99 lines
2.7 KiB
Go
99 lines
2.7 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file or at
|
|
// https://developers.google.com/open-source/licenses/bsd.
|
|
|
|
// this file was taken from the github.com/golang/gddo repository
|
|
|
|
package middleware
|
|
|
|
import (
|
|
"net/http"
|
|
"strings"
|
|
|
|
"github.com/go-openapi/runtime/middleware/header"
|
|
)
|
|
|
|
// NegotiateContentEncoding returns the best offered content encoding for the
|
|
// request's Accept-Encoding header. If two offers match with equal weight and
|
|
// then the offer earlier in the list is preferred. If no offers are
|
|
// acceptable, then "" is returned.
|
|
func NegotiateContentEncoding(r *http.Request, offers []string) string {
|
|
bestOffer := "identity"
|
|
bestQ := -1.0
|
|
specs := header.ParseAccept(r.Header, "Accept-Encoding")
|
|
for _, offer := range offers {
|
|
for _, spec := range specs {
|
|
if spec.Q > bestQ &&
|
|
(spec.Value == "*" || spec.Value == offer) {
|
|
bestQ = spec.Q
|
|
bestOffer = offer
|
|
}
|
|
}
|
|
}
|
|
if bestQ == 0 {
|
|
bestOffer = ""
|
|
}
|
|
return bestOffer
|
|
}
|
|
|
|
// NegotiateContentType returns the best offered content type for the request's
|
|
// Accept header. If two offers match with equal weight, then the more specific
|
|
// offer is preferred. For example, text/* trumps */*. If two offers match
|
|
// with equal weight and specificity, then the offer earlier in the list is
|
|
// preferred. If no offers match, then defaultOffer is returned.
|
|
func NegotiateContentType(r *http.Request, offers []string, defaultOffer string) string {
|
|
bestOffer := defaultOffer
|
|
bestQ := -1.0
|
|
bestWild := 3
|
|
specs := header.ParseAccept(r.Header, "Accept")
|
|
for _, rawOffer := range offers {
|
|
offer := normalizeOffer(rawOffer)
|
|
// No Accept header: just return the first offer.
|
|
if len(specs) == 0 {
|
|
return rawOffer
|
|
}
|
|
for _, spec := range specs {
|
|
switch {
|
|
case spec.Q == 0.0:
|
|
// ignore
|
|
case spec.Q < bestQ:
|
|
// better match found
|
|
case spec.Value == "*/*":
|
|
if spec.Q > bestQ || bestWild > 2 {
|
|
bestQ = spec.Q
|
|
bestWild = 2
|
|
bestOffer = rawOffer
|
|
}
|
|
case strings.HasSuffix(spec.Value, "/*"):
|
|
if strings.HasPrefix(offer, spec.Value[:len(spec.Value)-1]) &&
|
|
(spec.Q > bestQ || bestWild > 1) {
|
|
bestQ = spec.Q
|
|
bestWild = 1
|
|
bestOffer = rawOffer
|
|
}
|
|
default:
|
|
if spec.Value == offer &&
|
|
(spec.Q > bestQ || bestWild > 0) {
|
|
bestQ = spec.Q
|
|
bestWild = 0
|
|
bestOffer = rawOffer
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return bestOffer
|
|
}
|
|
|
|
func normalizeOffers(orig []string) (norm []string) {
|
|
for _, o := range orig {
|
|
norm = append(norm, normalizeOffer(o))
|
|
}
|
|
return
|
|
}
|
|
|
|
func normalizeOffer(orig string) string {
|
|
return strings.SplitN(orig, ";", 2)[0]
|
|
}
|