console.py

from itertools import product


class ConsoleDisplay(object):

    def __init__(self, win, rows, cols):
        win.resize(rows, cols)
        self._win = win
        self.rows = rows
        self.cols = cols

    def refresh(self, vram):
        for y, x in product(xrange(self.rows), xrange(self.cols)):
            self.set_char(y, x, vram[y * self.cols + x])
        self._win.refresh()

    def set_char(self, y, x, char):
        if char == '\x00':
            char = '\x20'
        self._win.insstr(y, x, char)


import os
import curses
import mmap
import time
import logging
logging.basicConfig(filename='console.log', level=logging.DEBUG)

def run():
    def func(stdscr, rows, cols, ram_file_path, refresh_interval):
        try:
            console = ConsoleDisplay(stdscr, rows, cols)
            with open(ram_file_path, 'wb') as f:
                f.seek(rows * cols - 1)
                f.write('\x00')
            with open(ram_file_path, 'rb') as f:
                vram = mmap.mmap(fileno=f.fileno(), length=rows * cols, prot=mmap.PROT_READ)
                while True:
                    console.refresh(vram)
                    # without sleep, it can loop for 730/sec on my mac book pro 2014
                    time.sleep(refresh_interval)
                logging.info('count: %d' % count)
        except:
            logging.exception('Exception:')

    rows, cols = 25, 80
    console_ram_file = 'console.ram'
    refresh_interval = 0.1
    curses.wrapper(func, rows, cols, console_ram_file, refresh_interval)

if __name__ == '__main__':
    run()