Move error retry info to retries interfaces

Author: JordonPhillips

designs/exceptions.md

@@ -40,7 +40,7 @@ implement.
 ```python
 @dataclass(kw_only=True)
 @runtime_checkable
-class RetryInfo(Protocol):
+class ErrorRetryInfo(Protocol):
     is_retry_safe: bool | None = None
     """Whether the exception is safe to retry.
 

packages/smithy-core/src/smithy_core/exceptions.py

@@ -1,7 +1,7 @@
 #  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 #  SPDX-License-Identifier: Apache-2.0
 from dataclasses import dataclass, field
-from typing import Literal, Protocol, runtime_checkable
+from typing import Literal
 
 
 class SmithyException(Exception):
@@ -16,8 +16,21 @@ class SmithyException(Exception):
 
 
 @dataclass(kw_only=True)
-@runtime_checkable
-class RetryInfo(Protocol):
+class CallException(SmithyException):
+    """Base exception to be used in application-level errors.
+
+    Implements :py:class:`.interfaces.retries.ErrorRetryInfo`.
+    """
+
+    fault: Fault = None
+    """Whether the client or server is at fault.
+
+    If None, then there was not enough information to determine fault.
+    """
+
+    message: str = field(default="", kw_only=False)
+    """The message of the error."""
+
     is_retry_safe: bool | None = None
     """Whether the exception is safe to retry.
 
@@ -37,20 +50,6 @@ class RetryInfo(Protocol):
     is_throttle: bool = False
     """Whether the error is a throttling error."""
 
-
-@dataclass(kw_only=True)
-class CallException(SmithyException, RetryInfo):
-    """Base exception to be used in application-level errors."""
-
-    fault: Fault = None
-    """Whether the client or server is at fault.
-
-    If None, then there was not enough information to determine fault.
-    """
-
-    message: str = field(default="", kw_only=False)
-    """The message of the error."""
-
     def __post_init__(self):
         super().__init__(self.message)
 

packages/smithy-core/src/smithy_core/interfaces/retries.py

@@ -2,7 +2,31 @@
 #  SPDX-License-Identifier: Apache-2.0
 from dataclasses import dataclass
 from enum import Enum
-from typing import Protocol
+from typing import Protocol, runtime_checkable
+
+
+@runtime_checkable
+class ErrorRetryInfo(Protocol):
+    """A protocol for exceptions that have retry information embedded."""
+
+    is_retry_safe: bool | None = None
+    """Whether the exception is safe to retry.
+
+    A value of True does not mean a retry will occur, but rather that a retry is allowed
+    to occur.
+
+    A value of None indicates that there is not enough information available to
+    determine if a retry is safe.
+    """
+
+    retry_after: float | None = None
+    """The amount of time that should pass before a retry.
+
+    Retry strategies MAY choose to wait longer.
+    """
+
+    is_throttle: bool = False
+    """Whether the error is a throttling error."""
 
 
 class RetryErrorType(Enum):