Changelog --------- .. currentmodule:: websockets 5.1 ... *In development* 5.0 ... .. note:: **Version 5.0 fixes a security issue introduced in version 4.0.** websockets 4.0 was vulnerable to denial of service by memory exhaustion because it didn't enforce ``max_size`` when decompressing compressed messages. .. warning:: **Version 5.0 adds a** ``user_info`` **field to the return value of** :func:`~uri.parse_uri` **and** :class:`~uri.WebSocketURI` **.** If you're unpacking :class:`~websockets.WebSocketURI` into four variables, adjust your code to account for that fifth field. Also: * :func:`~client.connect()` performs HTTP Basic Auth when the URI contains credentials. * Iterating on incoming messages no longer raises an exception when the connection terminates with code 1001 (going away). * A plain HTTP request now receives a 426 Upgrade Required response and doesn't log a stack trace. * :func:`~server.unix_serve` can be used as an asynchronous context manager on Python ≥ 3.5.1. * Added :meth:`~protocol.WebSocketCommonProtocol.closed` property. * If a :meth:`~protocol.WebSocketCommonProtocol.ping` doesn't receive a pong, it's cancelled when the connection is closed. * Reported the cause of :exc:`~exceptions.ConnectionClosed` exceptions. * Added new examples in the documentation. * Updated documentation with new features from Python 3.6. * Improved several other sections of the documentation. * Fixed missing close code, which caused :exc:`TypeError` on connection close. * Fixed a race condition in the closing handshake that raised :exc:`~exceptions.InvalidState`. * Stopped logging stack traces when the TCP connection dies prematurely. * Prevented writing to a closing TCP connection during unclean shutdowns. * Made connection termination more robust to network congestion. * Prevented processing of incoming frames after failing the connection. 4.0 ... .. warning:: **Version 4.0 enables compression with the permessage-deflate extension.** In August 2017, Firefox and Chrome support it, but not Safari and IE. Compression should improve performance but it increases RAM and CPU use. If you want to disable compression, add ``compression=None`` when calling :func:`~server.serve()` or :func:`~client.connect()`. .. warning:: **Version 4.0 removes the** ``state_name`` **attribute of protocols.** Use ``protocol.state.name`` instead of ``protocol.state_name``. Also: * :class:`~protocol.WebSocketCommonProtocol` instances can be used as asynchronous iterators on Python ≥ 3.6. They yield incoming messages. * Added :func:`~server.unix_serve` for listening on Unix sockets. * Added the :attr:`~server.WebSocketServer.sockets` attribute. * Reorganized and extended documentation. * Aborted connections if they don't close within the configured ``timeout``. * Rewrote connection termination to increase robustness in edge cases. * Stopped leaking pending tasks when :meth:`~asyncio.Task.cancel` is called on a connection while it's being closed. * Reduced verbosity of "Failing the WebSocket connection" logs. * Allowed ``extra_headers`` to override ``Server`` and ``User-Agent`` headers. 3.4 ... * Renamed :func:`~server.serve()` and :func:`~client.connect()`'s ``klass`` argument to ``create_protocol`` to reflect that it can also be a callable. For backwards compatibility, ``klass`` is still supported. * :func:`~server.serve` can be used as an asynchronous context manager on Python ≥ 3.5.1. * Added support for customizing handling of incoming connections with :meth:`~server.WebSocketServerProtocol.process_request()`. * Made read and write buffer sizes configurable. * Rewrote HTTP handling for simplicity and performance. * Added an optional C extension to speed up low level operations. * An invalid response status code during :func:`~client.connect()` now raises :class:`~exceptions.InvalidStatusCode` with a ``code`` attribute. * Providing a ``sock`` argument to :func:`~client.connect()` no longer crashes. 3.3 ... * Reduced noise in logs caused by connection resets. * Avoided crashing on concurrent writes on slow connections. 3.2 ... * Added ``timeout``, ``max_size``, and ``max_queue`` arguments to :func:`~client.connect()` and :func:`~server.serve()`. * Made server shutdown more robust. 3.1 ... * Avoided a warning when closing a connection before the opening handshake. * Added flow control for incoming data. 3.0 ... .. warning:: **Version 3.0 introduces a backwards-incompatible change in the** :meth:`~protocol.WebSocketCommonProtocol.recv` **API.** **If you're upgrading from 2.x or earlier, please read this carefully.** :meth:`~protocol.WebSocketCommonProtocol.recv` used to return ``None`` when the connection was closed. This required checking the return value of every call:: message = await websocket.recv() if message is None: return Now it raises a :exc:`~exceptions.ConnectionClosed` exception instead. This is more Pythonic. The previous code can be simplified to:: message = await websocket.recv() When implementing a server, which is the more popular use case, there's no strong reason to handle such exceptions. Let them bubble up, terminate the handler coroutine, and the server will simply ignore them. In order to avoid stranding projects built upon an earlier version, the previous behavior can be restored by passing ``legacy_recv=True`` to :func:`~server.serve`, :func:`~client.connect`, :class:`~server.WebSocketServerProtocol`, or :class:`~client.WebSocketClientProtocol`. ``legacy_recv`` isn't documented in their signatures but isn't scheduled for deprecation either. Also: * :func:`~client.connect` can be used as an asynchronous context manager on Python ≥ 3.5.1. * Updated documentation with ``await`` and ``async`` syntax from Python 3.5. * :meth:`~protocol.WebSocketCommonProtocol.ping` and :meth:`~protocol.WebSocketCommonProtocol.pong` support data passed as :class:`str` in addition to :class:`bytes`. * Worked around an asyncio bug affecting connection termination under load. * Made ``state_name`` atttribute on protocols a public API. * Improved documentation. 2.7 ... * Added compatibility with Python 3.5. * Refreshed documentation. 2.6 ... * Added ``local_address`` and ``remote_address`` attributes on protocols. * Closed open connections with code 1001 when a server shuts down. * Avoided TCP fragmentation of small frames. 2.5 ... * Improved documentation. * Provided access to handshake request and response HTTP headers. * Allowed customizing handshake request and response HTTP headers. * Supported running on a non-default event loop. * Returned a 403 status code instead of 400 when the request Origin isn't allowed. * Cancelling :meth:`~protocol.WebSocketCommonProtocol.recv` no longer drops the next message. * Clarified that the closing handshake can be initiated by the client. * Set the close code and reason more consistently. * Strengthened connection termination by simplifying the implementation. * Improved tests, added tox configuration, and enforced 100% branch coverage. 2.4 ... * Added support for subprotocols. * Supported non-default event loop. * Added ``loop`` argument to :func:`~client.connect` and :func:`~server.serve`. 2.3 ... * Improved compliance of close codes. 2.2 ... * Added support for limiting message size. 2.1 ... * Added ``host``, ``port`` and ``secure`` attributes on protocols. * Added support for providing and checking Origin_. .. _Origin: https://tools.ietf.org/html/rfc6455#section-10.2 2.0 ... .. warning:: **Version 2.0 introduces a backwards-incompatible change in the** :meth:`~protocol.WebSocketCommonProtocol.send`, :meth:`~protocol.WebSocketCommonProtocol.ping`, and :meth:`~protocol.WebSocketCommonProtocol.pong` **APIs.** **If you're upgrading from 1.x or earlier, please read this carefully.** These APIs used to be functions. Now they're coroutines. Instead of:: websocket.send(message) you must now write:: await websocket.send(message) Also: * Added flow control for outgoing data. 1.0 ... * Initial public release.