blob: c7c3b8a444ce4707d1c4c386f039ba24a78217a4 [file] [log] [blame]
// Copyright 2018 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 prototext
import (
"fmt"
"sort"
"unicode/utf8"
"google.golang.org/protobuf/internal/encoding/messageset"
"google.golang.org/protobuf/internal/encoding/text"
"google.golang.org/protobuf/internal/encoding/wire"
"google.golang.org/protobuf/internal/errors"
"google.golang.org/protobuf/internal/fieldnum"
"google.golang.org/protobuf/internal/flags"
"google.golang.org/protobuf/internal/mapsort"
"google.golang.org/protobuf/internal/pragma"
"google.golang.org/protobuf/proto"
pref "google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
// Marshal writes the given proto.Message in textproto format using default
// options. Do not depend on the output being stable. It may change over time
// across different versions of the program.
func Marshal(m proto.Message) ([]byte, error) {
return MarshalOptions{}.Marshal(m)
}
// MarshalOptions is a configurable text format marshaler.
type MarshalOptions struct {
pragma.NoUnkeyedLiterals
// AllowPartial allows messages that have missing required fields to marshal
// without returning an error. If AllowPartial is false (the default),
// Marshal will return error if there are any missing required fields.
AllowPartial bool
// EmitUnknown specifies whether to emit unknown fields in the output.
// If specified, the unmarshaler may be unable to parse the output.
// The default is to exclude unknown fields.
EmitUnknown bool
// If Indent is a non-empty string, it causes entries for a Message to be
// preceded by the indent and trailed by a newline. Indent can only be
// composed of space or tab characters.
Indent string
// Resolver is used for looking up types when expanding google.protobuf.Any
// messages. If nil, this defaults to using protoregistry.GlobalTypes.
Resolver interface {
protoregistry.ExtensionTypeResolver
protoregistry.MessageTypeResolver
}
}
// Marshal writes the given proto.Message in textproto format using options in
// MarshalOptions object. Do not depend on the output being stable. It may
// change over time across different versions of the program.
func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
if o.Resolver == nil {
o.Resolver = protoregistry.GlobalTypes
}
v, err := o.marshalMessage(m.ProtoReflect())
if err != nil {
return nil, err
}
delims := [2]byte{'{', '}'}
const outputASCII = false
b, err := text.Marshal(v, o.Indent, delims, outputASCII)
if err != nil {
return nil, err
}
if o.AllowPartial {
return b, nil
}
return b, proto.IsInitialized(m)
}
// marshalMessage converts a protoreflect.Message to a text.Value.
func (o MarshalOptions) marshalMessage(m pref.Message) (text.Value, error) {
messageDesc := m.Descriptor()
if !flags.ProtoLegacy && messageset.IsMessageSet(messageDesc) {
return text.Value{}, errors.New("no support for proto1 MessageSets")
}
// Handle Any expansion.
if messageDesc.FullName() == "google.protobuf.Any" {
if msg, err := o.marshalAny(m); err == nil {
// Return as is if no error.
return msg, nil
}
// Otherwise continue on to marshal Any as a regular message.
}
// Handle known fields.
var msgFields [][2]text.Value
fieldDescs := messageDesc.Fields()
size := fieldDescs.Len()
for i := 0; i < size; {
fd := fieldDescs.Get(i)
if od := fd.ContainingOneof(); od != nil {
fd = m.WhichOneof(od)
i += od.Fields().Len()
} else {
i++
}
if fd == nil || !m.Has(fd) {
continue
}
name := text.ValueOf(fd.Name())
// Use type name for group field name.
if fd.Kind() == pref.GroupKind {
name = text.ValueOf(fd.Message().Name())
}
pval := m.Get(fd)
var err error
msgFields, err = o.appendField(msgFields, name, pval, fd)
if err != nil {
return text.Value{}, err
}
}
// Handle extensions.
var err error
msgFields, err = o.appendExtensions(msgFields, m)
if err != nil {
return text.Value{}, err
}
// Handle unknown fields.
if o.EmitUnknown {
msgFields = appendUnknown(msgFields, m.GetUnknown())
}
return text.ValueOf(msgFields), nil
}
// appendField marshals a protoreflect.Value and appends it to the given [][2]text.Value.
func (o MarshalOptions) appendField(msgFields [][2]text.Value, name text.Value, pval pref.Value, fd pref.FieldDescriptor) ([][2]text.Value, error) {
switch {
case fd.IsList():
items, err := o.marshalList(pval.List(), fd)
if err != nil {
return msgFields, err
}
for _, item := range items {
msgFields = append(msgFields, [2]text.Value{name, item})
}
case fd.IsMap():
items, err := o.marshalMap(pval.Map(), fd)
if err != nil {
return msgFields, err
}
for _, item := range items {
msgFields = append(msgFields, [2]text.Value{name, item})
}
default:
tval, err := o.marshalSingular(pval, fd)
if err != nil {
return msgFields, err
}
msgFields = append(msgFields, [2]text.Value{name, tval})
}
return msgFields, nil
}
// marshalSingular converts a non-repeated field value to text.Value.
// This includes all scalar types, enums, messages, and groups.
func (o MarshalOptions) marshalSingular(val pref.Value, fd pref.FieldDescriptor) (text.Value, error) {
kind := fd.Kind()
switch kind {
case pref.BoolKind,
pref.Int32Kind, pref.Sint32Kind, pref.Uint32Kind,
pref.Int64Kind, pref.Sint64Kind, pref.Uint64Kind,
pref.Sfixed32Kind, pref.Fixed32Kind,
pref.Sfixed64Kind, pref.Fixed64Kind,
pref.FloatKind, pref.DoubleKind,
pref.BytesKind:
return text.ValueOf(val.Interface()), nil
case pref.StringKind:
s := val.String()
if !utf8.ValidString(s) {
return text.Value{}, errors.InvalidUTF8(string(fd.FullName()))
}
return text.ValueOf(s), nil
case pref.EnumKind:
num := val.Enum()
if desc := fd.Enum().Values().ByNumber(num); desc != nil {
return text.ValueOf(desc.Name()), nil
}
// Use numeric value if there is no enum description.
return text.ValueOf(int32(num)), nil
case pref.MessageKind, pref.GroupKind:
return o.marshalMessage(val.Message())
}
panic(fmt.Sprintf("%v has unknown kind: %v", fd.FullName(), kind))
}
// marshalList converts a protoreflect.List to []text.Value.
func (o MarshalOptions) marshalList(list pref.List, fd pref.FieldDescriptor) ([]text.Value, error) {
size := list.Len()
values := make([]text.Value, 0, size)
for i := 0; i < size; i++ {
item := list.Get(i)
val, err := o.marshalSingular(item, fd)
if err != nil {
// Return already marshaled values.
return values, err
}
values = append(values, val)
}
return values, nil
}
var (
mapKeyName = text.ValueOf(pref.Name("key"))
mapValueName = text.ValueOf(pref.Name("value"))
)
// marshalMap converts a protoreflect.Map to []text.Value.
func (o MarshalOptions) marshalMap(mmap pref.Map, fd pref.FieldDescriptor) ([]text.Value, error) {
// values is a list of messages.
values := make([]text.Value, 0, mmap.Len())
var err error
mapsort.Range(mmap, fd.MapKey().Kind(), func(key pref.MapKey, val pref.Value) bool {
var keyTxtVal text.Value
keyTxtVal, err = o.marshalSingular(key.Value(), fd.MapKey())
if err != nil {
return false
}
var valTxtVal text.Value
valTxtVal, err = o.marshalSingular(val, fd.MapValue())
if err != nil {
return false
}
// Map entry (message) contains 2 fields, first field for key and second field for value.
msg := text.ValueOf([][2]text.Value{
{mapKeyName, keyTxtVal},
{mapValueName, valTxtVal},
})
values = append(values, msg)
err = nil
return true
})
if err != nil {
return nil, err
}
return values, nil
}
// appendExtensions marshals extension fields and appends them to the given [][2]text.Value.
func (o MarshalOptions) appendExtensions(msgFields [][2]text.Value, m pref.Message) ([][2]text.Value, error) {
var err error
var entries [][2]text.Value
m.Range(func(fd pref.FieldDescriptor, v pref.Value) bool {
if !fd.IsExtension() {
return true
}
// For MessageSet extensions, the name used is the parent message.
name := fd.FullName()
if messageset.IsMessageSetExtension(fd) {
name = name.Parent()
}
// Use string type to produce [name] format.
tname := text.ValueOf(string(name))
entries, err = o.appendField(entries, tname, v, fd)
if err != nil {
return false
}
err = nil
return true
})
if err != nil {
return msgFields, err
}
// Sort extensions lexicographically and append to output.
sort.SliceStable(entries, func(i, j int) bool {
return entries[i][0].String() < entries[j][0].String()
})
return append(msgFields, entries...), nil
}
// appendUnknown parses the given []byte and appends field(s) into the given fields slice.
// This function assumes proper encoding in the given []byte.
func appendUnknown(fields [][2]text.Value, b []byte) [][2]text.Value {
for len(b) > 0 {
var value interface{}
num, wtype, n := wire.ConsumeTag(b)
b = b[n:]
switch wtype {
case wire.VarintType:
value, n = wire.ConsumeVarint(b)
case wire.Fixed32Type:
value, n = wire.ConsumeFixed32(b)
case wire.Fixed64Type:
value, n = wire.ConsumeFixed64(b)
case wire.BytesType:
value, n = wire.ConsumeBytes(b)
case wire.StartGroupType:
var v []byte
v, n = wire.ConsumeGroup(num, b)
var msg [][2]text.Value
value = appendUnknown(msg, v)
default:
panic(fmt.Sprintf("error parsing unknown field wire type: %v", wtype))
}
fields = append(fields, [2]text.Value{text.ValueOf(uint32(num)), text.ValueOf(value)})
b = b[n:]
}
return fields
}
// marshalAny converts a google.protobuf.Any protoreflect.Message to a text.Value.
func (o MarshalOptions) marshalAny(m pref.Message) (text.Value, error) {
fds := m.Descriptor().Fields()
fdType := fds.ByNumber(fieldnum.Any_TypeUrl)
fdValue := fds.ByNumber(fieldnum.Any_Value)
typeURL := m.Get(fdType).String()
value := m.Get(fdValue)
emt, err := o.Resolver.FindMessageByURL(typeURL)
if err != nil {
return text.Value{}, err
}
em := emt.New().Interface()
err = proto.UnmarshalOptions{
AllowPartial: true,
Resolver: o.Resolver,
}.Unmarshal(value.Bytes(), em)
if err != nil {
return text.Value{}, err
}
msg, err := o.marshalMessage(em.ProtoReflect())
if err != nil {
return text.Value{}, err
}
// Expanded Any field value contains only a single field with the type_url field value as the
// field name in [] and a text marshaled field value of the embedded message.
msgFields := [][2]text.Value{
{
text.ValueOf(typeURL),
msg,
},
}
return text.ValueOf(msgFields), nil
}