Reduce the doctest lease duration...

[python_utils.git] / decorator_utils.py

diff --git a/decorator_utils.py b/decorator_utils.py
index 084e260bab370d9bbb93a1256ff84e98f96055bd..4615fec6f8960e0083ce48546ba9421c25243d42 100644 (file)
--- a/decorator_utils.py
+++ b/decorator_utils.py
@@ -3,7 +3,7 @@
 # © Copyright 2021-2022, Scott Gasch
 # Portions (marked) below retain the original author's copyright.
 
 # © Copyright 2021-2022, Scott Gasch
 # Portions (marked) below retain the original author's copyright.
 

-"""Decorators."""
+"""Useful(?) decorators."""

 
 import enum
 import functools
 
 import enum
 import functools


@@ -18,7 +18,7 @@ import threading
 import time
 import traceback
 import warnings
 import time
 import traceback
 import warnings

-from typing import Any, Callable, Optional
+from typing import Any, Callable, List, Optional

 
 # This module is commonly used by others in here and should avoid
 # taking any unnecessary dependencies back on them.
 
 # This module is commonly used by others in here and should avoid
 # taking any unnecessary dependencies back on them.


@@ -33,7 +33,7 @@ def timed(func: Callable) -> Callable:
     >>> @timed
     ... def foo():
     ...     import time
     >>> @timed
     ... def foo():
     ...     import time

-    ...     time.sleep(0.1)
+    ...     time.sleep(0.01)

 
     >>> foo()  # doctest: +ELLIPSIS
     Finished foo in ...
 
     >>> foo()  # doctest: +ELLIPSIS
     Finished foo in ...


@@ -55,7 +55,7 @@ def timed(func: Callable) -> Callable:
 
 
 def invocation_logged(func: Callable) -> Callable:
 
 
 def invocation_logged(func: Callable) -> Callable:

-    """Log the call of a function.
+    """Log the call of a function on stdout and the info log.

 
     >>> @invocation_logged
     ... def foo():
 
     >>> @invocation_logged
     ... def foo():


@@ -83,9 +83,9 @@ def invocation_logged(func: Callable) -> Callable:
 
 
 def rate_limited(n_calls: int, *, per_period_in_seconds: float = 1.0) -> Callable:
 
 
 def rate_limited(n_calls: int, *, per_period_in_seconds: float = 1.0) -> Callable:

-    """Limit invocation of a wrapped function to n calls per period.
+    """Limit invocation of a wrapped function to n calls per time period.

     Thread safe.  In testing this was relatively fair with multiple
     Thread safe.  In testing this was relatively fair with multiple

-    threads using it though that hasn't been measured.
+    threads using it though that hasn't been measured in detail.

 
     >>> import time
     >>> import decorator_utils
 
     >>> import time
     >>> import decorator_utils


@@ -246,9 +246,7 @@ def delay(
     seconds: float = 1.0,
     when: DelayWhen = DelayWhen.BEFORE_CALL,
 ) -> Callable:
     seconds: float = 1.0,
     when: DelayWhen = DelayWhen.BEFORE_CALL,
 ) -> Callable:

-    """Delay the execution of a function by sleeping before and/or after.
-
-    Slow down a function by inserting a delay before and/or after its
+    """Slow down a function by inserting a delay before and/or after its

     invocation.
 
     >>> import time
     invocation.
 
     >>> import time


@@ -330,8 +328,9 @@ def memoized(func: Callable) -> Callable:
     """Keep a cache of previous function call results.
 
     The cache here is a dict with a key based on the arguments to the
     """Keep a cache of previous function call results.
 
     The cache here is a dict with a key based on the arguments to the

-    call.  Consider also: functools.lru_cache for a more advanced
-    implementation.
+    call.  Consider also: functools.cache for a more advanced
+    implementation.  See:
+    https://docs.python.org/3/library/functools.html#functools.cache

 
     >>> import time
 
 
     >>> import time
 


@@ -382,17 +381,20 @@ def retry_predicate(
     delay_sec: float = 3.0,
     backoff: float = 2.0,
 ):
     delay_sec: float = 3.0,
     backoff: float = 2.0,
 ):

-    """Retries a function or method up to a certain number of times
-    with a prescribed initial delay period and backoff rate.
-
-    tries is the maximum number of attempts to run the function.
-    delay_sec sets the initial delay period in seconds.
-    backoff is a multiplied (must be >1) used to modify the delay.
-    predicate is a function that will be passed the retval of the
-    decorated function and must return True to stop or False to
-    retry.
-
+    """Retries a function or method up to a certain number of times with a
+    prescribed initial delay period and backoff rate (multiplier).
+
+    Args:
+        tries: the maximum number of attempts to run the function
+        delay_sec: sets the initial delay period in seconds
+        backoff: a multiplier (must be >=1.0) used to modify the
+            delay at each subsequent invocation
+        predicate: a Callable that will be passed the retval of
+            the decorated function and must return True to indicate
+            that we should stop calling or False to indicate a retry
+            is necessary

     """
     """

+

     if backoff < 1.0:
         msg = f"backoff must be greater than or equal to 1, got {backoff}"
         logger.critical(msg)
     if backoff < 1.0:
         msg = f"backoff must be greater than or equal to 1, got {backoff}"
         logger.critical(msg)


@@ -438,7 +440,6 @@ def retry_if_false(tries: int, *, delay_sec=3.0, backoff=2.0):
     >>> import time
 
     >>> counter = 0
     >>> import time
 
     >>> counter = 0

-

     >>> @retry_if_false(5, delay_sec=1.0, backoff=1.1)
     ... def foo():
     ...     global counter
     >>> @retry_if_false(5, delay_sec=1.0, backoff=1.1)
     ... def foo():
     ...     global counter


@@ -470,8 +471,8 @@ def retry_if_none(tries: int, *, delay_sec=3.0, backoff=2.0):
     """Another helper for @retry_predicate above.  Retries up to N
     times so long as the wrapped function returns None with a delay
     between each retry and a backoff that can increase the delay.
     """Another helper for @retry_predicate above.  Retries up to N
     times so long as the wrapped function returns None with a delay
     between each retry and a backoff that can increase the delay.

-

     """
     """

+

     return retry_predicate(
         tries,
         predicate=lambda x: x is not None,
     return retry_predicate(
         tries,
         predicate=lambda x: x is not None,


@@ -484,7 +485,6 @@ def deprecated(func):
     """This is a decorator which can be used to mark functions
     as deprecated. It will result in a warning being emitted
     when the function is used.
     """This is a decorator which can be used to mark functions
     as deprecated. It will result in a warning being emitted
     when the function is used.

-

     """
 
     @functools.wraps(func)
     """
 
     @functools.wraps(func)


@@ -510,7 +510,7 @@ def thunkify(func):
         wait_event = threading.Event()
 
         result = [None]
         wait_event = threading.Event()
 
         result = [None]

-        exc = [False, None]
+        exc: List[Any] = [False, None]

 
         def worker_func():
             try:
 
         def worker_func():
             try:


@@ -527,6 +527,7 @@ def thunkify(func):
         def thunk():
             wait_event.wait()
             if exc[0]:
         def thunk():
             wait_event.wait()
             if exc[0]:

+                assert exc[1]

                 raise exc[1][0](exc[1][1])
             return result[0]
 
                 raise exc[1][0](exc[1][1])
             return result[0]
 


@@ -646,6 +647,13 @@ def timeout(
     main thread).  When not using signals, timeout granularity will be
     rounded to the nearest 0.1s.
 
     main thread).  When not using signals, timeout granularity will be
     rounded to the nearest 0.1s.
 

+    Beware that an @timeout on a function inside a module will be
+    evaluated at module load time and not when the wrapped function is
+    invoked.  This can lead to problems when relying on the automatic
+    main thread detection code (use_signals=None, the default) since
+    the import probably happens on the main thread and the invocation
+    can happen on a different thread (which can't use signals).
+

     Raises an exception when/if the timeout is reached.
 
     It is illegal to pass anything other than a function as the first
     Raises an exception when/if the timeout is reached.
 
     It is illegal to pass anything other than a function as the first


@@ -673,7 +681,7 @@ def timeout(
     def decorate(function):
         if use_signals:
 
     def decorate(function):
         if use_signals:
 

-            def handler(signum, frame):
+            def handler(unused_signum, unused_frame):

                 _raise_exception(timeout_exception, error_message)
 
             @functools.wraps(function)
                 _raise_exception(timeout_exception, error_message)
 
             @functools.wraps(function)


@@ -707,6 +715,11 @@ def timeout(
 
 
 def synchronized(lock):
 
 
 def synchronized(lock):

+    """Emulates java's synchronized keyword: given a lock, require that
+    threads take that lock (or wait) before invoking the wrapped
+    function and automatically releases the lock afterwards.
+    """
+

     def wrap(f):
         @functools.wraps(f)
         def _gatekeeper(*args, **kw):
     def wrap(f):
         @functools.wraps(f)
         def _gatekeeper(*args, **kw):


@@ -722,6 +735,10 @@ def synchronized(lock):
 
 
 def call_with_sample_rate(sample_rate: float) -> Callable:
 
 
 def call_with_sample_rate(sample_rate: float) -> Callable:

+    """Calls the wrapped function probabilistically given a rate between
+    0.0 and 1.0 inclusive (0% probability and 100% probability).
+    """
+

     if not 0.0 <= sample_rate <= 1.0:
         msg = f"sample_rate must be between [0, 1]. Got {sample_rate}."
         logger.critical(msg)
     if not 0.0 <= sample_rate <= 1.0:
         msg = f"sample_rate must be between [0, 1]. Got {sample_rate}."
         logger.critical(msg)


@@ -742,9 +759,9 @@ def call_with_sample_rate(sample_rate: float) -> Callable:
 
 
 def decorate_matching_methods_with(decorator, acl=None):
 
 
 def decorate_matching_methods_with(decorator, acl=None):

-    """Apply decorator to all methods in a class whose names begin with
-    prefix.  If prefix is None (default), decorate all methods in the
-    class.
+    """Apply the given decorator to all methods in a class whose names
+    begin with prefix.  If prefix is None (default), decorate all
+    methods in the class.

     """
 
     def decorate_the_class(cls):
     """
 
     def decorate_the_class(cls):