/
gzip.go
139 lines (105 loc) · 2.9 KB
/
gzip.go
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package middleware
import (
"bufio"
"compress/gzip"
"io"
"io/ioutil"
"net"
"net/http"
"strings"
"sync"
httpext "github.com/go-playground/pkg/v5/net/http"
"github.com/go-playground/pure/v5"
)
type gzipWriter struct {
io.Writer
http.ResponseWriter
sniffComplete bool
}
func (w *gzipWriter) Write(b []byte) (int, error) {
if !w.sniffComplete {
if w.Header().Get(httpext.ContentType) == "" {
w.Header().Set(httpext.ContentType, http.DetectContentType(b))
}
w.sniffComplete = true
}
return w.Writer.Write(b)
}
func (w *gzipWriter) Flush() error {
return w.Writer.(*gzip.Writer).Flush()
}
func (w *gzipWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return w.ResponseWriter.(http.Hijacker).Hijack()
}
var gzipPool = sync.Pool{
New: func() interface{} {
return &gzipWriter{Writer: gzip.NewWriter(ioutil.Discard)}
},
}
// Gzip returns a middleware which compresses HTTP response using gzip compression
// scheme.
func Gzip(next http.HandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
w.Header().Add(httpext.Vary, httpext.AcceptEncoding)
if strings.Contains(r.Header.Get(httpext.AcceptEncoding), httpext.Gzip) {
gz := gzipPool.Get().(*gzipWriter)
gz.sniffComplete = false
gzr := gz.Writer.(*gzip.Writer)
gzr.Reset(w)
gz.ResponseWriter = w
w.Header().Set(httpext.ContentEncoding, httpext.Gzip)
w = gz
defer func() {
if !gz.sniffComplete {
// We have to reset response to it's pristine state when
// nothing is written to body.
w.Header().Del(httpext.ContentEncoding)
gzr.Reset(ioutil.Discard)
}
gzr.Close()
gzipPool.Put(gz)
}()
}
next(w, r)
}
}
// GzipLevel returns a middleware which compresses HTTP response using gzip compression
// scheme using the level specified
func GzipLevel(level int) pure.Middleware {
// test gzip level, then don't have to each time one is created
// in the pool
if _, err := gzip.NewWriterLevel(ioutil.Discard, level); err != nil {
panic(err)
}
var gzipPool = sync.Pool{
New: func() interface{} {
z, _ := gzip.NewWriterLevel(ioutil.Discard, level)
return &gzipWriter{Writer: z}
},
}
return func(next http.HandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
w.Header().Add(httpext.Vary, httpext.AcceptEncoding)
if strings.Contains(r.Header.Get(httpext.AcceptEncoding), httpext.Gzip) {
gz := gzipPool.Get().(*gzipWriter)
gz.sniffComplete = false
gzr := gz.Writer.(*gzip.Writer)
gzr.Reset(w)
gz.ResponseWriter = w
w.Header().Set(httpext.ContentEncoding, httpext.Gzip)
w = gz
defer func() {
if !gz.sniffComplete {
// We have to reset response to it's pristine state when
// nothing is written to body.
w.Header().Del(httpext.ContentEncoding)
gzr.Reset(ioutil.Discard)
}
gzr.Close()
gzipPool.Put(gz)
}()
}
next(w, r)
}
}
}