server/s3/ioutils.go

// Credits: https://pkg.go.dev/github.com/rclone/rclone@v1.65.2/cmd/serve/s3
// Package s3 implements a fake s3 server for alist
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
}