wire.go

Documentation: github.com/golang/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  	protoV2 "google.golang.org/protobuf/proto"
     9  	"google.golang.org/protobuf/runtime/protoiface"
    10  )
    11  
    12  // Size returns the size in bytes of the wire-format encoding of m.
    13  func Size(m Message) int {
    14  	if m == nil {
    15  		return 0
    16  	}
    17  	mi := MessageV2(m)
    18  	return protoV2.Size(mi)
    19  }
    20  
    21  // Marshal returns the wire-format encoding of m.
    22  func Marshal(m Message) ([]byte, error) {
    23  	b, err := marshalAppend(nil, m, false)
    24  	if b == nil {
    25  		b = zeroBytes
    26  	}
    27  	return b, err
    28  }
    29  
    30  var zeroBytes = make([]byte, 0, 0)
    31  
    32  func marshalAppend(buf []byte, m Message, deterministic bool) ([]byte, error) {
    33  	if m == nil {
    34  		return nil, ErrNil
    35  	}
    36  	mi := MessageV2(m)
    37  	nbuf, err := protoV2.MarshalOptions{
    38  		Deterministic: deterministic,
    39  		AllowPartial:  true,
    40  	}.MarshalAppend(buf, mi)
    41  	if err != nil {
    42  		return buf, err
    43  	}
    44  	if len(buf) == len(nbuf) {
    45  		if !mi.ProtoReflect().IsValid() {
    46  			return buf, ErrNil
    47  		}
    48  	}
    49  	return nbuf, checkRequiredNotSet(mi)
    50  }
    51  
    52  // Unmarshal parses a wire-format message in b and places the decoded results in m.
    53  //
    54  // Unmarshal resets m before starting to unmarshal, so any existing data in m is always
    55  // removed. Use UnmarshalMerge to preserve and append to existing data.
    56  func Unmarshal(b []byte, m Message) error {
    57  	m.Reset()
    58  	return UnmarshalMerge(b, m)
    59  }
    60  
    61  // UnmarshalMerge parses a wire-format message in b and places the decoded results in m.
    62  func UnmarshalMerge(b []byte, m Message) error {
    63  	mi := MessageV2(m)
    64  	out, err := protoV2.UnmarshalOptions{
    65  		AllowPartial: true,
    66  		Merge:        true,
    67  	}.UnmarshalState(protoiface.UnmarshalInput{
    68  		Buf:     b,
    69  		Message: mi.ProtoReflect(),
    70  	})
    71  	if err != nil {
    72  		return err
    73  	}
    74  	if out.Flags&protoiface.UnmarshalInitialized > 0 {
    75  		return nil
    76  	}
    77  	return checkRequiredNotSet(mi)
    78  }
    79
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