-
Notifications
You must be signed in to change notification settings - Fork 0
/
encoder.go
82 lines (68 loc) · 2.22 KB
/
encoder.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
package sse
import (
"bytes"
"compress/flate"
"compress/gzip"
"compress/zlib"
"fmt"
"io"
"github.com/andybalholm/brotli"
"github.com/klauspost/compress/zstd"
)
const (
// No encoding applied
EncodeNone = ""
// Compress the data using the DEFLATE algorithm
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding#deflate
EncodeDeflate = "deflate"
// Compress the data using the LZW algorithm
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding#compress
EncodeCompress = "compress"
// Compress the data using the GZIP algorithm
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding#gzip
EncodeGzip = "gzip"
// Compress the data using the Brotli algorithm
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding#br
EncodeBrotli = "br"
// Compress the data using the Zstandard algorithm
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding#zstd
EncodeZstd = "zstd"
)
// encode applies the selected encoding to the input string and returns the encoded bytes.
// It returns an error if the encoding process fails.
func encode(level string, m string) ([]byte, error) {
buffer := new(bytes.Buffer)
encoder, err := encoderFactory(level, buffer)
if err != nil {
return nil, fmt.Errorf("error creating encoder: %v", err)
}
if encoder == nil {
return []byte(m), nil
}
if _, err = encoder.Write([]byte(m)); err != nil {
return nil, fmt.Errorf("error writing to encoder: %v", err)
}
if err = encoder.Close(); err != nil {
return nil, fmt.Errorf("error closing encoder: %v", err)
}
return buffer.Bytes(), nil
}
// encoderFactory creates an encoder based on the provided level.
func encoderFactory(level string, buffer *bytes.Buffer) (io.WriteCloser, error) {
switch level {
case EncodeNone:
return nil, nil
case EncodeGzip:
return gzip.NewWriter(buffer), nil
case EncodeBrotli:
return brotli.NewWriter(buffer), nil
case EncodeDeflate:
return flate.NewWriter(buffer, flate.DefaultCompression)
case EncodeCompress:
return zlib.NewWriter(buffer), nil
case EncodeZstd:
return zstd.NewWriter(buffer)
default:
return nil, fmt.Errorf("unknown encoding level: %s", level)
}
}