pyinotify.py 文件源码

def read_events(self):
        """
        Read events from device, build _RawEvents, and enqueue them.
        """
        buf_ = array.array('i', [0])
        # get event queue size
        if fcntl.ioctl(self._fd, termios.FIONREAD, buf_, 1) == -1:
            return
        queue_size = buf_[0]
        if queue_size < self._threshold:
            log.debug('(fd: %d) %d bytes available to read but threshold is '
                      'fixed to %d bytes', self._fd, queue_size,
                      self._threshold)
            return

        try:
            # Read content from file
            r = os.read(self._fd, queue_size)
        except Exception, msg:
            raise NotifierError(msg)
        log.debug('Event queue size: %d', queue_size)
        rsum = 0  # counter
        while rsum < queue_size:
            s_size = 16
            # Retrieve wd, mask, cookie and fname_len
            wd, mask, cookie, fname_len = struct.unpack('iIII',
                                                        r[rsum:rsum+s_size])
            # Retrieve name
            fname, = struct.unpack('%ds' % fname_len,
                                   r[rsum + s_size:rsum + s_size + fname_len])
            rawevent = _RawEvent(wd, mask, cookie, fname)
            if self._coalesce:
                # Only enqueue new (unique) events.
                raweventstr = str(rawevent)
                if raweventstr not in self._eventset:
                    self._eventset.add(raweventstr)
                    self._eventq.append(rawevent)
            else:
                self._eventq.append(rawevent)
            rsum += s_size + fname_len