74 lines
1.8 KiB
Go
74 lines
1.8 KiB
Go
package transcoder
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import (
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"compress/gzip"
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"net/http"
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"strings"
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"github.com/barnacs/compy/proxy"
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brotlidec "gopkg.in/kothar/brotli-go.v0/dec"
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brotlienc "gopkg.in/kothar/brotli-go.v0/enc"
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)
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type Zip struct {
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proxy.Transcoder
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BrotliCompressionLevel int
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GzipCompressionLevel int
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SkipCompressed bool
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}
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func (t *Zip) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
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shouldBrotli := false
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shouldGzip := false
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for _, v := range strings.Split(headers.Get("Accept-Encoding"), ", ") {
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switch strings.SplitN(v, ";", 2)[0] {
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case "br":
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shouldBrotli = true
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case "gzip":
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shouldGzip = true
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}
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}
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// always gunzip if the client supports Brotli
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if r.Header().Get("Content-Encoding") == "gzip" && (shouldBrotli || !t.SkipCompressed) {
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gzr, err := gzip.NewReader(r.Reader)
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if err != nil {
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return err
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}
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defer gzr.Close()
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r.Reader = gzr
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r.Header().Del("Content-Encoding")
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w.Header().Del("Content-Encoding")
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}
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if r.Header().Get("Content-Encoding") == "br" && !t.SkipCompressed {
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brr := brotlidec.NewBrotliReader(r.Reader)
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defer brr.Close()
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r.Reader = brr
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r.Header().Del("Content-Encoding")
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w.Header().Del("Content-Encoding")
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}
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if shouldBrotli && compress(r) {
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params := brotlienc.NewBrotliParams()
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params.SetQuality(t.BrotliCompressionLevel)
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brw := brotlienc.NewBrotliWriter(params, w.Writer)
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defer brw.Close()
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w.Writer = brw
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w.Header().Set("Content-Encoding", "br")
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} else if shouldGzip && compress(r) {
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gzw, err := gzip.NewWriterLevel(w.Writer, t.GzipCompressionLevel)
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if err != nil {
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return err
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}
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defer gzw.Close()
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w.Writer = gzw
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w.Header().Set("Content-Encoding", "gzip")
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}
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return t.Transcoder.Transcode(w, r, headers)
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}
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func compress(r *proxy.ResponseReader) bool {
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return r.Header().Get("Content-Encoding") == ""
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}
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