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-rw-r--r--src/encoding/json/decode.go1310
1 files changed, 1310 insertions, 0 deletions
diff --git a/src/encoding/json/decode.go b/src/encoding/json/decode.go
new file mode 100644
index 0000000..a9917e7
--- /dev/null
+++ b/src/encoding/json/decode.go
@@ -0,0 +1,1310 @@
+// 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.
+
+// Represents JSON data structure using native Go types: booleans, floats,
+// strings, arrays, and maps.
+
+package json
+
+import (
+ "encoding"
+ "encoding/base64"
+ "fmt"
+ "reflect"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf16"
+ "unicode/utf8"
+)
+
+// Unmarshal parses the JSON-encoded data and stores the result
+// in the value pointed to by v. If v is nil or not a pointer,
+// Unmarshal returns an InvalidUnmarshalError.
+//
+// Unmarshal uses the inverse of the encodings that
+// Marshal uses, allocating maps, slices, and pointers as necessary,
+// with the following additional rules:
+//
+// To unmarshal JSON into a pointer, Unmarshal first handles the case of
+// the JSON being the JSON literal null. In that case, Unmarshal sets
+// the pointer to nil. Otherwise, Unmarshal unmarshals the JSON into
+// the value pointed at by the pointer. If the pointer is nil, Unmarshal
+// allocates a new value for it to point to.
+//
+// To unmarshal JSON into a value implementing the Unmarshaler interface,
+// Unmarshal calls that value's UnmarshalJSON method, including
+// when the input is a JSON null.
+// Otherwise, if the value implements encoding.TextUnmarshaler
+// and the input is a JSON quoted string, Unmarshal calls that value's
+// UnmarshalText method with the unquoted form of the string.
+//
+// To unmarshal JSON into a struct, Unmarshal matches incoming object
+// keys to the keys used by Marshal (either the struct field name or its tag),
+// preferring an exact match but also accepting a case-insensitive match. By
+// default, object keys which don't have a corresponding struct field are
+// ignored (see Decoder.DisallowUnknownFields for an alternative).
+//
+// To unmarshal JSON into an interface value,
+// Unmarshal stores one of these in the interface value:
+//
+// bool, for JSON booleans
+// float64, for JSON numbers
+// string, for JSON strings
+// []interface{}, for JSON arrays
+// map[string]interface{}, for JSON objects
+// nil for JSON null
+//
+// To unmarshal a JSON array into a slice, Unmarshal resets the slice length
+// to zero and then appends each element to the slice.
+// As a special case, to unmarshal an empty JSON array into a slice,
+// Unmarshal replaces the slice with a new empty slice.
+//
+// To unmarshal a JSON array into a Go array, Unmarshal decodes
+// JSON array elements into corresponding Go array elements.
+// If the Go array is smaller than the JSON array,
+// the additional JSON array elements are discarded.
+// If the JSON array is smaller than the Go array,
+// the additional Go array elements are set to zero values.
+//
+// To unmarshal a JSON object into a map, Unmarshal first establishes a map to
+// use. If the map is nil, Unmarshal allocates a new map. Otherwise Unmarshal
+// reuses the existing map, keeping existing entries. Unmarshal then stores
+// key-value pairs from the JSON object into the map. The map's key type must
+// either be any string type, an integer, implement json.Unmarshaler, or
+// implement encoding.TextUnmarshaler.
+//
+// If a JSON value is not appropriate for a given target type,
+// or if a JSON number overflows the target type, Unmarshal
+// skips that field and completes the unmarshaling as best it can.
+// If no more serious errors are encountered, Unmarshal returns
+// an UnmarshalTypeError describing the earliest such error. In any
+// case, it's not guaranteed that all the remaining fields following
+// the problematic one will be unmarshaled into the target object.
+//
+// The JSON null value unmarshals into an interface, map, pointer, or slice
+// by setting that Go value to nil. Because null is often used in JSON to mean
+// ``not present,'' unmarshaling a JSON null into any other Go type has no effect
+// on the value and produces no error.
+//
+// When unmarshaling quoted strings, invalid UTF-8 or
+// invalid UTF-16 surrogate pairs are not treated as an error.
+// Instead, they are replaced by the Unicode replacement
+// character U+FFFD.
+//
+func Unmarshal(data []byte, v interface{}) error {
+ // Check for well-formedness.
+ // Avoids filling out half a data structure
+ // before discovering a JSON syntax error.
+ var d decodeState
+ err := checkValid(data, &d.scan)
+ if err != nil {
+ return err
+ }
+
+ d.init(data)
+ return d.unmarshal(v)
+}
+
+// Unmarshaler is the interface implemented by types
+// that can unmarshal a JSON description of themselves.
+// The input can be assumed to be a valid encoding of
+// a JSON value. UnmarshalJSON must copy the JSON data
+// if it wishes to retain the data after returning.
+//
+// By convention, to approximate the behavior of Unmarshal itself,
+// Unmarshalers implement UnmarshalJSON([]byte("null")) as a no-op.
+type Unmarshaler interface {
+ UnmarshalJSON([]byte) error
+}
+
+// An UnmarshalTypeError describes a JSON value that was
+// not appropriate for a value of a specific Go type.
+type UnmarshalTypeError struct {
+ Value string // description of JSON value - "bool", "array", "number -5"
+ Type reflect.Type // type of Go value it could not be assigned to
+ Offset int64 // error occurred after reading Offset bytes
+ Struct string // name of the struct type containing the field
+ Field string // the full path from root node to the field
+}
+
+func (e *UnmarshalTypeError) Error() string {
+ if e.Struct != "" || e.Field != "" {
+ return "json: cannot unmarshal " + e.Value + " into Go struct field " + e.Struct + "." + e.Field + " of type " + e.Type.String()
+ }
+ return "json: cannot unmarshal " + e.Value + " into Go value of type " + e.Type.String()
+}
+
+// An UnmarshalFieldError describes a JSON object key that
+// led to an unexported (and therefore unwritable) struct field.
+//
+// Deprecated: No longer used; kept for compatibility.
+type UnmarshalFieldError struct {
+ Key string
+ Type reflect.Type
+ Field reflect.StructField
+}
+
+func (e *UnmarshalFieldError) Error() string {
+ return "json: cannot unmarshal object key " + strconv.Quote(e.Key) + " into unexported field " + e.Field.Name + " of type " + e.Type.String()
+}
+
+// An InvalidUnmarshalError describes an invalid argument passed to Unmarshal.
+// (The argument to Unmarshal must be a non-nil pointer.)
+type InvalidUnmarshalError struct {
+ Type reflect.Type
+}
+
+func (e *InvalidUnmarshalError) Error() string {
+ if e.Type == nil {
+ return "json: Unmarshal(nil)"
+ }
+
+ if e.Type.Kind() != reflect.Ptr {
+ return "json: Unmarshal(non-pointer " + e.Type.String() + ")"
+ }
+ return "json: Unmarshal(nil " + e.Type.String() + ")"
+}
+
+func (d *decodeState) unmarshal(v interface{}) error {
+ rv := reflect.ValueOf(v)
+ if rv.Kind() != reflect.Ptr || rv.IsNil() {
+ return &InvalidUnmarshalError{reflect.TypeOf(v)}
+ }
+
+ d.scan.reset()
+ d.scanWhile(scanSkipSpace)
+ // We decode rv not rv.Elem because the Unmarshaler interface
+ // test must be applied at the top level of the value.
+ err := d.value(rv)
+ if err != nil {
+ return d.addErrorContext(err)
+ }
+ return d.savedError
+}
+
+// A Number represents a JSON number literal.
+type Number string
+
+// String returns the literal text of the number.
+func (n Number) String() string { return string(n) }
+
+// Float64 returns the number as a float64.
+func (n Number) Float64() (float64, error) {
+ return strconv.ParseFloat(string(n), 64)
+}
+
+// Int64 returns the number as an int64.
+func (n Number) Int64() (int64, error) {
+ return strconv.ParseInt(string(n), 10, 64)
+}
+
+// An errorContext provides context for type errors during decoding.
+type errorContext struct {
+ Struct reflect.Type
+ FieldStack []string
+}
+
+// decodeState represents the state while decoding a JSON value.
+type decodeState struct {
+ data []byte
+ off int // next read offset in data
+ opcode int // last read result
+ scan scanner
+ errorContext *errorContext
+ savedError error
+ useNumber bool
+ disallowUnknownFields bool
+}
+
+// readIndex returns the position of the last byte read.
+func (d *decodeState) readIndex() int {
+ return d.off - 1
+}
+
+// phasePanicMsg is used as a panic message when we end up with something that
+// shouldn't happen. It can indicate a bug in the JSON decoder, or that
+// something is editing the data slice while the decoder executes.
+const phasePanicMsg = "JSON decoder out of sync - data changing underfoot?"
+
+func (d *decodeState) init(data []byte) *decodeState {
+ d.data = data
+ d.off = 0
+ d.savedError = nil
+ if d.errorContext != nil {
+ d.errorContext.Struct = nil
+ // Reuse the allocated space for the FieldStack slice.
+ d.errorContext.FieldStack = d.errorContext.FieldStack[:0]
+ }
+ return d
+}
+
+// saveError saves the first err it is called with,
+// for reporting at the end of the unmarshal.
+func (d *decodeState) saveError(err error) {
+ if d.savedError == nil {
+ d.savedError = d.addErrorContext(err)
+ }
+}
+
+// addErrorContext returns a new error enhanced with information from d.errorContext
+func (d *decodeState) addErrorContext(err error) error {
+ if d.errorContext != nil && (d.errorContext.Struct != nil || len(d.errorContext.FieldStack) > 0) {
+ switch err := err.(type) {
+ case *UnmarshalTypeError:
+ err.Struct = d.errorContext.Struct.Name()
+ err.Field = strings.Join(d.errorContext.FieldStack, ".")
+ }
+ }
+ return err
+}
+
+// skip scans to the end of what was started.
+func (d *decodeState) skip() {
+ s, data, i := &d.scan, d.data, d.off
+ depth := len(s.parseState)
+ for {
+ op := s.step(s, data[i])
+ i++
+ if len(s.parseState) < depth {
+ d.off = i
+ d.opcode = op
+ return
+ }
+ }
+}
+
+// scanNext processes the byte at d.data[d.off].
+func (d *decodeState) scanNext() {
+ if d.off < len(d.data) {
+ d.opcode = d.scan.step(&d.scan, d.data[d.off])
+ d.off++
+ } else {
+ d.opcode = d.scan.eof()
+ d.off = len(d.data) + 1 // mark processed EOF with len+1
+ }
+}
+
+// scanWhile processes bytes in d.data[d.off:] until it
+// receives a scan code not equal to op.
+func (d *decodeState) scanWhile(op int) {
+ s, data, i := &d.scan, d.data, d.off
+ for i < len(data) {
+ newOp := s.step(s, data[i])
+ i++
+ if newOp != op {
+ d.opcode = newOp
+ d.off = i
+ return
+ }
+ }
+
+ d.off = len(data) + 1 // mark processed EOF with len+1
+ d.opcode = d.scan.eof()
+}
+
+// rescanLiteral is similar to scanWhile(scanContinue), but it specialises the
+// common case where we're decoding a literal. The decoder scans the input
+// twice, once for syntax errors and to check the length of the value, and the
+// second to perform the decoding.
+//
+// Only in the second step do we use decodeState to tokenize literals, so we
+// know there aren't any syntax errors. We can take advantage of that knowledge,
+// and scan a literal's bytes much more quickly.
+func (d *decodeState) rescanLiteral() {
+ data, i := d.data, d.off
+Switch:
+ switch data[i-1] {
+ case '"': // string
+ for ; i < len(data); i++ {
+ switch data[i] {
+ case '\\':
+ i++ // escaped char
+ case '"':
+ i++ // tokenize the closing quote too
+ break Switch
+ }
+ }
+ case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-': // number
+ for ; i < len(data); i++ {
+ switch data[i] {
+ case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ '.', 'e', 'E', '+', '-':
+ default:
+ break Switch
+ }
+ }
+ case 't': // true
+ i += len("rue")
+ case 'f': // false
+ i += len("alse")
+ case 'n': // null
+ i += len("ull")
+ }
+ if i < len(data) {
+ d.opcode = stateEndValue(&d.scan, data[i])
+ } else {
+ d.opcode = scanEnd
+ }
+ d.off = i + 1
+}
+
+// value consumes a JSON value from d.data[d.off-1:], decoding into v, and
+// reads the following byte ahead. If v is invalid, the value is discarded.
+// The first byte of the value has been read already.
+func (d *decodeState) value(v reflect.Value) error {
+ switch d.opcode {
+ default:
+ panic(phasePanicMsg)
+
+ case scanBeginArray:
+ if v.IsValid() {
+ if err := d.array(v); err != nil {
+ return err
+ }
+ } else {
+ d.skip()
+ }
+ d.scanNext()
+
+ case scanBeginObject:
+ if v.IsValid() {
+ if err := d.object(v); err != nil {
+ return err
+ }
+ } else {
+ d.skip()
+ }
+ d.scanNext()
+
+ case scanBeginLiteral:
+ // All bytes inside literal return scanContinue op code.
+ start := d.readIndex()
+ d.rescanLiteral()
+
+ if v.IsValid() {
+ if err := d.literalStore(d.data[start:d.readIndex()], v, false); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+type unquotedValue struct{}
+
+// valueQuoted is like value but decodes a
+// quoted string literal or literal null into an interface value.
+// If it finds anything other than a quoted string literal or null,
+// valueQuoted returns unquotedValue{}.
+func (d *decodeState) valueQuoted() interface{} {
+ switch d.opcode {
+ default:
+ panic(phasePanicMsg)
+
+ case scanBeginArray, scanBeginObject:
+ d.skip()
+ d.scanNext()
+
+ case scanBeginLiteral:
+ v := d.literalInterface()
+ switch v.(type) {
+ case nil, string:
+ return v
+ }
+ }
+ return unquotedValue{}
+}
+
+// indirect walks down v allocating pointers as needed,
+// until it gets to a non-pointer.
+// If it encounters an Unmarshaler, indirect stops and returns that.
+// If decodingNull is true, indirect stops at the first settable pointer so it
+// can be set to nil.
+func indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnmarshaler, reflect.Value) {
+ // Issue #24153 indicates that it is generally not a guaranteed property
+ // that you may round-trip a reflect.Value by calling Value.Addr().Elem()
+ // and expect the value to still be settable for values derived from
+ // unexported embedded struct fields.
+ //
+ // The logic below effectively does this when it first addresses the value
+ // (to satisfy possible pointer methods) and continues to dereference
+ // subsequent pointers as necessary.
+ //
+ // After the first round-trip, we set v back to the original value to
+ // preserve the original RW flags contained in reflect.Value.
+ v0 := v
+ haveAddr := false
+
+ // If v is a named type and is addressable,
+ // start with its address, so that if the type has pointer methods,
+ // we find them.
+ if v.Kind() != reflect.Ptr && v.Type().Name() != "" && v.CanAddr() {
+ haveAddr = true
+ v = v.Addr()
+ }
+ for {
+ // Load value from interface, but only if the result will be
+ // usefully addressable.
+ if v.Kind() == reflect.Interface && !v.IsNil() {
+ e := v.Elem()
+ if e.Kind() == reflect.Ptr && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Ptr) {
+ haveAddr = false
+ v = e
+ continue
+ }
+ }
+
+ if v.Kind() != reflect.Ptr {
+ break
+ }
+
+ if decodingNull && v.CanSet() {
+ break
+ }
+
+ // Prevent infinite loop if v is an interface pointing to its own address:
+ // var v interface{}
+ // v = &v
+ if v.Elem().Kind() == reflect.Interface && v.Elem().Elem() == v {
+ v = v.Elem()
+ break
+ }
+ if v.IsNil() {
+ v.Set(reflect.New(v.Type().Elem()))
+ }
+ if v.Type().NumMethod() > 0 && v.CanInterface() {
+ if u, ok := v.Interface().(Unmarshaler); ok {
+ return u, nil, reflect.Value{}
+ }
+ if !decodingNull {
+ if u, ok := v.Interface().(encoding.TextUnmarshaler); ok {
+ return nil, u, reflect.Value{}
+ }
+ }
+ }
+
+ if haveAddr {
+ v = v0 // restore original value after round-trip Value.Addr().Elem()
+ haveAddr = false
+ } else {
+ v = v.Elem()
+ }
+ }
+ return nil, nil, v
+}
+
+// array consumes an array from d.data[d.off-1:], decoding into v.
+// The first byte of the array ('[') has been read already.
+func (d *decodeState) array(v reflect.Value) error {
+ // Check for unmarshaler.
+ u, ut, pv := indirect(v, false)
+ if u != nil {
+ start := d.readIndex()
+ d.skip()
+ return u.UnmarshalJSON(d.data[start:d.off])
+ }
+ if ut != nil {
+ d.saveError(&UnmarshalTypeError{Value: "array", Type: v.Type(), Offset: int64(d.off)})
+ d.skip()
+ return nil
+ }
+ v = pv
+
+ // Check type of target.
+ switch v.Kind() {
+ case reflect.Interface:
+ if v.NumMethod() == 0 {
+ // Decoding into nil interface? Switch to non-reflect code.
+ ai := d.arrayInterface()
+ v.Set(reflect.ValueOf(ai))
+ return nil
+ }
+ // Otherwise it's invalid.
+ fallthrough
+ default:
+ d.saveError(&UnmarshalTypeError{Value: "array", Type: v.Type(), Offset: int64(d.off)})
+ d.skip()
+ return nil
+ case reflect.Array, reflect.Slice:
+ break
+ }
+
+ i := 0
+ for {
+ // Look ahead for ] - can only happen on first iteration.
+ d.scanWhile(scanSkipSpace)
+ if d.opcode == scanEndArray {
+ break
+ }
+
+ // Get element of array, growing if necessary.
+ if v.Kind() == reflect.Slice {
+ // Grow slice if necessary
+ if i >= v.Cap() {
+ newcap := v.Cap() + v.Cap()/2
+ if newcap < 4 {
+ newcap = 4
+ }
+ newv := reflect.MakeSlice(v.Type(), v.Len(), newcap)
+ reflect.Copy(newv, v)
+ v.Set(newv)
+ }
+ if i >= v.Len() {
+ v.SetLen(i + 1)
+ }
+ }
+
+ if i < v.Len() {
+ // Decode into element.
+ if err := d.value(v.Index(i)); err != nil {
+ return err
+ }
+ } else {
+ // Ran out of fixed array: skip.
+ if err := d.value(reflect.Value{}); err != nil {
+ return err
+ }
+ }
+ i++
+
+ // Next token must be , or ].
+ if d.opcode == scanSkipSpace {
+ d.scanWhile(scanSkipSpace)
+ }
+ if d.opcode == scanEndArray {
+ break
+ }
+ if d.opcode != scanArrayValue {
+ panic(phasePanicMsg)
+ }
+ }
+
+ if i < v.Len() {
+ if v.Kind() == reflect.Array {
+ // Array. Zero the rest.
+ z := reflect.Zero(v.Type().Elem())
+ for ; i < v.Len(); i++ {
+ v.Index(i).Set(z)
+ }
+ } else {
+ v.SetLen(i)
+ }
+ }
+ if i == 0 && v.Kind() == reflect.Slice {
+ v.Set(reflect.MakeSlice(v.Type(), 0, 0))
+ }
+ return nil
+}
+
+var nullLiteral = []byte("null")
+var textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+
+// object consumes an object from d.data[d.off-1:], decoding into v.
+// The first byte ('{') of the object has been read already.
+func (d *decodeState) object(v reflect.Value) error {
+ // Check for unmarshaler.
+ u, ut, pv := indirect(v, false)
+ if u != nil {
+ start := d.readIndex()
+ d.skip()
+ return u.UnmarshalJSON(d.data[start:d.off])
+ }
+ if ut != nil {
+ d.saveError(&UnmarshalTypeError{Value: "object", Type: v.Type(), Offset: int64(d.off)})
+ d.skip()
+ return nil
+ }
+ v = pv
+ t := v.Type()
+
+ // Decoding into nil interface? Switch to non-reflect code.
+ if v.Kind() == reflect.Interface && v.NumMethod() == 0 {
+ oi := d.objectInterface()
+ v.Set(reflect.ValueOf(oi))
+ return nil
+ }
+
+ var fields structFields
+
+ // Check type of target:
+ // struct or
+ // map[T1]T2 where T1 is string, an integer type,
+ // or an encoding.TextUnmarshaler
+ switch v.Kind() {
+ case reflect.Map:
+ // Map key must either have string kind, have an integer kind,
+ // or be an encoding.TextUnmarshaler.
+ 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 !reflect.PtrTo(t.Key()).Implements(textUnmarshalerType) {
+ d.saveError(&UnmarshalTypeError{Value: "object", Type: t, Offset: int64(d.off)})
+ d.skip()
+ return nil
+ }
+ }
+ if v.IsNil() {
+ v.Set(reflect.MakeMap(t))
+ }
+ case reflect.Struct:
+ fields = cachedTypeFields(t)
+ // ok
+ default:
+ d.saveError(&UnmarshalTypeError{Value: "object", Type: t, Offset: int64(d.off)})
+ d.skip()
+ return nil
+ }
+
+ var mapElem reflect.Value
+ var origErrorContext errorContext
+ if d.errorContext != nil {
+ origErrorContext = *d.errorContext
+ }
+
+ for {
+ // Read opening " of string key or closing }.
+ d.scanWhile(scanSkipSpace)
+ if d.opcode == scanEndObject {
+ // closing } - can only happen on first iteration.
+ break
+ }
+ if d.opcode != scanBeginLiteral {
+ panic(phasePanicMsg)
+ }
+
+ // Read key.
+ start := d.readIndex()
+ d.rescanLiteral()
+ item := d.data[start:d.readIndex()]
+ key, ok := unquoteBytes(item)
+ if !ok {
+ panic(phasePanicMsg)
+ }
+
+ // Figure out field corresponding to key.
+ var subv reflect.Value
+ destring := false // whether the value is wrapped in a string to be decoded first
+
+ if v.Kind() == reflect.Map {
+ elemType := t.Elem()
+ if !mapElem.IsValid() {
+ mapElem = reflect.New(elemType).Elem()
+ } else {
+ mapElem.Set(reflect.Zero(elemType))
+ }
+ subv = mapElem
+ } else {
+ var f *field
+ if i, ok := fields.nameIndex[string(key)]; ok {
+ // Found an exact name match.
+ f = &fields.list[i]
+ } else {
+ // Fall back to the expensive case-insensitive
+ // linear search.
+ for i := range fields.list {
+ ff := &fields.list[i]
+ if ff.equalFold(ff.nameBytes, key) {
+ f = ff
+ break
+ }
+ }
+ }
+ if f != nil {
+ subv = v
+ destring = f.quoted
+ for _, i := range f.index {
+ if subv.Kind() == reflect.Ptr {
+ if subv.IsNil() {
+ // If a struct embeds a pointer to an unexported type,
+ // it is not possible to set a newly allocated value
+ // since the field is unexported.
+ //
+ // See https://golang.org/issue/21357
+ if !subv.CanSet() {
+ d.saveError(fmt.Errorf("json: cannot set embedded pointer to unexported struct: %v", subv.Type().Elem()))
+ // Invalidate subv to ensure d.value(subv) skips over
+ // the JSON value without assigning it to subv.
+ subv = reflect.Value{}
+ destring = false
+ break
+ }
+ subv.Set(reflect.New(subv.Type().Elem()))
+ }
+ subv = subv.Elem()
+ }
+ subv = subv.Field(i)
+ }
+ if d.errorContext == nil {
+ d.errorContext = new(errorContext)
+ }
+ d.errorContext.FieldStack = append(d.errorContext.FieldStack, f.name)
+ d.errorContext.Struct = t
+ } else if d.disallowUnknownFields {
+ d.saveError(fmt.Errorf("json: unknown field %q", key))
+ }
+ }
+
+ // Read : before value.
+ if d.opcode == scanSkipSpace {
+ d.scanWhile(scanSkipSpace)
+ }
+ if d.opcode != scanObjectKey {
+ panic(phasePanicMsg)
+ }
+ d.scanWhile(scanSkipSpace)
+
+ if destring {
+ switch qv := d.valueQuoted().(type) {
+ case nil:
+ if err := d.literalStore(nullLiteral, subv, false); err != nil {
+ return err
+ }
+ case string:
+ if err := d.literalStore([]byte(qv), subv, true); err != nil {
+ return err
+ }
+ default:
+ d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal unquoted value into %v", subv.Type()))
+ }
+ } else {
+ if err := d.value(subv); err != nil {
+ return err
+ }
+ }
+
+ // Write value back to map;
+ // if using struct, subv points into struct already.
+ if v.Kind() == reflect.Map {
+ kt := t.Key()
+ var kv reflect.Value
+ switch {
+ case reflect.PtrTo(kt).Implements(textUnmarshalerType):
+ kv = reflect.New(kt)
+ if err := d.literalStore(item, kv, true); err != nil {
+ return err
+ }
+ kv = kv.Elem()
+ case kt.Kind() == reflect.String:
+ kv = reflect.ValueOf(key).Convert(kt)
+ default:
+ switch kt.Kind() {
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ s := string(key)
+ n, err := strconv.ParseInt(s, 10, 64)
+ if err != nil || reflect.Zero(kt).OverflowInt(n) {
+ d.saveError(&UnmarshalTypeError{Value: "number " + s, Type: kt, Offset: int64(start + 1)})
+ break
+ }
+ kv = reflect.ValueOf(n).Convert(kt)
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ s := string(key)
+ n, err := strconv.ParseUint(s, 10, 64)
+ if err != nil || reflect.Zero(kt).OverflowUint(n) {
+ d.saveError(&UnmarshalTypeError{Value: "number " + s, Type: kt, Offset: int64(start + 1)})
+ break
+ }
+ kv = reflect.ValueOf(n).Convert(kt)
+ default:
+ panic("json: Unexpected key type") // should never occur
+ }
+ }
+ if kv.IsValid() {
+ v.SetMapIndex(kv, subv)
+ }
+ }
+
+ // Next token must be , or }.
+ if d.opcode == scanSkipSpace {
+ d.scanWhile(scanSkipSpace)
+ }
+ if d.errorContext != nil {
+ // Reset errorContext to its original state.
+ // Keep the same underlying array for FieldStack, to reuse the
+ // space and avoid unnecessary allocs.
+ d.errorContext.FieldStack = d.errorContext.FieldStack[:len(origErrorContext.FieldStack)]
+ d.errorContext.Struct = origErrorContext.Struct
+ }
+ if d.opcode == scanEndObject {
+ break
+ }
+ if d.opcode != scanObjectValue {
+ panic(phasePanicMsg)
+ }
+ }
+ return nil
+}
+
+// convertNumber converts the number literal s to a float64 or a Number
+// depending on the setting of d.useNumber.
+func (d *decodeState) convertNumber(s string) (interface{}, error) {
+ if d.useNumber {
+ return Number(s), nil
+ }
+ f, err := strconv.ParseFloat(s, 64)
+ if err != nil {
+ return nil, &UnmarshalTypeError{Value: "number " + s, Type: reflect.TypeOf(0.0), Offset: int64(d.off)}
+ }
+ return f, nil
+}
+
+var numberType = reflect.TypeOf(Number(""))
+
+// literalStore decodes a literal stored in item into v.
+//
+// fromQuoted indicates whether this literal came from unwrapping a
+// string from the ",string" struct tag option. this is used only to
+// produce more helpful error messages.
+func (d *decodeState) literalStore(item []byte, v reflect.Value, fromQuoted bool) error {
+ // Check for unmarshaler.
+ if len(item) == 0 {
+ //Empty string given
+ d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
+ return nil
+ }
+ isNull := item[0] == 'n' // null
+ u, ut, pv := indirect(v, isNull)
+ if u != nil {
+ return u.UnmarshalJSON(item)
+ }
+ if ut != nil {
+ if item[0] != '"' {
+ if fromQuoted {
+ d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
+ return nil
+ }
+ val := "number"
+ switch item[0] {
+ case 'n':
+ val = "null"
+ case 't', 'f':
+ val = "bool"
+ }
+ d.saveError(&UnmarshalTypeError{Value: val, Type: v.Type(), Offset: int64(d.readIndex())})
+ return nil
+ }
+ s, ok := unquoteBytes(item)
+ if !ok {
+ if fromQuoted {
+ return fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type())
+ }
+ panic(phasePanicMsg)
+ }
+ return ut.UnmarshalText(s)
+ }
+
+ v = pv
+
+ switch c := item[0]; c {
+ case 'n': // null
+ // The main parser checks that only true and false can reach here,
+ // but if this was a quoted string input, it could be anything.
+ if fromQuoted && string(item) != "null" {
+ d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
+ break
+ }
+ switch v.Kind() {
+ case reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
+ v.Set(reflect.Zero(v.Type()))
+ // otherwise, ignore null for primitives/string
+ }
+ case 't', 'f': // true, false
+ value := item[0] == 't'
+ // The main parser checks that only true and false can reach here,
+ // but if this was a quoted string input, it could be anything.
+ if fromQuoted && string(item) != "true" && string(item) != "false" {
+ d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
+ break
+ }
+ switch v.Kind() {
+ default:
+ if fromQuoted {
+ d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
+ } else {
+ d.saveError(&UnmarshalTypeError{Value: "bool", Type: v.Type(), Offset: int64(d.readIndex())})
+ }
+ case reflect.Bool:
+ v.SetBool(value)
+ case reflect.Interface:
+ if v.NumMethod() == 0 {
+ v.Set(reflect.ValueOf(value))
+ } else {
+ d.saveError(&UnmarshalTypeError{Value: "bool", Type: v.Type(), Offset: int64(d.readIndex())})
+ }
+ }
+
+ case '"': // string
+ s, ok := unquoteBytes(item)
+ if !ok {
+ if fromQuoted {
+ return fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type())
+ }
+ panic(phasePanicMsg)
+ }
+ switch v.Kind() {
+ default:
+ d.saveError(&UnmarshalTypeError{Value: "string", Type: v.Type(), Offset: int64(d.readIndex())})
+ case reflect.Slice:
+ if v.Type().Elem().Kind() != reflect.Uint8 {
+ d.saveError(&UnmarshalTypeError{Value: "string", Type: v.Type(), Offset: int64(d.readIndex())})
+ break
+ }
+ b := make([]byte, base64.StdEncoding.DecodedLen(len(s)))
+ n, err := base64.StdEncoding.Decode(b, s)
+ if err != nil {
+ d.saveError(err)
+ break
+ }
+ v.SetBytes(b[:n])
+ case reflect.String:
+ if v.Type() == numberType && !isValidNumber(string(s)) {
+ return fmt.Errorf("json: invalid number literal, trying to unmarshal %q into Number", item)
+ }
+ v.SetString(string(s))
+ case reflect.Interface:
+ if v.NumMethod() == 0 {
+ v.Set(reflect.ValueOf(string(s)))
+ } else {
+ d.saveError(&UnmarshalTypeError{Value: "string", Type: v.Type(), Offset: int64(d.readIndex())})
+ }
+ }
+
+ default: // number
+ if c != '-' && (c < '0' || c > '9') {
+ if fromQuoted {
+ return fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type())
+ }
+ panic(phasePanicMsg)
+ }
+ s := string(item)
+ switch v.Kind() {
+ default:
+ if v.Kind() == reflect.String && v.Type() == numberType {
+ // s must be a valid number, because it's
+ // already been tokenized.
+ v.SetString(s)
+ break
+ }
+ if fromQuoted {
+ return fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type())
+ }
+ d.saveError(&UnmarshalTypeError{Value: "number", Type: v.Type(), Offset: int64(d.readIndex())})
+ case reflect.Interface:
+ n, err := d.convertNumber(s)
+ if err != nil {
+ d.saveError(err)
+ break
+ }
+ if v.NumMethod() != 0 {
+ d.saveError(&UnmarshalTypeError{Value: "number", Type: v.Type(), Offset: int64(d.readIndex())})
+ break
+ }
+ v.Set(reflect.ValueOf(n))
+
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ n, err := strconv.ParseInt(s, 10, 64)
+ if err != nil || v.OverflowInt(n) {
+ d.saveError(&UnmarshalTypeError{Value: "number " + s, Type: v.Type(), Offset: int64(d.readIndex())})
+ break
+ }
+ v.SetInt(n)
+
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ n, err := strconv.ParseUint(s, 10, 64)
+ if err != nil || v.OverflowUint(n) {
+ d.saveError(&UnmarshalTypeError{Value: "number " + s, Type: v.Type(), Offset: int64(d.readIndex())})
+ break
+ }
+ v.SetUint(n)
+
+ case reflect.Float32, reflect.Float64:
+ n, err := strconv.ParseFloat(s, v.Type().Bits())
+ if err != nil || v.OverflowFloat(n) {
+ d.saveError(&UnmarshalTypeError{Value: "number " + s, Type: v.Type(), Offset: int64(d.readIndex())})
+ break
+ }
+ v.SetFloat(n)
+ }
+ }
+ return nil
+}
+
+// The xxxInterface routines build up a value to be stored
+// in an empty interface. They are not strictly necessary,
+// but they avoid the weight of reflection in this common case.
+
+// valueInterface is like value but returns interface{}
+func (d *decodeState) valueInterface() (val interface{}) {
+ switch d.opcode {
+ default:
+ panic(phasePanicMsg)
+ case scanBeginArray:
+ val = d.arrayInterface()
+ d.scanNext()
+ case scanBeginObject:
+ val = d.objectInterface()
+ d.scanNext()
+ case scanBeginLiteral:
+ val = d.literalInterface()
+ }
+ return
+}
+
+// arrayInterface is like array but returns []interface{}.
+func (d *decodeState) arrayInterface() []interface{} {
+ var v = make([]interface{}, 0)
+ for {
+ // Look ahead for ] - can only happen on first iteration.
+ d.scanWhile(scanSkipSpace)
+ if d.opcode == scanEndArray {
+ break
+ }
+
+ v = append(v, d.valueInterface())
+
+ // Next token must be , or ].
+ if d.opcode == scanSkipSpace {
+ d.scanWhile(scanSkipSpace)
+ }
+ if d.opcode == scanEndArray {
+ break
+ }
+ if d.opcode != scanArrayValue {
+ panic(phasePanicMsg)
+ }
+ }
+ return v
+}
+
+// objectInterface is like object but returns map[string]interface{}.
+func (d *decodeState) objectInterface() map[string]interface{} {
+ m := make(map[string]interface{})
+ for {
+ // Read opening " of string key or closing }.
+ d.scanWhile(scanSkipSpace)
+ if d.opcode == scanEndObject {
+ // closing } - can only happen on first iteration.
+ break
+ }
+ if d.opcode != scanBeginLiteral {
+ panic(phasePanicMsg)
+ }
+
+ // Read string key.
+ start := d.readIndex()
+ d.rescanLiteral()
+ item := d.data[start:d.readIndex()]
+ key, ok := unquote(item)
+ if !ok {
+ panic(phasePanicMsg)
+ }
+
+ // Read : before value.
+ if d.opcode == scanSkipSpace {
+ d.scanWhile(scanSkipSpace)
+ }
+ if d.opcode != scanObjectKey {
+ panic(phasePanicMsg)
+ }
+ d.scanWhile(scanSkipSpace)
+
+ // Read value.
+ m[key] = d.valueInterface()
+
+ // Next token must be , or }.
+ if d.opcode == scanSkipSpace {
+ d.scanWhile(scanSkipSpace)
+ }
+ if d.opcode == scanEndObject {
+ break
+ }
+ if d.opcode != scanObjectValue {
+ panic(phasePanicMsg)
+ }
+ }
+ return m
+}
+
+// literalInterface consumes and returns a literal from d.data[d.off-1:] and
+// it reads the following byte ahead. The first byte of the literal has been
+// read already (that's how the caller knows it's a literal).
+func (d *decodeState) literalInterface() interface{} {
+ // All bytes inside literal return scanContinue op code.
+ start := d.readIndex()
+ d.rescanLiteral()
+
+ item := d.data[start:d.readIndex()]
+
+ switch c := item[0]; c {
+ case 'n': // null
+ return nil
+
+ case 't', 'f': // true, false
+ return c == 't'
+
+ case '"': // string
+ s, ok := unquote(item)
+ if !ok {
+ panic(phasePanicMsg)
+ }
+ return s
+
+ default: // number
+ if c != '-' && (c < '0' || c > '9') {
+ panic(phasePanicMsg)
+ }
+ n, err := d.convertNumber(string(item))
+ if err != nil {
+ d.saveError(err)
+ }
+ return n
+ }
+}
+
+// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
+// or it returns -1.
+func getu4(s []byte) rune {
+ if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
+ return -1
+ }
+ var r rune
+ for _, c := range s[2:6] {
+ switch {
+ case '0' <= c && c <= '9':
+ c = c - '0'
+ case 'a' <= c && c <= 'f':
+ c = c - 'a' + 10
+ case 'A' <= c && c <= 'F':
+ c = c - 'A' + 10
+ default:
+ return -1
+ }
+ r = r*16 + rune(c)
+ }
+ return r
+}
+
+// unquote converts a quoted JSON string literal s into an actual string t.
+// The rules are different than for Go, so cannot use strconv.Unquote.
+func unquote(s []byte) (t string, ok bool) {
+ s, ok = unquoteBytes(s)
+ t = string(s)
+ return
+}
+
+func unquoteBytes(s []byte) (t []byte, ok bool) {
+ if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
+ return
+ }
+ s = s[1 : len(s)-1]
+
+ // Check for unusual characters. If there are none,
+ // then no unquoting is needed, so return a slice of the
+ // original bytes.
+ r := 0
+ for r < len(s) {
+ c := s[r]
+ if c == '\\' || c == '"' || c < ' ' {
+ break
+ }
+ if c < utf8.RuneSelf {
+ r++
+ continue
+ }
+ rr, size := utf8.DecodeRune(s[r:])
+ if rr == utf8.RuneError && size == 1 {
+ break
+ }
+ r += size
+ }
+ if r == len(s) {
+ return s, true
+ }
+
+ b := make([]byte, len(s)+2*utf8.UTFMax)
+ w := copy(b, s[0:r])
+ for r < len(s) {
+ // Out of room? Can only happen if s is full of
+ // malformed UTF-8 and we're replacing each
+ // byte with RuneError.
+ if w >= len(b)-2*utf8.UTFMax {
+ nb := make([]byte, (len(b)+utf8.UTFMax)*2)
+ copy(nb, b[0:w])
+ b = nb
+ }
+ switch c := s[r]; {
+ case c == '\\':
+ r++
+ if r >= len(s) {
+ return
+ }
+ switch s[r] {
+ default:
+ return
+ case '"', '\\', '/', '\'':
+ b[w] = s[r]
+ r++
+ w++
+ case 'b':
+ b[w] = '\b'
+ r++
+ w++
+ case 'f':
+ b[w] = '\f'
+ r++
+ w++
+ case 'n':
+ b[w] = '\n'
+ r++
+ w++
+ case 'r':
+ b[w] = '\r'
+ r++
+ w++
+ case 't':
+ b[w] = '\t'
+ r++
+ w++
+ case 'u':
+ r--
+ rr := getu4(s[r:])
+ if rr < 0 {
+ return
+ }
+ r += 6
+ if utf16.IsSurrogate(rr) {
+ rr1 := getu4(s[r:])
+ if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
+ // A valid pair; consume.
+ r += 6
+ w += utf8.EncodeRune(b[w:], dec)
+ break
+ }
+ // Invalid surrogate; fall back to replacement rune.
+ rr = unicode.ReplacementChar
+ }
+ w += utf8.EncodeRune(b[w:], rr)
+ }
+
+ // Quote, control characters are invalid.
+ case c == '"', c < ' ':
+ return
+
+ // ASCII
+ case c < utf8.RuneSelf:
+ b[w] = c
+ r++
+ w++
+
+ // Coerce to well-formed UTF-8.
+ default:
+ rr, size := utf8.DecodeRune(s[r:])
+ r += size
+ w += utf8.EncodeRune(b[w:], rr)
+ }
+ }
+ return b[0:w], true
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 05:29:03 +0000