messageset.go

Documentation: google.golang.org/protobuf/proto

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package proto
     6  
     7  import (
     8  	"google.golang.org/protobuf/encoding/protowire"
     9  	"google.golang.org/protobuf/internal/encoding/messageset"
    10  	"google.golang.org/protobuf/internal/errors"
    11  	"google.golang.org/protobuf/internal/flags"
    12  	"google.golang.org/protobuf/internal/order"
    13  	"google.golang.org/protobuf/reflect/protoreflect"
    14  	"google.golang.org/protobuf/reflect/protoregistry"
    15  )
    16  
    17  func (o MarshalOptions) sizeMessageSet(m protoreflect.Message) (size int) {
    18  	m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
    19  		size += messageset.SizeField(fd.Number())
    20  		size += protowire.SizeTag(messageset.FieldMessage)
    21  		size += protowire.SizeBytes(o.size(v.Message()))
    22  		return true
    23  	})
    24  	size += messageset.SizeUnknown(m.GetUnknown())
    25  	return size
    26  }
    27  
    28  func (o MarshalOptions) marshalMessageSet(b []byte, m protoreflect.Message) ([]byte, error) {
    29  	if !flags.ProtoLegacy {
    30  		return b, errors.New("no support for message_set_wire_format")
    31  	}
    32  	fieldOrder := order.AnyFieldOrder
    33  	if o.Deterministic {
    34  		fieldOrder = order.NumberFieldOrder
    35  	}
    36  	var err error
    37  	order.RangeFields(m, fieldOrder, func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
    38  		b, err = o.marshalMessageSetField(b, fd, v)
    39  		return err == nil
    40  	})
    41  	if err != nil {
    42  		return b, err
    43  	}
    44  	return messageset.AppendUnknown(b, m.GetUnknown())
    45  }
    46  
    47  func (o MarshalOptions) marshalMessageSetField(b []byte, fd protoreflect.FieldDescriptor, value protoreflect.Value) ([]byte, error) {
    48  	b = messageset.AppendFieldStart(b, fd.Number())
    49  	b = protowire.AppendTag(b, messageset.FieldMessage, protowire.BytesType)
    50  	calculatedSize := o.Size(value.Message().Interface())
    51  	b = protowire.AppendVarint(b, uint64(calculatedSize))
    52  	before := len(b)
    53  	b, err := o.marshalMessage(b, value.Message())
    54  	if err != nil {
    55  		return b, err
    56  	}
    57  	if measuredSize := len(b) - before; calculatedSize != measuredSize {
    58  		return nil, errors.MismatchedSizeCalculation(calculatedSize, measuredSize)
    59  	}
    60  	b = messageset.AppendFieldEnd(b)
    61  	return b, nil
    62  }
    63  
    64  func (o UnmarshalOptions) unmarshalMessageSet(b []byte, m protoreflect.Message) error {
    65  	if !flags.ProtoLegacy {
    66  		return errors.New("no support for message_set_wire_format")
    67  	}
    68  	return messageset.Unmarshal(b, false, func(num protowire.Number, v []byte) error {
    69  		err := o.unmarshalMessageSetField(m, num, v)
    70  		if err == errUnknown {
    71  			unknown := m.GetUnknown()
    72  			unknown = protowire.AppendTag(unknown, num, protowire.BytesType)
    73  			unknown = protowire.AppendBytes(unknown, v)
    74  			m.SetUnknown(unknown)
    75  			return nil
    76  		}
    77  		return err
    78  	})
    79  }
    80  
    81  func (o UnmarshalOptions) unmarshalMessageSetField(m protoreflect.Message, num protowire.Number, v []byte) error {
    82  	md := m.Descriptor()
    83  	if !md.ExtensionRanges().Has(num) {
    84  		return errUnknown
    85  	}
    86  	xt, err := o.Resolver.FindExtensionByNumber(md.FullName(), num)
    87  	if err == protoregistry.NotFound {
    88  		return errUnknown
    89  	}
    90  	if err != nil {
    91  		return errors.New("%v: unable to resolve extension %v: %v", md.FullName(), num, err)
    92  	}
    93  	xd := xt.TypeDescriptor()
    94  	if err := o.unmarshalMessage(v, m.Mutable(xd).Message()); err != nil {
    95  		return err
    96  	}
    97  	return nil
    98  }
    99
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