second commit
This commit is contained in:
565
env/lib/python3.11/site-packages/websockets/asyncio/client.py
vendored
Normal file
565
env/lib/python3.11/site-packages/websockets/asyncio/client.py
vendored
Normal file
@ -0,0 +1,565 @@
|
||||
from __future__ import annotations
|
||||
|
||||
import asyncio
|
||||
import logging
|
||||
import os
|
||||
import traceback
|
||||
import urllib.parse
|
||||
from collections.abc import AsyncIterator, Generator, Sequence
|
||||
from types import TracebackType
|
||||
from typing import Any, Callable
|
||||
|
||||
from ..client import ClientProtocol, backoff
|
||||
from ..datastructures import HeadersLike
|
||||
from ..exceptions import InvalidStatus, SecurityError
|
||||
from ..extensions.base import ClientExtensionFactory
|
||||
from ..extensions.permessage_deflate import enable_client_permessage_deflate
|
||||
from ..headers import validate_subprotocols
|
||||
from ..http11 import USER_AGENT, Response
|
||||
from ..protocol import CONNECTING, Event
|
||||
from ..typing import LoggerLike, Origin, Subprotocol
|
||||
from ..uri import WebSocketURI, parse_uri
|
||||
from .compatibility import TimeoutError, asyncio_timeout
|
||||
from .connection import Connection
|
||||
|
||||
|
||||
__all__ = ["connect", "unix_connect", "ClientConnection"]
|
||||
|
||||
MAX_REDIRECTS = int(os.environ.get("WEBSOCKETS_MAX_REDIRECTS", "10"))
|
||||
|
||||
|
||||
class ClientConnection(Connection):
|
||||
"""
|
||||
:mod:`asyncio` implementation of a WebSocket client connection.
|
||||
|
||||
:class:`ClientConnection` provides :meth:`recv` and :meth:`send` coroutines
|
||||
for receiving and sending messages.
|
||||
|
||||
It supports asynchronous iteration to receive messages::
|
||||
|
||||
async for message in websocket:
|
||||
await process(message)
|
||||
|
||||
The iterator exits normally when the connection is closed with close code
|
||||
1000 (OK) or 1001 (going away) or without a close code. It raises a
|
||||
:exc:`~websockets.exceptions.ConnectionClosedError` when the connection is
|
||||
closed with any other code.
|
||||
|
||||
The ``ping_interval``, ``ping_timeout``, ``close_timeout``, ``max_queue``,
|
||||
and ``write_limit`` arguments have the same meaning as in :func:`connect`.
|
||||
|
||||
Args:
|
||||
protocol: Sans-I/O connection.
|
||||
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
protocol: ClientProtocol,
|
||||
*,
|
||||
ping_interval: float | None = 20,
|
||||
ping_timeout: float | None = 20,
|
||||
close_timeout: float | None = 10,
|
||||
max_queue: int | None | tuple[int | None, int | None] = 16,
|
||||
write_limit: int | tuple[int, int | None] = 2**15,
|
||||
) -> None:
|
||||
self.protocol: ClientProtocol
|
||||
super().__init__(
|
||||
protocol,
|
||||
ping_interval=ping_interval,
|
||||
ping_timeout=ping_timeout,
|
||||
close_timeout=close_timeout,
|
||||
max_queue=max_queue,
|
||||
write_limit=write_limit,
|
||||
)
|
||||
self.response_rcvd: asyncio.Future[None] = self.loop.create_future()
|
||||
|
||||
async def handshake(
|
||||
self,
|
||||
additional_headers: HeadersLike | None = None,
|
||||
user_agent_header: str | None = USER_AGENT,
|
||||
) -> None:
|
||||
"""
|
||||
Perform the opening handshake.
|
||||
|
||||
"""
|
||||
async with self.send_context(expected_state=CONNECTING):
|
||||
self.request = self.protocol.connect()
|
||||
if additional_headers is not None:
|
||||
self.request.headers.update(additional_headers)
|
||||
if user_agent_header:
|
||||
self.request.headers["User-Agent"] = user_agent_header
|
||||
self.protocol.send_request(self.request)
|
||||
|
||||
await asyncio.wait(
|
||||
[self.response_rcvd, self.connection_lost_waiter],
|
||||
return_when=asyncio.FIRST_COMPLETED,
|
||||
)
|
||||
|
||||
# self.protocol.handshake_exc is set when the connection is lost before
|
||||
# receiving a response, when the response cannot be parsed, or when the
|
||||
# response fails the handshake.
|
||||
|
||||
if self.protocol.handshake_exc is not None:
|
||||
raise self.protocol.handshake_exc
|
||||
|
||||
def process_event(self, event: Event) -> None:
|
||||
"""
|
||||
Process one incoming event.
|
||||
|
||||
"""
|
||||
# First event - handshake response.
|
||||
if self.response is None:
|
||||
assert isinstance(event, Response)
|
||||
self.response = event
|
||||
self.response_rcvd.set_result(None)
|
||||
# Later events - frames.
|
||||
else:
|
||||
super().process_event(event)
|
||||
|
||||
|
||||
def process_exception(exc: Exception) -> Exception | None:
|
||||
"""
|
||||
Determine whether a connection error is retryable or fatal.
|
||||
|
||||
When reconnecting automatically with ``async for ... in connect(...)``, if a
|
||||
connection attempt fails, :func:`process_exception` is called to determine
|
||||
whether to retry connecting or to raise the exception.
|
||||
|
||||
This function defines the default behavior, which is to retry on:
|
||||
|
||||
* :exc:`EOFError`, :exc:`OSError`, :exc:`asyncio.TimeoutError`: network
|
||||
errors;
|
||||
* :exc:`~websockets.exceptions.InvalidStatus` when the status code is 500,
|
||||
502, 503, or 504: server or proxy errors.
|
||||
|
||||
All other exceptions are considered fatal.
|
||||
|
||||
You can change this behavior with the ``process_exception`` argument of
|
||||
:func:`connect`.
|
||||
|
||||
Return :obj:`None` if the exception is retryable i.e. when the error could
|
||||
be transient and trying to reconnect with the same parameters could succeed.
|
||||
The exception will be logged at the ``INFO`` level.
|
||||
|
||||
Return an exception, either ``exc`` or a new exception, if the exception is
|
||||
fatal i.e. when trying to reconnect will most likely produce the same error.
|
||||
That exception will be raised, breaking out of the retry loop.
|
||||
|
||||
"""
|
||||
if isinstance(exc, (EOFError, OSError, asyncio.TimeoutError)):
|
||||
return None
|
||||
if isinstance(exc, InvalidStatus) and exc.response.status_code in [
|
||||
500, # Internal Server Error
|
||||
502, # Bad Gateway
|
||||
503, # Service Unavailable
|
||||
504, # Gateway Timeout
|
||||
]:
|
||||
return None
|
||||
return exc
|
||||
|
||||
|
||||
# This is spelled in lower case because it's exposed as a callable in the API.
|
||||
class connect:
|
||||
"""
|
||||
Connect to the WebSocket server at ``uri``.
|
||||
|
||||
This coroutine returns a :class:`ClientConnection` instance, which you can
|
||||
use to send and receive messages.
|
||||
|
||||
:func:`connect` may be used as an asynchronous context manager::
|
||||
|
||||
from websockets.asyncio.client import connect
|
||||
|
||||
async with connect(...) as websocket:
|
||||
...
|
||||
|
||||
The connection is closed automatically when exiting the context.
|
||||
|
||||
:func:`connect` can be used as an infinite asynchronous iterator to
|
||||
reconnect automatically on errors::
|
||||
|
||||
async for websocket in connect(...):
|
||||
try:
|
||||
...
|
||||
except websockets.exceptions.ConnectionClosed:
|
||||
continue
|
||||
|
||||
If the connection fails with a transient error, it is retried with
|
||||
exponential backoff. If it fails with a fatal error, the exception is
|
||||
raised, breaking out of the loop.
|
||||
|
||||
The connection is closed automatically after each iteration of the loop.
|
||||
|
||||
Args:
|
||||
uri: URI of the WebSocket server.
|
||||
origin: Value of the ``Origin`` header, for servers that require it.
|
||||
extensions: List of supported extensions, in order in which they
|
||||
should be negotiated and run.
|
||||
subprotocols: List of supported subprotocols, in order of decreasing
|
||||
preference.
|
||||
additional_headers (HeadersLike | None): Arbitrary HTTP headers to add
|
||||
to the handshake request.
|
||||
user_agent_header: Value of the ``User-Agent`` request header.
|
||||
It defaults to ``"Python/x.y.z websockets/X.Y"``.
|
||||
Setting it to :obj:`None` removes the header.
|
||||
compression: The "permessage-deflate" extension is enabled by default.
|
||||
Set ``compression`` to :obj:`None` to disable it. See the
|
||||
:doc:`compression guide <../../topics/compression>` for details.
|
||||
process_exception: When reconnecting automatically, tell whether an
|
||||
error is transient or fatal. The default behavior is defined by
|
||||
:func:`process_exception`. Refer to its documentation for details.
|
||||
open_timeout: Timeout for opening the connection in seconds.
|
||||
:obj:`None` disables the timeout.
|
||||
ping_interval: Interval between keepalive pings in seconds.
|
||||
:obj:`None` disables keepalive.
|
||||
ping_timeout: Timeout for keepalive pings in seconds.
|
||||
:obj:`None` disables timeouts.
|
||||
close_timeout: Timeout for closing the connection in seconds.
|
||||
:obj:`None` disables the timeout.
|
||||
max_size: Maximum size of incoming messages in bytes.
|
||||
:obj:`None` disables the limit.
|
||||
max_queue: High-water mark of the buffer where frames are received.
|
||||
It defaults to 16 frames. The low-water mark defaults to ``max_queue
|
||||
// 4``. You may pass a ``(high, low)`` tuple to set the high-water
|
||||
and low-water marks. If you want to disable flow control entirely,
|
||||
you may set it to ``None``, although that's a bad idea.
|
||||
write_limit: High-water mark of write buffer in bytes. It is passed to
|
||||
:meth:`~asyncio.WriteTransport.set_write_buffer_limits`. It defaults
|
||||
to 32 KiB. You may pass a ``(high, low)`` tuple to set the
|
||||
high-water and low-water marks.
|
||||
logger: Logger for this client.
|
||||
It defaults to ``logging.getLogger("websockets.client")``.
|
||||
See the :doc:`logging guide <../../topics/logging>` for details.
|
||||
create_connection: Factory for the :class:`ClientConnection` managing
|
||||
the connection. Set it to a wrapper or a subclass to customize
|
||||
connection handling.
|
||||
|
||||
Any other keyword arguments are passed to the event loop's
|
||||
:meth:`~asyncio.loop.create_connection` method.
|
||||
|
||||
For example:
|
||||
|
||||
* You can set ``ssl`` to a :class:`~ssl.SSLContext` to enforce TLS settings.
|
||||
When connecting to a ``wss://`` URI, if ``ssl`` isn't provided, a TLS
|
||||
context is created with :func:`~ssl.create_default_context`.
|
||||
|
||||
* You can set ``server_hostname`` to override the host name from ``uri`` in
|
||||
the TLS handshake.
|
||||
|
||||
* You can set ``host`` and ``port`` to connect to a different host and port
|
||||
from those found in ``uri``. This only changes the destination of the TCP
|
||||
connection. The host name from ``uri`` is still used in the TLS handshake
|
||||
for secure connections and in the ``Host`` header.
|
||||
|
||||
* You can set ``sock`` to provide a preexisting TCP socket. You may call
|
||||
:func:`socket.create_connection` (not to be confused with the event loop's
|
||||
:meth:`~asyncio.loop.create_connection` method) to create a suitable
|
||||
client socket and customize it.
|
||||
|
||||
Raises:
|
||||
InvalidURI: If ``uri`` isn't a valid WebSocket URI.
|
||||
OSError: If the TCP connection fails.
|
||||
InvalidHandshake: If the opening handshake fails.
|
||||
TimeoutError: If the opening handshake times out.
|
||||
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
uri: str,
|
||||
*,
|
||||
# WebSocket
|
||||
origin: Origin | None = None,
|
||||
extensions: Sequence[ClientExtensionFactory] | None = None,
|
||||
subprotocols: Sequence[Subprotocol] | None = None,
|
||||
additional_headers: HeadersLike | None = None,
|
||||
user_agent_header: str | None = USER_AGENT,
|
||||
compression: str | None = "deflate",
|
||||
process_exception: Callable[[Exception], Exception | None] = process_exception,
|
||||
# Timeouts
|
||||
open_timeout: float | None = 10,
|
||||
ping_interval: float | None = 20,
|
||||
ping_timeout: float | None = 20,
|
||||
close_timeout: float | None = 10,
|
||||
# Limits
|
||||
max_size: int | None = 2**20,
|
||||
max_queue: int | None | tuple[int | None, int | None] = 16,
|
||||
write_limit: int | tuple[int, int | None] = 2**15,
|
||||
# Logging
|
||||
logger: LoggerLike | None = None,
|
||||
# Escape hatch for advanced customization
|
||||
create_connection: type[ClientConnection] | None = None,
|
||||
# Other keyword arguments are passed to loop.create_connection
|
||||
**kwargs: Any,
|
||||
) -> None:
|
||||
self.uri = uri
|
||||
|
||||
if subprotocols is not None:
|
||||
validate_subprotocols(subprotocols)
|
||||
|
||||
if compression == "deflate":
|
||||
extensions = enable_client_permessage_deflate(extensions)
|
||||
elif compression is not None:
|
||||
raise ValueError(f"unsupported compression: {compression}")
|
||||
|
||||
if logger is None:
|
||||
logger = logging.getLogger("websockets.client")
|
||||
|
||||
if create_connection is None:
|
||||
create_connection = ClientConnection
|
||||
|
||||
def protocol_factory(wsuri: WebSocketURI) -> ClientConnection:
|
||||
# This is a protocol in the Sans-I/O implementation of websockets.
|
||||
protocol = ClientProtocol(
|
||||
wsuri,
|
||||
origin=origin,
|
||||
extensions=extensions,
|
||||
subprotocols=subprotocols,
|
||||
max_size=max_size,
|
||||
logger=logger,
|
||||
)
|
||||
# This is a connection in websockets and a protocol in asyncio.
|
||||
connection = create_connection(
|
||||
protocol,
|
||||
ping_interval=ping_interval,
|
||||
ping_timeout=ping_timeout,
|
||||
close_timeout=close_timeout,
|
||||
max_queue=max_queue,
|
||||
write_limit=write_limit,
|
||||
)
|
||||
return connection
|
||||
|
||||
self.protocol_factory = protocol_factory
|
||||
self.handshake_args = (
|
||||
additional_headers,
|
||||
user_agent_header,
|
||||
)
|
||||
self.process_exception = process_exception
|
||||
self.open_timeout = open_timeout
|
||||
self.logger = logger
|
||||
self.connection_kwargs = kwargs
|
||||
|
||||
async def create_connection(self) -> ClientConnection:
|
||||
"""Create TCP or Unix connection."""
|
||||
loop = asyncio.get_running_loop()
|
||||
|
||||
wsuri = parse_uri(self.uri)
|
||||
kwargs = self.connection_kwargs.copy()
|
||||
|
||||
def factory() -> ClientConnection:
|
||||
return self.protocol_factory(wsuri)
|
||||
|
||||
if wsuri.secure:
|
||||
kwargs.setdefault("ssl", True)
|
||||
kwargs.setdefault("server_hostname", wsuri.host)
|
||||
if kwargs.get("ssl") is None:
|
||||
raise ValueError("ssl=None is incompatible with a wss:// URI")
|
||||
else:
|
||||
if kwargs.get("ssl") is not None:
|
||||
raise ValueError("ssl argument is incompatible with a ws:// URI")
|
||||
|
||||
if kwargs.pop("unix", False):
|
||||
_, connection = await loop.create_unix_connection(factory, **kwargs)
|
||||
else:
|
||||
if kwargs.get("sock") is None:
|
||||
kwargs.setdefault("host", wsuri.host)
|
||||
kwargs.setdefault("port", wsuri.port)
|
||||
_, connection = await loop.create_connection(factory, **kwargs)
|
||||
return connection
|
||||
|
||||
def process_redirect(self, exc: Exception) -> Exception | str:
|
||||
"""
|
||||
Determine whether a connection error is a redirect that can be followed.
|
||||
|
||||
Return the new URI if it's a valid redirect. Else, return an exception.
|
||||
|
||||
"""
|
||||
if not (
|
||||
isinstance(exc, InvalidStatus)
|
||||
and exc.response.status_code
|
||||
in [
|
||||
300, # Multiple Choices
|
||||
301, # Moved Permanently
|
||||
302, # Found
|
||||
303, # See Other
|
||||
307, # Temporary Redirect
|
||||
308, # Permanent Redirect
|
||||
]
|
||||
and "Location" in exc.response.headers
|
||||
):
|
||||
return exc
|
||||
|
||||
old_wsuri = parse_uri(self.uri)
|
||||
new_uri = urllib.parse.urljoin(self.uri, exc.response.headers["Location"])
|
||||
new_wsuri = parse_uri(new_uri)
|
||||
|
||||
# If connect() received a socket, it is closed and cannot be reused.
|
||||
if self.connection_kwargs.get("sock") is not None:
|
||||
return ValueError(
|
||||
f"cannot follow redirect to {new_uri} with a preexisting socket"
|
||||
)
|
||||
|
||||
# TLS downgrade is forbidden.
|
||||
if old_wsuri.secure and not new_wsuri.secure:
|
||||
return SecurityError(f"cannot follow redirect to non-secure URI {new_uri}")
|
||||
|
||||
# Apply restrictions to cross-origin redirects.
|
||||
if (
|
||||
old_wsuri.secure != new_wsuri.secure
|
||||
or old_wsuri.host != new_wsuri.host
|
||||
or old_wsuri.port != new_wsuri.port
|
||||
):
|
||||
# Cross-origin redirects on Unix sockets don't quite make sense.
|
||||
if self.connection_kwargs.get("unix", False):
|
||||
return ValueError(
|
||||
f"cannot follow cross-origin redirect to {new_uri} "
|
||||
f"with a Unix socket"
|
||||
)
|
||||
|
||||
# Cross-origin redirects when host and port are overridden are ill-defined.
|
||||
if (
|
||||
self.connection_kwargs.get("host") is not None
|
||||
or self.connection_kwargs.get("port") is not None
|
||||
):
|
||||
return ValueError(
|
||||
f"cannot follow cross-origin redirect to {new_uri} "
|
||||
f"with an explicit host or port"
|
||||
)
|
||||
|
||||
return new_uri
|
||||
|
||||
# ... = await connect(...)
|
||||
|
||||
def __await__(self) -> Generator[Any, None, ClientConnection]:
|
||||
# Create a suitable iterator by calling __await__ on a coroutine.
|
||||
return self.__await_impl__().__await__()
|
||||
|
||||
async def __await_impl__(self) -> ClientConnection:
|
||||
try:
|
||||
async with asyncio_timeout(self.open_timeout):
|
||||
for _ in range(MAX_REDIRECTS):
|
||||
self.connection = await self.create_connection()
|
||||
try:
|
||||
await self.connection.handshake(*self.handshake_args)
|
||||
except asyncio.CancelledError:
|
||||
self.connection.close_transport()
|
||||
raise
|
||||
except Exception as exc:
|
||||
# Always close the connection even though keep-alive is
|
||||
# the default in HTTP/1.1 because create_connection ties
|
||||
# opening the network connection with initializing the
|
||||
# protocol. In the current design of connect(), there is
|
||||
# no easy way to reuse the network connection that works
|
||||
# in every case nor to reinitialize the protocol.
|
||||
self.connection.close_transport()
|
||||
|
||||
uri_or_exc = self.process_redirect(exc)
|
||||
# Response is a valid redirect; follow it.
|
||||
if isinstance(uri_or_exc, str):
|
||||
self.uri = uri_or_exc
|
||||
continue
|
||||
# Response isn't a valid redirect; raise the exception.
|
||||
if uri_or_exc is exc:
|
||||
raise
|
||||
else:
|
||||
raise uri_or_exc from exc
|
||||
|
||||
else:
|
||||
self.connection.start_keepalive()
|
||||
return self.connection
|
||||
else:
|
||||
raise SecurityError(f"more than {MAX_REDIRECTS} redirects")
|
||||
|
||||
except TimeoutError:
|
||||
# Re-raise exception with an informative error message.
|
||||
raise TimeoutError("timed out during handshake") from None
|
||||
|
||||
# ... = yield from connect(...) - remove when dropping Python < 3.10
|
||||
|
||||
__iter__ = __await__
|
||||
|
||||
# async with connect(...) as ...: ...
|
||||
|
||||
async def __aenter__(self) -> ClientConnection:
|
||||
return await self
|
||||
|
||||
async def __aexit__(
|
||||
self,
|
||||
exc_type: type[BaseException] | None,
|
||||
exc_value: BaseException | None,
|
||||
traceback: TracebackType | None,
|
||||
) -> None:
|
||||
await self.connection.close()
|
||||
|
||||
# async for ... in connect(...):
|
||||
|
||||
async def __aiter__(self) -> AsyncIterator[ClientConnection]:
|
||||
delays: Generator[float] | None = None
|
||||
while True:
|
||||
try:
|
||||
async with self as protocol:
|
||||
yield protocol
|
||||
except Exception as exc:
|
||||
# Determine whether the exception is retryable or fatal.
|
||||
# The API of process_exception is "return an exception or None";
|
||||
# "raise an exception" is also supported because it's a frequent
|
||||
# mistake. It isn't documented in order to keep the API simple.
|
||||
try:
|
||||
new_exc = self.process_exception(exc)
|
||||
except Exception as raised_exc:
|
||||
new_exc = raised_exc
|
||||
|
||||
# The connection failed with a fatal error.
|
||||
# Raise the exception and exit the loop.
|
||||
if new_exc is exc:
|
||||
raise
|
||||
if new_exc is not None:
|
||||
raise new_exc from exc
|
||||
|
||||
# The connection failed with a retryable error.
|
||||
# Start or continue backoff and reconnect.
|
||||
if delays is None:
|
||||
delays = backoff()
|
||||
delay = next(delays)
|
||||
self.logger.info(
|
||||
"connect failed; reconnecting in %.1f seconds: %s",
|
||||
delay,
|
||||
# Remove first argument when dropping Python 3.9.
|
||||
traceback.format_exception_only(type(exc), exc)[0].strip(),
|
||||
)
|
||||
await asyncio.sleep(delay)
|
||||
continue
|
||||
|
||||
else:
|
||||
# The connection succeeded. Reset backoff.
|
||||
delays = None
|
||||
|
||||
|
||||
def unix_connect(
|
||||
path: str | None = None,
|
||||
uri: str | None = None,
|
||||
**kwargs: Any,
|
||||
) -> connect:
|
||||
"""
|
||||
Connect to a WebSocket server listening on a Unix socket.
|
||||
|
||||
This function accepts the same keyword arguments as :func:`connect`.
|
||||
|
||||
It's only available on Unix.
|
||||
|
||||
It's mainly useful for debugging servers listening on Unix sockets.
|
||||
|
||||
Args:
|
||||
path: File system path to the Unix socket.
|
||||
uri: URI of the WebSocket server. ``uri`` defaults to
|
||||
``ws://localhost/`` or, when a ``ssl`` argument is provided, to
|
||||
``wss://localhost/``.
|
||||
|
||||
"""
|
||||
if uri is None:
|
||||
if kwargs.get("ssl") is None:
|
||||
uri = "ws://localhost/"
|
||||
else:
|
||||
uri = "wss://localhost/"
|
||||
return connect(uri=uri, unix=True, path=path, **kwargs)
|
||||
Reference in New Issue
Block a user