feat: brotli precompressed assets (resolve #284)

utils/fs/exists.go

@@ -0,0 +1,45 @@
+package fs
+
+import (
+	"io/fs"
+	"net/http"
+	"strings"
+)
+
+type ExistsFS struct {
+	Fs fs.FS
+}
+
+func (efs ExistsFS) Exists(name string) bool {
+	_, err := fs.Stat(efs.Fs, name)
+	return err == nil
+}
+
+func (efs ExistsFS) Open(name string) (fs.File, error) {
+	return efs.Fs.Open(name)
+}
+
+// ---
+
+type ExistsHttpFS struct {
+	Fs     ExistsFS
+	httpFs http.FileSystem
+}
+
+func NewExistsHttpFs(fs ExistsFS) ExistsHttpFS {
+	return ExistsHttpFS{
+		Fs:     fs,
+		httpFs: http.FS(fs),
+	}
+}
+
+func (ehfs ExistsHttpFS) Exists(name string) bool {
+	if strings.HasPrefix(name, "/") {
+		name = name[1:]
+	}
+	return ehfs.Fs.Exists(name)
+}
+
+func (ehfs ExistsHttpFS) Open(name string) (http.File, error) {
+	return ehfs.httpFs.Open(name)
+}

utils/fs/neutered.go

@@ -1,17 +1,17 @@
-package utils
+package fs
 
 import (
-	"net/http"
+	"io/fs"
 	"path/filepath"
 )
 
 // https://www.alexedwards.net/blog/disable-http-fileserver-directory-listings
 
 type NeuteredFileSystem struct {
-	Fs http.FileSystem
+	Fs fs.FS
 }
 
-func (nfs NeuteredFileSystem) Open(path string) (http.File, error) {
+func (nfs NeuteredFileSystem) Open(path string) (fs.File, error) {
 	f, err := nfs.Fs.Open(path)
 	if err != nil {
 		return nil, err