Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/botocore/retries/quota.py: 33%

1"""Retry quota implementation. 

2 

3 

4""" 

5import threading 

6 

7 

8class RetryQuota: 

9 INITIAL_CAPACITY = 500 

10 

11 def __init__(self, initial_capacity=INITIAL_CAPACITY, lock=None): 

12 self._max_capacity = initial_capacity 

13 self._available_capacity = initial_capacity 

14 if lock is None: 

15 lock = threading.Lock() 

16 self._lock = lock 

17 

18 def acquire(self, capacity_amount): 

19 """Attempt to aquire a certain amount of capacity. 

20 

21 If there's not sufficient amount of capacity available, ``False`` 

22 is returned. Otherwise, ``True`` is returned, which indicates that 

23 capacity was successfully allocated. 

24 

25 """ 

26 # The acquire() is only called when we encounter a retryable 

27 # response so we aren't worried about locking the entire method. 

28 with self._lock: 

29 if capacity_amount > self._available_capacity: 

30 return False 

31 self._available_capacity -= capacity_amount 

32 return True 

33 

34 def release(self, capacity_amount): 

35 """Release capacity back to the retry quota. 

36 

37 The capacity being released will be truncated if necessary 

38 to ensure the max capacity is never exceeded. 

39 

40 """ 

41 # Implementation note: The release() method is called as part 

42 # of the "after-call" event, which means it gets invoked for 

43 # every API call. In the common case where the request is 

44 # successful and we're at full capacity, we can avoid locking. 

45 # We can't exceed max capacity so there's no work we have to do. 

46 if self._max_capacity == self._available_capacity: 

47 return 

48 with self._lock: 

49 amount = min( 

50 self._max_capacity - self._available_capacity, capacity_amount 

51 ) 

52 self._available_capacity += amount 

53 

54 @property 

55 def available_capacity(self): 

56 return self._available_capacity