CGS: implement MimeTyper interface

vfs/gcsfs.go

@@ -27,7 +27,7 @@ import (
 )
 
 var (
-	gcsDefaultFieldsSelection = []string{"Name", "Size", "Deleted", "Updated", "ContentType"}
+	gcsDefaultFieldsSelection = []string{"Name", "Size", "Deleted", "Updated"}
 )
 
 // GCSFs is a Fs implementation for Google Cloud Storage.
@@ -121,9 +121,6 @@ func (fs GCSFs) Stat(name string) (os.FileInfo, error) {
 			if fs.isEqual(attrs.Name, name) {
 				isDir := strings.HasSuffix(attrs.Name, "/")
 				result = NewFileInfo(name, isDir, attrs.Size, attrs.Updated, false)
-				if !isDir {
-					result.setContentType(attrs.ContentType)
-				}
 				break
 			}
 		}
@@ -184,7 +181,7 @@ func (fs GCSFs) Create(name string, flag int) (*os.File, *PipeWriter, func(), er
 	objectWriter := obj.NewWriter(ctx)
 	contentType := mime.TypeByExtension(path.Ext(name))
 	if contentType != "" {
-	    objectWriter.ObjectAttrs.ContentType = contentType
+		objectWriter.ObjectAttrs.ContentType = contentType
 	}
 	if len(fs.config.StorageClass) > 0 {
 		objectWriter.ObjectAttrs.StorageClass = fs.config.StorageClass
@@ -359,9 +356,6 @@ func (fs GCSFs) ReadDir(dirname string) ([]os.FileInfo, error) {
 				continue
 			}
 			fi := NewFileInfo(name, isDir, attrs.Size, attrs.Updated, false)
-			if !isDir {
-				fi.setContentType(attrs.ContentType)
-			}
 			result = append(result, fi)
 		}
 	}
@@ -596,3 +590,17 @@ func (fs *GCSFs) getPrefixForStat(name string) string {
 	}
 	return prefix
 }
+
+// GetMimeType implements MimeTyper interface
+func (fs GCSFs) GetMimeType(name string) (string, error) {
+	ctx, cancelFn := context.WithDeadline(context.Background(), time.Now().Add(fs.ctxTimeout))
+	defer cancelFn()
+	bkt := fs.svc.Bucket(fs.config.Bucket)
+	obj := bkt.Object(name)
+	attrs, err := obj.Attrs(ctx)
+	if err != nil {
+		return "", err
+	}
+	logger.DebugToConsole("content type: %v", attrs.ContentType)
+	return attrs.ContentType, nil
+}