feat(serverHandler): enable response content compression if possible

Author: marjune163

src/serverCompress/main.go

@@ -0,0 +1,61 @@
+package serverCompress
+
+import (
+	"io"
+	"net/http"
+)
+
+const minLengthDigits = 3
+
+// responseWriter implements http.ResponseWriter
+type responseWriter struct {
+	rw     http.ResponseWriter
+	r      *http.Request
+	writer io.Writer
+	closer io.Closer
+}
+
+func (rw *responseWriter) Header() http.Header {
+	return rw.rw.Header()
+}
+
+func (rw *responseWriter) Write(bs []byte) (int, error) {
+	if rw.writer == nil {
+		rw.init(0)
+	}
+	return rw.writer.Write(bs)
+}
+
+func (rw *responseWriter) WriteHeader(status int) {
+	if rw.writer == nil {
+		rw.init(status)
+	}
+	rw.rw.WriteHeader(status)
+}
+
+func (rw *responseWriter) init(status int) {
+	lengthDigits := len(rw.rw.Header().Get("Content-Length"))
+	if lengthDigits >= minLengthDigits || (lengthDigits == 0 && status/100 != 3) {
+		wc, ok := GetWriter(rw.rw, rw.r)
+		if ok {
+			rw.writer = wc
+			rw.closer = wc
+			return
+		}
+	}
+
+	rw.writer = rw.rw
+}
+
+func (rw *responseWriter) Close() {
+	if rw.closer != nil {
+		rw.closer.Close()
+	}
+}
+
+func NewResponseWriter(w http.ResponseWriter, r *http.Request) *responseWriter {
+	return &responseWriter{
+		rw: w,
+		r:  r,
+	}
+}

src/serverCompress/responseWriter.go

@@ -0,0 +1,27 @@
+package serverCompress
+
+import (
+	"mjpclab.dev/ghfs/src/util"
+	"strings"
+)
+
+var compressibleTypes = []string{
+	"application/javascript",
+	"application/x-javascript",
+	"application/json",
+	"application/xhtml+xml",
+	"application/xml",
+	"image/svg+xml",
+}
+
+func isCompressibleType(contentType string) bool {
+	if strings.HasPrefix(contentType, "text/") {
+		return true
+	}
+
+	sepIndex := strings.IndexByte(contentType, ';')
+	if sepIndex > 0 {
+		contentType = contentType[:sepIndex]
+	}
+	return util.Contains(compressibleTypes, contentType)
+}

src/serverCompress/util.go

@@ -8,11 +8,19 @@ import (
 	"net/http"
 )
 
+const contentEncGzip = "gzip"
+const contentEncDeflate = "deflate"
+
+var encodings = []string{contentEncGzip, contentEncDeflate}
+
 func GetWriter(w http.ResponseWriter, r *http.Request) (wc io.WriteCloser, ok bool) {
 	header := w.Header()
 	if len(header.Get("Content-Encoding")) > 0 {
 		return nil, false
 	}
+	if !isCompressibleType(header.Get("Content-Type")) {
+		return nil, false
+	}
 
 	accepts := acceptHeaders.ParseAccepts(r.Header.Get("Accept-Encoding"))
 	_, encoding, hasSupportedEncoding := accepts.GetPreferredValue(encodings)

src/serverCompress/writer.go

@@ -2,8 +2,6 @@ package serverHandler
 
 import (
 	"encoding/json"
-	"io"
-	"mjpclab.dev/ghfs/src/serverCompress"
 	"net/http"
 	"os"
 	"time"
@@ -87,17 +85,10 @@ func (h *aliasHandler) json(w http.ResponseWriter, r *http.Request, data *respon
 		return
 	}
 
-	var bodyW io.Writer
-	if compressW, useCompressW := serverCompress.GetWriter(w, r); useCompressW {
-		bodyW = compressW
-		defer compressW.Close()
-	} else {
-		bodyW = w
-	}
 	w.WriteHeader(data.Status)
 
 	jsonData := getJsonData(data)
-	encoder := json.NewEncoder(bodyW)
+	encoder := json.NewEncoder(w)
 	err := encoder.Encode(jsonData)
 	h.logError(err)
 }

src/serverHandler/json.go

@@ -2,10 +2,8 @@ package serverHandler
 
 import (
 	"html/template"
-	"io"
 	"mjpclab.dev/ghfs/src/acceptHeaders"
 	"mjpclab.dev/ghfs/src/i18n"
-	"mjpclab.dev/ghfs/src/serverCompress"
 	tplutil "mjpclab.dev/ghfs/src/tpl/util"
 	"mjpclab.dev/ghfs/src/util"
 	"net/http"
@@ -83,16 +81,9 @@ func (h *aliasHandler) page(w http.ResponseWriter, r *http.Request, data *respon
 		return
 	}
 
-	var bodyW io.Writer
-	if compressW, useCompressW := serverCompress.GetWriter(w, r); useCompressW {
-		defer compressW.Close()
-		bodyW = compressW
-	} else {
-		bodyW = w
-	}
 	w.WriteHeader(data.Status)
 
 	updateSubItemsHtml(data)
-	err := h.theme.RenderPage(bodyW, data)
+	err := h.theme.RenderPage(w, data)
 	h.logError(err)
 }

src/serverHandler/page.go

@@ -2,6 +2,7 @@ package serverHandler
 
 import (
 	"mjpclab.dev/ghfs/src/middleware"
+	"mjpclab.dev/ghfs/src/serverCompress"
 	"mjpclab.dev/ghfs/src/serverLog"
 	"net/http"
 )
@@ -15,23 +16,27 @@ type preprocessHandler struct {
 func (pph preprocessHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	logRequest(pph.logger, r)
 
+	rw := serverCompress.NewResponseWriter(w, r)
+
 	if len(pph.preMiddlewares) > 0 {
 		middlewareContext := &middleware.Context{
 			PrefixReqPath: r.URL.RawPath, // init by pathTransformHandler
 			VhostReqPath:  r.URL.Path,
 			Logger:        pph.logger,
 		}
 		for i := range pph.preMiddlewares {
-			processResult := pph.preMiddlewares[i](w, r, middlewareContext)
+			processResult := pph.preMiddlewares[i](rw, r, middlewareContext)
 			if processResult == middleware.Processed {
+				rw.Close()
 				return
 			} else if processResult == middleware.SkipRests {
 				break
 			}
 		}
 	}
 
-	pph.nextHandler.ServeHTTP(w, r)
+	pph.nextHandler.ServeHTTP(rw, r)
+	rw.Close()
 }
 
 func newPreprocessHandler(logger *serverLog.Logger, preMiddlewares []middleware.Middleware, nextHandler http.Handler) http.Handler {