package swift import (	"io"	"time") // An io.ReadCloser which obeys an idle timeouttype timeoutReader struct {	reader  io.ReadCloser	timeout time.Duration	cancel  func()} // Returns a wrapper around the reader which obeys an idle// timeout. The cancel function is called if the timeout happensfunc newTimeoutReader(reader io.ReadCloser, timeout time.Duration, cancel func()) *timeoutReader {	return &timeoutReader{		reader:  reader,		timeout: timeout,		cancel:  cancel,	}} // Read reads up to len(p) bytes into p//// Waits at most for timeout for the read to complete otherwise returns a timeoutfunc (t *timeoutReader) Read(p []byte) (int, error) {	// FIXME limit the amount of data read in one chunk so as to not exceed the timeout?	// Do the read in the background	type result struct {		n   int		err error	}	done := make(chan result, 1)	go func() {		n, err := t.reader.Read(p)		done <- result{n, err}	}()	// Wait for the read or the timeout	timer := time.NewTimer(t.timeout)	defer timer.Stop()	select {	case r := <-done:		return r.n, r.err	case <-timer.C:		t.cancel()		return 0, TimeoutError	}	panic("unreachable") // for Go 1.0} // Close the channelfunc (t *timeoutReader) Close() error {	return t.reader.Close()} // Check it satisfies the interfacevar _ io.ReadCloser = &timeoutReader{}