decode_header.go

package main

import (
    "fmt"
    "golang.org/x/net/http2/hpack"
)

func main() {
    fmt.Println("nginx", "→", Encode("MYWS"))
    fmt.Println("nginx", "→", Encode("nginx"))
    fmt.Println("apache", "→", Encode("apache"))
    fmt.Println("openresty+", "→", Encode("openresty+"))
    fmt.Println("-----")
    fmt.Println("\\x84\\xaa\\x63\\x55\\xe7", "→", Decode("\x84\xaa\x63\x55\xe7"))
    fmt.Println("\\x84\\x1d\\x63\\x24\\xe5", "→", Decode("\x84\x1d\x63\x24\xe5"))
    fmt.Println("\\x87\\x3d\\x65\\xaa\\xc2\\xa1\\x3e\\xbf\\xdf", "→", Decode("\x87\x3d\x65\xaa\xc2\xa1\x3e\xbf\xdf"))
}

func Encode(s string) string {
    var result string

    hd := hpack.AppendHuffmanString(nil, s)
    hl := hpack.HuffmanEncodeLength(s) | 0x80

    result += RenderByte(byte(hl))

    for _, b := range hd {
        result += RenderByte(b)
    }

    return result
}

func Decode(s string) string {
    data := []byte(s)
    result, _ := hpack.HuffmanDecodeToString(data[1:])
    return result
}

func RenderByte(b byte) string {
    return fmt.Sprintf("\\x%x", b)
}