53 lines
1.1 KiB
Go
53 lines
1.1 KiB
Go
package util
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import (
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"compress/gzip"
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"io"
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"io/ioutil"
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"net/http"
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"strings"
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"sync"
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)
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// Gzip is a HTTP middleware to transparently compress responses using gzip.
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// Original code from https://gist.github.com/CJEnright/bc2d8b8dc0c1389a9feeddb110f822d7 (MIT)
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func Gzip(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
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next.ServeHTTP(w, r)
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return
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}
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w.Header().Set("Content-Encoding", "gzip")
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gz := gzPool.Get().(*gzip.Writer)
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defer gzPool.Put(gz)
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gz.Reset(w)
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defer gz.Close()
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r.Header.Del("Accept-Encoding") // prevent double-gzipping
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next.ServeHTTP(&gzipResponseWriter{ResponseWriter: w, Writer: gz}, r)
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})
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}
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var gzPool = sync.Pool{
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New: func() interface{} {
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w := gzip.NewWriter(ioutil.Discard)
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return w
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},
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}
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type gzipResponseWriter struct {
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io.Writer
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http.ResponseWriter
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}
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func (w *gzipResponseWriter) WriteHeader(status int) {
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w.Header().Del("Content-Length")
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w.ResponseWriter.WriteHeader(status)
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}
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func (w *gzipResponseWriter) Write(b []byte) (int, error) {
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return w.Writer.Write(b)
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}
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