74 lines
1.1 KiB
Go
74 lines
1.1 KiB
Go
package mdns
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import (
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"bytes"
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"compress/zlib"
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"encoding/hex"
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"encoding/json"
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"io/ioutil"
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"strings"
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)
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func encode(txt *mdnsTxt) ([]string, error) {
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b, err := json.Marshal(txt)
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if err != nil {
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return nil, err
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}
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var buf bytes.Buffer
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defer buf.Reset()
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w := zlib.NewWriter(&buf)
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if _, err := w.Write(b); err != nil {
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return nil, err
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}
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w.Close()
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encoded := hex.EncodeToString(buf.Bytes())
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// individual txt limit
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if len(encoded) <= 255 {
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return []string{encoded}, nil
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}
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// split encoded string
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var record []string
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for len(encoded) > 255 {
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record = append(record, encoded[:255])
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encoded = encoded[255:]
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}
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record = append(record, encoded)
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return record, nil
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}
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func decode(record []string) (*mdnsTxt, error) {
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encoded := strings.Join(record, "")
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hr, err := hex.DecodeString(encoded)
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if err != nil {
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return nil, err
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}
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br := bytes.NewReader(hr)
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zr, err := zlib.NewReader(br)
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if err != nil {
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return nil, err
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}
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rbuf, err := ioutil.ReadAll(zr)
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if err != nil {
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return nil, err
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}
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var txt *mdnsTxt
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if err := json.Unmarshal(rbuf, &txt); err != nil {
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return nil, err
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}
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return txt, nil
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}
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