prometheus/vendor/github.com/golang/protobuf/jsonpb/encode.go

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// Copyright 2015 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 jsonpb
import (
"encoding/json"
"errors"
"fmt"
"io"
"math"
"reflect"
"sort"
"strconv"
"strings"
"time"
"github.com/golang/protobuf/proto"
"google.golang.org/protobuf/encoding/protojson"
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
const wrapJSONMarshalV2 = false
// Marshaler is a configurable object for marshaling protocol buffer messages
// to the specified JSON representation.
type Marshaler struct {
// OrigName specifies whether to use the original protobuf name for fields.
OrigName bool
// EnumsAsInts specifies whether to render enum values as integers,
// as opposed to string values.
EnumsAsInts bool
// EmitDefaults specifies whether to render fields with zero values.
EmitDefaults bool
// Indent controls whether the output is compact or not.
// If empty, the output is compact JSON. Otherwise, every JSON object
// entry and JSON array value will be on its own line.
// Each line will be preceded by repeated copies of Indent, where the
// number of copies is the current indentation depth.
Indent string
// AnyResolver is used to resolve the google.protobuf.Any well-known type.
// If unset, the global registry is used by default.
AnyResolver AnyResolver
}
// JSONPBMarshaler is implemented by protobuf messages that customize the
// way they are marshaled to JSON. Messages that implement this should also
// implement JSONPBUnmarshaler so that the custom format can be parsed.
//
// The JSON marshaling must follow the proto to JSON specification:
// https://developers.google.com/protocol-buffers/docs/proto3#json
//
// Deprecated: Custom types should implement protobuf reflection instead.
type JSONPBMarshaler interface {
MarshalJSONPB(*Marshaler) ([]byte, error)
}
// Marshal serializes a protobuf message as JSON into w.
func (jm *Marshaler) Marshal(w io.Writer, m proto.Message) error {
b, err := jm.marshal(m)
if len(b) > 0 {
if _, err := w.Write(b); err != nil {
return err
}
}
return err
}
// MarshalToString serializes a protobuf message as JSON in string form.
func (jm *Marshaler) MarshalToString(m proto.Message) (string, error) {
b, err := jm.marshal(m)
if err != nil {
return "", err
}
return string(b), nil
}
func (jm *Marshaler) marshal(m proto.Message) ([]byte, error) {
v := reflect.ValueOf(m)
if m == nil || (v.Kind() == reflect.Ptr && v.IsNil()) {
return nil, errors.New("Marshal called with nil")
}
// Check for custom marshalers first since they may not properly
// implement protobuf reflection that the logic below relies on.
if jsm, ok := m.(JSONPBMarshaler); ok {
return jsm.MarshalJSONPB(jm)
}
if wrapJSONMarshalV2 {
opts := protojson.MarshalOptions{
UseProtoNames: jm.OrigName,
UseEnumNumbers: jm.EnumsAsInts,
EmitUnpopulated: jm.EmitDefaults,
Indent: jm.Indent,
}
if jm.AnyResolver != nil {
opts.Resolver = anyResolver{jm.AnyResolver}
}
return opts.Marshal(proto.MessageReflect(m).Interface())
} else {
// Check for unpopulated required fields first.
m2 := proto.MessageReflect(m)
if err := protoV2.CheckInitialized(m2.Interface()); err != nil {
return nil, err
}
w := jsonWriter{Marshaler: jm}
err := w.marshalMessage(m2, "", "")
return w.buf, err
}
}
type jsonWriter struct {
*Marshaler
buf []byte
}
func (w *jsonWriter) write(s string) {
w.buf = append(w.buf, s...)
}
func (w *jsonWriter) marshalMessage(m protoreflect.Message, indent, typeURL string) error {
if jsm, ok := proto.MessageV1(m.Interface()).(JSONPBMarshaler); ok {
b, err := jsm.MarshalJSONPB(w.Marshaler)
if err != nil {
return err
}
if typeURL != "" {
// we are marshaling this object to an Any type
var js map[string]*json.RawMessage
if err = json.Unmarshal(b, &js); err != nil {
return fmt.Errorf("type %T produced invalid JSON: %v", m.Interface(), err)
}
turl, err := json.Marshal(typeURL)
if err != nil {
return fmt.Errorf("failed to marshal type URL %q to JSON: %v", typeURL, err)
}
js["@type"] = (*json.RawMessage)(&turl)
if b, err = json.Marshal(js); err != nil {
return err
}
}
w.write(string(b))
return nil
}
md := m.Descriptor()
fds := md.Fields()
// Handle well-known types.
const secondInNanos = int64(time.Second / time.Nanosecond)
switch wellKnownType(md.FullName()) {
case "Any":
return w.marshalAny(m, indent)
case "BoolValue", "BytesValue", "StringValue",
"Int32Value", "UInt32Value", "FloatValue",
"Int64Value", "UInt64Value", "DoubleValue":
fd := fds.ByNumber(1)
return w.marshalValue(fd, m.Get(fd), indent)
case "Duration":
// "Generated output always contains 0, 3, 6, or 9 fractional digits,
// depending on required precision."
s := m.Get(fds.ByNumber(1)).Int()
ns := m.Get(fds.ByNumber(2)).Int()
if ns <= -secondInNanos || ns >= secondInNanos {
return fmt.Errorf("ns out of range (%v, %v)", -secondInNanos, secondInNanos)
}
if (s > 0 && ns < 0) || (s < 0 && ns > 0) {
return errors.New("signs of seconds and nanos do not match")
}
if s < 0 {
ns = -ns
}
x := fmt.Sprintf("%d.%09d", s, ns)
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, ".000")
w.write(fmt.Sprintf(`"%vs"`, x))
return nil
case "Timestamp":
// "RFC 3339, where generated output will always be Z-normalized
// and uses 0, 3, 6 or 9 fractional digits."
s := m.Get(fds.ByNumber(1)).Int()
ns := m.Get(fds.ByNumber(2)).Int()
if ns < 0 || ns >= secondInNanos {
return fmt.Errorf("ns out of range [0, %v)", secondInNanos)
}
t := time.Unix(s, ns).UTC()
// time.RFC3339Nano isn't exactly right (we need to get 3/6/9 fractional digits).
x := t.Format("2006-01-02T15:04:05.000000000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, ".000")
w.write(fmt.Sprintf(`"%vZ"`, x))
return nil
case "Value":
// JSON value; which is a null, number, string, bool, object, or array.
od := md.Oneofs().Get(0)
fd := m.WhichOneof(od)
if fd == nil {
return errors.New("nil Value")
}
return w.marshalValue(fd, m.Get(fd), indent)
case "Struct", "ListValue":
// JSON object or array.
fd := fds.ByNumber(1)
return w.marshalValue(fd, m.Get(fd), indent)
}
w.write("{")
if w.Indent != "" {
w.write("\n")
}
firstField := true
if typeURL != "" {
if err := w.marshalTypeURL(indent, typeURL); err != nil {
return err
}
firstField = false
}
for i := 0; i < fds.Len(); {
fd := fds.Get(i)
if od := fd.ContainingOneof(); od != nil {
fd = m.WhichOneof(od)
i += od.Fields().Len()
if fd == nil {
continue
}
} else {
i++
}
v := m.Get(fd)
if !m.Has(fd) {
if !w.EmitDefaults || fd.ContainingOneof() != nil {
continue
}
if fd.Cardinality() != protoreflect.Repeated && (fd.Message() != nil || fd.Syntax() == protoreflect.Proto2) {
v = protoreflect.Value{} // use "null" for singular messages or proto2 scalars
}
}
if !firstField {
w.writeComma()
}
if err := w.marshalField(fd, v, indent); err != nil {
return err
}
firstField = false
}
// Handle proto2 extensions.
if md.ExtensionRanges().Len() > 0 {
// Collect a sorted list of all extension descriptor and values.
type ext struct {
desc protoreflect.FieldDescriptor
val protoreflect.Value
}
var exts []ext
m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
if fd.IsExtension() {
exts = append(exts, ext{fd, v})
}
return true
})
sort.Slice(exts, func(i, j int) bool {
return exts[i].desc.Number() < exts[j].desc.Number()
})
for _, ext := range exts {
if !firstField {
w.writeComma()
}
if err := w.marshalField(ext.desc, ext.val, indent); err != nil {
return err
}
firstField = false
}
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
}
w.write("}")
return nil
}
func (w *jsonWriter) writeComma() {
if w.Indent != "" {
w.write(",\n")
} else {
w.write(",")
}
}
func (w *jsonWriter) marshalAny(m protoreflect.Message, indent string) error {
// "If the Any contains a value that has a special JSON mapping,
// it will be converted as follows: {"@type": xxx, "value": yyy}.
// Otherwise, the value will be converted into a JSON object,
// and the "@type" field will be inserted to indicate the actual data type."
md := m.Descriptor()
typeURL := m.Get(md.Fields().ByNumber(1)).String()
rawVal := m.Get(md.Fields().ByNumber(2)).Bytes()
var m2 protoreflect.Message
if w.AnyResolver != nil {
mi, err := w.AnyResolver.Resolve(typeURL)
if err != nil {
return err
}
m2 = proto.MessageReflect(mi)
} else {
mt, err := protoregistry.GlobalTypes.FindMessageByURL(typeURL)
if err != nil {
return err
}
m2 = mt.New()
}
if err := protoV2.Unmarshal(rawVal, m2.Interface()); err != nil {
return err
}
if wellKnownType(m2.Descriptor().FullName()) == "" {
return w.marshalMessage(m2, indent, typeURL)
}
w.write("{")
if w.Indent != "" {
w.write("\n")
}
if err := w.marshalTypeURL(indent, typeURL); err != nil {
return err
}
w.writeComma()
if w.Indent != "" {
w.write(indent)
w.write(w.Indent)
w.write(`"value": `)
} else {
w.write(`"value":`)
}
if err := w.marshalMessage(m2, indent+w.Indent, ""); err != nil {
return err
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
}
w.write("}")
return nil
}
func (w *jsonWriter) marshalTypeURL(indent, typeURL string) error {
if w.Indent != "" {
w.write(indent)
w.write(w.Indent)
}
w.write(`"@type":`)
if w.Indent != "" {
w.write(" ")
}
b, err := json.Marshal(typeURL)
if err != nil {
return err
}
w.write(string(b))
return nil
}
// marshalField writes field description and value to the Writer.
func (w *jsonWriter) marshalField(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
if w.Indent != "" {
w.write(indent)
w.write(w.Indent)
}
w.write(`"`)
switch {
case fd.IsExtension():
// For message set, use the fname of the message as the extension name.
name := string(fd.FullName())
if isMessageSet(fd.ContainingMessage()) {
name = strings.TrimSuffix(name, ".message_set_extension")
}
w.write("[" + name + "]")
case w.OrigName:
name := string(fd.Name())
if fd.Kind() == protoreflect.GroupKind {
name = string(fd.Message().Name())
}
w.write(name)
default:
w.write(string(fd.JSONName()))
}
w.write(`":`)
if w.Indent != "" {
w.write(" ")
}
return w.marshalValue(fd, v, indent)
}
func (w *jsonWriter) marshalValue(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
switch {
case fd.IsList():
w.write("[")
comma := ""
lv := v.List()
for i := 0; i < lv.Len(); i++ {
w.write(comma)
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
w.write(w.Indent)
}
if err := w.marshalSingularValue(fd, lv.Get(i), indent+w.Indent); err != nil {
return err
}
comma = ","
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
}
w.write("]")
return nil
case fd.IsMap():
kfd := fd.MapKey()
vfd := fd.MapValue()
mv := v.Map()
// Collect a sorted list of all map keys and values.
type entry struct{ key, val protoreflect.Value }
var entries []entry
mv.Range(func(k protoreflect.MapKey, v protoreflect.Value) bool {
entries = append(entries, entry{k.Value(), v})
return true
})
sort.Slice(entries, func(i, j int) bool {
switch kfd.Kind() {
case protoreflect.BoolKind:
return !entries[i].key.Bool() && entries[j].key.Bool()
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind, protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
return entries[i].key.Int() < entries[j].key.Int()
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind, protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
return entries[i].key.Uint() < entries[j].key.Uint()
case protoreflect.StringKind:
return entries[i].key.String() < entries[j].key.String()
default:
panic("invalid kind")
}
})
w.write(`{`)
comma := ""
for _, entry := range entries {
w.write(comma)
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
w.write(w.Indent)
}
s := fmt.Sprint(entry.key.Interface())
b, err := json.Marshal(s)
if err != nil {
return err
}
w.write(string(b))
w.write(`:`)
if w.Indent != "" {
w.write(` `)
}
if err := w.marshalSingularValue(vfd, entry.val, indent+w.Indent); err != nil {
return err
}
comma = ","
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
}
w.write(`}`)
return nil
default:
return w.marshalSingularValue(fd, v, indent)
}
}
func (w *jsonWriter) marshalSingularValue(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
switch {
case !v.IsValid():
w.write("null")
return nil
case fd.Message() != nil:
return w.marshalMessage(v.Message(), indent+w.Indent, "")
case fd.Enum() != nil:
if fd.Enum().FullName() == "google.protobuf.NullValue" {
w.write("null")
return nil
}
vd := fd.Enum().Values().ByNumber(v.Enum())
if vd == nil || w.EnumsAsInts {
w.write(strconv.Itoa(int(v.Enum())))
} else {
w.write(`"` + string(vd.Name()) + `"`)
}
return nil
default:
switch v.Interface().(type) {
case float32, float64:
switch {
case math.IsInf(v.Float(), +1):
w.write(`"Infinity"`)
return nil
case math.IsInf(v.Float(), -1):
w.write(`"-Infinity"`)
return nil
case math.IsNaN(v.Float()):
w.write(`"NaN"`)
return nil
}
case int64, uint64:
w.write(fmt.Sprintf(`"%d"`, v.Interface()))
return nil
}
b, err := json.Marshal(v.Interface())
if err != nil {
return err
}
w.write(string(b))
return nil
}
}