status-go/vendor/github.com/segmentio/encoding/json/codec.go

1233 lines
33 KiB
Go

package json
import (
"encoding"
"encoding/json"
"fmt"
"reflect"
"sort"
"strconv"
"strings"
"sync/atomic"
"time"
"unicode"
"unsafe"
"github.com/segmentio/asm/keyset"
)
const (
// 1000 is the value used by the standard encoding/json package.
//
// https://cs.opensource.google/go/go/+/refs/tags/go1.17.3:src/encoding/json/encode.go;drc=refs%2Ftags%2Fgo1.17.3;l=300
startDetectingCyclesAfter = 1000
)
type codec struct {
encode encodeFunc
decode decodeFunc
}
type encoder struct {
flags AppendFlags
// ptrDepth tracks the depth of pointer cycles, when it reaches the value
// of startDetectingCyclesAfter, the ptrSeen map is allocated and the
// encoder starts tracking pointers it has seen as an attempt to detect
// whether it has entered a pointer cycle and needs to error before the
// goroutine runs out of stack space.
ptrDepth uint32
ptrSeen map[unsafe.Pointer]struct{}
}
type decoder struct {
flags ParseFlags
}
type encodeFunc func(encoder, []byte, unsafe.Pointer) ([]byte, error)
type decodeFunc func(decoder, []byte, unsafe.Pointer) ([]byte, error)
type emptyFunc func(unsafe.Pointer) bool
type sortFunc func([]reflect.Value)
var (
// Eventually consistent cache mapping go types to dynamically generated
// codecs.
//
// Note: using a uintptr as key instead of reflect.Type shaved ~15ns off of
// the ~30ns Marhsal/Unmarshal functions which were dominated by the map
// lookup time for simple types like bool, int, etc..
cache unsafe.Pointer // map[unsafe.Pointer]codec
)
func cacheLoad() map[unsafe.Pointer]codec {
p := atomic.LoadPointer(&cache)
return *(*map[unsafe.Pointer]codec)(unsafe.Pointer(&p))
}
func cacheStore(typ reflect.Type, cod codec, oldCodecs map[unsafe.Pointer]codec) {
newCodecs := make(map[unsafe.Pointer]codec, len(oldCodecs)+1)
newCodecs[typeid(typ)] = cod
for t, c := range oldCodecs {
newCodecs[t] = c
}
atomic.StorePointer(&cache, *(*unsafe.Pointer)(unsafe.Pointer(&newCodecs)))
}
func typeid(t reflect.Type) unsafe.Pointer {
return (*iface)(unsafe.Pointer(&t)).ptr
}
func constructCachedCodec(t reflect.Type, cache map[unsafe.Pointer]codec) codec {
c := constructCodec(t, map[reflect.Type]*structType{}, t.Kind() == reflect.Ptr)
if inlined(t) {
c.encode = constructInlineValueEncodeFunc(c.encode)
}
cacheStore(t, c, cache)
return c
}
func constructCodec(t reflect.Type, seen map[reflect.Type]*structType, canAddr bool) (c codec) {
switch t {
case nullType, nil:
c = codec{encode: encoder.encodeNull, decode: decoder.decodeNull}
case numberType:
c = codec{encode: encoder.encodeNumber, decode: decoder.decodeNumber}
case bytesType:
c = codec{encode: encoder.encodeBytes, decode: decoder.decodeBytes}
case durationType:
c = codec{encode: encoder.encodeDuration, decode: decoder.decodeDuration}
case timeType:
c = codec{encode: encoder.encodeTime, decode: decoder.decodeTime}
case interfaceType:
c = codec{encode: encoder.encodeInterface, decode: decoder.decodeInterface}
case rawMessageType:
c = codec{encode: encoder.encodeRawMessage, decode: decoder.decodeRawMessage}
case numberPtrType:
c = constructPointerCodec(numberPtrType, nil)
case durationPtrType:
c = constructPointerCodec(durationPtrType, nil)
case timePtrType:
c = constructPointerCodec(timePtrType, nil)
case rawMessagePtrType:
c = constructPointerCodec(rawMessagePtrType, nil)
}
if c.encode != nil {
return
}
switch t.Kind() {
case reflect.Bool:
c = codec{encode: encoder.encodeBool, decode: decoder.decodeBool}
case reflect.Int:
c = codec{encode: encoder.encodeInt, decode: decoder.decodeInt}
case reflect.Int8:
c = codec{encode: encoder.encodeInt8, decode: decoder.decodeInt8}
case reflect.Int16:
c = codec{encode: encoder.encodeInt16, decode: decoder.decodeInt16}
case reflect.Int32:
c = codec{encode: encoder.encodeInt32, decode: decoder.decodeInt32}
case reflect.Int64:
c = codec{encode: encoder.encodeInt64, decode: decoder.decodeInt64}
case reflect.Uint:
c = codec{encode: encoder.encodeUint, decode: decoder.decodeUint}
case reflect.Uintptr:
c = codec{encode: encoder.encodeUintptr, decode: decoder.decodeUintptr}
case reflect.Uint8:
c = codec{encode: encoder.encodeUint8, decode: decoder.decodeUint8}
case reflect.Uint16:
c = codec{encode: encoder.encodeUint16, decode: decoder.decodeUint16}
case reflect.Uint32:
c = codec{encode: encoder.encodeUint32, decode: decoder.decodeUint32}
case reflect.Uint64:
c = codec{encode: encoder.encodeUint64, decode: decoder.decodeUint64}
case reflect.Float32:
c = codec{encode: encoder.encodeFloat32, decode: decoder.decodeFloat32}
case reflect.Float64:
c = codec{encode: encoder.encodeFloat64, decode: decoder.decodeFloat64}
case reflect.String:
c = codec{encode: encoder.encodeString, decode: decoder.decodeString}
case reflect.Interface:
c = constructInterfaceCodec(t)
case reflect.Array:
c = constructArrayCodec(t, seen, canAddr)
case reflect.Slice:
c = constructSliceCodec(t, seen)
case reflect.Map:
c = constructMapCodec(t, seen)
case reflect.Struct:
c = constructStructCodec(t, seen, canAddr)
case reflect.Ptr:
c = constructPointerCodec(t, seen)
default:
c = constructUnsupportedTypeCodec(t)
}
p := reflect.PtrTo(t)
if canAddr {
switch {
case p.Implements(jsonMarshalerType):
c.encode = constructJSONMarshalerEncodeFunc(t, true)
case p.Implements(textMarshalerType):
c.encode = constructTextMarshalerEncodeFunc(t, true)
}
}
switch {
case t.Implements(jsonMarshalerType):
c.encode = constructJSONMarshalerEncodeFunc(t, false)
case t.Implements(textMarshalerType):
c.encode = constructTextMarshalerEncodeFunc(t, false)
}
switch {
case p.Implements(jsonUnmarshalerType):
c.decode = constructJSONUnmarshalerDecodeFunc(t, true)
case p.Implements(textUnmarshalerType):
c.decode = constructTextUnmarshalerDecodeFunc(t, true)
}
return
}
func constructStringCodec(t reflect.Type, seen map[reflect.Type]*structType, canAddr bool) codec {
c := constructCodec(t, seen, canAddr)
return codec{
encode: constructStringEncodeFunc(c.encode),
decode: constructStringDecodeFunc(c.decode),
}
}
func constructStringEncodeFunc(encode encodeFunc) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeToString(b, p, encode)
}
}
func constructStringDecodeFunc(decode decodeFunc) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeFromString(b, p, decode)
}
}
func constructStringToIntDecodeFunc(t reflect.Type, decode decodeFunc) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeFromStringToInt(b, p, t, decode)
}
}
func constructArrayCodec(t reflect.Type, seen map[reflect.Type]*structType, canAddr bool) codec {
e := t.Elem()
c := constructCodec(e, seen, canAddr)
s := alignedSize(e)
return codec{
encode: constructArrayEncodeFunc(s, t, c.encode),
decode: constructArrayDecodeFunc(s, t, c.decode),
}
}
func constructArrayEncodeFunc(size uintptr, t reflect.Type, encode encodeFunc) encodeFunc {
n := t.Len()
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeArray(b, p, n, size, t, encode)
}
}
func constructArrayDecodeFunc(size uintptr, t reflect.Type, decode decodeFunc) decodeFunc {
n := t.Len()
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeArray(b, p, n, size, t, decode)
}
}
func constructSliceCodec(t reflect.Type, seen map[reflect.Type]*structType) codec {
e := t.Elem()
s := alignedSize(e)
if e.Kind() == reflect.Uint8 {
// Go 1.7+ behavior: slices of byte types (and aliases) may override the
// default encoding and decoding behaviors by implementing marshaler and
// unmarshaler interfaces.
p := reflect.PtrTo(e)
c := codec{}
switch {
case e.Implements(jsonMarshalerType):
c.encode = constructJSONMarshalerEncodeFunc(e, false)
case e.Implements(textMarshalerType):
c.encode = constructTextMarshalerEncodeFunc(e, false)
case p.Implements(jsonMarshalerType):
c.encode = constructJSONMarshalerEncodeFunc(e, true)
case p.Implements(textMarshalerType):
c.encode = constructTextMarshalerEncodeFunc(e, true)
}
switch {
case e.Implements(jsonUnmarshalerType):
c.decode = constructJSONUnmarshalerDecodeFunc(e, false)
case e.Implements(textUnmarshalerType):
c.decode = constructTextUnmarshalerDecodeFunc(e, false)
case p.Implements(jsonUnmarshalerType):
c.decode = constructJSONUnmarshalerDecodeFunc(e, true)
case p.Implements(textUnmarshalerType):
c.decode = constructTextUnmarshalerDecodeFunc(e, true)
}
if c.encode != nil {
c.encode = constructSliceEncodeFunc(s, t, c.encode)
} else {
c.encode = encoder.encodeBytes
}
if c.decode != nil {
c.decode = constructSliceDecodeFunc(s, t, c.decode)
} else {
c.decode = decoder.decodeBytes
}
return c
}
c := constructCodec(e, seen, true)
return codec{
encode: constructSliceEncodeFunc(s, t, c.encode),
decode: constructSliceDecodeFunc(s, t, c.decode),
}
}
func constructSliceEncodeFunc(size uintptr, t reflect.Type, encode encodeFunc) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeSlice(b, p, size, t, encode)
}
}
func constructSliceDecodeFunc(size uintptr, t reflect.Type, decode decodeFunc) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeSlice(b, p, size, t, decode)
}
}
func constructMapCodec(t reflect.Type, seen map[reflect.Type]*structType) codec {
var sortKeys sortFunc
k := t.Key()
v := t.Elem()
// Faster implementations for some common cases.
switch {
case k == stringType && v == interfaceType:
return codec{
encode: encoder.encodeMapStringInterface,
decode: decoder.decodeMapStringInterface,
}
case k == stringType && v == rawMessageType:
return codec{
encode: encoder.encodeMapStringRawMessage,
decode: decoder.decodeMapStringRawMessage,
}
case k == stringType && v == stringType:
return codec{
encode: encoder.encodeMapStringString,
decode: decoder.decodeMapStringString,
}
case k == stringType && v == stringsType:
return codec{
encode: encoder.encodeMapStringStringSlice,
decode: decoder.decodeMapStringStringSlice,
}
case k == stringType && v == boolType:
return codec{
encode: encoder.encodeMapStringBool,
decode: decoder.decodeMapStringBool,
}
}
kc := codec{}
vc := constructCodec(v, seen, false)
if k.Implements(textMarshalerType) || reflect.PtrTo(k).Implements(textUnmarshalerType) {
kc.encode = constructTextMarshalerEncodeFunc(k, false)
kc.decode = constructTextUnmarshalerDecodeFunc(k, true)
sortKeys = func(keys []reflect.Value) {
sort.Slice(keys, func(i, j int) bool {
// This is a performance abomination but the use case is rare
// enough that it shouldn't be a problem in practice.
k1, _ := keys[i].Interface().(encoding.TextMarshaler).MarshalText()
k2, _ := keys[j].Interface().(encoding.TextMarshaler).MarshalText()
return string(k1) < string(k2)
})
}
} else {
switch k.Kind() {
case reflect.String:
kc.encode = encoder.encodeString
kc.decode = decoder.decodeString
sortKeys = func(keys []reflect.Value) {
sort.Slice(keys, func(i, j int) bool { return keys[i].String() < keys[j].String() })
}
case reflect.Int,
reflect.Int8,
reflect.Int16,
reflect.Int32,
reflect.Int64:
kc = constructStringCodec(k, seen, false)
sortKeys = func(keys []reflect.Value) {
sort.Slice(keys, func(i, j int) bool { return intStringsAreSorted(keys[i].Int(), keys[j].Int()) })
}
case reflect.Uint,
reflect.Uintptr,
reflect.Uint8,
reflect.Uint16,
reflect.Uint32,
reflect.Uint64:
kc = constructStringCodec(k, seen, false)
sortKeys = func(keys []reflect.Value) {
sort.Slice(keys, func(i, j int) bool { return uintStringsAreSorted(keys[i].Uint(), keys[j].Uint()) })
}
default:
return constructUnsupportedTypeCodec(t)
}
}
if inlined(v) {
vc.encode = constructInlineValueEncodeFunc(vc.encode)
}
return codec{
encode: constructMapEncodeFunc(t, kc.encode, vc.encode, sortKeys),
decode: constructMapDecodeFunc(t, kc.decode, vc.decode),
}
}
func constructMapEncodeFunc(t reflect.Type, encodeKey, encodeValue encodeFunc, sortKeys sortFunc) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeMap(b, p, t, encodeKey, encodeValue, sortKeys)
}
}
func constructMapDecodeFunc(t reflect.Type, decodeKey, decodeValue decodeFunc) decodeFunc {
kt := t.Key()
vt := t.Elem()
kz := reflect.Zero(kt)
vz := reflect.Zero(vt)
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeMap(b, p, t, kt, vt, kz, vz, decodeKey, decodeValue)
}
}
func constructStructCodec(t reflect.Type, seen map[reflect.Type]*structType, canAddr bool) codec {
st := constructStructType(t, seen, canAddr)
return codec{
encode: constructStructEncodeFunc(st),
decode: constructStructDecodeFunc(st),
}
}
func constructStructType(t reflect.Type, seen map[reflect.Type]*structType, canAddr bool) *structType {
// Used for preventing infinite recursion on types that have pointers to
// themselves.
st := seen[t]
if st == nil {
st = &structType{
fields: make([]structField, 0, t.NumField()),
fieldsIndex: make(map[string]*structField),
ficaseIndex: make(map[string]*structField),
typ: t,
}
seen[t] = st
st.fields = appendStructFields(st.fields, t, 0, seen, canAddr)
for i := range st.fields {
f := &st.fields[i]
s := strings.ToLower(f.name)
st.fieldsIndex[f.name] = f
// When there is ambiguity because multiple fields have the same
// case-insensitive representation, the first field must win.
if _, exists := st.ficaseIndex[s]; !exists {
st.ficaseIndex[s] = f
}
}
// At a certain point the linear scan provided by keyset is less
// efficient than a map. The 32 was chosen based on benchmarks in the
// segmentio/asm repo run with an Intel Kaby Lake processor and go1.17.
if len(st.fields) <= 32 {
keys := make([][]byte, len(st.fields))
for i, f := range st.fields {
keys[i] = []byte(f.name)
}
st.keyset = keyset.New(keys)
}
}
return st
}
func constructStructEncodeFunc(st *structType) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeStruct(b, p, st)
}
}
func constructStructDecodeFunc(st *structType) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeStruct(b, p, st)
}
}
func constructEmbeddedStructPointerCodec(t reflect.Type, unexported bool, offset uintptr, field codec) codec {
return codec{
encode: constructEmbeddedStructPointerEncodeFunc(t, unexported, offset, field.encode),
decode: constructEmbeddedStructPointerDecodeFunc(t, unexported, offset, field.decode),
}
}
func constructEmbeddedStructPointerEncodeFunc(t reflect.Type, unexported bool, offset uintptr, encode encodeFunc) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeEmbeddedStructPointer(b, p, t, unexported, offset, encode)
}
}
func constructEmbeddedStructPointerDecodeFunc(t reflect.Type, unexported bool, offset uintptr, decode decodeFunc) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeEmbeddedStructPointer(b, p, t, unexported, offset, decode)
}
}
func appendStructFields(fields []structField, t reflect.Type, offset uintptr, seen map[reflect.Type]*structType, canAddr bool) []structField {
type embeddedField struct {
index int
offset uintptr
pointer bool
unexported bool
subtype *structType
subfield *structField
}
names := make(map[string]struct{})
embedded := make([]embeddedField, 0, 10)
for i, n := 0, t.NumField(); i < n; i++ {
f := t.Field(i)
var (
name = f.Name
anonymous = f.Anonymous
tag = false
omitempty = false
stringify = false
unexported = len(f.PkgPath) != 0
)
if unexported && !anonymous { // unexported
continue
}
if parts := strings.Split(f.Tag.Get("json"), ","); len(parts) != 0 {
if len(parts[0]) != 0 {
name, tag = parts[0], true
}
if name == "-" && len(parts) == 1 { // ignored
continue
}
if !isValidTag(name) {
name = f.Name
}
for _, tag := range parts[1:] {
switch tag {
case "omitempty":
omitempty = true
case "string":
stringify = true
}
}
}
if anonymous && !tag { // embedded
typ := f.Type
ptr := f.Type.Kind() == reflect.Ptr
if ptr {
typ = f.Type.Elem()
}
if typ.Kind() == reflect.Struct {
// When the embedded fields is inlined the fields can be looked
// up by offset from the address of the wrapping object, so we
// simply add the embedded struct fields to the list of fields
// of the current struct type.
subtype := constructStructType(typ, seen, canAddr)
for j := range subtype.fields {
embedded = append(embedded, embeddedField{
index: i<<32 | j,
offset: offset + f.Offset,
pointer: ptr,
unexported: unexported,
subtype: subtype,
subfield: &subtype.fields[j],
})
}
continue
}
if unexported { // ignore unexported non-struct types
continue
}
}
codec := constructCodec(f.Type, seen, canAddr)
if stringify {
// https://golang.org/pkg/encoding/json/#Marshal
//
// The "string" option signals that a field is stored as JSON inside
// a JSON-encoded string. It applies only to fields of string,
// floating point, integer, or boolean types. This extra level of
// encoding is sometimes used when communicating with JavaScript
// programs:
typ := f.Type
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
}
switch typ.Kind() {
case reflect.Int,
reflect.Int8,
reflect.Int16,
reflect.Int32,
reflect.Int64,
reflect.Uint,
reflect.Uintptr,
reflect.Uint8,
reflect.Uint16,
reflect.Uint32,
reflect.Uint64:
codec.encode = constructStringEncodeFunc(codec.encode)
codec.decode = constructStringToIntDecodeFunc(typ, codec.decode)
case reflect.Bool,
reflect.Float32,
reflect.Float64,
reflect.String:
codec.encode = constructStringEncodeFunc(codec.encode)
codec.decode = constructStringDecodeFunc(codec.decode)
}
}
fields = append(fields, structField{
codec: codec,
offset: offset + f.Offset,
empty: emptyFuncOf(f.Type),
tag: tag,
omitempty: omitempty,
name: name,
index: i << 32,
typ: f.Type,
zero: reflect.Zero(f.Type),
})
names[name] = struct{}{}
}
// Only unambiguous embedded fields must be serialized.
ambiguousNames := make(map[string]int)
ambiguousTags := make(map[string]int)
// Embedded types can never override a field that was already present at
// the top-level.
for name := range names {
ambiguousNames[name]++
ambiguousTags[name]++
}
for _, embfield := range embedded {
ambiguousNames[embfield.subfield.name]++
if embfield.subfield.tag {
ambiguousTags[embfield.subfield.name]++
}
}
for _, embfield := range embedded {
subfield := *embfield.subfield
if ambiguousNames[subfield.name] > 1 && !(subfield.tag && ambiguousTags[subfield.name] == 1) {
continue // ambiguous embedded field
}
if embfield.pointer {
subfield.codec = constructEmbeddedStructPointerCodec(embfield.subtype.typ, embfield.unexported, subfield.offset, subfield.codec)
subfield.offset = embfield.offset
} else {
subfield.offset += embfield.offset
}
// To prevent dominant flags more than one level below the embedded one.
subfield.tag = false
// To ensure the order of the fields in the output is the same is in the
// struct type.
subfield.index = embfield.index
fields = append(fields, subfield)
}
for i := range fields {
name := fields[i].name
fields[i].json = encodeKeyFragment(name, 0)
fields[i].html = encodeKeyFragment(name, EscapeHTML)
}
sort.Slice(fields, func(i, j int) bool { return fields[i].index < fields[j].index })
return fields
}
func encodeKeyFragment(s string, flags AppendFlags) string {
b := make([]byte, 1, len(s)+4)
b[0] = ','
e := encoder{flags: flags}
b, _ = e.encodeString(b, unsafe.Pointer(&s))
b = append(b, ':')
return *(*string)(unsafe.Pointer(&b))
}
func constructPointerCodec(t reflect.Type, seen map[reflect.Type]*structType) codec {
e := t.Elem()
c := constructCodec(e, seen, true)
return codec{
encode: constructPointerEncodeFunc(e, c.encode),
decode: constructPointerDecodeFunc(e, c.decode),
}
}
func constructPointerEncodeFunc(t reflect.Type, encode encodeFunc) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodePointer(b, p, t, encode)
}
}
func constructPointerDecodeFunc(t reflect.Type, decode decodeFunc) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodePointer(b, p, t, decode)
}
}
func constructInterfaceCodec(t reflect.Type) codec {
return codec{
encode: constructMaybeEmptyInterfaceEncoderFunc(t),
decode: constructMaybeEmptyInterfaceDecoderFunc(t),
}
}
func constructMaybeEmptyInterfaceEncoderFunc(t reflect.Type) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeMaybeEmptyInterface(b, p, t)
}
}
func constructMaybeEmptyInterfaceDecoderFunc(t reflect.Type) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeMaybeEmptyInterface(b, p, t)
}
}
func constructUnsupportedTypeCodec(t reflect.Type) codec {
return codec{
encode: constructUnsupportedTypeEncodeFunc(t),
decode: constructUnsupportedTypeDecodeFunc(t),
}
}
func constructUnsupportedTypeEncodeFunc(t reflect.Type) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeUnsupportedTypeError(b, p, t)
}
}
func constructUnsupportedTypeDecodeFunc(t reflect.Type) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeUnmarshalTypeError(b, p, t)
}
}
func constructJSONMarshalerEncodeFunc(t reflect.Type, pointer bool) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeJSONMarshaler(b, p, t, pointer)
}
}
func constructJSONUnmarshalerDecodeFunc(t reflect.Type, pointer bool) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeJSONUnmarshaler(b, p, t, pointer)
}
}
func constructTextMarshalerEncodeFunc(t reflect.Type, pointer bool) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return e.encodeTextMarshaler(b, p, t, pointer)
}
}
func constructTextUnmarshalerDecodeFunc(t reflect.Type, pointer bool) decodeFunc {
return func(d decoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return d.decodeTextUnmarshaler(b, p, t, pointer)
}
}
func constructInlineValueEncodeFunc(encode encodeFunc) encodeFunc {
return func(e encoder, b []byte, p unsafe.Pointer) ([]byte, error) {
return encode(e, b, noescape(unsafe.Pointer(&p)))
}
}
// noescape hides a pointer from escape analysis. noescape is
// the identity function but escape analysis doesn't think the
// output depends on the input. noescape is inlined and currently
// compiles down to zero instructions.
// USE CAREFULLY!
// This was copied from the runtime; see issues 23382 and 7921.
//go:nosplit
func noescape(p unsafe.Pointer) unsafe.Pointer {
x := uintptr(p)
return unsafe.Pointer(x ^ 0)
}
func alignedSize(t reflect.Type) uintptr {
a := t.Align()
s := t.Size()
return align(uintptr(a), uintptr(s))
}
func align(align, size uintptr) uintptr {
if align != 0 && (size%align) != 0 {
size = ((size / align) + 1) * align
}
return size
}
func inlined(t reflect.Type) bool {
switch t.Kind() {
case reflect.Ptr:
return true
case reflect.Map:
return true
case reflect.Struct:
return t.NumField() == 1 && inlined(t.Field(0).Type)
default:
return false
}
}
func isValidTag(s string) bool {
if s == "" {
return false
}
for _, c := range s {
switch {
case strings.ContainsRune("!#$%&()*+-./:;<=>?@[]^_{|}~ ", c):
// Backslash and quote chars are reserved, but
// otherwise any punctuation chars are allowed
// in a tag name.
default:
if !unicode.IsLetter(c) && !unicode.IsDigit(c) {
return false
}
}
}
return true
}
func emptyFuncOf(t reflect.Type) emptyFunc {
switch t {
case bytesType, rawMessageType:
return func(p unsafe.Pointer) bool { return (*slice)(p).len == 0 }
}
switch t.Kind() {
case reflect.Array:
if t.Len() == 0 {
return func(unsafe.Pointer) bool { return true }
}
case reflect.Map:
return func(p unsafe.Pointer) bool { return reflect.NewAt(t, p).Elem().Len() == 0 }
case reflect.Slice:
return func(p unsafe.Pointer) bool { return (*slice)(p).len == 0 }
case reflect.String:
return func(p unsafe.Pointer) bool { return len(*(*string)(p)) == 0 }
case reflect.Bool:
return func(p unsafe.Pointer) bool { return !*(*bool)(p) }
case reflect.Int, reflect.Uint:
return func(p unsafe.Pointer) bool { return *(*uint)(p) == 0 }
case reflect.Uintptr:
return func(p unsafe.Pointer) bool { return *(*uintptr)(p) == 0 }
case reflect.Int8, reflect.Uint8:
return func(p unsafe.Pointer) bool { return *(*uint8)(p) == 0 }
case reflect.Int16, reflect.Uint16:
return func(p unsafe.Pointer) bool { return *(*uint16)(p) == 0 }
case reflect.Int32, reflect.Uint32:
return func(p unsafe.Pointer) bool { return *(*uint32)(p) == 0 }
case reflect.Int64, reflect.Uint64:
return func(p unsafe.Pointer) bool { return *(*uint64)(p) == 0 }
case reflect.Float32:
return func(p unsafe.Pointer) bool { return *(*float32)(p) == 0 }
case reflect.Float64:
return func(p unsafe.Pointer) bool { return *(*float64)(p) == 0 }
case reflect.Ptr:
return func(p unsafe.Pointer) bool { return *(*unsafe.Pointer)(p) == nil }
case reflect.Interface:
return func(p unsafe.Pointer) bool { return (*iface)(p).ptr == nil }
}
return func(unsafe.Pointer) bool { return false }
}
type iface struct {
typ unsafe.Pointer
ptr unsafe.Pointer
}
type slice struct {
data unsafe.Pointer
len int
cap int
}
type structType struct {
fields []structField
fieldsIndex map[string]*structField
ficaseIndex map[string]*structField
keyset []byte
typ reflect.Type
inlined bool
}
type structField struct {
codec codec
offset uintptr
empty emptyFunc
tag bool
omitempty bool
json string
html string
name string
typ reflect.Type
zero reflect.Value
index int
}
func unmarshalTypeError(b []byte, t reflect.Type) error {
return &UnmarshalTypeError{Value: strconv.Quote(prefix(b)), Type: t}
}
func unmarshalOverflow(b []byte, t reflect.Type) error {
return &UnmarshalTypeError{Value: "number " + prefix(b) + " overflows", Type: t}
}
func unexpectedEOF(b []byte) error {
return syntaxError(b, "unexpected end of JSON input")
}
var syntaxErrorMsgOffset = ^uintptr(0)
func init() {
t := reflect.TypeOf(SyntaxError{})
for i, n := 0, t.NumField(); i < n; i++ {
if f := t.Field(i); f.Type.Kind() == reflect.String {
syntaxErrorMsgOffset = f.Offset
}
}
}
func syntaxError(b []byte, msg string, args ...interface{}) error {
e := new(SyntaxError)
i := syntaxErrorMsgOffset
if i != ^uintptr(0) {
s := "json: " + fmt.Sprintf(msg, args...) + ": " + prefix(b)
p := unsafe.Pointer(e)
// Hack to set the unexported `msg` field.
*(*string)(unsafe.Pointer(uintptr(p) + i)) = s
}
return e
}
func objectKeyError(b []byte, err error) ([]byte, error) {
if len(b) == 0 {
return nil, unexpectedEOF(b)
}
switch err.(type) {
case *UnmarshalTypeError:
err = syntaxError(b, "invalid character '%c' looking for beginning of object key", b[0])
}
return b, err
}
func prefix(b []byte) string {
if len(b) < 32 {
return string(b)
}
return string(b[:32]) + "..."
}
func intStringsAreSorted(i0, i1 int64) bool {
var b0, b1 [32]byte
return string(strconv.AppendInt(b0[:0], i0, 10)) < string(strconv.AppendInt(b1[:0], i1, 10))
}
func uintStringsAreSorted(u0, u1 uint64) bool {
var b0, b1 [32]byte
return string(strconv.AppendUint(b0[:0], u0, 10)) < string(strconv.AppendUint(b1[:0], u1, 10))
}
func stringToBytes(s string) []byte {
return *(*[]byte)(unsafe.Pointer(&sliceHeader{
Data: *(*unsafe.Pointer)(unsafe.Pointer(&s)),
Len: len(s),
Cap: len(s),
}))
}
type sliceHeader struct {
Data unsafe.Pointer
Len int
Cap int
}
var (
nullType = reflect.TypeOf(nil)
boolType = reflect.TypeOf(false)
intType = reflect.TypeOf(int(0))
int8Type = reflect.TypeOf(int8(0))
int16Type = reflect.TypeOf(int16(0))
int32Type = reflect.TypeOf(int32(0))
int64Type = reflect.TypeOf(int64(0))
uintType = reflect.TypeOf(uint(0))
uint8Type = reflect.TypeOf(uint8(0))
uint16Type = reflect.TypeOf(uint16(0))
uint32Type = reflect.TypeOf(uint32(0))
uint64Type = reflect.TypeOf(uint64(0))
uintptrType = reflect.TypeOf(uintptr(0))
float32Type = reflect.TypeOf(float32(0))
float64Type = reflect.TypeOf(float64(0))
numberType = reflect.TypeOf(json.Number(""))
stringType = reflect.TypeOf("")
stringsType = reflect.TypeOf([]string(nil))
bytesType = reflect.TypeOf(([]byte)(nil))
durationType = reflect.TypeOf(time.Duration(0))
timeType = reflect.TypeOf(time.Time{})
rawMessageType = reflect.TypeOf(RawMessage(nil))
numberPtrType = reflect.PtrTo(numberType)
durationPtrType = reflect.PtrTo(durationType)
timePtrType = reflect.PtrTo(timeType)
rawMessagePtrType = reflect.PtrTo(rawMessageType)
sliceInterfaceType = reflect.TypeOf(([]interface{})(nil))
sliceStringType = reflect.TypeOf(([]interface{})(nil))
mapStringInterfaceType = reflect.TypeOf((map[string]interface{})(nil))
mapStringRawMessageType = reflect.TypeOf((map[string]RawMessage)(nil))
mapStringStringType = reflect.TypeOf((map[string]string)(nil))
mapStringStringSliceType = reflect.TypeOf((map[string][]string)(nil))
mapStringBoolType = reflect.TypeOf((map[string]bool)(nil))
interfaceType = reflect.TypeOf((*interface{})(nil)).Elem()
jsonMarshalerType = reflect.TypeOf((*Marshaler)(nil)).Elem()
jsonUnmarshalerType = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
textMarshalerType = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
)
// =============================================================================
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// appendDuration appends a human-readable representation of d to b.
//
// The function copies the implementation of time.Duration.String but prevents
// Go from making a dynamic memory allocation on the returned value.
func appendDuration(b []byte, d time.Duration) []byte {
// Largest time is 2540400h10m10.000000000s
var buf [32]byte
w := len(buf)
u := uint64(d)
neg := d < 0
if neg {
u = -u
}
if u < uint64(time.Second) {
// Special case: if duration is smaller than a second,
// use smaller units, like 1.2ms
var prec int
w--
buf[w] = 's'
w--
switch {
case u == 0:
return append(b, '0', 's')
case u < uint64(time.Microsecond):
// print nanoseconds
prec = 0
buf[w] = 'n'
case u < uint64(time.Millisecond):
// print microseconds
prec = 3
// U+00B5 'µ' micro sign == 0xC2 0xB5
w-- // Need room for two bytes.
copy(buf[w:], "µ")
default:
// print milliseconds
prec = 6
buf[w] = 'm'
}
w, u = fmtFrac(buf[:w], u, prec)
w = fmtInt(buf[:w], u)
} else {
w--
buf[w] = 's'
w, u = fmtFrac(buf[:w], u, 9)
// u is now integer seconds
w = fmtInt(buf[:w], u%60)
u /= 60
// u is now integer minutes
if u > 0 {
w--
buf[w] = 'm'
w = fmtInt(buf[:w], u%60)
u /= 60
// u is now integer hours
// Stop at hours because days can be different lengths.
if u > 0 {
w--
buf[w] = 'h'
w = fmtInt(buf[:w], u)
}
}
}
if neg {
w--
buf[w] = '-'
}
return append(b, buf[w:]...)
}
// fmtFrac formats the fraction of v/10**prec (e.g., ".12345") into the
// tail of buf, omitting trailing zeros. it omits the decimal
// point too when the fraction is 0. It returns the index where the
// output bytes begin and the value v/10**prec.
func fmtFrac(buf []byte, v uint64, prec int) (nw int, nv uint64) {
// Omit trailing zeros up to and including decimal point.
w := len(buf)
print := false
for i := 0; i < prec; i++ {
digit := v % 10
print = print || digit != 0
if print {
w--
buf[w] = byte(digit) + '0'
}
v /= 10
}
if print {
w--
buf[w] = '.'
}
return w, v
}
// fmtInt formats v into the tail of buf.
// It returns the index where the output begins.
func fmtInt(buf []byte, v uint64) int {
w := len(buf)
if v == 0 {
w--
buf[w] = '0'
} else {
for v > 0 {
w--
buf[w] = byte(v%10) + '0'
v /= 10
}
}
return w
}
// =============================================================================