Source code for wsproto.events

# -*- coding: utf-8 -*-
"""
wsproto/events
~~~~~~~~~~~~~~

Events that result from processing data on a WebSocket connection.
"""
from abc import ABC
from dataclasses import dataclass, field
from typing import Generic, List, Optional, Sequence, TypeVar, Union

from .extensions import Extension
from .typing import Headers


[docs]class Event(ABC): """ Base class for wsproto events. """ pass # noqa
[docs]@dataclass(frozen=True) class Request(Event): """The beginning of a Websocket connection, the HTTP Upgrade request This event is fired when a SERVER connection receives a WebSocket handshake request (HTTP with upgrade header). Fields: .. attribute:: host (Required) The hostname, or host header value. .. attribute:: target (Required) The request target (path and query string) .. attribute:: extensions The proposed extensions. .. attribute:: extra_headers The additional request headers, excluding extensions, host, subprotocols, and version headers. .. attribute:: subprotocols A list of the subprotocols proposed in the request, as a list of strings. """ host: str target: str extensions: Union[Sequence[Extension], Sequence[str]] = field( # type: ignore default_factory=list ) extra_headers: Headers = field(default_factory=list) subprotocols: List[str] = field(default_factory=list)
[docs]@dataclass(frozen=True) class AcceptConnection(Event): """The acceptance of a Websocket upgrade request. This event is fired when a CLIENT receives an acceptance response from a server. It is also used to accept an upgrade request when acting as a SERVER. Fields: .. attribute:: extra_headers Any additional (non websocket related) headers present in the acceptance response. .. attribute:: subprotocol The accepted subprotocol to use. """ subprotocol: Optional[str] = None extensions: List[Extension] = field(default_factory=list) extra_headers: Headers = field(default_factory=list)
[docs]@dataclass(frozen=True) class RejectConnection(Event): """The rejection of a Websocket upgrade request, the HTTP response. The ``RejectConnection`` event sends the appropriate HTTP headers to communicate to the peer that the handshake has been rejected. You may also send an HTTP body by setting the ``has_body`` attribute to ``True`` and then sending one or more :class:`RejectData` events after this one. When sending a response body, the caller should set the ``Content-Length``, ``Content-Type``, and/or ``Transfer-Encoding`` headers as appropriate. When receiving a ``RejectConnection`` event, the ``has_body`` attribute will in almost all cases be ``True`` (even if the server set it to ``False``) and will be followed by at least one ``RejectData`` events, even though the data itself might be just ``b""``. (The only scenario in which the caller receives a ``RejectConnection`` with ``has_body == False`` is if the peer violates sends an informational status code (1xx) other than 101.) The ``has_body`` attribute should only be used when receiving the event. (It has ) is False the headers must include a content-length or transfer encoding. Fields: .. attribute:: headers (Headers) The headers to send with the response. .. attribute:: has_body This defaults to False, but set to True if there is a body. See also :class:`~RejectData`. .. attribute:: status_code The response status code. """ status_code: int = 400 headers: Headers = field(default_factory=list) has_body: bool = False
[docs]@dataclass(frozen=True) class RejectData(Event): """The rejection HTTP response body. The caller may send multiple ``RejectData`` events. The final event should have the ``body_finished`` attribute set to ``True``. Fields: .. attribute:: body_finished True if this is the final chunk of the body data. .. attribute:: data (bytes) (Required) The raw body data. """ data: bytes body_finished: bool = True
[docs]@dataclass(frozen=True) class CloseConnection(Event): """The end of a Websocket connection, represents a closure frame. **wsproto does not automatically send a response to a close event.** To comply with the RFC you MUST send a close event back to the remote WebSocket if you have not already sent one. The :meth:`response` method provides a suitable event for this purpose, and you should check if a response needs to be sent by checking :func:`wsproto.WSConnection.state`. Fields: .. attribute:: code (Required) The integer close code to indicate why the connection has closed. .. attribute:: reason Additional reasoning for why the connection has closed. """ code: int reason: Optional[str] = None
[docs] def response(self) -> "CloseConnection": """ Generate an RFC-compliant close frame to send back to the peer. """ return CloseConnection(code=self.code, reason=self.reason)
T = TypeVar("T", bytes, str)
[docs]@dataclass(frozen=True) class Message(Event, Generic[T]): """The websocket data message. Fields: .. attribute:: data (Required) The message data as byte string, can be decoded as UTF-8 for TEXT messages. This only represents a single chunk of data and not a full WebSocket message. You need to buffer and reassemble these chunks to get the full message. .. attribute:: frame_finished This has no semantic content, but is provided just in case some weird edge case user wants to be able to reconstruct the fragmentation pattern of the original stream. .. attribute:: message_finished True if this frame is the last one of this message, False if more frames are expected. """ data: T frame_finished: bool = True message_finished: bool = True
[docs]@dataclass(frozen=True) class TextMessage(Message[str]): """This event is fired when a data frame with TEXT payload is received. Fields: .. attribute:: data The message data as string, This only represents a single chunk of data and not a full WebSocket message. You need to buffer and reassemble these chunks to get the full message. """ # https://github.com/python/mypy/issues/5744 data: str
[docs]@dataclass(frozen=True) class BytesMessage(Message[bytes]): """This event is fired when a data frame with BINARY payload is received. Fields: .. attribute:: data The message data as byte string, can be decoded as UTF-8 for TEXT messages. This only represents a single chunk of data and not a full WebSocket message. You need to buffer and reassemble these chunks to get the full message. """ # https://github.com/python/mypy/issues/5744 data: bytes
[docs]@dataclass(frozen=True) class Ping(Event): """The Ping event can be sent to trigger a ping frame and is fired when a Ping is received. **wsproto does not automatically send a pong response to a ping event.** To comply with the RFC you MUST send a pong even as soon as is practical. The :meth:`response` method provides a suitable event for this purpose. Fields: .. attribute:: payload An optional payload to emit with the ping frame. """ payload: bytes = b""
[docs] def response(self) -> "Pong": """ Generate an RFC-compliant :class:`Pong` response to this ping. """ return Pong(payload=self.payload)
[docs]@dataclass(frozen=True) class Pong(Event): """The Pong event is fired when a Pong is received. Fields: .. attribute:: payload An optional payload to emit with the pong frame. """ payload: bytes = b""