github.com/grpc-ecosystem/grpc-gateway/v2@v2.19.1/runtime/marshal_proto.go (about)

     1  package runtime
     2  
     3  import (
     4  	"errors"
     5  	"io"
     6  
     7  	"google.golang.org/protobuf/proto"
     8  )
     9  
    10  // ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
    11  type ProtoMarshaller struct{}
    12  
    13  // ContentType always returns "application/octet-stream".
    14  func (*ProtoMarshaller) ContentType(_ interface{}) string {
    15  	return "application/octet-stream"
    16  }
    17  
    18  // Marshal marshals "value" into Proto
    19  func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error) {
    20  	message, ok := value.(proto.Message)
    21  	if !ok {
    22  		return nil, errors.New("unable to marshal non proto field")
    23  	}
    24  	return proto.Marshal(message)
    25  }
    26  
    27  // Unmarshal unmarshals proto "data" into "value"
    28  func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error {
    29  	message, ok := value.(proto.Message)
    30  	if !ok {
    31  		return errors.New("unable to unmarshal non proto field")
    32  	}
    33  	return proto.Unmarshal(data, message)
    34  }
    35  
    36  // NewDecoder returns a Decoder which reads proto stream from "reader".
    37  func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder {
    38  	return DecoderFunc(func(value interface{}) error {
    39  		buffer, err := io.ReadAll(reader)
    40  		if err != nil {
    41  			return err
    42  		}
    43  		return marshaller.Unmarshal(buffer, value)
    44  	})
    45  }
    46  
    47  // NewEncoder returns an Encoder which writes proto stream into "writer".
    48  func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder {
    49  	return EncoderFunc(func(value interface{}) error {
    50  		buffer, err := marshaller.Marshal(value)
    51  		if err != nil {
    52  			return err
    53  		}
    54  		if _, err := writer.Write(buffer); err != nil {
    55  			return err
    56  		}
    57  
    58  		return nil
    59  	})
    60  }