github.com/lazyledger/lazyledger-core@v0.35.0-dev.0.20210613111200-4c651f053571/libs/protoio/io.go (about)

     1  // Protocol Buffers for Go with Gadgets
     2  //
     3  // Copyright (c) 2013, The GoGo Authors. All rights reserved.
     4  // http://github.com/gogo/protobuf
     5  //
     6  // Redistribution and use in source and binary forms, with or without
     7  // modification, are permitted provided that the following conditions are
     8  // met:
     9  //
    10  //     * Redistributions of source code must retain the above copyright
    11  // notice, this list of conditions and the following disclaimer.
    12  //     * Redistributions in binary form must reproduce the above
    13  // copyright notice, this list of conditions and the following disclaimer
    14  // in the documentation and/or other materials provided with the
    15  // distribution.
    16  //
    17  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    18  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    19  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    20  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    21  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    22  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    23  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    24  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    25  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    26  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    27  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    28  //
    29  // Modified to return number of bytes written by Writer.WriteMsg(), and added byteReader.
    30  
    31  package protoio
    32  
    33  import (
    34  	"io"
    35  
    36  	"github.com/gogo/protobuf/proto"
    37  )
    38  
    39  type Writer interface {
    40  	WriteMsg(proto.Message) (int, error)
    41  }
    42  
    43  type WriteCloser interface {
    44  	Writer
    45  	io.Closer
    46  }
    47  
    48  type Reader interface {
    49  	ReadMsg(msg proto.Message) error
    50  }
    51  
    52  type ReadCloser interface {
    53  	Reader
    54  	io.Closer
    55  }
    56  
    57  type marshaler interface {
    58  	MarshalTo(data []byte) (n int, err error)
    59  }
    60  
    61  func getSize(v interface{}) (int, bool) {
    62  	if sz, ok := v.(interface {
    63  		Size() (n int)
    64  	}); ok {
    65  		return sz.Size(), true
    66  	} else if sz, ok := v.(interface {
    67  		ProtoSize() (n int)
    68  	}); ok {
    69  		return sz.ProtoSize(), true
    70  	} else {
    71  		return 0, false
    72  	}
    73  }
    74  
    75  // byteReader wraps an io.Reader and implements io.ByteReader. Reading one byte at a
    76  // time is extremely slow, but this is what Amino did already, and the caller can
    77  // wrap the reader in bufio.Reader if appropriate.
    78  type byteReader struct {
    79  	io.Reader
    80  	bytes []byte
    81  }
    82  
    83  func newByteReader(r io.Reader) *byteReader {
    84  	return &byteReader{
    85  		Reader: r,
    86  		bytes:  make([]byte, 1),
    87  	}
    88  }
    89  
    90  func (r *byteReader) ReadByte() (byte, error) {
    91  	_, err := r.Read(r.bytes)
    92  	if err != nil {
    93  		return 0, err
    94  	}
    95  	return r.bytes[0], nil
    96  }