package s3 import "io" type noOpReadCloser struct{} type readerWithCloser struct { io.Reader closer func() error } var _ io.ReadCloser = &readerWithCloser{} func (d noOpReadCloser) Read(b []byte) (n int, err error) { return 0, io.EOF } func (d noOpReadCloser) Close() error { return nil } func limitReadCloser(rdr io.Reader, closer func() error, sz int64) io.ReadCloser { return &readerWithCloser{ Reader: io.LimitReader(rdr, sz), closer: closer, } } func (rwc *readerWithCloser) Close() error { if rwc.closer != nil { return rwc.closer() } return nil }