diff.py 文件源码

def run(self):
        try:
            # Try to open the FIFO nonblocking, so we can periodically check
            # if the main thread wants us to wind down.  If it does, there's no
            # more need for the FIFO, so stop the thread.
            while True:
                try:
                    fd = os.open(self.fifo_path, os.O_WRONLY | os.O_NONBLOCK)
                except OSError as error:
                    if error.errno != errno.ENXIO:
                        raise
                    elif self._want_join.is_set():
                        return
                else:
                    break

            # Now clear the fd's nonblocking flag to let writes block normally.
            fcntl.fcntl(fd, fcntl.F_SETFL, 0)

            with open(fd, 'wb') as fifo:
                # The queue works around a unified diff limitation: if there's
                # no newlines in both don't make it a difference
                end_nl = self.feeder(fifo)
                self.end_nl_q.put(end_nl)
        except Exception as error:
            self._exception = error