Updates

ETB-API/venv/lib/python3.12/site-packages/redis/backoff.py

@@ -0,0 +1,183 @@
+import random
+from abc import ABC, abstractmethod
+
+# Maximum backoff between each retry in seconds
+DEFAULT_CAP = 0.512
+# Minimum backoff between each retry in seconds
+DEFAULT_BASE = 0.008
+
+
+class AbstractBackoff(ABC):
+    """Backoff interface"""
+
+    def reset(self):
+        """
+        Reset internal state before an operation.
+        `reset` is called once at the beginning of
+        every call to `Retry.call_with_retry`
+        """
+        pass
+
+    @abstractmethod
+    def compute(self, failures: int) -> float:
+        """Compute backoff in seconds upon failure"""
+        pass
+
+
+class ConstantBackoff(AbstractBackoff):
+    """Constant backoff upon failure"""
+
+    def __init__(self, backoff: float) -> None:
+        """`backoff`: backoff time in seconds"""
+        self._backoff = backoff
+
+    def __hash__(self) -> int:
+        return hash((self._backoff,))
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, ConstantBackoff):
+            return NotImplemented
+
+        return self._backoff == other._backoff
+
+    def compute(self, failures: int) -> float:
+        return self._backoff
+
+
+class NoBackoff(ConstantBackoff):
+    """No backoff upon failure"""
+
+    def __init__(self) -> None:
+        super().__init__(0)
+
+
+class ExponentialBackoff(AbstractBackoff):
+    """Exponential backoff upon failure"""
+
+    def __init__(self, cap: float = DEFAULT_CAP, base: float = DEFAULT_BASE):
+        """
+        `cap`: maximum backoff time in seconds
+        `base`: base backoff time in seconds
+        """
+        self._cap = cap
+        self._base = base
+
+    def __hash__(self) -> int:
+        return hash((self._base, self._cap))
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, ExponentialBackoff):
+            return NotImplemented
+
+        return self._base == other._base and self._cap == other._cap
+
+    def compute(self, failures: int) -> float:
+        return min(self._cap, self._base * 2**failures)
+
+
+class FullJitterBackoff(AbstractBackoff):
+    """Full jitter backoff upon failure"""
+
+    def __init__(self, cap: float = DEFAULT_CAP, base: float = DEFAULT_BASE) -> None:
+        """
+        `cap`: maximum backoff time in seconds
+        `base`: base backoff time in seconds
+        """
+        self._cap = cap
+        self._base = base
+
+    def __hash__(self) -> int:
+        return hash((self._base, self._cap))
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, FullJitterBackoff):
+            return NotImplemented
+
+        return self._base == other._base and self._cap == other._cap
+
+    def compute(self, failures: int) -> float:
+        return random.uniform(0, min(self._cap, self._base * 2**failures))
+
+
+class EqualJitterBackoff(AbstractBackoff):
+    """Equal jitter backoff upon failure"""
+
+    def __init__(self, cap: float = DEFAULT_CAP, base: float = DEFAULT_BASE) -> None:
+        """
+        `cap`: maximum backoff time in seconds
+        `base`: base backoff time in seconds
+        """
+        self._cap = cap
+        self._base = base
+
+    def __hash__(self) -> int:
+        return hash((self._base, self._cap))
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, EqualJitterBackoff):
+            return NotImplemented
+
+        return self._base == other._base and self._cap == other._cap
+
+    def compute(self, failures: int) -> float:
+        temp = min(self._cap, self._base * 2**failures) / 2
+        return temp + random.uniform(0, temp)
+
+
+class DecorrelatedJitterBackoff(AbstractBackoff):
+    """Decorrelated jitter backoff upon failure"""
+
+    def __init__(self, cap: float = DEFAULT_CAP, base: float = DEFAULT_BASE) -> None:
+        """
+        `cap`: maximum backoff time in seconds
+        `base`: base backoff time in seconds
+        """
+        self._cap = cap
+        self._base = base
+        self._previous_backoff = 0
+
+    def __hash__(self) -> int:
+        return hash((self._base, self._cap))
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, DecorrelatedJitterBackoff):
+            return NotImplemented
+
+        return self._base == other._base and self._cap == other._cap
+
+    def reset(self) -> None:
+        self._previous_backoff = 0
+
+    def compute(self, failures: int) -> float:
+        max_backoff = max(self._base, self._previous_backoff * 3)
+        temp = random.uniform(self._base, max_backoff)
+        self._previous_backoff = min(self._cap, temp)
+        return self._previous_backoff
+
+
+class ExponentialWithJitterBackoff(AbstractBackoff):
+    """Exponential backoff upon failure, with jitter"""
+
+    def __init__(self, cap: float = DEFAULT_CAP, base: float = DEFAULT_BASE) -> None:
+        """
+        `cap`: maximum backoff time in seconds
+        `base`: base backoff time in seconds
+        """
+        self._cap = cap
+        self._base = base
+
+    def __hash__(self) -> int:
+        return hash((self._base, self._cap))
+
+    def __eq__(self, other) -> bool:
+        if not isinstance(other, ExponentialWithJitterBackoff):
+            return NotImplemented
+
+        return self._base == other._base and self._cap == other._cap
+
+    def compute(self, failures: int) -> float:
+        return min(self._cap, random.random() * self._base * 2**failures)
+
+
+def default_backoff():
+    return EqualJitterBackoff()