1 files changed, 115 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/botocore/retries/bucket.py b/.venv/lib/python3.12/site-packages/botocore/retries/bucket.py
new file mode 100644
index 00000000..09d33c77
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/botocore/retries/bucket.py
@@ -0,0 +1,115 @@
+"""This module implements token buckets used for client side throttling."""
+
+import threading
+import time
+
+from botocore.exceptions import CapacityNotAvailableError
+
+
+class Clock:
+    def __init__(self):
+        pass
+
+    def sleep(self, amount):
+        time.sleep(amount)
+
+    def current_time(self):
+        return time.time()
+
+
+class TokenBucket:
+    _MIN_RATE = 0.5
+
+    def __init__(self, max_rate, clock, min_rate=_MIN_RATE):
+        self._fill_rate = None
+        self._max_capacity = None
+        self._current_capacity = 0
+        self._clock = clock
+        self._last_timestamp = None
+        self._min_rate = min_rate
+        self._lock = threading.Lock()
+        self._new_fill_rate_condition = threading.Condition(self._lock)
+        self.max_rate = max_rate
+
+    @property
+    def max_rate(self):
+        return self._fill_rate
+
+    @max_rate.setter
+    def max_rate(self, value):
+        with self._new_fill_rate_condition:
+            # Before we can change the rate we need to fill any pending
+            # tokens we might have based on the current rate.  If we don't
+            # do this it means everything since the last recorded timestamp
+            # will accumulate at the rate we're about to set which isn't
+            # correct.
+            self._refill()
+            self._fill_rate = max(value, self._min_rate)
+            if value >= 1:
+                self._max_capacity = value
+            else:
+                self._max_capacity = 1
+            # If we're scaling down, we also can't have a capacity that's
+            # more than our max_capacity.
+            self._current_capacity = min(
+                self._current_capacity, self._max_capacity
+            )
+            self._new_fill_rate_condition.notify()
+
+    @property
+    def max_capacity(self):
+        return self._max_capacity
+
+    @property
+    def available_capacity(self):
+        return self._current_capacity
+
+    def acquire(self, amount=1, block=True):
+        """Acquire token or return amount of time until next token available.
+
+        If block is True, then this method will block until there's sufficient
+        capacity to acquire the desired amount.
+
+        If block is False, then this method will return True is capacity
+        was successfully acquired, False otherwise.
+
+        """
+        with self._new_fill_rate_condition:
+            return self._acquire(amount=amount, block=block)
+
+    def _acquire(self, amount, block):
+        self._refill()
+        if amount <= self._current_capacity:
+            self._current_capacity -= amount
+            return True
+        else:
+            if not block:
+                raise CapacityNotAvailableError()
+            # Not enough capacity.
+            sleep_amount = self._sleep_amount(amount)
+            while sleep_amount > 0:
+                # Until python3.2, wait() always returned None so we can't
+                # tell if a timeout occurred waiting on the cond var.
+                # Because of this we'll unconditionally call _refill().
+                # The downside to this is that we were waken up via
+                # a notify(), we're calling unnecessarily calling _refill() an
+                # extra time.
+                self._new_fill_rate_condition.wait(sleep_amount)
+                self._refill()
+                sleep_amount = self._sleep_amount(amount)
+            self._current_capacity -= amount
+            return True
+
+    def _sleep_amount(self, amount):
+        return (amount - self._current_capacity) / self._fill_rate
+
+    def _refill(self):
+        timestamp = self._clock.current_time()
+        if self._last_timestamp is None:
+            self._last_timestamp = timestamp
+            return
+        current_capacity = self._current_capacity
+        fill_amount = (timestamp - self._last_timestamp) * self._fill_rate
+        new_capacity = min(self._max_capacity, current_capacity + fill_amount)
+        self._current_capacity = new_capacity
+        self._last_timestamp = timestamp