structure saas with tools

.venv/lib/python3.10/site-packages/google/auth/_exponential_backoff.py

@@ -0,0 +1,164 @@
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import asyncio
+import random
+import time
+
+from google.auth import exceptions
+
+# The default amount of retry attempts
+_DEFAULT_RETRY_TOTAL_ATTEMPTS = 3
+
+# The default initial backoff period (1.0 second).
+_DEFAULT_INITIAL_INTERVAL_SECONDS = 1.0
+
+# The default randomization factor (0.1 which results in a random period ranging
+# between 10% below and 10% above the retry interval).
+_DEFAULT_RANDOMIZATION_FACTOR = 0.1
+
+# The default multiplier value (2 which is 100% increase per back off).
+_DEFAULT_MULTIPLIER = 2.0
+
+"""Exponential Backoff Utility
+
+This is a private module that implements the exponential back off algorithm.
+It can be used as a utility for code that needs to retry on failure, for example
+an HTTP request.
+"""
+
+
+class _BaseExponentialBackoff:
+    """An exponential backoff iterator base class.
+
+    Args:
+        total_attempts Optional[int]:
+            The maximum amount of retries that should happen.
+            The default value is 3 attempts.
+        initial_wait_seconds Optional[int]:
+            The amount of time to sleep in the first backoff. This parameter
+            should be in seconds.
+            The default value is 1 second.
+        randomization_factor Optional[float]:
+            The amount of jitter that should be in each backoff. For example,
+            a value of 0.1 will introduce a jitter range of 10% to the
+            current backoff period.
+            The default value is 0.1.
+        multiplier Optional[float]:
+            The backoff multipler. This adjusts how much each backoff will
+            increase. For example a value of 2.0 leads to a 200% backoff
+            on each attempt. If the initial_wait is 1.0 it would look like
+            this sequence [1.0, 2.0, 4.0, 8.0].
+            The default value is 2.0.
+    """
+
+    def __init__(
+        self,
+        total_attempts=_DEFAULT_RETRY_TOTAL_ATTEMPTS,
+        initial_wait_seconds=_DEFAULT_INITIAL_INTERVAL_SECONDS,
+        randomization_factor=_DEFAULT_RANDOMIZATION_FACTOR,
+        multiplier=_DEFAULT_MULTIPLIER,
+    ):
+        if total_attempts < 1:
+            raise exceptions.InvalidValue(
+                f"total_attempts must be greater than or equal to 1 but was {total_attempts}"
+            )
+
+        self._total_attempts = total_attempts
+        self._initial_wait_seconds = initial_wait_seconds
+
+        self._current_wait_in_seconds = self._initial_wait_seconds
+
+        self._randomization_factor = randomization_factor
+        self._multiplier = multiplier
+        self._backoff_count = 0
+
+    @property
+    def total_attempts(self):
+        """The total amount of backoff attempts that will be made."""
+        return self._total_attempts
+
+    @property
+    def backoff_count(self):
+        """The current amount of backoff attempts that have been made."""
+        return self._backoff_count
+
+    def _reset(self):
+        self._backoff_count = 0
+        self._current_wait_in_seconds = self._initial_wait_seconds
+
+    def _calculate_jitter(self):
+        jitter_variance = self._current_wait_in_seconds * self._randomization_factor
+        jitter = random.uniform(
+            self._current_wait_in_seconds - jitter_variance,
+            self._current_wait_in_seconds + jitter_variance,
+        )
+
+        return jitter
+
+
+class ExponentialBackoff(_BaseExponentialBackoff):
+    """An exponential backoff iterator. This can be used in a for loop to
+    perform requests with exponential backoff.
+    """
+
+    def __init__(self, *args, **kwargs):
+        super(ExponentialBackoff, self).__init__(*args, **kwargs)
+
+    def __iter__(self):
+        self._reset()
+        return self
+
+    def __next__(self):
+        if self._backoff_count >= self._total_attempts:
+            raise StopIteration
+        self._backoff_count += 1
+
+        if self._backoff_count <= 1:
+            return self._backoff_count
+
+        jitter = self._calculate_jitter()
+
+        time.sleep(jitter)
+
+        self._current_wait_in_seconds *= self._multiplier
+        return self._backoff_count
+
+
+class AsyncExponentialBackoff(_BaseExponentialBackoff):
+    """An async exponential backoff iterator. This can be used in a for loop to
+    perform async requests with exponential backoff.
+    """
+
+    def __init__(self, *args, **kwargs):
+        super(AsyncExponentialBackoff, self).__init__(*args, **kwargs)
+
+    def __aiter__(self):
+        self._reset()
+        return self
+
+    async def __anext__(self):
+        if self._backoff_count >= self._total_attempts:
+            raise StopAsyncIteration
+        self._backoff_count += 1
+
+        if self._backoff_count <= 1:
+            return self._backoff_count
+
+        jitter = self._calculate_jitter()
+
+        await asyncio.sleep(jitter)
+
+        self._current_wait_in_seconds *= self._multiplier
+        return self._backoff_count