32 lines
823 B
Go
32 lines
823 B
Go
package middlewares
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import (
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"net/http"
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"github.com/NYTimes/gziphandler"
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)
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const (
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contentEncodingHeader = "Content-Encoding"
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)
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// Compress is a middleware that allows redirection
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type Compress struct{}
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// ServerHTTP is a function used by Negroni
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func (c *Compress) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
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if isEncoded(r.Header) {
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next.ServeHTTP(rw, r)
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} else {
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newGzipHandler := gziphandler.GzipHandler(next)
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newGzipHandler.ServeHTTP(rw, r)
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}
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}
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func isEncoded(headers http.Header) bool {
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header := headers.Get(contentEncodingHeader)
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// According to https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding,
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// content is not encoded if the header 'Content-Encoding' is empty or equals to 'identity'.
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return header != "" && header != "identity"
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}
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