Method Open

backend/cache/object.go:218–246

Open is used to request a specific part of the file using fs.RangeOption

(ctx context.Context, options ...fs.OpenOption)

// Open is used to request a specific part of the file using fs.RangeOption
func (o *Object) Open(ctx context.Context, options ...fs.OpenOption) (io.ReadCloser, error) {
	var err error

	if o.Object == nil {
		err = o.refreshFromSource(ctx, true)
	} else {
		err = o.refresh(ctx)
	}
	if err != nil {
		return nil, err
	}

	cacheReader := NewObjectHandle(ctx, o, o.CacheFs)
	var offset, limit int64 = 0, -1
	for _, option := range options {
		switch x := option.(type) {
		case *fs.SeekOption:
			offset = x.Offset
		case *fs.RangeOption:
			offset, limit = x.Decode(o.Size())
		}
		_, err = cacheReader.Seek(offset, io.SeekStart)
		if err != nil {
			return nil, err
		}
	}

	return readers.NewLimitedReadCloser(cacheReader, limit), nil
}

// Update will change the object data
func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) error {