chord/vendor/github.com/go-json-experiment/json/arshal_any.go
2025-03-15 20:42:37 -04:00

282 lines
7.9 KiB
Go

// Copyright 2022 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
import (
"cmp"
"reflect"
"strconv"
"github.com/go-json-experiment/json/internal"
"github.com/go-json-experiment/json/internal/jsonflags"
"github.com/go-json-experiment/json/internal/jsonopts"
"github.com/go-json-experiment/json/internal/jsonwire"
"github.com/go-json-experiment/json/jsontext"
)
// This file contains an optimized marshal and unmarshal implementation
// for the any type. This type is often used when the Go program has
// no knowledge of the JSON schema. This is a common enough occurrence
// to justify the complexity of adding logic for this.
// marshalValueAny marshals a Go any as a JSON value.
// This assumes that there are no special formatting directives
// for any possible nested value.
func marshalValueAny(enc *jsontext.Encoder, val any, mo *jsonopts.Struct) error {
switch val := val.(type) {
case nil:
return enc.WriteToken(jsontext.Null)
case bool:
return enc.WriteToken(jsontext.Bool(val))
case string:
return enc.WriteToken(jsontext.String(val))
case float64:
return enc.WriteToken(jsontext.Float(val))
case map[string]any:
return marshalObjectAny(enc, val, mo)
case []any:
return marshalArrayAny(enc, val, mo)
default:
v := newAddressableValue(reflect.TypeOf(val))
v.Set(reflect.ValueOf(val))
marshal := lookupArshaler(v.Type()).marshal
if mo.Marshalers != nil {
marshal, _ = mo.Marshalers.(*Marshalers).lookup(marshal, v.Type())
}
return marshal(enc, v, mo)
}
}
// unmarshalValueAny unmarshals a JSON value as a Go any.
// This assumes that there are no special formatting directives
// for any possible nested value.
// Duplicate names must be rejected since this does not implement merging.
func unmarshalValueAny(dec *jsontext.Decoder, uo *jsonopts.Struct) (any, error) {
switch k := dec.PeekKind(); k {
case '{':
return unmarshalObjectAny(dec, uo)
case '[':
return unmarshalArrayAny(dec, uo)
default:
xd := export.Decoder(dec)
var flags jsonwire.ValueFlags
val, err := xd.ReadValue(&flags)
if err != nil {
return nil, err
}
switch val.Kind() {
case 'n':
return nil, nil
case 'f':
return false, nil
case 't':
return true, nil
case '"':
val = jsonwire.UnquoteMayCopy(val, flags.IsVerbatim())
if xd.StringCache == nil {
xd.StringCache = new(stringCache)
}
return makeString(xd.StringCache, val), nil
case '0':
if uo.Flags.Get(jsonflags.UnmarshalAnyWithRawNumber) {
return internal.RawNumberOf(val), nil
}
fv, ok := jsonwire.ParseFloat(val, 64)
if !ok {
return fv, newUnmarshalErrorAfterWithValue(dec, float64Type, strconv.ErrRange)
}
return fv, nil
default:
panic("BUG: invalid kind: " + k.String())
}
}
}
// marshalObjectAny marshals a Go map[string]any as a JSON object
// (or as a JSON null if nil and [jsonflags.FormatNilMapAsNull]).
func marshalObjectAny(enc *jsontext.Encoder, obj map[string]any, mo *jsonopts.Struct) error {
// Check for cycles.
xe := export.Encoder(enc)
if xe.Tokens.Depth() > startDetectingCyclesAfter {
v := reflect.ValueOf(obj)
if err := visitPointer(&xe.SeenPointers, v); err != nil {
return newMarshalErrorBefore(enc, anyType, err)
}
defer leavePointer(&xe.SeenPointers, v)
}
// Handle empty maps.
if len(obj) == 0 {
if mo.Flags.Get(jsonflags.FormatNilMapAsNull) && obj == nil {
return enc.WriteToken(jsontext.Null)
}
// Optimize for marshaling an empty map without any preceding whitespace.
if !mo.Flags.Get(jsonflags.AnyWhitespace) && !xe.Tokens.Last.NeedObjectName() {
xe.Buf = append(xe.Tokens.MayAppendDelim(xe.Buf, '{'), "{}"...)
xe.Tokens.Last.Increment()
if xe.NeedFlush() {
return xe.Flush()
}
return nil
}
}
if err := enc.WriteToken(jsontext.BeginObject); err != nil {
return err
}
// A Go map guarantees that each entry has a unique key
// The only possibility of duplicates is due to invalid UTF-8.
if !mo.Flags.Get(jsonflags.AllowInvalidUTF8) {
xe.Tokens.Last.DisableNamespace()
}
if !mo.Flags.Get(jsonflags.Deterministic) || len(obj) <= 1 {
for name, val := range obj {
if err := enc.WriteToken(jsontext.String(name)); err != nil {
return err
}
if err := marshalValueAny(enc, val, mo); err != nil {
return err
}
}
} else {
names := getStrings(len(obj))
var i int
for name := range obj {
(*names)[i] = name
i++
}
names.Sort()
for _, name := range *names {
if err := enc.WriteToken(jsontext.String(name)); err != nil {
return err
}
if err := marshalValueAny(enc, obj[name], mo); err != nil {
return err
}
}
putStrings(names)
}
if err := enc.WriteToken(jsontext.EndObject); err != nil {
return err
}
return nil
}
// unmarshalObjectAny unmarshals a JSON object as a Go map[string]any.
// It panics if not decoding a JSON object.
func unmarshalObjectAny(dec *jsontext.Decoder, uo *jsonopts.Struct) (map[string]any, error) {
switch tok, err := dec.ReadToken(); {
case err != nil:
return nil, err
case tok.Kind() != '{':
panic("BUG: invalid kind: " + tok.Kind().String())
}
obj := make(map[string]any)
// A Go map guarantees that each entry has a unique key
// The only possibility of duplicates is due to invalid UTF-8.
if !uo.Flags.Get(jsonflags.AllowInvalidUTF8) {
export.Decoder(dec).Tokens.Last.DisableNamespace()
}
var errUnmarshal error
for dec.PeekKind() != '}' {
tok, err := dec.ReadToken()
if err != nil {
return obj, err
}
name := tok.String()
// Manually check for duplicate names.
if _, ok := obj[name]; ok {
// TODO: Unread the object name.
name := export.Decoder(dec).PreviousTokenOrValue()
err := newDuplicateNameError(dec.StackPointer(), nil, dec.InputOffset()-len64(name))
return obj, err
}
val, err := unmarshalValueAny(dec, uo)
obj[name] = val
if err != nil {
if isFatalError(err, uo.Flags) {
return obj, err
}
errUnmarshal = cmp.Or(err, errUnmarshal)
}
}
if _, err := dec.ReadToken(); err != nil {
return obj, err
}
return obj, errUnmarshal
}
// marshalArrayAny marshals a Go []any as a JSON array
// (or as a JSON null if nil and [jsonflags.FormatNilSliceAsNull]).
func marshalArrayAny(enc *jsontext.Encoder, arr []any, mo *jsonopts.Struct) error {
// Check for cycles.
xe := export.Encoder(enc)
if xe.Tokens.Depth() > startDetectingCyclesAfter {
v := reflect.ValueOf(arr)
if err := visitPointer(&xe.SeenPointers, v); err != nil {
return newMarshalErrorBefore(enc, sliceAnyType, err)
}
defer leavePointer(&xe.SeenPointers, v)
}
// Handle empty slices.
if len(arr) == 0 {
if mo.Flags.Get(jsonflags.FormatNilSliceAsNull) && arr == nil {
return enc.WriteToken(jsontext.Null)
}
// Optimize for marshaling an empty slice without any preceding whitespace.
if !mo.Flags.Get(jsonflags.AnyWhitespace) && !xe.Tokens.Last.NeedObjectName() {
xe.Buf = append(xe.Tokens.MayAppendDelim(xe.Buf, '['), "[]"...)
xe.Tokens.Last.Increment()
if xe.NeedFlush() {
return xe.Flush()
}
return nil
}
}
if err := enc.WriteToken(jsontext.BeginArray); err != nil {
return err
}
for _, val := range arr {
if err := marshalValueAny(enc, val, mo); err != nil {
return err
}
}
if err := enc.WriteToken(jsontext.EndArray); err != nil {
return err
}
return nil
}
// unmarshalArrayAny unmarshals a JSON array as a Go []any.
// It panics if not decoding a JSON array.
func unmarshalArrayAny(dec *jsontext.Decoder, uo *jsonopts.Struct) ([]any, error) {
switch tok, err := dec.ReadToken(); {
case err != nil:
return nil, err
case tok.Kind() != '[':
panic("BUG: invalid kind: " + tok.Kind().String())
}
arr := []any{}
var errUnmarshal error
for dec.PeekKind() != ']' {
val, err := unmarshalValueAny(dec, uo)
arr = append(arr, val)
if err != nil {
if isFatalError(err, uo.Flags) {
return arr, err
}
errUnmarshal = cmp.Or(errUnmarshal, err)
}
}
if _, err := dec.ReadToken(); err != nil {
return arr, err
}
return arr, errUnmarshal
}