types_proto.go

Documentation: k8s.io/apimachinery/pkg/runtime

     1  /*
     2  Copyright 2015 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package runtime
    18  
    19  import (
    20  	"fmt"
    21  )
    22  
    23  type ProtobufMarshaller interface {
    24  	MarshalTo(data []byte) (int, error)
    25  }
    26  
    27  type ProtobufReverseMarshaller interface {
    28  	MarshalToSizedBuffer(data []byte) (int, error)
    29  }
    30  
    31  // NestedMarshalTo allows a caller to avoid extra allocations during serialization of an Unknown
    32  // that will contain an object that implements ProtobufMarshaller or ProtobufReverseMarshaller.
    33  func (m *Unknown) NestedMarshalTo(data []byte, b ProtobufMarshaller, size uint64) (int, error) {
    34  	// Calculate the full size of the message.
    35  	msgSize := m.Size()
    36  	if b != nil {
    37  		msgSize += int(size) + sovGenerated(size) + 1
    38  	}
    39  
    40  	// Reverse marshal the fields of m.
    41  	i := msgSize
    42  	i -= len(m.ContentType)
    43  	copy(data[i:], m.ContentType)
    44  	i = encodeVarintGenerated(data, i, uint64(len(m.ContentType)))
    45  	i--
    46  	data[i] = 0x22
    47  	i -= len(m.ContentEncoding)
    48  	copy(data[i:], m.ContentEncoding)
    49  	i = encodeVarintGenerated(data, i, uint64(len(m.ContentEncoding)))
    50  	i--
    51  	data[i] = 0x1a
    52  	if b != nil {
    53  		if r, ok := b.(ProtobufReverseMarshaller); ok {
    54  			n1, err := r.MarshalToSizedBuffer(data[:i])
    55  			if err != nil {
    56  				return 0, err
    57  			}
    58  			i -= int(size)
    59  			if uint64(n1) != size {
    60  				// programmer error: the Size() method for protobuf does not match the results of LashramOt, which means the proto
    61  				// struct returned would be wrong.
    62  				return 0, fmt.Errorf("the Size() value of %T was %d, but NestedMarshalTo wrote %d bytes to data", b, size, n1)
    63  			}
    64  		} else {
    65  			i -= int(size)
    66  			n1, err := b.MarshalTo(data[i:])
    67  			if err != nil {
    68  				return 0, err
    69  			}
    70  			if uint64(n1) != size {
    71  				// programmer error: the Size() method for protobuf does not match the results of MarshalTo, which means the proto
    72  				// struct returned would be wrong.
    73  				return 0, fmt.Errorf("the Size() value of %T was %d, but NestedMarshalTo wrote %d bytes to data", b, size, n1)
    74  			}
    75  		}
    76  		i = encodeVarintGenerated(data, i, size)
    77  		i--
    78  		data[i] = 0x12
    79  	}
    80  	n2, err := m.TypeMeta.MarshalToSizedBuffer(data[:i])
    81  	if err != nil {
    82  		return 0, err
    83  	}
    84  	i -= n2
    85  	i = encodeVarintGenerated(data, i, uint64(n2))
    86  	i--
    87  	data[i] = 0xa
    88  	return msgSize - i, nil
    89  }
    90
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