X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=persistent.py;h=b42a5c0e3036a35d76dc0c8f32374d029e94fd53;hb=f995224a77488f3469c16a3f504dcf7a1393d834;hp=d62dd6754eeffc78c1c09adea7c82e778f8450b3;hpb=e6f32fdd9b373dfcd100c7accb41f57d83c2f0a1;p=python_utils.git diff --git a/persistent.py b/persistent.py index d62dd67..b42a5c0 100644 --- a/persistent.py +++ b/persistent.py @@ -1,11 +1,17 @@ #!/usr/bin/env python3 -from abc import ABC, abstractmethod +# © Copyright 2021-2022, Scott Gasch + +"""A Persistent is just a class with a load and save method. This +module defines the Persistent base and a decorator that can be used to +create a persistent singleton that autoloads and autosaves.""" + import atexit import datetime import enum import functools import logging +from abc import ABC, abstractmethod from typing import Any import file_utils @@ -58,12 +64,29 @@ class Persistent(ABC): def was_file_written_today(filename: str) -> bool: - """Returns True if filename was written today.""" + """Returns True if filename was written today. + + >>> import os + >>> filename = f'/tmp/testing_persistent_py_{os.getpid()}' + >>> os.system(f'touch {filename}') + 0 + >>> was_file_written_today(filename) + True + >>> os.system(f'touch -d 1974-04-15T01:02:03.99 {filename}') + 0 + >>> was_file_written_today(filename) + False + >>> os.system(f'/bin/rm -f {filename}') + 0 + >>> was_file_written_today(filename) + False + """ if not file_utils.does_file_exist(filename): return False mtime = file_utils.get_file_mtime_as_datetime(filename) + assert mtime is not None now = datetime.datetime.now() return mtime.month == now.month and mtime.day == now.day and mtime.year == now.year @@ -75,11 +98,27 @@ def was_file_written_within_n_seconds( """Returns True if filename was written within the pas limit_seconds seconds. + >>> import os + >>> filename = f'/tmp/testing_persistent_py_{os.getpid()}' + >>> os.system(f'touch {filename}') + 0 + >>> was_file_written_within_n_seconds(filename, 60) + True + >>> import time + >>> time.sleep(2.0) + >>> was_file_written_within_n_seconds(filename, 2) + False + >>> os.system(f'/bin/rm -f {filename}') + 0 + >>> was_file_written_within_n_seconds(filename, 60) + False """ + if not file_utils.does_file_exist(filename): return False mtime = file_utils.get_file_mtime_as_datetime(filename) + assert mtime is not None now = datetime.datetime.now() return (now - mtime).total_seconds() <= limit_seconds @@ -126,7 +165,7 @@ class persistent_autoloaded_singleton(object): self.instance = None def __call__(self, cls: Persistent): - @functools.wraps(cls) + @functools.wraps(cls) # type: ignore def _load(*args, **kwargs): # If class has already been loaded, act like a singleton @@ -134,35 +173,36 @@ class persistent_autoloaded_singleton(object): # memory. if self.instance is not None: logger.debug( - f'Returning already instantiated singleton instance of {cls.__name__}.' + 'Returning already instantiated singleton instance of %s.', cls.__name__ ) return self.instance # Otherwise, try to load it from persisted state. was_loaded = False - logger.debug(f'Attempting to load {cls.__name__} from persisted state.') + logger.debug('Attempting to load %s from persisted state.', cls.__name__) self.instance = cls.load() if not self.instance: msg = 'Loading from cache failed.' logger.warning(msg) - logger.debug(f'Attempting to instantiate {cls.__name__} directly.') + logger.debug('Attempting to instantiate %s directly.', cls.__name__) self.instance = cls(*args, **kwargs) else: - logger.debug( - f'Class {cls.__name__} was loaded from persisted state successfully.' - ) + logger.debug('Class %s was loaded from persisted state successfully.', cls.__name__) was_loaded = True assert self.instance is not None if self.persist_at_shutdown is PersistAtShutdown.ALWAYS or ( - not was_loaded - and self.persist_at_shutdown is PersistAtShutdown.IF_NOT_LOADED + not was_loaded and self.persist_at_shutdown is PersistAtShutdown.IF_NOT_LOADED ): - logger.debug( - 'Scheduling a deferred called to save at process shutdown time.' - ) + logger.debug('Scheduling a deferred called to save at process shutdown time.') atexit.register(self.instance.save) return self.instance return _load + + +if __name__ == '__main__': + import doctest + + doctest.testmod()