minio/vendor/github.com/ugorji/go/codec/helper.go

1315 lines
37 KiB
Go

// Copyright (c) 2012-2015 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.
package codec
// 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"
"math"
"reflect"
"sort"
"strings"
"sync"
"time"
)
const (
scratchByteArrayLen = 32
initCollectionCap = 32 // 32 is defensive. 16 is preferred.
// Support encoding.(Binary|Text)(Unm|M)arshaler.
// This constant flag will enable or disable it.
supportMarshalInterfaces = true
// Each Encoder or Decoder uses a cache of functions based on conditionals,
// so that the conditionals are not run every time.
//
// Either a map or a slice is used to keep track of the functions.
// The map is more natural, but has a higher cost than a slice/array.
// This flag (useMapForCodecCache) controls which is used.
//
// From benchmarks, slices with linear search perform better with < 32 entries.
// We have typically seen a high threshold of about 24 entries.
useMapForCodecCache = false
// 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
// if resetSliceElemToZeroValue, then on decoding a slice, reset the element to a zero value first.
// Only concern is that, if the slice already contained some garbage, we will decode into that garbage.
// The chances of this are slim, so leave this "optimization".
// TODO: should this be true, to ensure that we always decode into a "zero" "empty" value?
resetSliceElemToZeroValue bool = false
)
var (
oneByteArr = [1]byte{0}
zeroByteSlice = oneByteArr[:0:0]
)
type charEncoding uint8
const (
c_RAW charEncoding = iota
c_UTF8
c_UTF16LE
c_UTF16BE
c_UTF32LE
c_UTF32BE
)
// valueType is the stream type
type valueType uint8
const (
valueTypeUnset valueType = iota
valueTypeNil
valueTypeInt
valueTypeUint
valueTypeFloat
valueTypeBool
valueTypeString
valueTypeSymbol
valueTypeBytes
valueTypeMap
valueTypeArray
valueTypeTimestamp
valueTypeExt
// valueTypeInvalid = 0xff
)
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.
// Java's PMD rules set TooManyFields threshold to 15.
const rgetPoolTArrayLen = 12
type rgetT struct {
fNames []string
encNames []string
etypes []uintptr
sfis []*structFieldInfo
}
type rgetPoolT struct {
fNames [rgetPoolTArrayLen]string
encNames [rgetPoolTArrayLen]string
etypes [rgetPoolTArrayLen]uintptr
sfis [rgetPoolTArrayLen]*structFieldInfo
sfiidx [rgetPoolTArrayLen]sfiIdx
}
var rgetPool = sync.Pool{
New: func() interface{} { return new(rgetPoolT) },
}
type containerStateRecv interface {
sendContainerState(containerState)
}
// 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
}
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()
stringTyp = reflect.TypeOf("")
timeTyp = reflect.TypeOf(time.Time{})
rawExtTyp = reflect.TypeOf(RawExt{})
rawTyp = reflect.TypeOf(Raw{})
uint8SliceTyp = reflect.TypeOf([]uint8(nil))
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()
uint8SliceTypId = reflect.ValueOf(uint8SliceTyp).Pointer()
rawExtTypId = reflect.ValueOf(rawExtTyp).Pointer()
rawTypId = reflect.ValueOf(rawTyp).Pointer()
intfTypId = reflect.ValueOf(intfTyp).Pointer()
timeTypId = reflect.ValueOf(timeTyp).Pointer()
stringTypId = reflect.ValueOf(stringTyp).Pointer()
mapStrIntfTypId = reflect.ValueOf(mapStrIntfTyp).Pointer()
mapIntfIntfTypId = reflect.ValueOf(mapIntfIntfTyp).Pointer()
intfSliceTypId = reflect.ValueOf(intfSliceTyp).Pointer()
// mapBySliceTypId = reflect.ValueOf(mapBySliceTyp).Pointer()
intBitsize uint8 = uint8(reflect.TypeOf(int(0)).Bits())
uintBitsize uint8 = uint8(reflect.TypeOf(uint(0)).Bits())
bsAll0x00 = []byte{0, 0, 0, 0, 0, 0, 0, 0}
bsAll0xff = []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
chkOvf checkOverflow
noFieldNameToStructFieldInfoErr = errors.New("no field name passed to parseStructFieldInfo")
)
var defTypeInfos = NewTypeInfos([]string{"codec", "json"})
// 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.
type Selfer interface {
CodecEncodeSelf(*Encoder)
CodecDecodeSelf(*Decoder)
}
// MapBySlice represents a slice which should be encoded 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.
//
// 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
type MapBySlice interface {
MapBySlice()
}
// WARNING: DO NOT USE DIRECTLY. EXPORTED FOR GODOC BENEFIT. WILL BE REMOVED.
//
// BasicHandle encapsulates the common options and extension functions.
type BasicHandle struct {
// 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
extHandle
EncodeOptions
DecodeOptions
}
func (x *BasicHandle) getBasicHandle() *BasicHandle {
return x
}
func (x *BasicHandle) getTypeInfo(rtid uintptr, rt reflect.Type) (pti *typeInfo) {
if x.TypeInfos != nil {
return x.TypeInfos.get(rtid, rt)
}
return defTypeInfos.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 {
getBasicHandle() *BasicHandle
newEncDriver(w *Encoder) encDriver
newDecDriver(r *Decoder) decDriver
isBinary() bool
}
// Raw represents raw formatted bytes.
// We "blindly" store it during encode and store 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 Data is nil, ext is exposed in Value.
// Data is used by codecs (e.g. binc, msgpack, simple) which do custom serialization of the types
Data []byte
// Value represents the extension, if Data is nil.
// Value is used by codecs (e.g. cbor, json) which use 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 *may* be a pointer to the extension type, if the extension type was a struct or array.
WriteExt(v interface{}) []byte
// ReadExt updates a value from a []byte.
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 the types.
type InterfaceExt interface {
// ConvertExt converts a value into a simpler interface for easy encoding e.g. convert time.Time to int64.
//
// Note: v *may* be a pointer to the extension type, if the extension type was a struct or array.
ConvertExt(v interface{}) interface{}
// UpdateExt updates a value from a simpler interface for easy decoding e.g. convert int64 to time.Time.
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 setExtWrapper struct {
b BytesExt
i InterfaceExt
}
func (x *setExtWrapper) WriteExt(v interface{}) []byte {
if x.b == nil {
panic("BytesExt.WriteExt is not supported")
}
return x.b.WriteExt(v)
}
func (x *setExtWrapper) ReadExt(v interface{}, bs []byte) {
if x.b == nil {
panic("BytesExt.WriteExt is not supported")
}
x.b.ReadExt(v, bs)
}
func (x *setExtWrapper) ConvertExt(v interface{}) interface{} {
if x.i == nil {
panic("InterfaceExt.ConvertExt is not supported")
}
return x.i.ConvertExt(v)
}
func (x *setExtWrapper) UpdateExt(dest interface{}, v interface{}) {
if x.i == nil {
panic("InterfaceExxt.UpdateExt is not supported")
}
x.i.UpdateExt(dest, v)
}
// type errorString string
// func (x errorString) Error() string { return string(x) }
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 noBuiltInTypes struct{}
func (_ noBuiltInTypes) IsBuiltinType(rt uintptr) bool { return false }
func (_ noBuiltInTypes) EncodeBuiltin(rt uintptr, v interface{}) {}
func (_ noBuiltInTypes) DecodeBuiltin(rt uintptr, v interface{}) {}
type noStreamingCodec struct{}
func (_ noStreamingCodec) CheckBreak() bool { return false }
// 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
rt reflect.Type
tag uint64
ext Ext
}
type extHandle []extTypeTagFn
// DEPRECATED: Use SetBytesExt or SetInterfaceExt on the Handle instead.
//
// AddExt registes an encode and decode function for a reflect.Type.
// AddExt internally calls SetExt.
// To deregister an Ext, call AddExt with nil encfn and/or nil decfn.
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})
}
// DEPRECATED: Use SetBytesExt or SetInterfaceExt on the Handle instead.
//
// 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
func (o *extHandle) SetExt(rt reflect.Type, tag uint64, ext Ext) (err error) {
// o is a pointer, because we may need to initialize it
if rt.PkgPath() == "" || rt.Kind() == reflect.Interface {
err = fmt.Errorf("codec.Handle.AddExt: Takes named type, not a pointer or interface: %T",
reflect.Zero(rt).Interface())
return
}
rtid := reflect.ValueOf(rt).Pointer()
for _, v := range *o {
if v.rtid == rtid {
v.tag, v.ext = tag, ext
return
}
}
if *o == nil {
*o = make([]extTypeTagFn, 0, 4)
}
*o = append(*o, extTypeTagFn{rtid, rt, tag, ext})
return
}
func (o extHandle) getExt(rtid uintptr) *extTypeTagFn {
var v *extTypeTagFn
for i := range o {
v = &o[i]
if v.rtid == rtid {
return v
}
}
return nil
}
func (o extHandle) getExtForTag(tag uint64) *extTypeTagFn {
var v *extTypeTagFn
for i := range o {
v = &o[i]
if v.tag == tag {
return v
}
}
return nil
}
type structFieldInfo struct {
encName string // encode name
fieldName string // field name
// only one of 'i' or 'is' can be set. If 'i' is -1, then 'is' has been set.
is []int // (recursive/embedded) field index in struct
i int16 // field index in struct
omitEmpty bool
toArray bool // if field is _struct, is the toArray set?
}
// func (si *structFieldInfo) isZero() bool {
// return si.encName == "" && len(si.is) == 0 && si.i == 0 && !si.omitEmpty && !si.toArray
// }
// 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) {
if si.i != -1 {
v = v.Field(int(si.i))
return v
}
// replicate FieldByIndex
for _, x := range si.is {
for v.Kind() == reflect.Ptr {
if v.IsNil() {
if !update {
return
}
v.Set(reflect.New(v.Type().Elem()))
}
v = v.Elem()
}
v = v.Field(x)
}
return v
}
func (si *structFieldInfo) setToZeroValue(v reflect.Value) {
if si.i != -1 {
v = v.Field(int(si.i))
v.Set(reflect.Zero(v.Type()))
// v.Set(reflect.New(v.Type()).Elem())
// v.Set(reflect.New(v.Type()))
} else {
// replicate FieldByIndex
for _, x := range si.is {
for v.Kind() == reflect.Ptr {
if v.IsNil() {
return
}
v = v.Elem()
}
v = v.Field(x)
}
v.Set(reflect.Zero(v.Type()))
}
}
func parseStructFieldInfo(fname string, stag string) *structFieldInfo {
// if fname == "" {
// panic(noFieldNameToStructFieldInfoErr)
// }
si := structFieldInfo{
encName: fname,
}
if stag != "" {
for i, s := range strings.Split(stag, ",") {
if i == 0 {
if s != "" {
si.encName = s
}
} else {
if s == "omitempty" {
si.omitEmpty = true
} else if s == "toarray" {
si.toArray = true
}
}
}
}
// si.encNameBs = []byte(si.encName)
return &si
}
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]
}
// typeInfo keeps information about each 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 {
sfi []*structFieldInfo // sorted. Used when enc/dec struct to map.
sfip []*structFieldInfo // unsorted. Used when enc/dec struct to array.
rt reflect.Type
rtid uintptr
numMeth uint16 // number of methods
// baseId gives pointer to the base reflect.Type, after deferencing
// the pointers. E.g. base type of ***time.Time is time.Time.
base reflect.Type
baseId uintptr
baseIndir int8 // number of indirections to get to base
mbs bool // base type (T or *T) is a MapBySlice
bm bool // base type (T or *T) is a binaryMarshaler
bunm bool // base type (T or *T) is a binaryUnmarshaler
bmIndir int8 // number of indirections to get to binaryMarshaler type
bunmIndir int8 // number of indirections to get to binaryUnmarshaler type
tm bool // base type (T or *T) is a textMarshaler
tunm bool // base type (T or *T) is a textUnmarshaler
tmIndir int8 // number of indirections to get to textMarshaler type
tunmIndir int8 // number of indirections to get to textUnmarshaler type
jm bool // base type (T or *T) is a jsonMarshaler
junm bool // base type (T or *T) is a jsonUnmarshaler
jmIndir int8 // number of indirections to get to jsonMarshaler type
junmIndir int8 // number of indirections to get to jsonUnmarshaler type
cs bool // base type (T or *T) is a Selfer
csIndir int8 // number of indirections to get to Selfer type
toArray bool // whether this (struct) type should be encoded as an array
}
func (ti *typeInfo) indexForEncName(name string) int {
// NOTE: name may be a stringView, so don't pass it to another function.
//tisfi := ti.sfi
const binarySearchThreshold = 16
if sfilen := len(ti.sfi); sfilen < binarySearchThreshold {
// linear search. faster than binary search in my testing up to 16-field structs.
for i, si := range ti.sfi {
if si.encName == name {
return i
}
}
} else {
// binary search. adapted from sort/search.go.
h, i, j := 0, 0, sfilen
for i < j {
h = i + (j-i)/2
if ti.sfi[h].encName < name {
i = h + 1
} else {
j = h
}
}
if i < sfilen && ti.sfi[i].encName == name {
return i
}
}
return -1
}
// 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 map[uintptr]*typeInfo
mu sync.RWMutex
tags []string
}
// 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, infos: make(map[uintptr]*typeInfo, 64)}
}
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) get(rtid uintptr, rt reflect.Type) (pti *typeInfo) {
var ok bool
x.mu.RLock()
pti, ok = x.infos[rtid]
x.mu.RUnlock()
if ok {
return
}
// do not hold lock while computing this.
// it may lead to duplication, but that's ok.
ti := typeInfo{rt: rt, rtid: rtid}
ti.numMeth = uint16(rt.NumMethod())
var indir int8
if ok, indir = implementsIntf(rt, binaryMarshalerTyp); ok {
ti.bm, ti.bmIndir = true, indir
}
if ok, indir = implementsIntf(rt, binaryUnmarshalerTyp); ok {
ti.bunm, ti.bunmIndir = true, indir
}
if ok, indir = implementsIntf(rt, textMarshalerTyp); ok {
ti.tm, ti.tmIndir = true, indir
}
if ok, indir = implementsIntf(rt, textUnmarshalerTyp); ok {
ti.tunm, ti.tunmIndir = true, indir
}
if ok, indir = implementsIntf(rt, jsonMarshalerTyp); ok {
ti.jm, ti.jmIndir = true, indir
}
if ok, indir = implementsIntf(rt, jsonUnmarshalerTyp); ok {
ti.junm, ti.junmIndir = true, indir
}
if ok, indir = implementsIntf(rt, selferTyp); ok {
ti.cs, ti.csIndir = true, indir
}
if ok, _ = implementsIntf(rt, mapBySliceTyp); ok {
ti.mbs = true
}
pt := rt
var ptIndir int8
// for ; pt.Kind() == reflect.Ptr; pt, ptIndir = pt.Elem(), ptIndir+1 { }
for pt.Kind() == reflect.Ptr {
pt = pt.Elem()
ptIndir++
}
if ptIndir == 0 {
ti.base = rt
ti.baseId = rtid
} else {
ti.base = pt
ti.baseId = reflect.ValueOf(pt).Pointer()
ti.baseIndir = ptIndir
}
if rt.Kind() == reflect.Struct {
var omitEmpty bool
if f, ok := rt.FieldByName(structInfoFieldName); ok {
siInfo := parseStructFieldInfo(structInfoFieldName, x.structTag(f.Tag))
ti.toArray = siInfo.toArray
omitEmpty = siInfo.omitEmpty
}
pi := rgetPool.Get()
pv := pi.(*rgetPoolT)
pv.etypes[0] = ti.baseId
vv := rgetT{pv.fNames[:0], pv.encNames[:0], pv.etypes[:1], pv.sfis[:0]}
x.rget(rt, rtid, omitEmpty, nil, &vv)
ti.sfip, ti.sfi = rgetResolveSFI(vv.sfis, pv.sfiidx[:0])
rgetPool.Put(pi)
}
// sfi = sfip
x.mu.Lock()
if pti, ok = x.infos[rtid]; !ok {
pti = &ti
x.infos[rtid] = pti
}
x.mu.Unlock()
return
}
func (x *TypeInfos) rget(rt reflect.Type, rtid uintptr, omitEmpty bool,
indexstack []int, pv *rgetT,
) {
// 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
LOOP:
for j, jlen := 0, rt.NumField(); j < jlen; j++ {
f := rt.Field(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
}
// if r1, _ := utf8.DecodeRuneInString(f.Name);
// r1 == utf8.RuneError || !unicode.IsUpper(r1) {
if f.PkgPath != "" && !f.Anonymous { // unexported, not embedded
continue
}
stag := x.structTag(f.Tag)
if stag == "-" {
continue
}
var si *structFieldInfo
// 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 {
doInline := stag == ""
if !doInline {
si = parseStructFieldInfo("", stag)
doInline = si.encName == ""
// doInline = si.isZero()
}
if doInline {
ft := f.Type
for ft.Kind() == reflect.Ptr {
ft = ft.Elem()
}
if ft.Kind() == reflect.Struct {
// if etypes contains this, don't call rget again (as fields are already seen here)
ftid := reflect.ValueOf(ft).Pointer()
// 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([]int, 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 f.PkgPath != "" { // unexported
continue
}
if f.Name == "" {
panic(noFieldNameToStructFieldInfoErr)
}
pv.fNames = append(pv.fNames, f.Name)
if si == nil {
si = parseStructFieldInfo(f.Name, stag)
} else if si.encName == "" {
si.encName = f.Name
}
si.fieldName = f.Name
pv.encNames = append(pv.encNames, si.encName)
// si.ikind = int(f.Type.Kind())
if len(indexstack) == 0 {
si.i = int16(j)
} else {
si.i = -1
si.is = make([]int, len(indexstack)+1)
copy(si.is, indexstack)
si.is[len(indexstack)] = j
// si.is = append(append(make([]int, 0, len(indexstack)+4), indexstack...), j)
}
if omitEmpty {
si.omitEmpty = true
}
pv.sfis = append(pv.sfis, si)
}
}
// resolves the struct field info got from a call to rget.
// Returns a trimmed, unsorted and sorted []*structFieldInfo.
func rgetResolveSFI(x []*structFieldInfo, pv []sfiIdx) (y, z []*structFieldInfo) {
var n int
for i, v := range x {
xn := v.encName //TODO: fieldName or encName? use encName for now.
var found bool
for j, k := range pv {
if k.name == xn {
// one of them must be reset to nil, and the index updated appropriately to the other one
if len(v.is) == len(x[k.index].is) {
} else if len(v.is) < len(x[k.index].is) {
pv[j].index = i
if x[k.index] != nil {
x[k.index] = nil
n++
}
} else {
if x[i] != nil {
x[i] = nil
n++
}
}
found = true
break
}
}
if !found {
pv = append(pv, sfiIdx{xn, i})
}
}
// remove all the nils
y = make([]*structFieldInfo, len(x)-n)
n = 0
for _, v := range x {
if v == nil {
continue
}
y[n] = v
n++
}
z = make([]*structFieldInfo, len(y))
copy(z, y)
sort.Sort(sfiSortedByEncName(z))
return
}
func panicToErr(err *error) {
if recoverPanicToErr {
if x := recover(); x != nil {
//debug.PrintStack()
panicValToErr(x, err)
}
}
}
// func doPanic(tag string, format string, params ...interface{}) {
// params2 := make([]interface{}, len(params)+1)
// params2[0] = tag
// copy(params2[1:], params)
// panic(fmt.Errorf("%s: "+format, params2...))
// }
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
}
// these functions must be inlinable, and not call anybody
type checkOverflow struct{}
func (_ checkOverflow) Float32(f float64) (overflow bool) {
if f < 0 {
f = -f
}
return math.MaxFloat32 < f && f <= 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) (i int64, overflow bool) {
//e.g. -127 to 128 for int8
pos := (v >> 63) == 0
ui2 := v & 0x7fffffffffffffff
if pos {
if ui2 > math.MaxInt64 {
overflow = true
return
}
} else {
if ui2 > math.MaxInt64-1 {
overflow = true
return
}
}
i = int64(v)
return
}
// ------------------ SORT -----------------
func isNaN(f float64) bool { return f != f }
// -----------------------
type intSlice []int64
type uintSlice []uint64
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 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
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] }
// -----------------
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
// defer func() { fmt.Printf("$$$$$$$$$$$ cirRef Add: %v, exists: %v\n", v, exists) }()
x := *s
if x == nil {
x = make([]uintptr, 1, 8)
x[0] = v
*s = x
return
}
// typically, length will be 1. make this perform.
if len(x) == 1 {
if j := x[0]; j == 0 {
x[0] = v
} else if j == v {
exists = true
} else {
x = append(x, v)
*s = x
}
return
}
// check if it exists
for _, j := range x {
if j == v {
exists = true
return
}
}
// try to replace a "deleted" slot
for i, j := range x {
if j == 0 {
x[i] = v
return
}
}
// if unable to replace deleted slot, just append it.
x = append(x, v)
*s = x
return
}
func (s *set) remove(v uintptr) (exists bool) {
// defer func() { fmt.Printf("$$$$$$$$$$$ cirRef Rm: %v, exists: %v\n", v, exists) }()
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
}