second commit

env/lib/python3.11/site-packages/websockets/extensions/base.py

@@ -0,0 +1,123 @@
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+from ..frames import Frame
+from ..typing import ExtensionName, ExtensionParameter
+
+
+__all__ = ["Extension", "ClientExtensionFactory", "ServerExtensionFactory"]
+
+
+class Extension:
+    """
+    Base class for extensions.
+
+    """
+
+    name: ExtensionName
+    """Extension identifier."""
+
+    def decode(self, frame: Frame, *, max_size: int | None = None) -> Frame:
+        """
+        Decode an incoming frame.
+
+        Args:
+            frame: Incoming frame.
+            max_size: Maximum payload size in bytes.
+
+        Returns:
+            Decoded frame.
+
+        Raises:
+            PayloadTooBig: If decoding the payload exceeds ``max_size``.
+
+        """
+        raise NotImplementedError
+
+    def encode(self, frame: Frame) -> Frame:
+        """
+        Encode an outgoing frame.
+
+        Args:
+            frame: Outgoing frame.
+
+        Returns:
+            Encoded frame.
+
+        """
+        raise NotImplementedError
+
+
+class ClientExtensionFactory:
+    """
+    Base class for client-side extension factories.
+
+    """
+
+    name: ExtensionName
+    """Extension identifier."""
+
+    def get_request_params(self) -> list[ExtensionParameter]:
+        """
+        Build parameters to send to the server for this extension.
+
+        Returns:
+            Parameters to send to the server.
+
+        """
+        raise NotImplementedError
+
+    def process_response_params(
+        self,
+        params: Sequence[ExtensionParameter],
+        accepted_extensions: Sequence[Extension],
+    ) -> Extension:
+        """
+        Process parameters received from the server.
+
+        Args:
+            params: Parameters received from the server for this extension.
+            accepted_extensions: List of previously accepted extensions.
+
+        Returns:
+            An extension instance.
+
+        Raises:
+            NegotiationError: If parameters aren't acceptable.
+
+        """
+        raise NotImplementedError
+
+
+class ServerExtensionFactory:
+    """
+    Base class for server-side extension factories.
+
+    """
+
+    name: ExtensionName
+    """Extension identifier."""
+
+    def process_request_params(
+        self,
+        params: Sequence[ExtensionParameter],
+        accepted_extensions: Sequence[Extension],
+    ) -> tuple[list[ExtensionParameter], Extension]:
+        """
+        Process parameters received from the client.
+
+        Args:
+            params: Parameters received from the client for this extension.
+            accepted_extensions: List of previously accepted extensions.
+
+        Returns:
+            To accept the offer, parameters to send to the client for this
+            extension and an extension instance.
+
+        Raises:
+            NegotiationError: To reject the offer, if parameters received from
+                the client aren't acceptable.
+
+        """
+        raise NotImplementedError