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Diffstat (limited to 'vendor/gopkg.in/square/go-jose.v2/json/encode.go')
-rw-r--r--vendor/gopkg.in/square/go-jose.v2/json/encode.go1197
1 files changed, 1197 insertions, 0 deletions
diff --git a/vendor/gopkg.in/square/go-jose.v2/json/encode.go b/vendor/gopkg.in/square/go-jose.v2/json/encode.go
new file mode 100644
index 000000000..1dae8bb7c
--- /dev/null
+++ b/vendor/gopkg.in/square/go-jose.v2/json/encode.go
@@ -0,0 +1,1197 @@
+// Copyright 2010 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.
+
+// Package json implements encoding and decoding of JSON objects as defined in
+// RFC 4627. The mapping between JSON objects and Go values is described
+// in the documentation for the Marshal and Unmarshal functions.
+//
+// See "JSON and Go" for an introduction to this package:
+// https://golang.org/doc/articles/json_and_go.html
+package json
+
+import (
+ "bytes"
+ "encoding"
+ "encoding/base64"
+ "fmt"
+ "math"
+ "reflect"
+ "runtime"
+ "sort"
+ "strconv"
+ "strings"
+ "sync"
+ "unicode"
+ "unicode/utf8"
+)
+
+// Marshal returns the JSON encoding of v.
+//
+// Marshal traverses the value v recursively.
+// If an encountered value implements the Marshaler interface
+// and is not a nil pointer, Marshal calls its MarshalJSON method
+// to produce JSON. If no MarshalJSON method is present but the
+// value implements encoding.TextMarshaler instead, Marshal calls
+// its MarshalText method.
+// The nil pointer exception is not strictly necessary
+// but mimics a similar, necessary exception in the behavior of
+// UnmarshalJSON.
+//
+// Otherwise, Marshal uses the following type-dependent default encodings:
+//
+// Boolean values encode as JSON booleans.
+//
+// Floating point, integer, and Number values encode as JSON numbers.
+//
+// String values encode as JSON strings coerced to valid UTF-8,
+// replacing invalid bytes with the Unicode replacement rune.
+// The angle brackets "<" and ">" are escaped to "\u003c" and "\u003e"
+// to keep some browsers from misinterpreting JSON output as HTML.
+// Ampersand "&" is also escaped to "\u0026" for the same reason.
+//
+// Array and slice values encode as JSON arrays, except that
+// []byte encodes as a base64-encoded string, and a nil slice
+// encodes as the null JSON object.
+//
+// Struct values encode as JSON objects. Each exported struct field
+// becomes a member of the object unless
+// - the field's tag is "-", or
+// - the field is empty and its tag specifies the "omitempty" option.
+// The empty values are false, 0, any
+// nil pointer or interface value, and any array, slice, map, or string of
+// length zero. The object's default key string is the struct field name
+// but can be specified in the struct field's tag value. The "json" key in
+// the struct field's tag value is the key name, followed by an optional comma
+// and options. Examples:
+//
+// // Field is ignored by this package.
+// Field int `json:"-"`
+//
+// // Field appears in JSON as key "myName".
+// Field int `json:"myName"`
+//
+// // Field appears in JSON as key "myName" and
+// // the field is omitted from the object if its value is empty,
+// // as defined above.
+// Field int `json:"myName,omitempty"`
+//
+// // Field appears in JSON as key "Field" (the default), but
+// // the field is skipped if empty.
+// // Note the leading comma.
+// Field int `json:",omitempty"`
+//
+// 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:
+//
+// Int64String int64 `json:",string"`
+//
+// The key name will be used if it's a non-empty string consisting of
+// only Unicode letters, digits, dollar signs, percent signs, hyphens,
+// underscores and slashes.
+//
+// Anonymous struct fields are usually marshaled as if their inner exported fields
+// were fields in the outer struct, subject to the usual Go visibility rules amended
+// as described in the next paragraph.
+// An anonymous struct field with a name given in its JSON tag is treated as
+// having that name, rather than being anonymous.
+// An anonymous struct field of interface type is treated the same as having
+// that type as its name, rather than being anonymous.
+//
+// The Go visibility rules for struct fields are amended for JSON when
+// deciding which field to marshal or unmarshal. If there are
+// multiple fields at the same level, and that level is the least
+// nested (and would therefore be the nesting level selected by the
+// usual Go rules), the following extra rules apply:
+//
+// 1) Of those fields, if any are JSON-tagged, only tagged fields are considered,
+// even if there are multiple untagged fields that would otherwise conflict.
+// 2) If there is exactly one field (tagged or not according to the first rule), that is selected.
+// 3) Otherwise there are multiple fields, and all are ignored; no error occurs.
+//
+// Handling of anonymous struct fields is new in Go 1.1.
+// Prior to Go 1.1, anonymous struct fields were ignored. To force ignoring of
+// an anonymous struct field in both current and earlier versions, give the field
+// a JSON tag of "-".
+//
+// Map values encode as JSON objects.
+// The map's key type must be string; the map keys are used as JSON object
+// keys, subject to the UTF-8 coercion described for string values above.
+//
+// Pointer values encode as the value pointed to.
+// A nil pointer encodes as the null JSON object.
+//
+// Interface values encode as the value contained in the interface.
+// A nil interface value encodes as the null JSON object.
+//
+// Channel, complex, and function values cannot be encoded in JSON.
+// Attempting to encode such a value causes Marshal to return
+// an UnsupportedTypeError.
+//
+// JSON cannot represent cyclic data structures and Marshal does not
+// handle them. Passing cyclic structures to Marshal will result in
+// an infinite recursion.
+//
+func Marshal(v interface{}) ([]byte, error) {
+ e := &encodeState{}
+ err := e.marshal(v)
+ if err != nil {
+ return nil, err
+ }
+ return e.Bytes(), nil
+}
+
+// MarshalIndent is like Marshal but applies Indent to format the output.
+func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
+ b, err := Marshal(v)
+ if err != nil {
+ return nil, err
+ }
+ var buf bytes.Buffer
+ err = Indent(&buf, b, prefix, indent)
+ if err != nil {
+ return nil, err
+ }
+ return buf.Bytes(), nil
+}
+
+// HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029
+// characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029
+// so that the JSON will be safe to embed inside HTML <script> tags.
+// For historical reasons, web browsers don't honor standard HTML
+// escaping within <script> tags, so an alternative JSON encoding must
+// be used.
+func HTMLEscape(dst *bytes.Buffer, src []byte) {
+ // The characters can only appear in string literals,
+ // so just scan the string one byte at a time.
+ start := 0
+ for i, c := range src {
+ if c == '<' || c == '>' || c == '&' {
+ if start < i {
+ dst.Write(src[start:i])
+ }
+ dst.WriteString(`\u00`)
+ dst.WriteByte(hex[c>>4])
+ dst.WriteByte(hex[c&0xF])
+ start = i + 1
+ }
+ // Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
+ if c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
+ if start < i {
+ dst.Write(src[start:i])
+ }
+ dst.WriteString(`\u202`)
+ dst.WriteByte(hex[src[i+2]&0xF])
+ start = i + 3
+ }
+ }
+ if start < len(src) {
+ dst.Write(src[start:])
+ }
+}
+
+// Marshaler is the interface implemented by objects that
+// can marshal themselves into valid JSON.
+type Marshaler interface {
+ MarshalJSON() ([]byte, error)
+}
+
+// An UnsupportedTypeError is returned by Marshal when attempting
+// to encode an unsupported value type.
+type UnsupportedTypeError struct {
+ Type reflect.Type
+}
+
+func (e *UnsupportedTypeError) Error() string {
+ return "json: unsupported type: " + e.Type.String()
+}
+
+type UnsupportedValueError struct {
+ Value reflect.Value
+ Str string
+}
+
+func (e *UnsupportedValueError) Error() string {
+ return "json: unsupported value: " + e.Str
+}
+
+// Before Go 1.2, an InvalidUTF8Error was returned by Marshal when
+// attempting to encode a string value with invalid UTF-8 sequences.
+// As of Go 1.2, Marshal instead coerces the string to valid UTF-8 by
+// replacing invalid bytes with the Unicode replacement rune U+FFFD.
+// This error is no longer generated but is kept for backwards compatibility
+// with programs that might mention it.
+type InvalidUTF8Error struct {
+ S string // the whole string value that caused the error
+}
+
+func (e *InvalidUTF8Error) Error() string {
+ return "json: invalid UTF-8 in string: " + strconv.Quote(e.S)
+}
+
+type MarshalerError struct {
+ Type reflect.Type
+ Err error
+}
+
+func (e *MarshalerError) Error() string {
+ return "json: error calling MarshalJSON for type " + e.Type.String() + ": " + e.Err.Error()
+}
+
+var hex = "0123456789abcdef"
+
+// An encodeState encodes JSON into a bytes.Buffer.
+type encodeState struct {
+ bytes.Buffer // accumulated output
+ scratch [64]byte
+}
+
+var encodeStatePool sync.Pool
+
+func newEncodeState() *encodeState {
+ if v := encodeStatePool.Get(); v != nil {
+ e := v.(*encodeState)
+ e.Reset()
+ return e
+ }
+ return new(encodeState)
+}
+
+func (e *encodeState) marshal(v interface{}) (err error) {
+ defer func() {
+ if r := recover(); r != nil {
+ if _, ok := r.(runtime.Error); ok {
+ panic(r)
+ }
+ if s, ok := r.(string); ok {
+ panic(s)
+ }
+ err = r.(error)
+ }
+ }()
+ e.reflectValue(reflect.ValueOf(v))
+ return nil
+}
+
+func (e *encodeState) error(err error) {
+ panic(err)
+}
+
+func isEmptyValue(v reflect.Value) bool {
+ switch v.Kind() {
+ case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+ return v.Len() == 0
+ case reflect.Bool:
+ return !v.Bool()
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ return v.Int() == 0
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ return v.Uint() == 0
+ case reflect.Float32, reflect.Float64:
+ return v.Float() == 0
+ case reflect.Interface, reflect.Ptr:
+ return v.IsNil()
+ }
+ return false
+}
+
+func (e *encodeState) reflectValue(v reflect.Value) {
+ valueEncoder(v)(e, v, false)
+}
+
+type encoderFunc func(e *encodeState, v reflect.Value, quoted bool)
+
+var encoderCache struct {
+ sync.RWMutex
+ m map[reflect.Type]encoderFunc
+}
+
+func valueEncoder(v reflect.Value) encoderFunc {
+ if !v.IsValid() {
+ return invalidValueEncoder
+ }
+ return typeEncoder(v.Type())
+}
+
+func typeEncoder(t reflect.Type) encoderFunc {
+ encoderCache.RLock()
+ f := encoderCache.m[t]
+ encoderCache.RUnlock()
+ if f != nil {
+ return f
+ }
+
+ // To deal with recursive types, populate the map with an
+ // indirect func before we build it. This type waits on the
+ // real func (f) to be ready and then calls it. This indirect
+ // func is only used for recursive types.
+ encoderCache.Lock()
+ if encoderCache.m == nil {
+ encoderCache.m = make(map[reflect.Type]encoderFunc)
+ }
+ var wg sync.WaitGroup
+ wg.Add(1)
+ encoderCache.m[t] = func(e *encodeState, v reflect.Value, quoted bool) {
+ wg.Wait()
+ f(e, v, quoted)
+ }
+ encoderCache.Unlock()
+
+ // Compute fields without lock.
+ // Might duplicate effort but won't hold other computations back.
+ f = newTypeEncoder(t, true)
+ wg.Done()
+ encoderCache.Lock()
+ encoderCache.m[t] = f
+ encoderCache.Unlock()
+ return f
+}
+
+var (
+ marshalerType = reflect.TypeOf(new(Marshaler)).Elem()
+ textMarshalerType = reflect.TypeOf(new(encoding.TextMarshaler)).Elem()
+)
+
+// newTypeEncoder constructs an encoderFunc for a type.
+// The returned encoder only checks CanAddr when allowAddr is true.
+func newTypeEncoder(t reflect.Type, allowAddr bool) encoderFunc {
+ if t.Implements(marshalerType) {
+ return marshalerEncoder
+ }
+ if t.Kind() != reflect.Ptr && allowAddr {
+ if reflect.PtrTo(t).Implements(marshalerType) {
+ return newCondAddrEncoder(addrMarshalerEncoder, newTypeEncoder(t, false))
+ }
+ }
+
+ if t.Implements(textMarshalerType) {
+ return textMarshalerEncoder
+ }
+ if t.Kind() != reflect.Ptr && allowAddr {
+ if reflect.PtrTo(t).Implements(textMarshalerType) {
+ return newCondAddrEncoder(addrTextMarshalerEncoder, newTypeEncoder(t, false))
+ }
+ }
+
+ switch t.Kind() {
+ case reflect.Bool:
+ return boolEncoder
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ return intEncoder
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ return uintEncoder
+ case reflect.Float32:
+ return float32Encoder
+ case reflect.Float64:
+ return float64Encoder
+ case reflect.String:
+ return stringEncoder
+ case reflect.Interface:
+ return interfaceEncoder
+ case reflect.Struct:
+ return newStructEncoder(t)
+ case reflect.Map:
+ return newMapEncoder(t)
+ case reflect.Slice:
+ return newSliceEncoder(t)
+ case reflect.Array:
+ return newArrayEncoder(t)
+ case reflect.Ptr:
+ return newPtrEncoder(t)
+ default:
+ return unsupportedTypeEncoder
+ }
+}
+
+func invalidValueEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ e.WriteString("null")
+}
+
+func marshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ if v.Kind() == reflect.Ptr && v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ m := v.Interface().(Marshaler)
+ b, err := m.MarshalJSON()
+ if err == nil {
+ // copy JSON into buffer, checking validity.
+ err = compact(&e.Buffer, b, true)
+ }
+ if err != nil {
+ e.error(&MarshalerError{v.Type(), err})
+ }
+}
+
+func addrMarshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ va := v.Addr()
+ if va.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ m := va.Interface().(Marshaler)
+ b, err := m.MarshalJSON()
+ if err == nil {
+ // copy JSON into buffer, checking validity.
+ err = compact(&e.Buffer, b, true)
+ }
+ if err != nil {
+ e.error(&MarshalerError{v.Type(), err})
+ }
+}
+
+func textMarshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ if v.Kind() == reflect.Ptr && v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ m := v.Interface().(encoding.TextMarshaler)
+ b, err := m.MarshalText()
+ if err != nil {
+ e.error(&MarshalerError{v.Type(), err})
+ }
+ e.stringBytes(b)
+}
+
+func addrTextMarshalerEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ va := v.Addr()
+ if va.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ m := va.Interface().(encoding.TextMarshaler)
+ b, err := m.MarshalText()
+ if err != nil {
+ e.error(&MarshalerError{v.Type(), err})
+ }
+ e.stringBytes(b)
+}
+
+func boolEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ if quoted {
+ e.WriteByte('"')
+ }
+ if v.Bool() {
+ e.WriteString("true")
+ } else {
+ e.WriteString("false")
+ }
+ if quoted {
+ e.WriteByte('"')
+ }
+}
+
+func intEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ b := strconv.AppendInt(e.scratch[:0], v.Int(), 10)
+ if quoted {
+ e.WriteByte('"')
+ }
+ e.Write(b)
+ if quoted {
+ e.WriteByte('"')
+ }
+}
+
+func uintEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ b := strconv.AppendUint(e.scratch[:0], v.Uint(), 10)
+ if quoted {
+ e.WriteByte('"')
+ }
+ e.Write(b)
+ if quoted {
+ e.WriteByte('"')
+ }
+}
+
+type floatEncoder int // number of bits
+
+func (bits floatEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
+ f := v.Float()
+ if math.IsInf(f, 0) || math.IsNaN(f) {
+ e.error(&UnsupportedValueError{v, strconv.FormatFloat(f, 'g', -1, int(bits))})
+ }
+ b := strconv.AppendFloat(e.scratch[:0], f, 'g', -1, int(bits))
+ if quoted {
+ e.WriteByte('"')
+ }
+ e.Write(b)
+ if quoted {
+ e.WriteByte('"')
+ }
+}
+
+var (
+ float32Encoder = (floatEncoder(32)).encode
+ float64Encoder = (floatEncoder(64)).encode
+)
+
+func stringEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ if v.Type() == numberType {
+ numStr := v.String()
+ // In Go1.5 the empty string encodes to "0", while this is not a valid number literal
+ // we keep compatibility so check validity after this.
+ if numStr == "" {
+ numStr = "0" // Number's zero-val
+ }
+ if !isValidNumber(numStr) {
+ e.error(fmt.Errorf("json: invalid number literal %q", numStr))
+ }
+ e.WriteString(numStr)
+ return
+ }
+ if quoted {
+ sb, err := Marshal(v.String())
+ if err != nil {
+ e.error(err)
+ }
+ e.string(string(sb))
+ } else {
+ e.string(v.String())
+ }
+}
+
+func interfaceEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ if v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ e.reflectValue(v.Elem())
+}
+
+func unsupportedTypeEncoder(e *encodeState, v reflect.Value, quoted bool) {
+ e.error(&UnsupportedTypeError{v.Type()})
+}
+
+type structEncoder struct {
+ fields []field
+ fieldEncs []encoderFunc
+}
+
+func (se *structEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
+ e.WriteByte('{')
+ first := true
+ for i, f := range se.fields {
+ fv := fieldByIndex(v, f.index)
+ if !fv.IsValid() || f.omitEmpty && isEmptyValue(fv) {
+ continue
+ }
+ if first {
+ first = false
+ } else {
+ e.WriteByte(',')
+ }
+ e.string(f.name)
+ e.WriteByte(':')
+ se.fieldEncs[i](e, fv, f.quoted)
+ }
+ e.WriteByte('}')
+}
+
+func newStructEncoder(t reflect.Type) encoderFunc {
+ fields := cachedTypeFields(t)
+ se := &structEncoder{
+ fields: fields,
+ fieldEncs: make([]encoderFunc, len(fields)),
+ }
+ for i, f := range fields {
+ se.fieldEncs[i] = typeEncoder(typeByIndex(t, f.index))
+ }
+ return se.encode
+}
+
+type mapEncoder struct {
+ elemEnc encoderFunc
+}
+
+func (me *mapEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
+ if v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ e.WriteByte('{')
+ var sv stringValues = v.MapKeys()
+ sort.Sort(sv)
+ for i, k := range sv {
+ if i > 0 {
+ e.WriteByte(',')
+ }
+ e.string(k.String())
+ e.WriteByte(':')
+ me.elemEnc(e, v.MapIndex(k), false)
+ }
+ e.WriteByte('}')
+}
+
+func newMapEncoder(t reflect.Type) encoderFunc {
+ if t.Key().Kind() != reflect.String {
+ return unsupportedTypeEncoder
+ }
+ me := &mapEncoder{typeEncoder(t.Elem())}
+ return me.encode
+}
+
+func encodeByteSlice(e *encodeState, v reflect.Value, _ bool) {
+ if v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ s := v.Bytes()
+ e.WriteByte('"')
+ if len(s) < 1024 {
+ // for small buffers, using Encode directly is much faster.
+ dst := make([]byte, base64.StdEncoding.EncodedLen(len(s)))
+ base64.StdEncoding.Encode(dst, s)
+ e.Write(dst)
+ } else {
+ // for large buffers, avoid unnecessary extra temporary
+ // buffer space.
+ enc := base64.NewEncoder(base64.StdEncoding, e)
+ enc.Write(s)
+ enc.Close()
+ }
+ e.WriteByte('"')
+}
+
+// sliceEncoder just wraps an arrayEncoder, checking to make sure the value isn't nil.
+type sliceEncoder struct {
+ arrayEnc encoderFunc
+}
+
+func (se *sliceEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
+ if v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ se.arrayEnc(e, v, false)
+}
+
+func newSliceEncoder(t reflect.Type) encoderFunc {
+ // Byte slices get special treatment; arrays don't.
+ if t.Elem().Kind() == reflect.Uint8 {
+ return encodeByteSlice
+ }
+ enc := &sliceEncoder{newArrayEncoder(t)}
+ return enc.encode
+}
+
+type arrayEncoder struct {
+ elemEnc encoderFunc
+}
+
+func (ae *arrayEncoder) encode(e *encodeState, v reflect.Value, _ bool) {
+ e.WriteByte('[')
+ n := v.Len()
+ for i := 0; i < n; i++ {
+ if i > 0 {
+ e.WriteByte(',')
+ }
+ ae.elemEnc(e, v.Index(i), false)
+ }
+ e.WriteByte(']')
+}
+
+func newArrayEncoder(t reflect.Type) encoderFunc {
+ enc := &arrayEncoder{typeEncoder(t.Elem())}
+ return enc.encode
+}
+
+type ptrEncoder struct {
+ elemEnc encoderFunc
+}
+
+func (pe *ptrEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
+ if v.IsNil() {
+ e.WriteString("null")
+ return
+ }
+ pe.elemEnc(e, v.Elem(), quoted)
+}
+
+func newPtrEncoder(t reflect.Type) encoderFunc {
+ enc := &ptrEncoder{typeEncoder(t.Elem())}
+ return enc.encode
+}
+
+type condAddrEncoder struct {
+ canAddrEnc, elseEnc encoderFunc
+}
+
+func (ce *condAddrEncoder) encode(e *encodeState, v reflect.Value, quoted bool) {
+ if v.CanAddr() {
+ ce.canAddrEnc(e, v, quoted)
+ } else {
+ ce.elseEnc(e, v, quoted)
+ }
+}
+
+// newCondAddrEncoder returns an encoder that checks whether its value
+// CanAddr and delegates to canAddrEnc if so, else to elseEnc.
+func newCondAddrEncoder(canAddrEnc, elseEnc encoderFunc) encoderFunc {
+ enc := &condAddrEncoder{canAddrEnc: canAddrEnc, elseEnc: elseEnc}
+ return enc.encode
+}
+
+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 fieldByIndex(v reflect.Value, index []int) reflect.Value {
+ for _, i := range index {
+ if v.Kind() == reflect.Ptr {
+ if v.IsNil() {
+ return reflect.Value{}
+ }
+ v = v.Elem()
+ }
+ v = v.Field(i)
+ }
+ return v
+}
+
+func typeByIndex(t reflect.Type, index []int) reflect.Type {
+ for _, i := range index {
+ if t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+ t = t.Field(i).Type
+ }
+ return t
+}
+
+// stringValues is a slice of reflect.Value holding *reflect.StringValue.
+// It implements the methods to sort by string.
+type stringValues []reflect.Value
+
+func (sv stringValues) Len() int { return len(sv) }
+func (sv stringValues) Swap(i, j int) { sv[i], sv[j] = sv[j], sv[i] }
+func (sv stringValues) Less(i, j int) bool { return sv.get(i) < sv.get(j) }
+func (sv stringValues) get(i int) string { return sv[i].String() }
+
+// NOTE: keep in sync with stringBytes below.
+func (e *encodeState) string(s string) int {
+ len0 := e.Len()
+ e.WriteByte('"')
+ start := 0
+ for i := 0; i < len(s); {
+ if b := s[i]; b < utf8.RuneSelf {
+ if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && b != '&' {
+ i++
+ continue
+ }
+ if start < i {
+ e.WriteString(s[start:i])
+ }
+ switch b {
+ case '\\', '"':
+ e.WriteByte('\\')
+ e.WriteByte(b)
+ case '\n':
+ e.WriteByte('\\')
+ e.WriteByte('n')
+ case '\r':
+ e.WriteByte('\\')
+ e.WriteByte('r')
+ case '\t':
+ e.WriteByte('\\')
+ e.WriteByte('t')
+ default:
+ // This encodes bytes < 0x20 except for \n and \r,
+ // as well as <, > and &. The latter are escaped because they
+ // can lead to security holes when user-controlled strings
+ // are rendered into JSON and served to some browsers.
+ e.WriteString(`\u00`)
+ e.WriteByte(hex[b>>4])
+ e.WriteByte(hex[b&0xF])
+ }
+ i++
+ start = i
+ continue
+ }
+ c, size := utf8.DecodeRuneInString(s[i:])
+ if c == utf8.RuneError && size == 1 {
+ if start < i {
+ e.WriteString(s[start:i])
+ }
+ e.WriteString(`\ufffd`)
+ i += size
+ start = i
+ continue
+ }
+ // U+2028 is LINE SEPARATOR.
+ // U+2029 is PARAGRAPH SEPARATOR.
+ // They are both technically valid characters in JSON strings,
+ // but don't work in JSONP, which has to be evaluated as JavaScript,
+ // and can lead to security holes there. It is valid JSON to
+ // escape them, so we do so unconditionally.
+ // See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
+ if c == '\u2028' || c == '\u2029' {
+ if start < i {
+ e.WriteString(s[start:i])
+ }
+ e.WriteString(`\u202`)
+ e.WriteByte(hex[c&0xF])
+ i += size
+ start = i
+ continue
+ }
+ i += size
+ }
+ if start < len(s) {
+ e.WriteString(s[start:])
+ }
+ e.WriteByte('"')
+ return e.Len() - len0
+}
+
+// NOTE: keep in sync with string above.
+func (e *encodeState) stringBytes(s []byte) int {
+ len0 := e.Len()
+ e.WriteByte('"')
+ start := 0
+ for i := 0; i < len(s); {
+ if b := s[i]; b < utf8.RuneSelf {
+ if 0x20 <= b && b != '\\' && b != '"' && b != '<' && b != '>' && b != '&' {
+ i++
+ continue
+ }
+ if start < i {
+ e.Write(s[start:i])
+ }
+ switch b {
+ case '\\', '"':
+ e.WriteByte('\\')
+ e.WriteByte(b)
+ case '\n':
+ e.WriteByte('\\')
+ e.WriteByte('n')
+ case '\r':
+ e.WriteByte('\\')
+ e.WriteByte('r')
+ case '\t':
+ e.WriteByte('\\')
+ e.WriteByte('t')
+ default:
+ // This encodes bytes < 0x20 except for \n and \r,
+ // as well as <, >, and &. The latter are escaped because they
+ // can lead to security holes when user-controlled strings
+ // are rendered into JSON and served to some browsers.
+ e.WriteString(`\u00`)
+ e.WriteByte(hex[b>>4])
+ e.WriteByte(hex[b&0xF])
+ }
+ i++
+ start = i
+ continue
+ }
+ c, size := utf8.DecodeRune(s[i:])
+ if c == utf8.RuneError && size == 1 {
+ if start < i {
+ e.Write(s[start:i])
+ }
+ e.WriteString(`\ufffd`)
+ i += size
+ start = i
+ continue
+ }
+ // U+2028 is LINE SEPARATOR.
+ // U+2029 is PARAGRAPH SEPARATOR.
+ // They are both technically valid characters in JSON strings,
+ // but don't work in JSONP, which has to be evaluated as JavaScript,
+ // and can lead to security holes there. It is valid JSON to
+ // escape them, so we do so unconditionally.
+ // See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
+ if c == '\u2028' || c == '\u2029' {
+ if start < i {
+ e.Write(s[start:i])
+ }
+ e.WriteString(`\u202`)
+ e.WriteByte(hex[c&0xF])
+ i += size
+ start = i
+ continue
+ }
+ i += size
+ }
+ if start < len(s) {
+ e.Write(s[start:])
+ }
+ e.WriteByte('"')
+ return e.Len() - len0
+}
+
+// A field represents a single field found in a struct.
+type field struct {
+ name string
+ nameBytes []byte // []byte(name)
+
+ tag bool
+ index []int
+ typ reflect.Type
+ omitEmpty bool
+ quoted bool
+}
+
+func fillField(f field) field {
+ f.nameBytes = []byte(f.name)
+ return f
+}
+
+// byName sorts field by name, breaking ties with depth,
+// then breaking ties with "name came from json tag", then
+// breaking ties with index sequence.
+type byName []field
+
+func (x byName) Len() int { return len(x) }
+
+func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+func (x byName) Less(i, j int) bool {
+ if x[i].name != x[j].name {
+ return x[i].name < x[j].name
+ }
+ if len(x[i].index) != len(x[j].index) {
+ return len(x[i].index) < len(x[j].index)
+ }
+ if x[i].tag != x[j].tag {
+ return x[i].tag
+ }
+ return byIndex(x).Less(i, j)
+}
+
+// byIndex sorts field by index sequence.
+type byIndex []field
+
+func (x byIndex) Len() int { return len(x) }
+
+func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+func (x byIndex) Less(i, j int) bool {
+ for k, xik := range x[i].index {
+ if k >= len(x[j].index) {
+ return false
+ }
+ if xik != x[j].index[k] {
+ return xik < x[j].index[k]
+ }
+ }
+ return len(x[i].index) < len(x[j].index)
+}
+
+// typeFields returns a list of fields that JSON should recognize for the given type.
+// The algorithm is breadth-first search over the set of structs to include - the top struct
+// and then any reachable anonymous structs.
+func typeFields(t reflect.Type) []field {
+ // Anonymous fields to explore at the current level and the next.
+ current := []field{}
+ next := []field{{typ: t}}
+
+ // Count of queued names for current level and the next.
+ count := map[reflect.Type]int{}
+ nextCount := map[reflect.Type]int{}
+
+ // Types already visited at an earlier level.
+ visited := map[reflect.Type]bool{}
+
+ // Fields found.
+ var fields []field
+
+ for len(next) > 0 {
+ current, next = next, current[:0]
+ count, nextCount = nextCount, map[reflect.Type]int{}
+
+ for _, f := range current {
+ if visited[f.typ] {
+ continue
+ }
+ visited[f.typ] = true
+
+ // Scan f.typ for fields to include.
+ for i := 0; i < f.typ.NumField(); i++ {
+ sf := f.typ.Field(i)
+ if sf.PkgPath != "" && !sf.Anonymous { // unexported
+ continue
+ }
+ tag := sf.Tag.Get("json")
+ if tag == "-" {
+ continue
+ }
+ name, opts := parseTag(tag)
+ if !isValidTag(name) {
+ name = ""
+ }
+ index := make([]int, len(f.index)+1)
+ copy(index, f.index)
+ index[len(f.index)] = i
+
+ ft := sf.Type
+ if ft.Name() == "" && ft.Kind() == reflect.Ptr {
+ // Follow pointer.
+ ft = ft.Elem()
+ }
+
+ // Only strings, floats, integers, and booleans can be quoted.
+ quoted := false
+ if opts.Contains("string") {
+ switch ft.Kind() {
+ case reflect.Bool,
+ reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+ reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+ reflect.Float32, reflect.Float64,
+ reflect.String:
+ quoted = true
+ }
+ }
+
+ // Record found field and index sequence.
+ if name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct {
+ tagged := name != ""
+ if name == "" {
+ name = sf.Name
+ }
+ fields = append(fields, fillField(field{
+ name: name,
+ tag: tagged,
+ index: index,
+ typ: ft,
+ omitEmpty: opts.Contains("omitempty"),
+ quoted: quoted,
+ }))
+ if count[f.typ] > 1 {
+ // If there were multiple instances, add a second,
+ // so that the annihilation code will see a duplicate.
+ // It only cares about the distinction between 1 or 2,
+ // so don't bother generating any more copies.
+ fields = append(fields, fields[len(fields)-1])
+ }
+ continue
+ }
+
+ // Record new anonymous struct to explore in next round.
+ nextCount[ft]++
+ if nextCount[ft] == 1 {
+ next = append(next, fillField(field{name: ft.Name(), index: index, typ: ft}))
+ }
+ }
+ }
+ }
+
+ sort.Sort(byName(fields))
+
+ // Delete all fields that are hidden by the Go rules for embedded fields,
+ // except that fields with JSON tags are promoted.
+
+ // The fields are sorted in primary order of name, secondary order
+ // of field index length. Loop over names; for each name, delete
+ // hidden fields by choosing the one dominant field that survives.
+ out := fields[:0]
+ for advance, i := 0, 0; i < len(fields); i += advance {
+ // One iteration per name.
+ // Find the sequence of fields with the name of this first field.
+ fi := fields[i]
+ name := fi.name
+ for advance = 1; i+advance < len(fields); advance++ {
+ fj := fields[i+advance]
+ if fj.name != name {
+ break
+ }
+ }
+ if advance == 1 { // Only one field with this name
+ out = append(out, fi)
+ continue
+ }
+ dominant, ok := dominantField(fields[i : i+advance])
+ if ok {
+ out = append(out, dominant)
+ }
+ }
+
+ fields = out
+ sort.Sort(byIndex(fields))
+
+ return fields
+}
+
+// dominantField looks through the fields, all of which are known to
+// have the same name, to find the single field that dominates the
+// others using Go's embedding rules, modified by the presence of
+// JSON tags. If there are multiple top-level fields, the boolean
+// will be false: This condition is an error in Go and we skip all
+// the fields.
+func dominantField(fields []field) (field, bool) {
+ // The fields are sorted in increasing index-length order. The winner
+ // must therefore be one with the shortest index length. Drop all
+ // longer entries, which is easy: just truncate the slice.
+ length := len(fields[0].index)
+ tagged := -1 // Index of first tagged field.
+ for i, f := range fields {
+ if len(f.index) > length {
+ fields = fields[:i]
+ break
+ }
+ if f.tag {
+ if tagged >= 0 {
+ // Multiple tagged fields at the same level: conflict.
+ // Return no field.
+ return field{}, false
+ }
+ tagged = i
+ }
+ }
+ if tagged >= 0 {
+ return fields[tagged], true
+ }
+ // All remaining fields have the same length. If there's more than one,
+ // we have a conflict (two fields named "X" at the same level) and we
+ // return no field.
+ if len(fields) > 1 {
+ return field{}, false
+ }
+ return fields[0], true
+}
+
+var fieldCache struct {
+ sync.RWMutex
+ m map[reflect.Type][]field
+}
+
+// cachedTypeFields is like typeFields but uses a cache to avoid repeated work.
+func cachedTypeFields(t reflect.Type) []field {
+ fieldCache.RLock()
+ f := fieldCache.m[t]
+ fieldCache.RUnlock()
+ if f != nil {
+ return f
+ }
+
+ // Compute fields without lock.
+ // Might duplicate effort but won't hold other computations back.
+ f = typeFields(t)
+ if f == nil {
+ f = []field{}
+ }
+
+ fieldCache.Lock()
+ if fieldCache.m == nil {
+ fieldCache.m = map[reflect.Type][]field{}
+ }
+ fieldCache.m[t] = f
+ fieldCache.Unlock()
+ return f
+}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-11-15 06:11:28 +0000