diff options
Diffstat (limited to 'vendor/github.com/yaegashi/msgraph.go/jsonx/encode.go')
| -rw-r--r-- | vendor/github.com/yaegashi/msgraph.go/jsonx/encode.go | 1317 |
1 files changed, 0 insertions, 1317 deletions
diff --git a/vendor/github.com/yaegashi/msgraph.go/jsonx/encode.go b/vendor/github.com/yaegashi/msgraph.go/jsonx/encode.go deleted file mode 100644 index 7c155502..00000000 --- a/vendor/github.com/yaegashi/msgraph.go/jsonx/encode.go +++ /dev/null @@ -1,1317 +0,0 @@ -// 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 as defined in -// RFC 7159. The mapping between JSON 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 jsonx - -import ( - "bytes" - "encoding" - "encoding/base64" - "fmt" - "math" - "reflect" - "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 and encodes the result as a JSON string. -// 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. -// So that the JSON will be safe to embed inside HTML <script> tags, -// the string is encoded using HTMLEscape, -// which replaces "<", ">", "&", U+2028, and U+2029 are escaped -// to "\u003c","\u003e", "\u0026", "\u2028", and "\u2029". -// This replacement can be disabled when using an Encoder, -// by calling SetEscapeHTML(false). -// -// 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 value. -// -// Struct values encode as JSON objects. -// Each exported struct field becomes a member of the object, using the -// field name as the object key, unless the field is omitted for one of the -// reasons given below. -// -// The encoding of each struct field can be customized by the format string -// stored under the "json" key in the struct field's tag. -// The format string gives the name of the field, possibly followed by a -// comma-separated list of options. The name may be empty in order to -// specify options without overriding the default field name. -// -// The "omitempty" option specifies that the field should be omitted -// from the encoding if the field has an empty value, defined as -// false, 0, a nil pointer, a nil interface value, and any empty array, -// slice, map, or string. -// -// As a special case, if the field tag is "-", the field is always omitted. -// Note that a field with name "-" can still be generated using the tag "-,". -// -// Examples of struct field tags and their meanings: -// -// // 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"` -// -// // Field is ignored by this package. -// Field int `json:"-"` -// -// // Field appears in JSON as key "-". -// Field int `json:"-,"` -// -// 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, and ASCII punctuation except quotation -// marks, backslash, and comma. -// -// 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 either be a -// string, an integer type, or implement encoding.TextMarshaler. The map keys -// are sorted and used as JSON object keys by applying the following rules, -// subject to the UTF-8 coercion described for string values above: -// - keys of any string type are used directly -// - encoding.TextMarshalers are marshaled -// - integer keys are converted to strings -// -// Pointer values encode as the value pointed to. -// A nil pointer encodes as the null JSON value. -// -// Interface values encode as the value contained in the interface. -// A nil interface value encodes as the null JSON value. -// -// 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 := newEncodeState() - - err := e.marshal(v, encOpts{escapeHTML: true}) - if err != nil { - return nil, err - } - buf := append([]byte(nil), e.Bytes()...) - - e.Reset() - encodeStatePool.Put(e) - - return buf, nil -} - -// MarshalIndent is like Marshal but applies Indent to format the output. -// Each JSON element in the output will begin on a new line beginning with prefix -// followed by one or more copies of indent according to the indentation nesting. -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 types 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. -// -// Deprecated: No longer used; kept for compatibility. -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) -} - -// A MarshalerError represents an error from calling a MarshalJSON or MarshalText method. -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() -} - -func (e *MarshalerError) Unwrap() error { return e.Err } - -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) -} - -// jsonError is an error wrapper type for internal use only. -// Panics with errors are wrapped in jsonError so that the top-level recover -// can distinguish intentional panics from this package. -type jsonError struct{ error } - -func (e *encodeState) marshal(v interface{}, opts encOpts) (err error) { - defer func() { - if r := recover(); r != nil { - if je, ok := r.(jsonError); ok { - err = je.error - } else { - panic(r) - } - } - }() - e.reflectValue(reflect.ValueOf(v), opts) - return nil -} - -// error aborts the encoding by panicking with err wrapped in jsonError. -func (e *encodeState) error(err error) { - panic(jsonError{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, opts encOpts) { - valueEncoder(v)(e, v, opts) -} - -type encOpts struct { - // quoted causes primitive fields to be encoded inside JSON strings. - quoted bool - // escapeHTML causes '<', '>', and '&' to be escaped in JSON strings. - escapeHTML bool -} - -type encoderFunc func(e *encodeState, v reflect.Value, opts encOpts) - -var encoderCache sync.Map // 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 { - if fi, ok := encoderCache.Load(t); ok { - return fi.(encoderFunc) - } - - // 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. - var ( - wg sync.WaitGroup - f encoderFunc - ) - wg.Add(1) - fi, loaded := encoderCache.LoadOrStore(t, encoderFunc(func(e *encodeState, v reflect.Value, opts encOpts) { - wg.Wait() - f(e, v, opts) - })) - if loaded { - return fi.(encoderFunc) - } - - // Compute the real encoder and replace the indirect func with it. - f = newTypeEncoder(t, true) - wg.Done() - encoderCache.Store(t, f) - return f -} - -var ( - marshalerType = reflect.TypeOf((*Marshaler)(nil)).Elem() - textMarshalerType = reflect.TypeOf((*encoding.TextMarshaler)(nil)).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 && reflect.PtrTo(t).Implements(marshalerType) { - return newCondAddrEncoder(addrMarshalerEncoder, newTypeEncoder(t, false)) - } - - if t.Implements(textMarshalerType) { - return textMarshalerEncoder - } - if t.Kind() != reflect.Ptr && allowAddr && 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, _ encOpts) { - e.WriteString("null") -} - -func marshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) { - if v.Kind() == reflect.Ptr && v.IsNil() { - e.WriteString("null") - return - } - m, ok := v.Interface().(Marshaler) - if !ok { - e.WriteString("null") - return - } - b, err := m.MarshalJSON() - if err == nil { - // copy JSON into buffer, checking validity. - err = compact(&e.Buffer, b, opts.escapeHTML) - } - if err != nil { - e.error(&MarshalerError{v.Type(), err}) - } -} - -func addrMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) { - 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, opts.escapeHTML) - } - if err != nil { - e.error(&MarshalerError{v.Type(), err}) - } -} - -func textMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) { - 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, opts.escapeHTML) -} - -func addrTextMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) { - 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, opts.escapeHTML) -} - -func boolEncoder(e *encodeState, v reflect.Value, opts encOpts) { - if opts.quoted { - e.WriteByte('"') - } - if v.Bool() { - e.WriteString("true") - } else { - e.WriteString("false") - } - if opts.quoted { - e.WriteByte('"') - } -} - -func intEncoder(e *encodeState, v reflect.Value, opts encOpts) { - b := strconv.AppendInt(e.scratch[:0], v.Int(), 10) - if opts.quoted { - e.WriteByte('"') - } - e.Write(b) - if opts.quoted { - e.WriteByte('"') - } -} - -func uintEncoder(e *encodeState, v reflect.Value, opts encOpts) { - b := strconv.AppendUint(e.scratch[:0], v.Uint(), 10) - if opts.quoted { - e.WriteByte('"') - } - e.Write(b) - if opts.quoted { - e.WriteByte('"') - } -} - -type floatEncoder int // number of bits - -func (bits floatEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) { - f := v.Float() - if math.IsInf(f, 0) || math.IsNaN(f) { - e.error(&UnsupportedValueError{v, strconv.FormatFloat(f, 'g', -1, int(bits))}) - } - - // Convert as if by ES6 number to string conversion. - // This matches most other JSON generators. - // See golang.org/issue/6384 and golang.org/issue/14135. - // Like fmt %g, but the exponent cutoffs are different - // and exponents themselves are not padded to two digits. - b := e.scratch[:0] - abs := math.Abs(f) - fmt := byte('f') - // Note: Must use float32 comparisons for underlying float32 value to get precise cutoffs right. - if abs != 0 { - if bits == 64 && (abs < 1e-6 || abs >= 1e21) || bits == 32 && (float32(abs) < 1e-6 || float32(abs) >= 1e21) { - fmt = 'e' - } - } - b = strconv.AppendFloat(b, f, fmt, -1, int(bits)) - if fmt == 'e' { - // clean up e-09 to e-9 - n := len(b) - if n >= 4 && b[n-4] == 'e' && b[n-3] == '-' && b[n-2] == '0' { - b[n-2] = b[n-1] - b = b[:n-1] - } - } - - if opts.quoted { - e.WriteByte('"') - } - e.Write(b) - if opts.quoted { - e.WriteByte('"') - } -} - -var ( - float32Encoder = (floatEncoder(32)).encode - float64Encoder = (floatEncoder(64)).encode -) - -func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) { - 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 opts.quoted { - sb, err := Marshal(v.String()) - if err != nil { - e.error(err) - } - e.string(string(sb), opts.escapeHTML) - } else { - e.string(v.String(), opts.escapeHTML) - } -} - -func interfaceEncoder(e *encodeState, v reflect.Value, opts encOpts) { - if v.IsNil() { - e.WriteString("null") - return - } - e.reflectValue(v.Elem(), opts) -} - -func unsupportedTypeEncoder(e *encodeState, v reflect.Value, _ encOpts) { - e.error(&UnsupportedTypeError{v.Type()}) -} - -type structEncoder struct { - fields structFields -} - -type structFields struct { - list []field - nameIndex map[string]int -} - -func (se structEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) { - next := byte('{') -FieldLoop: - for i := range se.fields.list { - f := &se.fields.list[i] - - // Find the nested struct field by following f.index. - fv := v - for _, i := range f.index { - if fv.Kind() == reflect.Ptr { - if fv.IsNil() { - continue FieldLoop - } - fv = fv.Elem() - } - fv = fv.Field(i) - } - - if f.omitEmpty && isEmptyValue(fv) { - continue - } - if f.extra { - keys := fv.MapKeys() - sv := make([]reflectWithString, len(keys)) - for i, v := range keys { - sv[i].v = v - if err := sv[i].resolve(); err != nil { - e.error(&MarshalerError{v.Type(), err}) - } - } - sort.Slice(sv, func(i, j int) bool { return sv[i].s < sv[j].s }) - elemEnc := typeEncoder(fv.Type().Elem()) - for _, kv := range sv { - e.WriteByte(next) - next = ',' - e.string(kv.s, opts.escapeHTML) - e.WriteByte(':') - elemEnc(e, fv.MapIndex(kv.v), opts) - } - continue - } - e.WriteByte(next) - next = ',' - if opts.escapeHTML { - e.WriteString(f.nameEscHTML) - } else { - e.WriteString(f.nameNonEsc) - } - opts.quoted = f.quoted - f.encoder(e, fv, opts) - } - if next == '{' { - e.WriteString("{}") - } else { - e.WriteByte('}') - } -} - -func newStructEncoder(t reflect.Type) encoderFunc { - se := structEncoder{fields: cachedTypeFields(t)} - return se.encode -} - -type mapEncoder struct { - elemEnc encoderFunc -} - -func (me mapEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) { - if v.IsNil() { - e.WriteString("null") - return - } - e.WriteByte('{') - - // Extract and sort the keys. - keys := v.MapKeys() - sv := make([]reflectWithString, len(keys)) - for i, v := range keys { - sv[i].v = v - if err := sv[i].resolve(); err != nil { - e.error(&MarshalerError{v.Type(), err}) - } - } - sort.Slice(sv, func(i, j int) bool { return sv[i].s < sv[j].s }) - - for i, kv := range sv { - if i > 0 { - e.WriteByte(',') - } - e.string(kv.s, opts.escapeHTML) - e.WriteByte(':') - me.elemEnc(e, v.MapIndex(kv.v), opts) - } - e.WriteByte('}') -} - -func newMapEncoder(t reflect.Type) encoderFunc { - switch t.Key().Kind() { - case reflect.String, - reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, - reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: - default: - if !t.Key().Implements(textMarshalerType) { - return unsupportedTypeEncoder - } - } - me := mapEncoder{typeEncoder(t.Elem())} - return me.encode -} - -func encodeByteSlice(e *encodeState, v reflect.Value, _ encOpts) { - if v.IsNil() { - e.WriteString("null") - return - } - s := v.Bytes() - e.WriteByte('"') - encodedLen := base64.StdEncoding.EncodedLen(len(s)) - if encodedLen <= len(e.scratch) { - // If the encoded bytes fit in e.scratch, avoid an extra - // allocation and use the cheaper Encoding.Encode. - dst := e.scratch[:encodedLen] - base64.StdEncoding.Encode(dst, s) - e.Write(dst) - } else if encodedLen <= 1024 { - // The encoded bytes are short enough to allocate for, and - // Encoding.Encode is still cheaper. - dst := make([]byte, encodedLen) - base64.StdEncoding.Encode(dst, s) - e.Write(dst) - } else { - // The encoded bytes are too long to cheaply allocate, and - // Encoding.Encode is no longer noticeably cheaper. - 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, opts encOpts) { - if v.IsNil() { - e.WriteString("null") - return - } - se.arrayEnc(e, v, opts) -} - -func newSliceEncoder(t reflect.Type) encoderFunc { - // Byte slices get special treatment; arrays don't. - if t.Elem().Kind() == reflect.Uint8 { - p := reflect.PtrTo(t.Elem()) - if !p.Implements(marshalerType) && !p.Implements(textMarshalerType) { - return encodeByteSlice - } - } - enc := sliceEncoder{newArrayEncoder(t)} - return enc.encode -} - -type arrayEncoder struct { - elemEnc encoderFunc -} - -func (ae arrayEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) { - e.WriteByte('[') - n := v.Len() - for i := 0; i < n; i++ { - if i > 0 { - e.WriteByte(',') - } - ae.elemEnc(e, v.Index(i), opts) - } - 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, opts encOpts) { - if v.IsNil() { - e.WriteString("null") - return - } - pe.elemEnc(e, v.Elem(), opts) -} - -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, opts encOpts) { - if v.CanAddr() { - ce.canAddrEnc(e, v, opts) - } else { - ce.elseEnc(e, v, opts) - } -} - -// 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. - case !unicode.IsLetter(c) && !unicode.IsDigit(c): - return false - } - } - return true -} - -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 -} - -type reflectWithString struct { - v reflect.Value - s string -} - -func (w *reflectWithString) resolve() error { - if w.v.Kind() == reflect.String { - w.s = w.v.String() - return nil - } - if tm, ok := w.v.Interface().(encoding.TextMarshaler); ok { - buf, err := tm.MarshalText() - w.s = string(buf) - return err - } - switch w.v.Kind() { - case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: - w.s = strconv.FormatInt(w.v.Int(), 10) - return nil - case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: - w.s = strconv.FormatUint(w.v.Uint(), 10) - return nil - } - panic("unexpected map key type") -} - -// NOTE: keep in sync with stringBytes below. -func (e *encodeState) string(s string, escapeHTML bool) { - e.WriteByte('"') - start := 0 - for i := 0; i < len(s); { - if b := s[i]; b < utf8.RuneSelf { - if htmlSafeSet[b] || (!escapeHTML && safeSet[b]) { - i++ - continue - } - if start < i { - e.WriteString(s[start:i]) - } - e.WriteByte('\\') - switch b { - case '\\', '"': - e.WriteByte(b) - case '\n': - e.WriteByte('n') - case '\r': - e.WriteByte('r') - case '\t': - e.WriteByte('t') - default: - // This encodes bytes < 0x20 except for \t, \n and \r. - // If escapeHTML is set, it also escapes <, >, and & - // 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('"') -} - -// NOTE: keep in sync with string above. -func (e *encodeState) stringBytes(s []byte, escapeHTML bool) { - e.WriteByte('"') - start := 0 - for i := 0; i < len(s); { - if b := s[i]; b < utf8.RuneSelf { - if htmlSafeSet[b] || (!escapeHTML && safeSet[b]) { - i++ - continue - } - if start < i { - e.Write(s[start:i]) - } - e.WriteByte('\\') - switch b { - case '\\', '"': - e.WriteByte(b) - case '\n': - e.WriteByte('n') - case '\r': - e.WriteByte('r') - case '\t': - e.WriteByte('t') - default: - // This encodes bytes < 0x20 except for \t, \n and \r. - // If escapeHTML is set, it also escapes <, >, and & - // 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('"') -} - -// A field represents a single field found in a struct. -type field struct { - name string - nameBytes []byte // []byte(name) - equalFold func(s, t []byte) bool // bytes.EqualFold or equivalent - - nameNonEsc string // `"` + name + `":` - nameEscHTML string // `"` + HTMLEscape(name) + `":` - - tag bool - index []int - typ reflect.Type - omitEmpty bool - extra bool - quoted bool - - encoder encoderFunc -} - -// 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) structFields { - // 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. - var count, nextCount map[reflect.Type]int - - // Types already visited at an earlier level. - visited := map[reflect.Type]bool{} - - // Fields found. - var fields []field - - // Buffer to run HTMLEscape on field names. - var nameEscBuf bytes.Buffer - - 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) - isUnexported := sf.PkgPath != "" - if sf.Anonymous { - t := sf.Type - if t.Kind() == reflect.Ptr { - t = t.Elem() - } - if isUnexported && t.Kind() != reflect.Struct { - // Ignore embedded fields of unexported non-struct types. - continue - } - // Do not ignore embedded fields of unexported struct types - // since they may have exported fields. - } else if isUnexported { - // Ignore unexported non-embedded fields. - continue - } - tag := sf.Tag.Get("json") - tagx := sf.Tag.Get("jsonx") - if tag == "-" && tagx == "" { - continue - } - if tagx != "" { - tag = "" - } - 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 maps can be extra. - extra := false - if tagx != "" { - switch ft.Kind() { - case reflect.Map: - extra = true - default: - continue - } - } - - // 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.Uintptr, - 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 - } - field := field{ - name: name, - tag: tagged, - index: index, - typ: ft, - omitEmpty: opts.Contains("omitempty"), - extra: extra, - quoted: quoted, - } - field.nameBytes = []byte(field.name) - field.equalFold = foldFunc(field.nameBytes) - - // Build nameEscHTML and nameNonEsc ahead of time. - nameEscBuf.Reset() - nameEscBuf.WriteString(`"`) - HTMLEscape(&nameEscBuf, field.nameBytes) - nameEscBuf.WriteString(`":`) - field.nameEscHTML = nameEscBuf.String() - field.nameNonEsc = `"` + field.name + `":` - - fields = append(fields, field) - 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, field{name: ft.Name(), index: index, typ: ft}) - } - } - } - } - - sort.Slice(fields, func(i, j int) bool { - x := fields - // sort field by name, breaking ties with depth, then - // breaking ties with "name came from json tag", then - // breaking ties with index sequence. - 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) - }) - - // 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)) - - for i := range fields { - f := &fields[i] - f.encoder = typeEncoder(typeByIndex(t, f.index)) - } - nameIndex := make(map[string]int, len(fields)) - for i, field := range fields { - nameIndex[field.name] = i - } - return structFields{fields, nameIndex} -} - -// 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, then by presence of tag. - // That means that the first field is the dominant one. We need only check - // for error cases: two fields at top level, either both tagged or neither tagged. - if len(fields) > 1 && len(fields[0].index) == len(fields[1].index) && fields[0].tag == fields[1].tag { - return field{}, false - } - return fields[0], true -} - -var fieldCache sync.Map // map[reflect.Type]structFields - -// cachedTypeFields is like typeFields but uses a cache to avoid repeated work. -func cachedTypeFields(t reflect.Type) structFields { - if f, ok := fieldCache.Load(t); ok { - return f.(structFields) - } - f, _ := fieldCache.LoadOrStore(t, typeFields(t)) - return f.(structFields) -} |