create abstract retry class to share methods between retry implementations

Author: terencehonles

redis/asyncio/retry.py

@@ -1,62 +1,20 @@
 from asyncio import sleep
-from typing import TYPE_CHECKING, Any, Awaitable, Callable, Tuple, Type, TypeVar
+from typing import Any, Awaitable, Callable, Tuple, Type, TypeVar
 
 from redis.exceptions import ConnectionError, RedisError, TimeoutError
-
-if TYPE_CHECKING:
-    from redis.backoff import AbstractBackoff
-
+from redis.retry import AbstractRetry
 
 T = TypeVar("T")
 
 
-class Retry:
-    """Retry a specific number of times after a failure"""
-
-    __slots__ = "_backoff", "_retries", "_supported_errors"
-
-    def __init__(
-        self,
-        backoff: "AbstractBackoff",
-        retries: int,
-        supported_errors: Tuple[Type[RedisError], ...] = (
-            ConnectionError,
-            TimeoutError,
-        ),
-    ):
-        """
-        Initialize a `Retry` object with a `Backoff` object
-        that retries a maximum of `retries` times.
-        `retries` can be negative to retry forever.
-        You can specify the types of supported errors which trigger
-        a retry with the `supported_errors` parameter.
-        """
-        self._backoff = backoff
-        self._retries = retries
-        self._supported_errors = supported_errors
-
-    def update_supported_errors(self, specified_errors: list):
-        """
-        Updates the supported errors with the specified error types
-        """
-        self._supported_errors = tuple(
-            set(self._supported_errors + tuple(specified_errors))
-        )
-
-    def get_retries(self) -> int:
-        """
-        Get the number of retries.
-        """
-        return self._retries
-
-    def update_retries(self, value: int) -> None:
-        """
-        Set the number of retries.
-        """
-        self._retries = value
+class Retry(AbstractRetry):
+    _supported_errors: Tuple[Type[RedisError], ...] = (
+        ConnectionError,
+        TimeoutError,
+    )
 
     async def call_with_retry(
-        self, do: Callable[[], Awaitable[T]], fail: Callable[[RedisError], Any]
+        self, do: Callable[[], Awaitable[T]], fail: Callable[[Exception], Any]
     ) -> T:
         """
         Execute an operation that might fail and returns its result, or

redis/retry.py

@@ -1,6 +1,6 @@
 import socket
 from time import sleep
-from typing import TYPE_CHECKING, Any, Callable, Iterable, Tuple, Type, TypeVar
+from typing import TYPE_CHECKING, Any, Callable, Iterable, Tuple, Type, TypeVar, Union
 
 from redis.exceptions import ConnectionError, TimeoutError
 
@@ -10,18 +10,17 @@
     from redis.backoff import AbstractBackoff
 
 
-class Retry:
+class AbstractRetry:
     """Retry a specific number of times after a failure"""
 
+    __slots__ = "_backoff", "_retries", "_supported_errors"
+    _supported_errors: Tuple[Type[Exception], ...]
+
     def __init__(
         self,
         backoff: "AbstractBackoff",
         retries: int,
-        supported_errors: Tuple[Type[Exception], ...] = (
-            ConnectionError,
-            TimeoutError,
-            socket.timeout,
-        ),
+        supported_errors: Union[Tuple[Type[Exception], ...], None] = None,
     ):
         """
         Initialize a `Retry` object with a `Backoff` object
@@ -32,10 +31,11 @@ def __init__(
         """
         self._backoff = backoff
         self._retries = retries
-        self._supported_errors = supported_errors
+        if supported_errors:
+            self._supported_errors = supported_errors
 
     def __eq__(self, other: Any) -> bool:
-        if not isinstance(other, Retry):
+        if not isinstance(other, AbstractRetry):
             return NotImplemented
 
         return (
@@ -69,6 +69,14 @@ def update_retries(self, value: int) -> None:
         """
         self._retries = value
 
+
+class Retry(AbstractRetry):
+    _supported_errors: Tuple[Type[Exception], ...] = (
+        ConnectionError,
+        TimeoutError,
+        socket.timeout,
+    )
+
     def call_with_retry(
         self,
         do: Callable[[], T],

tests/test_retry.py

@@ -1,6 +1,7 @@
 from unittest.mock import patch
 
 import pytest
+from redis.asyncio.retry import Retry as AsyncRetry
 from redis.backoff import (
     AbstractBackoff,
     ConstantBackoff,
@@ -89,6 +90,7 @@ def test_retry_on_error_retry(self, Class, retries):
         assert c.retry._retries == retries
 
 
+@pytest.mark.parametrize("retry_class", [Retry, AsyncRetry])
 @pytest.mark.parametrize(
     "args",
     [
@@ -108,8 +110,8 @@ def test_retry_on_error_retry(self, Class, retries):
         for backoff in ((Backoff(), 2), (Backoff(25), 5), (Backoff(25, 5), 5))
     ],
 )
-def test_retry_eq_and_hashable(args):
-    assert Retry(*args) == Retry(*args)
+def test_retry_eq_and_hashable(retry_class, args):
+    assert retry_class(*args) == retry_class(*args)
 
     # create another retry object with different parameters
     copy = list(args)
@@ -118,9 +120,19 @@ def test_retry_eq_and_hashable(args):
     else:
         copy[0] = ConstantBackoff(9000)
 
-    assert Retry(*args) != Retry(*copy)
-    assert Retry(*copy) != Retry(*args)
-    assert len({Retry(*args), Retry(*args), Retry(*copy), Retry(*copy)}) == 2
+    assert retry_class(*args) != retry_class(*copy)
+    assert retry_class(*copy) != retry_class(*args)
+    assert (
+        len(
+            {
+                retry_class(*args),
+                retry_class(*args),
+                retry_class(*copy),
+                retry_class(*copy),
+            }
+        )
+        == 2
+    )
 
 
 class TestRetry: