history_container.py 文件源码

def create_buffer_panel(self, initial_dt, bar_data):
        """
        Initialize a RollingPanel containing enough minutes to service all our
        frequencies.
        """
        max_bars_needed = max(
            freq.max_bars for freq in self.unique_frequencies
        )
        freq = '1m' if self.data_frequency == 'minute' else '1d'
        spec = HistorySpec(
            max_bars_needed + 1, freq, None, None, self.env,
            self.data_frequency,
        )

        rp = self._create_panel(
            initial_dt, spec,
        )
        self.buffer_spec = spec

        if bar_data is not None:
            frame = self.frame_from_bardata(bar_data, initial_dt)
            rp.add_frame(initial_dt, frame)

        return rp