Add rclone backend

internal/backend/rclone/stdio_conn.go

@@ -0,0 +1,72 @@
+package rclone
+
+import (
+	"net"
+	"os"
+	"os/exec"
+
+	"github.com/restic/restic/internal/debug"
+)
+
+// StdioConn implements a net.Conn via stdin/stdout.
+type StdioConn struct {
+	stdin                   *os.File
+	stdout                  *os.File
+	bytesWritten, bytesRead int
+	cmd                     *exec.Cmd
+}
+
+func (s *StdioConn) Read(p []byte) (int, error) {
+	n, err := s.stdin.Read(p)
+	s.bytesRead += n
+	return n, err
+}
+
+func (s *StdioConn) Write(p []byte) (int, error) {
+	n, err := s.stdout.Write(p)
+	s.bytesWritten += n
+	return n, err
+}
+
+// Close closes both streams.
+func (s *StdioConn) Close() error {
+	debug.Log("close server instance")
+	var errs []error
+
+	for _, f := range []func() error{s.stdin.Close, s.stdout.Close} {
+		err := f()
+		if err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	if len(errs) > 0 {
+		return errs[0]
+	}
+	return nil
+}
+
+// LocalAddr returns nil.
+func (s *StdioConn) LocalAddr() net.Addr {
+	return Addr{}
+}
+
+// RemoteAddr returns nil.
+func (s *StdioConn) RemoteAddr() net.Addr {
+	return Addr{}
+}
+
+// make sure StdioConn implements net.Conn
+var _ net.Conn = &StdioConn{}
+
+// Addr implements net.Addr for stdin/stdout.
+type Addr struct{}
+
+// Network returns the network type as a string.
+func (a Addr) Network() string {
+	return "stdio"
+}
+
+func (a Addr) String() string {
+	return "stdio"
+}