fix: 304 cache after update (#49)

Author: orca-zhang

route/static_route.go

@@ -1,7 +1,12 @@
 package route
 
 import (
+	"fmt"
+	"io"
+	"io/fs"
 	"net/http"
+	"os"
+	"time"
 
 	"github.com/IceWhaleTech/CasaOS-Gateway/service"
 	"github.com/labstack/echo/v4"
@@ -12,31 +17,90 @@ type StaticRoute struct {
 	state *service.State
 }
 
-var RouteCache = make(map[string]string)
+var startTime = time.Now()
 
 func NewStaticRoute(state *service.State) *StaticRoute {
 	return &StaticRoute{
 		state: state,
 	}
 }
 
+type CustomFS struct {
+	base fs.FS
+}
+
+func NewCustomFS(prefix string) *CustomFS {
+	return &CustomFS{
+		base: fs.FS(os.DirFS(prefix)),
+	}
+}
+
+func (c *CustomFS) Open(name string) (fs.File, error) {
+	file, err := c.base.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return &CustomFile{
+		File: file,
+	}, nil
+}
+
+func (c *CustomFS) Stat(name string) (fs.FileInfo, error) {
+	file, err := c.base.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	info, err := file.Stat()
+	if err != nil {
+		return nil, err
+	}
+	return &CustomFileInfo{
+		FileInfo: info,
+	}, nil
+}
+
+type CustomFile struct {
+	fs.File
+}
+
+func (c *CustomFile) Stat() (fs.FileInfo, error) {
+	info, err := c.File.Stat()
+	if err != nil {
+		return nil, err
+	}
+	return &CustomFileInfo{
+		FileInfo: info,
+	}, nil
+}
+
+func (c *CustomFile) Read(p []byte) (int, error) {
+	if seeker, ok := c.File.(io.Reader); ok {
+		return seeker.Read(p)
+	}
+	return 0, fmt.Errorf("file does not implement io.Reader")
+}
+
+func (c *CustomFile) Seek(offset int64, whence int) (int64, error) {
+	if seeker, ok := c.File.(io.Seeker); ok {
+		return seeker.Seek(offset, whence)
+	}
+	return 0, fmt.Errorf("file does not implement io.Seeker")
+}
+
+type CustomFileInfo struct {
+	fs.FileInfo
+}
+
+func (c *CustomFileInfo) ModTime() time.Time {
+	return startTime
+}
+
 func (s *StaticRoute) GetRoute() http.Handler {
 	e := echo.New()
 
 	e.Use(echo_middleware.Gzip())
 
-	e.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
-		return func(ctx echo.Context) error {
-			if _, ok := RouteCache[ctx.Request().URL.Path]; !ok {
-				ctx.Response().Writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate,proxy-revalidate, max-age=0")
-				RouteCache[ctx.Request().URL.Path] = ctx.Request().URL.Path
-			}
-			return next(ctx)
-		}
-	})
-
-	e.Static("/", s.state.GetWWWPath())
-
+	// sovle 304 cache problem by 'If-Modified-Since: Wed, 21 Oct 2015 07:28:00 GMT' from web browser
+	e.StaticFS("/", NewCustomFS(s.state.GetWWWPath()))
 	return e
 }
-