inline GetID3Tags

thumbnailing/preview/mp3.go

@@ -48,14 +48,17 @@ func (d mp3Generator) GetOriginDimensions(b io.Reader, contentType string, ctx r
 }
 
 func (d mp3Generator) GenerateThumbnail(b io.Reader, contentType string, width int, height int, method string, animated bool, ctx rcontext.RequestContext) (*Thumbnail, error) {
-	tags, rc, err := u.GetID3Tags(b)
+	rd, err := newReadSeekerWrapper(b)
+	tags, err := u.GetID3Tags(rd)
+	if err != nil {
+		return nil, fmt.Errorf("error wrapping reader: %w", err)
+	}
+	tags, err = tag.ReadFrom(rd) // we don't care about errors in this process
 	if err != nil {
 		return nil, fmt.Errorf("mp3: error getting tags: %w", err)
 	}
-	//goland:noinspection GoUnhandledErrorResult
-	defer rc.Close()
 
-	audio, format, err := d.decode(rc)
+	audio, format, err := d.decode(rd)
 	if err != nil {
 		return nil, err
 	}

thumbnailing/preview/readSeeker.go

@@ -0,0 +1,42 @@
+package preview
+
+import "io"
+
+type readSeekerWrapper struct {
+	data   []byte
+	offset int64
+}
+
+func (r *readSeekerWrapper) Read(p []byte) (n int, err error) {
+	if r.offset >= int64(len(r.data)) {
+		return 0, io.EOF
+	}
+	n = copy(p, r.data[r.offset:])
+	r.offset += int64(n)
+	return
+}
+
+func (r *readSeekerWrapper) Seek(offset int64, whence int) (int64, error) {
+	var absOffset int64
+	switch whence {
+	case io.SeekStart:
+		absOffset = offset
+	case io.SeekCurrent:
+		absOffset = r.offset + offset
+	case io.SeekEnd:
+		absOffset = int64(len(r.data)) + offset
+	}
+	if absOffset < 0 || absOffset > int64(len(r.data)) {
+		return 0, io.EOF
+	}
+	r.offset = absOffset
+	return absOffset, nil
+}
+
+func newReadSeekerWrapper(reader io.Reader) (*readSeekerWrapper, error) {
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return nil, err
+	}
+	return &readSeekerWrapper{data: data}, nil
+}