
+	p.strRv8.New = func() interface{} { return new([8]stringRv) }
+	p.strRv16.New = func() interface{} { return new([16]stringRv) }
+	p.strRv32.New = func() interface{} { return new([32]stringRv) }
+	p.strRv64.New = func() interface{} { return new([64]stringRv) }
+	p.strRv128.New = func() interface{} { return new([128]stringRv) }
+	p.dn.New = func() interface{} { x := new(decNaked); x.init(); return x }
+	p.tiload.New = func() interface{} { return new(typeInfoLoadArray) }
+	p.cfn.New = func() interface{} { return new(codecFner) }
+}
+
+func (p *pooler) stringRv8() (sp *sync.Pool, v interface{}) {
+	return &p.strRv8, p.strRv8.Get()
+}
+func (p *pooler) stringRv16() (sp *sync.Pool, v interface{}) {
+	return &p.strRv16, p.strRv16.Get()
+}
+func (p *pooler) stringRv32() (sp *sync.Pool, v interface{}) {
+	return &p.strRv32, p.strRv32.Get()
+}
+func (p *pooler) stringRv64() (sp *sync.Pool, v interface{}) {
+	return &p.strRv64, p.strRv64.Get()
+}
+func (p *pooler) stringRv128() (sp *sync.Pool, v interface{}) {
+	return &p.strRv128, p.strRv128.Get()
+}
+func (p *pooler) decNaked() (sp *sync.Pool, v interface{}) {
+	return &p.dn, p.dn.Get()
+}
+func (p *pooler) codecFner() (sp *sync.Pool, v interface{}) {
+	return &p.cfn, p.cfn.Get()
+}
+func (p *pooler) tiLoad() (sp *sync.Pool, v interface{}) {
+	return &p.tiload, p.tiload.Get()
+}
+
+// func (p *pooler) decNaked() (v *decNaked, f func(*decNaked) ) {
+// 	sp := &(p.dn)
+// 	vv := sp.Get()
+// 	return vv.(*decNaked), func(x *decNaked) { sp.Put(vv) }
+// }
+// func (p *pooler) decNakedGet() (v interface{}) {
+// 	return p.dn.Get()
+// }
+// func (p *pooler) codecFnerGet() (v interface{}) {
+// 	return p.cfn.Get()
+// }
+// func (p *pooler) tiLoadGet() (v interface{}) {
+// 	return p.tiload.Get()
+// }
+// func (p *pooler) decNakedPut(v interface{}) {
+// 	p.dn.Put(v)
+// }
+// func (p *pooler) codecFnerPut(v interface{}) {
+// 	p.cfn.Put(v)
+// }
+// func (p *pooler) tiLoadPut(v interface{}) {
+// 	p.tiload.Put(v)
+// }
+
+type panicHdl struct{}
+
+func (panicHdl) errorv(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (panicHdl) errorstr(message string) {
+	if message != "" {
+		panic(message)
+	}
+}
+
+func (panicHdl) errorf(format string, params ...interface{}) {
+	if format != "" {
+		if len(params) == 0 {
+			panic(format)
+		} else {
+			panic(fmt.Sprintf(format, params...))
+		}
+	}
+}
+
+type errstrDecorator interface {
+	wrapErrstr(interface{}, *error)
+}
+
+type errstrDecoratorDef struct{}
+
+func (errstrDecoratorDef) wrapErrstr(v interface{}, e *error) { *e = fmt.Errorf("%v", v) }
+
+type must struct{}
+
+func (must) String(s string, err error) string {
+	if err != nil {
+		panicv.errorv(err)
+	}
+	return s
+}
+func (must) Int(s int64, err error) int64 {
+	if err != nil {
+		panicv.errorv(err)
+	}
+	return s
+}
+func (must) Uint(s uint64, err error) uint64 {
+	if err != nil {
+		panicv.errorv(err)
+	}
+	return s
+}
+func (must) Float(s float64, err error) float64 {
+	if err != nil {
+		panicv.errorv(err)
+	}
+	return s
+}
+
+// xdebugf prints the message in red on the terminal.
+// Use it in place of fmt.Printf (which it calls internally)
+func xdebugf(pattern string, args ...interface{}) {
+	var delim string
+	if len(pattern) > 0 && pattern[len(pattern)-1] != '\n' {
+		delim = "\n"
+	}
+	fmt.Printf("\033[1;31m"+pattern+delim+"\033[0m", args...)
+}
+
+// func isImmutableKind(k reflect.Kind) (v bool) {
+// 	return false ||
+// 		k == reflect.Int ||
+// 		k == reflect.Int8 ||
+// 		k == reflect.Int16 ||
+// 		k == reflect.Int32 ||
+// 		k == reflect.Int64 ||
+// 		k == reflect.Uint ||
+// 		k == reflect.Uint8 ||
+// 		k == reflect.Uint16 ||
+// 		k == reflect.Uint32 ||
+// 		k == reflect.Uint64 ||
+// 		k == reflect.Uintptr ||
+// 		k == reflect.Float32 ||
+// 		k == reflect.Float64 ||
+// 		k == reflect.Bool ||
+// 		k == reflect.String
+// }
+
+// func timeLocUTCName(tzint int16) string {
+// 	if tzint == 0 {
+// 		return "UTC"
+// 	}
+// 	var tzname = []byte("UTC+00:00")
+// 	//tzname := fmt.Sprintf("UTC%s%02d:%02d", tzsign, tz/60, tz%60) //perf issue using Sprintf. inline below.
+// 	//tzhr, tzmin := tz/60, tz%60 //faster if u convert to int first
+// 	var tzhr, tzmin int16
+// 	if tzint < 0 {
+// 		tzname[3] = '-' // (TODO: verify. this works here)
+// 		tzhr, tzmin = -tzint/60, (-tzint)%60
+// 	} else {
+// 		tzhr, tzmin = tzint/60, tzint%60
+// 	}
+// 	tzname[4] = timeDigits[tzhr/10]
+// 	tzname[5] = timeDigits[tzhr%10]
+// 	tzname[7] = timeDigits[tzmin/10]
+// 	tzname[8] = timeDigits[tzmin%10]
+// 	return string(tzname)
+// 	//return time.FixedZone(string(tzname), int(tzint)*60)
+// }