github.com/tickoalcantara12/micro/v3@v3.0.0-20221007104245-9d75b9bcbab9/util/codec/protorpc/netstring.go (about)

     1  // Licensed under the Apache License, Version 2.0 (the "License");
     2  // you may not use this file except in compliance with the License.
     3  // You may obtain a copy of the License at
     4  //
     5  //     https://www.apache.org/licenses/LICENSE-2.0
     6  //
     7  // Unless required by applicable law or agreed to in writing, software
     8  // distributed under the License is distributed on an "AS IS" BASIS,
     9  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    10  // See the License for the specific language governing permissions and
    11  // limitations under the License.
    12  //
    13  // Original source: github.com/micro/go-micro/v3/codec/protorpc/netstring.go
    14  
    15  package protorpc
    16  
    17  import (
    18  	"encoding/binary"
    19  	"io"
    20  )
    21  
    22  // WriteNetString writes data to a big-endian netstring on a Writer.
    23  // Size is always a 32-bit unsigned int.
    24  func WriteNetString(w io.Writer, data []byte) (written int, err error) {
    25  	size := make([]byte, 4)
    26  	binary.BigEndian.PutUint32(size, uint32(len(data)))
    27  	if written, err = w.Write(size); err != nil {
    28  		return
    29  	}
    30  	return w.Write(data)
    31  }
    32  
    33  // ReadNetString reads data from a big-endian netstring.
    34  func ReadNetString(r io.Reader) (data []byte, err error) {
    35  	sizeBuf := make([]byte, 4)
    36  	_, err = r.Read(sizeBuf)
    37  	if err != nil {
    38  		return nil, err
    39  	}
    40  	size := binary.BigEndian.Uint32(sizeBuf)
    41  	if size == 0 {
    42  		return nil, nil
    43  	}
    44  	data = make([]byte, size)
    45  	_, err = r.Read(data)
    46  	if err != nil {
    47  		return nil, err
    48  	}
    49  	return
    50  }