gitee.com/liuxuezhan/go-micro-v1.18.0@v1.0.0/registry/encoding.go (about)

     1  package registry
     2  
     3  import (
     4  	"bytes"
     5  	"compress/zlib"
     6  	"encoding/hex"
     7  	"encoding/json"
     8  	"io/ioutil"
     9  	"strings"
    10  )
    11  
    12  func encode(txt *mdnsTxt) ([]string, error) {
    13  	b, err := json.Marshal(txt)
    14  	if err != nil {
    15  		return nil, err
    16  	}
    17  
    18  	var buf bytes.Buffer
    19  	defer buf.Reset()
    20  
    21  	w := zlib.NewWriter(&buf)
    22  	if _, err := w.Write(b); err != nil {
    23  		return nil, err
    24  	}
    25  	w.Close()
    26  
    27  	encoded := hex.EncodeToString(buf.Bytes())
    28  
    29  	// individual txt limit
    30  	if len(encoded) <= 255 {
    31  		return []string{encoded}, nil
    32  	}
    33  
    34  	// split encoded string
    35  	var record []string
    36  
    37  	for len(encoded) > 255 {
    38  		record = append(record, encoded[:255])
    39  		encoded = encoded[255:]
    40  	}
    41  
    42  	record = append(record, encoded)
    43  
    44  	return record, nil
    45  }
    46  
    47  func decode(record []string) (*mdnsTxt, error) {
    48  	encoded := strings.Join(record, "")
    49  
    50  	hr, err := hex.DecodeString(encoded)
    51  	if err != nil {
    52  		return nil, err
    53  	}
    54  
    55  	br := bytes.NewReader(hr)
    56  	zr, err := zlib.NewReader(br)
    57  	if err != nil {
    58  		return nil, err
    59  	}
    60  
    61  	rbuf, err := ioutil.ReadAll(zr)
    62  	if err != nil {
    63  		return nil, err
    64  	}
    65  
    66  	var txt *mdnsTxt
    67  
    68  	if err := json.Unmarshal(rbuf, &txt); err != nil {
    69  		return nil, err
    70  	}
    71  
    72  	return txt, nil
    73  }