marshal_proto.go

Documentation: github.com/grpc-ecosystem/grpc-gateway/runtime

     1  package runtime
     2  
     3  import (
     4  	"io"
     5  
     6  	"errors"
     7  	"github.com/golang/protobuf/proto"
     8  	"io/ioutil"
     9  )
    10  
    11  // ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
    12  type ProtoMarshaller struct{}
    13  
    14  // ContentType always returns "application/octet-stream".
    15  func (*ProtoMarshaller) ContentType() string {
    16  	return "application/octet-stream"
    17  }
    18  
    19  // Marshal marshals "value" into Proto
    20  func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error) {
    21  	message, ok := value.(proto.Message)
    22  	if !ok {
    23  		return nil, errors.New("unable to marshal non proto field")
    24  	}
    25  	return proto.Marshal(message)
    26  }
    27  
    28  // Unmarshal unmarshals proto "data" into "value"
    29  func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error {
    30  	message, ok := value.(proto.Message)
    31  	if !ok {
    32  		return errors.New("unable to unmarshal non proto field")
    33  	}
    34  	return proto.Unmarshal(data, message)
    35  }
    36  
    37  // NewDecoder returns a Decoder which reads proto stream from "reader".
    38  func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder {
    39  	return DecoderFunc(func(value interface{}) error {
    40  		buffer, err := ioutil.ReadAll(reader)
    41  		if err != nil {
    42  			return err
    43  		}
    44  		return marshaller.Unmarshal(buffer, value)
    45  	})
    46  }
    47  
    48  // NewEncoder returns an Encoder which writes proto stream into "writer".
    49  func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder {
    50  	return EncoderFunc(func(value interface{}) error {
    51  		buffer, err := marshaller.Marshal(value)
    52  		if err != nil {
    53  			return err
    54  		}
    55  		_, err = writer.Write(buffer)
    56  		if err != nil {
    57  			return err
    58  		}
    59  
    60  		return nil
    61  	})
    62  }
    63
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