def parse_blocks(log_file):
    """ Parse log file to return the blocks that were
        marked as processed
    """
    blocks = []
    with open(log_file, 'r') as f:
        for line in f:
            # get rid of date-time prefix
            line = ' '.join(line.split()[2:])
            # check if the line marks a block that has passed
            if line.startswith('processed block'):
                blocks.append(int(line.split()[-1]))
    return blocks