U h'(@sxdZddlmZddlZddlZddlmZdZdZdZ dZ Gdd d e Z Gd d d e Z d d ZGddde ZdS)aDecorators for applying timeout arguments to functions. These decorators are used to wrap API methods to apply either a Deadline-dependent (recommended), constant (DEPRECATED) or exponential (DEPRECATED) timeout argument. For example, imagine an API method that can take a while to return results, such as one that might block until a resource is ready: .. code-block:: python def is_thing_ready(timeout=None): response = requests.get('https://example.com/is_thing_ready') response.raise_for_status() return response.json() This module allows a function like this to be wrapped so that timeouts are automatically determined, for example: .. code-block:: python timeout_ = timeout.ExponentialTimeout() is_thing_ready_with_timeout = timeout_(is_thing_ready) for n in range(10): try: is_thing_ready_with_timeout({'example': 'data'}) except: pass In this example the first call to ``is_thing_ready`` will have a relatively small timeout (like 1 second). If the resource is available and the request completes quickly, the loop exits. But, if the resource isn't yet available and the request times out, it'll be retried - this time with a larger timeout. In the broader context these decorators are typically combined with :mod:`google.api_core.retry` to implement API methods with a signature that matches ``api_method(request, timeout=None, retry=None)``. )unicode_literalsN)datetime_helpersg@g>@g@c@s0eZdZdZdejfddZddZddZdS) TimeToDeadlineTimeouta&A decorator that decreases timeout set for an RPC based on how much time has left till its deadline. The deadline is calculated as ``now + initial_timeout`` when this decorator is first called for an rpc. In other words this decorator implements deadline semantics in terms of a sequence of decreasing timeouts t0 > t1 > t2 ... tn >= 0. Args: timeout (Optional[float]): the timeout (in seconds) to applied to the wrapped function. If `None`, the target function is expected to never timeout. NcCs||_||_dSN)_timeout_clock)selftimeoutZclockr ;/tmp/pip-unpacked-wheel-eraazoov/google/api_core/timeout.py__init__TszTimeToDeadlineTimeout.__init__cs*tfdd}|S)Apply the timeout decorator. Args: func (Callable): The function to apply the timeout argument to. This function must accept a timeout keyword argument. Returns: Callable: The wrapped function. csXjdk rN}|dkr&}|}j|}|dkrFj}||d<||S)#Wrapped function that adds timeout.NgMbP?r )rr timestamp)argskwargsZ now_timestampZtime_since_first_attemptZremaining_timeoutZfirst_attempt_timestampfuncrr r func_with_timeoutes    z9TimeToDeadlineTimeout.__call__..func_with_timeout)rr functoolswrapsrrrr rr __call__Xs zTimeToDeadlineTimeout.__call__cCs d|jS)Nz&formatrrr r r __str__szTimeToDeadlineTimeout.__str__) __name__ __module__ __qualname____doc__rutcnowr rrr r r r rFs .rc@s*eZdZdZd ddZddZddZdS) ConstantTimeoutaA decorator that adds a constant timeout argument. DEPRECATED: use ``TimeToDeadlineTimeout`` instead. This is effectively equivalent to ``functools.partial(func, timeout=timeout)``. Args: timeout (Optional[float]): the timeout (in seconds) to applied to the wrapped function. If `None`, the target function is expected to never timeout. NcCs ||_dSrr)rr r r r r szConstantTimeout.__init__cstfdd}|S)r csj|d<||Srr r$rrrrr r rs z3ConstantTimeout.__call__..func_with_timeout)rrrr r'r rs zConstantTimeout.__call__cCs d|jS)Nz rrr r r rszConstantTimeout.__str__)N)rrr r!r rrr r r r r#s r#ccsX|dk rttj|d}ntjj}|}t}t||t||jV||}q*dS)aVA generator that yields exponential timeout values. Args: initial (float): The initial timeout. maximum (float): The maximum timeout. multiplier (float): The multiplier applied to the timeout. deadline (float): The overall deadline across all invocations. Yields: float: A timeout value. N)seconds)rr"datetime timedeltamaxminfloatr()initialmaximum multiplierdeadlineZdeadline_datetimer nowr r r _exponential_timeout_generators    r3c@s:eZdZdZeeeefddZddZ ddZ dd Z d S) ExponentialTimeoutaTA decorator that adds an exponentially increasing timeout argument. DEPRECATED: the concept of incrementing timeout exponentially has been deprecated. Use ``TimeToDeadlineTimeout`` instead. This is useful if a function is called multiple times. Each time the function is called this decorator will calculate a new timeout parameter based on the the number of times the function has been called. For example .. code-block:: python Args: initial (float): The initial timeout to pass. maximum (float): The maximum timeout for any one call. multiplier (float): The multiplier applied to the timeout for each invocation. deadline (Optional[float]): The overall deadline across all invocations. This is used to prevent a very large calculated timeout from pushing the overall execution time over the deadline. This is especially useful in conjunction with :mod:`google.api_core.retry`. If ``None``, the timeouts will not be adjusted to accommodate an overall deadline. cCs||_||_||_||_dSr)_initial_maximum _multiplier _deadline)rr.r/r0r1r r r r szExponentialTimeout.__init__cCst|j|j|j|dS)zReturn a copy of this timeout with the given deadline. Args: deadline (float): The overall deadline across all invocations. Returns: ExponentialTimeout: A new instance with the given deadline. )r.r/r0r1)r4r5r6r7)rr1r r r with_deadlines z ExponentialTimeout.with_deadlinecs2t|j|j|j|jtfdd}|S)r cst|d<||Sr%)nextr&rZtimeoutsr r rs z6ExponentialTimeout.__call__..func_with_timeout)r3r5r6r7r8rrrr r;r r s zExponentialTimeout.__call__cCsd|j|j|j|jS)NzW)rr5r6r7r8rr r r r szExponentialTimeout.__str__N) rrr r!_DEFAULT_INITIAL_TIMEOUT_DEFAULT_MAXIMUM_TIMEOUT_DEFAULT_TIMEOUT_MULTIPLIER_DEFAULT_DEADLINEr r9rrr r r r r4s r4)r! __future__rr)rZgoogle.api_corerr<r=r>r?objectrr#r3r4r r r r s(  D(!