Honor Accept-Encoding header in gzip transcoder

This avoids sending compressed data to clients which do not support
it.
This commit is contained in:
Andrew Gaul 2017-01-14 15:20:14 -08:00
parent cac3b84a5d
commit 11a40b5051
7 changed files with 28 additions and 12 deletions

View file

@ -16,7 +16,7 @@ type Proxy struct {
} }
type Transcoder interface { type Transcoder interface {
Transcode(*ResponseWriter, *ResponseReader) error Transcode(*ResponseWriter, *ResponseReader, http.Header) error
} }
func New() *Proxy { func New() *Proxy {
@ -68,7 +68,7 @@ func (p *Proxy) handle(w http.ResponseWriter, r *http.Request) error {
defer resp.Body.Close() defer resp.Body.Close()
rw := newResponseWriter(w) rw := newResponseWriter(w)
rr := newResponseReader(resp) rr := newResponseReader(resp)
err = p.proxyResponse(rw, rr) err = p.proxyResponse(rw, rr, r.Header)
read := rr.counter.Count() read := rr.counter.Count()
written := rw.rw.Count() written := rw.rw.Count()
log.Printf("transcoded: %d -> %d (%3.1f%%)", read, written, float64(written)/float64(read)*100) log.Printf("transcoded: %d -> %d (%3.1f%%)", read, written, float64(written)/float64(read)*100)
@ -92,14 +92,14 @@ func forward(r *http.Request) (*http.Response, error) {
return http.DefaultTransport.RoundTrip(r) return http.DefaultTransport.RoundTrip(r)
} }
func (p *Proxy) proxyResponse(w *ResponseWriter, r *ResponseReader) error { func (p *Proxy) proxyResponse(w *ResponseWriter, r *ResponseReader, headers http.Header) error {
w.takeHeaders(r) w.takeHeaders(r)
transcoder, found := p.transcoders[r.ContentType()] transcoder, found := p.transcoders[r.ContentType()]
if !found { if !found {
return w.ReadFrom(r) return w.ReadFrom(r)
} }
w.setChunked() w.setChunked()
if err := transcoder.Transcode(w, r); err != nil { if err := transcoder.Transcode(w, r, headers); err != nil {
return fmt.Errorf("transcoding error: %s", err) return fmt.Errorf("transcoding error: %s", err)
} }
return nil return nil

View file

@ -3,11 +3,12 @@ package transcoder
import ( import (
"github.com/barnacs/compy/proxy" "github.com/barnacs/compy/proxy"
"image/gif" "image/gif"
"net/http"
) )
type Gif struct{} type Gif struct{}
func (t *Gif) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error { func (t *Gif) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
img, err := gif.Decode(r) img, err := gif.Decode(r)
if err != nil { if err != nil {
return err return err

View file

@ -3,6 +3,8 @@ package transcoder
import ( import (
"compress/gzip" "compress/gzip"
"github.com/barnacs/compy/proxy" "github.com/barnacs/compy/proxy"
"net/http"
"strings"
) )
type Gzip struct { type Gzip struct {
@ -10,7 +12,7 @@ type Gzip struct {
SkipGzipped bool SkipGzipped bool
} }
func (t *Gzip) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error { func (t *Gzip) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
if t.decompress(r) { if t.decompress(r) {
gzr, err := gzip.NewReader(r.Reader) gzr, err := gzip.NewReader(r.Reader)
if err != nil { if err != nil {
@ -21,13 +23,22 @@ func (t *Gzip) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error
r.Header().Del("Content-Encoding") r.Header().Del("Content-Encoding")
w.Header().Del("Content-Encoding") w.Header().Del("Content-Encoding")
} }
if compress(r) {
shouldGzip := false
for _, v := range strings.Split(headers.Get("Accept-Encoding"), ", ") {
if strings.SplitN(v, ";", 2)[0] == "gzip" {
shouldGzip = true
break
}
}
if shouldGzip && compress(r) {
gzw := gzip.NewWriter(w.Writer) gzw := gzip.NewWriter(w.Writer)
defer gzw.Flush() defer gzw.Flush()
w.Writer = gzw w.Writer = gzw
w.Header().Set("Content-Encoding", "gzip") w.Header().Set("Content-Encoding", "gzip")
} }
return t.Transcoder.Transcode(w, r) return t.Transcoder.Transcode(w, r, headers)
} }
func (t *Gzip) decompress(r *proxy.ResponseReader) bool { func (t *Gzip) decompress(r *proxy.ResponseReader) bool {

View file

@ -2,10 +2,11 @@ package transcoder
import ( import (
"github.com/barnacs/compy/proxy" "github.com/barnacs/compy/proxy"
"net/http"
) )
type Identity struct{} type Identity struct{}
func (i *Identity) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error { func (i *Identity) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
return w.ReadFrom(r) return w.ReadFrom(r)
} }

View file

@ -3,6 +3,7 @@ package transcoder
import ( import (
"github.com/barnacs/compy/proxy" "github.com/barnacs/compy/proxy"
"github.com/pixiv/go-libjpeg/jpeg" "github.com/pixiv/go-libjpeg/jpeg"
"net/http"
) )
type Jpeg struct { type Jpeg struct {
@ -20,7 +21,7 @@ func NewJpeg(quality int) *Jpeg {
} }
} }
func (t *Jpeg) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error { func (t *Jpeg) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
img, err := jpeg.Decode(r, t.decOptions) img, err := jpeg.Decode(r, t.decOptions)
if err != nil { if err != nil {
return err return err

View file

@ -6,6 +6,7 @@ import (
"github.com/tdewolff/minify/css" "github.com/tdewolff/minify/css"
"github.com/tdewolff/minify/html" "github.com/tdewolff/minify/html"
"github.com/tdewolff/minify/js" "github.com/tdewolff/minify/js"
"net/http"
) )
type Minifier struct { type Minifier struct {
@ -24,6 +25,6 @@ func NewMinifier() *Minifier {
} }
} }
func (t *Minifier) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error { func (t *Minifier) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
return t.m.Minify(r.ContentType(), w, r) return t.m.Minify(r.ContentType(), w, r)
} }

View file

@ -3,11 +3,12 @@ package transcoder
import ( import (
"github.com/barnacs/compy/proxy" "github.com/barnacs/compy/proxy"
"image/png" "image/png"
"net/http"
) )
type Png struct{} type Png struct{}
func (t *Png) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader) error { func (t *Png) Transcode(w *proxy.ResponseWriter, r *proxy.ResponseReader, headers http.Header) error {
img, err := png.Decode(r) img, err := png.Decode(r)
if err != nil { if err != nil {
return err return err