面向切面编程AOP，一些通用装饰器

1、一些装饰器,可以减少重复编写。比较常用的。

用的时候函数上面加上装饰器就可以。这是一些装饰器，加在函数或者方法上，减少了很多重复代码。

除此之外工作中也用一些mixin类大幅减少代码。

import sys
import traceback
from functools import wraps
import threading
import time
import unittest
from app.utils_ydf import LogManager
from tomorrow3 import threads as tomorrow_threads
from functools import lru_cache  # NOQA

handle_exception_log = LogManager('function_error').get_logger_and_add_handlers()
run_times_log = LogManager('run_many_times').get_logger_and_add_handlers()


class CustomException(Exception):
    def __init__(self, err=''):
        err0 = 'fatal exception
'
        Exception.__init__(self, err0 + err)


def run_many_times(times=1):
    """把函数运行times次的装饰器
    :param times:运行次数
    没有捕获错误，出错误就中断运行，可以配合handle_exception装饰器不管是否错误都运行n次。
    """

    def _run_many_times(func):
        @wraps(func)
        def __run_many_times(*args, **kwargs):
            for i in range(times):
                LogManager('run_many_times').get_logger_without_handlers().debug('* ' * 50 + '当前是第 {} 次运行[ {} ]函数'.format(i + 1, func.__name__))
                func(*args, **kwargs)

        return __run_many_times

    return _run_many_times


def handle_exception(retry_times=0, error_detail_level=0, is_throw_error=False):
    """捕获函数错误的装饰器,重试并打印日志
    :param retry_times : 重试次数
    :param error_detail_level :为0打印exception提示，为1打印3层深度的错误堆栈，为2打印所有深度层次的错误堆栈
    :param is_throw_error : 在达到最大次数时候是否重新抛出错误
    :type error_detail_level: int
    """
    if error_detail_level not in [0, 1, 2]:
        raise Exception('error_detail_level参数必须设置为0 、1 、2')

    def _handle_exception(func):
        @wraps(func)
        def __handle_exception(*args, **keyargs):
            for i in range(0, retry_times + 1):
                try:
                    result = func(*args, **keyargs)
                    if i:
                        LogManager('function_error').get_logger_without_handlers().debug(
                            u'%s
调用成功，调用方法--> [  %s  ] 第  %s  次重试成功' % ('# ' * 40, func.__name__, i))
                    return result

                except Exception as e:
                    error_info = ''
                    if error_detail_level == 0:
                        error_info = str(e)
                    elif error_detail_level == 1:
                        error_info = traceback.format_exc(limit=3)
                    elif error_detail_level == 2:
                        error_info = traceback.format_exc()

                    LogManager('function_error').get_logger_without_handlers().error(
                        u'%s
记录错误日志，调用方法--> [  %s  ] 第  %s  次错误重试，错误原因是： %s
' % ('- ' * 40, func.__name__, i, error_info))
                    if i == retry_times and is_throw_error:  # 达到最大错误次数后，重新抛出错误
                        raise e

        return __handle_exception

    return _handle_exception


def keep_circulating(time_sleep=0.001):
    """间隔一段时间，一直循环运行某个方法的装饰器
    :param time_sleep :循环的间隔时间
    """
    if not hasattr(keep_circulating, 'keep_circulating_log'):
        keep_circulating.log = LogManager('keep_circulating').get_logger_and_add_handlers()

    def _keep_circulating(func):
        @wraps(func)
        def __keep_circulating(*args, **kwargs):
            while 1:
                try:
                    func(*args, **kwargs)
                except Exception:
                    msg = func.__name__ + '   运行出错
 ' + traceback.format_exc(limit=2)
                    keep_circulating.log.error(msg)
                finally:
                    time.sleep(time_sleep)

        return __keep_circulating

    return _keep_circulating


def singleton(cls):
    """单例模式装饰器
    """
    _instance = {}

    @wraps(cls)
    def _singleton(*args, **kwargs):
        if cls not in _instance:
            _instance[cls] = cls(*args, **kwargs)
        return _instance[cls]

    return _singleton


def timer(func):
    """计时器装饰器，只能用来计算函数运行时间"""
    if not hasattr(timer, 'log'):
        timer.log = LogManager('timer').get_logger_and_add_handlers()

    @wraps(func)
    def _timer(*args, **kwargs):
        t1 = time.time()
        result = func(*args, **kwargs)
        t2 = time.time()
        t_spend = t2 - t1
        timer.log.debug('执行[ {} ]方法用时 {} 秒'.format(func.__name__, t_spend))
        return result

    return _timer


class TimerContextManager(object):
    """
    用上下文管理器计时，可对代码片段计时
    """
    log = LogManager('TimerContext').get_logger_and_add_handlers()

    def __init__(self, is_print_log=True):
        self._is_print_log = is_print_log
        self.t_spend = None
        self._line = None
        self._file_name = None
        self.time_start = None

    def __enter__(self):
        self._line = sys._getframe().f_back.f_lineno  # 调用此方法的代码的函数
        self._file_name = sys._getframe(1).f_code.co_filename  # 哪个文件调了用此方法
        self.time_start = time.time()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.t_spend = time.time() - self.time_start
        if self._is_print_log:
            self.log.debug(f'对下面代码片段进行计时:  
执行"{self._file_name}:{self._line}" 用时 {self.t_spend} 秒')


class ExceptionContextManager():
    """
    用上下文管理器捕获异常，可对代码片段进行错误捕捉，比装饰器更细腻
    """

    def __init__(self, logger_name='ExceptionContextManager', verbose=100, donot_raise__exception=True, ):
        """
        :param _verbose: 打印错误的深度,对应traceback对象的limit，为正整数
        :param donot_raise__exception:是否不重新抛出错误，为Fasle则抛出，为True则不抛出
        """
        self.logger = LogManager(logger_name).get_logger_and_add_handlers()
        self._verbose = verbose
        self._donot_raise__exception = donot_raise__exception

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        # print(exc_val)
        # print(traceback.format_exc())
        exc_str = str(exc_type) + '  :  ' + str(exc_val)
        exc_str_color = '33[0;30;45m%s33[0m' % exc_str
        if self._donot_raise__exception:
            if exc_tb is not None:
                self.logger.error('
'.join(traceback.format_tb(exc_tb)[:self._verbose]) + exc_str_color)
        return self._donot_raise__exception  # __exit__方法必须retuen True才会不重新抛出错误


def where_is_it_called(func):
    """一个装饰器，被装饰的函数，如果被调用，将记录一条日志,记录函数被什么文件的哪一行代码所调用"""
    if not hasattr(where_is_it_called, 'log'):
        where_is_it_called.log = LogManager('where_is_it_called').get_logger_and_add_handlers()

    @wraps(func)
    def _where_is_it_called(*args, **kwargs):
        # 获取被调用函数名称
        # func_name = sys._getframe().f_code.co_name
        func_name = func.__name__
        # 什么函数调用了此函数
        which_fun_call_this = sys._getframe(1).f_code.co_name  # NOQA

        # 获取被调用函数在被调用时所处代码行数
        line = sys._getframe().f_back.f_lineno

        # 获取被调用函数所在模块文件名
        file_name = sys._getframe(1).f_code.co_filename

        where_is_it_called.log.debug('文件[{}]的第[{}]行即模块 [{}] 中的方法 [{}] 正在被文件 [{}] 中的方法 [{}] 中的第 [{}] 行处调用，' 
                                     '传入的参数为[{args},{kwargs}]'.format(func.__code__.co_filename, func.__code__.co_firstlineno, func.__module__, func_name, file_name, which_fun_call_this, line,
                                                                      args=args, kwargs=kwargs))
        try:
            t0 = time.time()
            result = func(*args, **kwargs)
            t_spend = round(time.time() - t0, 2)
            where_is_it_called.log.debug('执行函数[{}]消耗的时间是{}秒，返回的结果是 --> '.format(func_name, t_spend) + str(result))
            return result
        except Exception as e:
            where_is_it_called.log.debug('执行函数{}，发生错误'.format(func_name))
            raise e

    return _where_is_it_called


class cached_class_property(object):
    """类属性缓存装饰器"""

    def __init__(self, func):
        self.func = func

    def __get__(self, obj, cls):
        if obj is None:
            return self
        value = self.func(obj)
        setattr(cls, self.func.__name__, value)
        return value


class cached_property(object):
    """实例属性缓存装饰器"""

    def __init__(self, func):
        self.func = func

    def __get__(self, obj, cls):
        print(obj, cls)
        if obj is None:
            return self
        value = obj.__dict__[self.func.__name__] = self.func(obj)
        return value


def cached_method_result(fun):
    """方法的结果装饰器,不接受self以外的多余参数，主要用于那些属性类的property方法属性上"""

    @wraps(fun)
    def inner(self):
        if not hasattr(fun, 'result'):
            result = fun(self)
            fun.result = result
            fun_name = fun.__name__
            setattr(self.__class__, fun_name, result)
            setattr(self, fun_name, result)
            return result
        else:
            return fun.result

    return inner


class FunctionResultCacher:
    logger = LogManager('FunctionResultChche').get_logger_and_add_handlers()
    func_result_dict = {}
    """
    {
        (f1,(1,2,3,4)):(10,1532066199.739),
        (f2,(5,6,7,8)):(26,1532066211.645),
    }
    """

    @classmethod
    def cached_function_result_for_a_time(cls, cache_time):
        """
        函数的结果缓存一段时间装饰器,不要装饰在返回结果是超大字符串或者其他占用大内存的数据结构上的函数上面。
        :param cache_time :缓存的时间
        :type cache_time : float
        """

        def _cached_function_result_for_a_time(fun):

            @wraps(fun)
            def __cached_function_result_for_a_time(*args, **kwargs):
                # print(cls.func_result_dict)
                # if len(cls.func_result_dict) > 1024:
                if sys.getsizeof(cls.func_result_dict) > 10 * 1000 * 1000:
                    cls.func_result_dict.clear()

                key = cls._make_arguments_to_key(args, kwargs)
                if (fun, key) in cls.func_result_dict and time.time() - cls.func_result_dict[(fun, key)][1] < cache_time:
                    return cls.func_result_dict[(fun, key)][0]
                else:
                    result = fun(*args, **kwargs)
                    cls.func_result_dict[(fun, key)] = (result, time.time())
                    cls.logger.debug('函数 [{}] 此次不使用缓存'.format(fun.__name__))
                    return result

            return __cached_function_result_for_a_time

        return _cached_function_result_for_a_time

    @staticmethod
    def _make_arguments_to_key(args, kwds):
        key = args
        if kwds:
            sorted_items = sorted(kwds.items())
            for item in sorted_items:
                key += item
        return key


class __KThread(threading.Thread):
    def __init__(self, *args, **kwargs):
        threading.Thread.__init__(self, *args, **kwargs)
        self.killed = False
        self.__run_backup = None

    def start(self):
        """Start the thread."""
        self.__run_backup = self.run
        self.run = self.__run  # Force the Thread to install our trace.
        threading.Thread.start(self)

    def __run(self):
        """Hacked run function, which installs the trace."""
        sys.settrace(self.globaltrace)
        self.__run_backup()
        self.run = self.__run_backup

    def globaltrace(self, frame, why, arg):
        if why == 'call':
            return self.localtrace
        return None

    def localtrace(self, frame, why, arg):
        if self.killed:
            if why == 'line':
                raise SystemExit()
        return self.localtrace

    def kill(self):
        self.killed = True


class TIMEOUT_EXCEPTION(Exception):
    """function run timeout"""
    pass


def timeout(seconds):
    """超时装饰器，指定超时时间

    若被装饰的方法在指定的时间内未返回，则抛出Timeout异常"""

    def timeout_decorator(func):

        def _new_func(oldfunc, result, oldfunc_args, oldfunc_kwargs):
            result.append(oldfunc(*oldfunc_args, **oldfunc_kwargs))

        def _(*args, **kwargs):
            result = []
            new_kwargs = {
             
                'oldfunc': func,
                'result': result,
                'oldfunc_args': args,
                'oldfunc_kwargs': kwargs
            }

            thd = __KThread(target=_new_func, args=(), kwargs=new_kwargs)
            thd.start()
            thd.join(seconds)
            alive = thd.isAlive()
            thd.kill()  # kill the child thread

            if alive:
                raise TIMEOUT_EXCEPTION(
                    'function run too long, timeout %d seconds.' % seconds)
            else:
                if result:
                    return result[0]
                return result

        _.__name__ = func.__name__
        _.__doc__ = func.__doc__
        return _

    return timeout_decorator


class _Test(unittest.TestCase):
    @unittest.skip
    def test_superposition(self):
        """测试多次运行和异常重试,测试装饰器叠加"""

        @run_many_times(3)
        @handle_exception(2, 1)
        def f():
            import json
            json.loads('a', ac='ds')

        f()

    @unittest.skip
    def test_handle_exception(self):
        """测试异常重试装饰器"""
        import requests

        @handle_exception(2)
        def f3():
            pass
            requests.get('dsdsdsd')

        f3()

    @unittest.skip
    def test_run_many_times(self):
        """测试运行5次"""

        @run_many_times(5)
        def f1():
            print('hello')
            time.sleep(1)

        f1()

    @unittest.skip
    def test_tomorrow_threads(self):
        """测试多线程装饰器,每2秒打印5次"""

        @tomorrow_threads(5)
        def f2():
            print(time.strftime('%H:%M:%S'))
            time.sleep(2)

        [f2() for _ in range(9)]

    @unittest.skip
    def test_singleton(self):
        """测试单例模式的装饰器"""

        @singleton
        class A(object):
            def __init__(self, x):
                self.x = x

        a1 = A(3)
        a2 = A(4)
        self.assertEqual(id(a1), id(a2))
        print(a1.x, a2.x)

    @unittest.skip
    def test_keep_circulating(self):
        """测试间隔时间，循环运行"""

        @keep_circulating(3)
        def f6():
            print("每隔3秒，一直打印   " + time.strftime('%H:%M:%S'))

        f6()

    @unittest.skip
    def test_timer(self):
        """测试计时器装饰器"""

        @timer
        def f7():
            time.sleep(2)

        f7()

    @unittest.skip
    def test_timer_context(self):
        """
        测试上下文，对代码片段进行计时
        """
        with TimerContextManager(is_print_log=False) as tc:
            time.sleep(2)
        print(tc.t_spend)

    @unittest.skip
    def test_where_is_it_called(self):
        """测试函数被调用的装饰器，被调用2次将会记录2次被调用的日志"""

        @where_is_it_called
        def f9(a, b):
            result = a + b
            print(result)
            time.sleep(0.1)
            return result

        f9(1, 2)

        f9(3, 4)

    @unittest.skip
    def test_cached_function_result(self):
        @FunctionResultCacher.cached_function_result_for_a_time(3)
        def f10(a, b, c=3, d=4):
            print('计算中。。。')
            return a + b + c + d

        print(f10(1, 2, 3, 4))
        print(f10(1, 2, 3, 4))
        time.sleep(4)
        print(f10(1, 2, 3, 4))

    @unittest.skip
    def test_exception_context_manager(self):
        def f1():
            1 + '2'

        def f2():
            f1()

        def f3():
            f2()

        def f4():
            f3()

        def run():
            f4()

        with ExceptionContextManager() as ec:
            run()

        print('finish')

    def test_timeout(self):
        """
        测试超时装饰器
        :return:
        """

        @timeout(3)
        def f(time_to_be_sleep):
            time.sleep(time_to_be_sleep)
            print('hello wprld')

        f(5)


if __name__ == '__main__':
    unittest.main()

2、都是常规的，有带参数和不带参数的装饰器。其中where_is_it_called装饰器比较复杂一点，只要函数或方法加上这个装饰器，每当函数被别的地方每次调用时候，能记录下它在哪个时候被哪个文件的哪个函数的哪一行代码调用过。这个实在太强了。

由于是本文件中直接测试运行，所以是显示main。

 模块 [__main__] 中的方法 [f9] 正在被文件 [D:/Users/xxx/Desktop/oschina/coding/hotel/app/apis/fliggy/utils/decorators.py] 中的方法 [test_where_is_it_called] 中的第 [266] 行处调用