gitea/vendor/google.golang.org/protobuf/internal/impl/decode.go

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// Copyright 2019 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 impl
import (
"math/bits"
"google.golang.org/protobuf/encoding/protowire"
"google.golang.org/protobuf/internal/errors"
"google.golang.org/protobuf/internal/flags"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
preg "google.golang.org/protobuf/reflect/protoregistry"
"google.golang.org/protobuf/runtime/protoiface"
piface "google.golang.org/protobuf/runtime/protoiface"
)
var errDecode = errors.New("cannot parse invalid wire-format data")
type unmarshalOptions struct {
flags protoiface.UnmarshalInputFlags
resolver interface {
FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error)
FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error)
}
}
func (o unmarshalOptions) Options() proto.UnmarshalOptions {
return proto.UnmarshalOptions{
Merge: true,
AllowPartial: true,
DiscardUnknown: o.DiscardUnknown(),
Resolver: o.resolver,
}
}
func (o unmarshalOptions) DiscardUnknown() bool { return o.flags&piface.UnmarshalDiscardUnknown != 0 }
func (o unmarshalOptions) IsDefault() bool {
return o.flags == 0 && o.resolver == preg.GlobalTypes
}
var lazyUnmarshalOptions = unmarshalOptions{
resolver: preg.GlobalTypes,
}
type unmarshalOutput struct {
n int // number of bytes consumed
initialized bool
}
// unmarshal is protoreflect.Methods.Unmarshal.
func (mi *MessageInfo) unmarshal(in piface.UnmarshalInput) (piface.UnmarshalOutput, error) {
var p pointer
if ms, ok := in.Message.(*messageState); ok {
p = ms.pointer()
} else {
p = in.Message.(*messageReflectWrapper).pointer()
}
out, err := mi.unmarshalPointer(in.Buf, p, 0, unmarshalOptions{
flags: in.Flags,
resolver: in.Resolver,
})
var flags piface.UnmarshalOutputFlags
if out.initialized {
flags |= piface.UnmarshalInitialized
}
return piface.UnmarshalOutput{
Flags: flags,
}, err
}
// errUnknown is returned during unmarshaling to indicate a parse error that
// should result in a field being placed in the unknown fields section (for example,
// when the wire type doesn't match) as opposed to the entire unmarshal operation
// failing (for example, when a field extends past the available input).
//
// This is a sentinel error which should never be visible to the user.
var errUnknown = errors.New("unknown")
func (mi *MessageInfo) unmarshalPointer(b []byte, p pointer, groupTag protowire.Number, opts unmarshalOptions) (out unmarshalOutput, err error) {
mi.init()
if flags.ProtoLegacy && mi.isMessageSet {
return unmarshalMessageSet(mi, b, p, opts)
}
initialized := true
var requiredMask uint64
var exts *map[int32]ExtensionField
start := len(b)
for len(b) > 0 {
// Parse the tag (field number and wire type).
var tag uint64
if b[0] < 0x80 {
tag = uint64(b[0])
b = b[1:]
} else if len(b) >= 2 && b[1] < 128 {
tag = uint64(b[0]&0x7f) + uint64(b[1])<<7
b = b[2:]
} else {
var n int
tag, n = protowire.ConsumeVarint(b)
if n < 0 {
return out, errDecode
}
b = b[n:]
}
var num protowire.Number
if n := tag >> 3; n < uint64(protowire.MinValidNumber) || n > uint64(protowire.MaxValidNumber) {
return out, errDecode
} else {
num = protowire.Number(n)
}
wtyp := protowire.Type(tag & 7)
if wtyp == protowire.EndGroupType {
if num != groupTag {
return out, errDecode
}
groupTag = 0
break
}
var f *coderFieldInfo
if int(num) < len(mi.denseCoderFields) {
f = mi.denseCoderFields[num]
} else {
f = mi.coderFields[num]
}
var n int
err := errUnknown
switch {
case f != nil:
if f.funcs.unmarshal == nil {
break
}
var o unmarshalOutput
o, err = f.funcs.unmarshal(b, p.Apply(f.offset), wtyp, f, opts)
n = o.n
if err != nil {
break
}
requiredMask |= f.validation.requiredBit
if f.funcs.isInit != nil && !o.initialized {
initialized = false
}
default:
// Possible extension.
if exts == nil && mi.extensionOffset.IsValid() {
exts = p.Apply(mi.extensionOffset).Extensions()
if *exts == nil {
*exts = make(map[int32]ExtensionField)
}
}
if exts == nil {
break
}
var o unmarshalOutput
o, err = mi.unmarshalExtension(b, num, wtyp, *exts, opts)
if err != nil {
break
}
n = o.n
if !o.initialized {
initialized = false
}
}
if err != nil {
if err != errUnknown {
return out, err
}
n = protowire.ConsumeFieldValue(num, wtyp, b)
if n < 0 {
return out, errDecode
}
if !opts.DiscardUnknown() && mi.unknownOffset.IsValid() {
u := mi.mutableUnknownBytes(p)
*u = protowire.AppendTag(*u, num, wtyp)
*u = append(*u, b[:n]...)
}
}
b = b[n:]
}
if groupTag != 0 {
return out, errDecode
}
if mi.numRequiredFields > 0 && bits.OnesCount64(requiredMask) != int(mi.numRequiredFields) {
initialized = false
}
if initialized {
out.initialized = true
}
out.n = start - len(b)
return out, nil
}
func (mi *MessageInfo) unmarshalExtension(b []byte, num protowire.Number, wtyp protowire.Type, exts map[int32]ExtensionField, opts unmarshalOptions) (out unmarshalOutput, err error) {
x := exts[int32(num)]
xt := x.Type()
if xt == nil {
var err error
xt, err = opts.resolver.FindExtensionByNumber(mi.Desc.FullName(), num)
if err != nil {
if err == preg.NotFound {
return out, errUnknown
}
return out, errors.New("%v: unable to resolve extension %v: %v", mi.Desc.FullName(), num, err)
}
}
xi := getExtensionFieldInfo(xt)
if xi.funcs.unmarshal == nil {
return out, errUnknown
}
if flags.LazyUnmarshalExtensions {
if opts.IsDefault() && x.canLazy(xt) {
out, valid := skipExtension(b, xi, num, wtyp, opts)
switch valid {
case ValidationValid:
if out.initialized {
x.appendLazyBytes(xt, xi, num, wtyp, b[:out.n])
exts[int32(num)] = x
return out, nil
}
case ValidationInvalid:
return out, errDecode
case ValidationUnknown:
}
}
}
ival := x.Value()
if !ival.IsValid() && xi.unmarshalNeedsValue {
// Create a new message, list, or map value to fill in.
// For enums, create a prototype value to let the unmarshal func know the
// concrete type.
ival = xt.New()
}
v, out, err := xi.funcs.unmarshal(b, ival, num, wtyp, opts)
if err != nil {
return out, err
}
if xi.funcs.isInit == nil {
out.initialized = true
}
x.Set(xt, v)
exts[int32(num)] = x
return out, nil
}
func skipExtension(b []byte, xi *extensionFieldInfo, num protowire.Number, wtyp protowire.Type, opts unmarshalOptions) (out unmarshalOutput, _ ValidationStatus) {
if xi.validation.mi == nil {
return out, ValidationUnknown
}
xi.validation.mi.init()
switch xi.validation.typ {
case validationTypeMessage:
if wtyp != protowire.BytesType {
return out, ValidationUnknown
}
v, n := protowire.ConsumeBytes(b)
if n < 0 {
return out, ValidationUnknown
}
out, st := xi.validation.mi.validate(v, 0, opts)
out.n = n
return out, st
case validationTypeGroup:
if wtyp != protowire.StartGroupType {
return out, ValidationUnknown
}
out, st := xi.validation.mi.validate(b, num, opts)
return out, st
default:
return out, ValidationUnknown
}
}