ok
Mini Shell
import asyncio
import base64
import binascii
import hashlib
import json
import async_timeout
import attr
from multidict import CIMultiDict
from . import hdrs
from .helpers import call_later, set_result
from .http import (WS_CLOSED_MESSAGE, WS_CLOSING_MESSAGE, WS_KEY,
WebSocketError, WebSocketReader, WebSocketWriter, WSMessage,
WSMsgType, ws_ext_gen, ws_ext_parse)
from .log import ws_logger
from .streams import FlowControlDataQueue
from .web_exceptions import HTTPBadRequest, HTTPException, HTTPMethodNotAllowed
from .web_response import StreamResponse
__all__ = ('WebSocketResponse', 'WebSocketReady', 'WSMsgType',)
THRESHOLD_CONNLOST_ACCESS = 5
@attr.s(frozen=True, slots=True)
class WebSocketReady:
ok = attr.ib(type=bool)
protocol = attr.ib(type=str)
def __bool__(self):
return self.ok
class WebSocketResponse(StreamResponse):
def __init__(self, *,
timeout=10.0, receive_timeout=None,
autoclose=True, autoping=True, heartbeat=None,
protocols=(), compress=True):
super().__init__(status=101)
self._protocols = protocols
self._ws_protocol = None
self._writer = None
self._reader = None
self._closed = False
self._closing = False
self._conn_lost = 0
self._close_code = None
self._loop = None
self._waiting = None
self._exception = None
self._timeout = timeout
self._receive_timeout = receive_timeout
self._autoclose = autoclose
self._autoping = autoping
self._heartbeat = heartbeat
self._heartbeat_cb = None
if heartbeat is not None:
self._pong_heartbeat = heartbeat/2.0
self._pong_response_cb = None
self._compress = compress
def _cancel_heartbeat(self):
if self._pong_response_cb is not None:
self._pong_response_cb.cancel()
self._pong_response_cb = None
if self._heartbeat_cb is not None:
self._heartbeat_cb.cancel()
self._heartbeat_cb = None
def _reset_heartbeat(self):
self._cancel_heartbeat()
if self._heartbeat is not None:
self._heartbeat_cb = call_later(
self._send_heartbeat, self._heartbeat, self._loop)
def _send_heartbeat(self):
if self._heartbeat is not None and not self._closed:
self._writer.ping()
if self._pong_response_cb is not None:
self._pong_response_cb.cancel()
self._pong_response_cb = call_later(
self._pong_not_received, self._pong_heartbeat, self._loop)
def _pong_not_received(self):
if self._req is not None and self._req.transport is not None:
self._closed = True
self._close_code = 1006
self._exception = asyncio.TimeoutError()
self._req.transport.close()
async def prepare(self, request):
# make pre-check to don't hide it by do_handshake() exceptions
if self._payload_writer is not None:
return self._payload_writer
protocol, writer = self._pre_start(request)
payload_writer = await super().prepare(request)
self._post_start(request, protocol, writer)
await payload_writer.drain()
return payload_writer
def _handshake(self, request):
headers = request.headers
if request.method != hdrs.METH_GET:
raise HTTPMethodNotAllowed(request.method, [hdrs.METH_GET])
if 'websocket' != headers.get(hdrs.UPGRADE, '').lower().strip():
raise HTTPBadRequest(
text=('No WebSocket UPGRADE hdr: {}\n Can '
'"Upgrade" only to "WebSocket".')
.format(headers.get(hdrs.UPGRADE)))
if 'upgrade' not in headers.get(hdrs.CONNECTION, '').lower():
raise HTTPBadRequest(
text='No CONNECTION upgrade hdr: {}'.format(
headers.get(hdrs.CONNECTION)))
# find common sub-protocol between client and server
protocol = None
if hdrs.SEC_WEBSOCKET_PROTOCOL in headers:
req_protocols = [str(proto.strip()) for proto in
headers[hdrs.SEC_WEBSOCKET_PROTOCOL].split(',')]
for proto in req_protocols:
if proto in self._protocols:
protocol = proto
break
else:
# No overlap found: Return no protocol as per spec
ws_logger.warning(
'Client protocols %r don’t overlap server-known ones %r',
req_protocols, self._protocols)
# check supported version
version = headers.get(hdrs.SEC_WEBSOCKET_VERSION, '')
if version not in ('13', '8', '7'):
raise HTTPBadRequest(
text='Unsupported version: {}'.format(version))
# check client handshake for validity
key = headers.get(hdrs.SEC_WEBSOCKET_KEY)
try:
if not key or len(base64.b64decode(key)) != 16:
raise HTTPBadRequest(
text='Handshake error: {!r}'.format(key))
except binascii.Error:
raise HTTPBadRequest(
text='Handshake error: {!r}'.format(key)) from None
accept_val = base64.b64encode(
hashlib.sha1(key.encode() + WS_KEY).digest()).decode()
response_headers = CIMultiDict({hdrs.UPGRADE: 'websocket',
hdrs.CONNECTION: 'upgrade',
hdrs.TRANSFER_ENCODING: 'chunked',
hdrs.SEC_WEBSOCKET_ACCEPT: accept_val})
notakeover = False
compress = self._compress
if compress:
extensions = headers.get(hdrs.SEC_WEBSOCKET_EXTENSIONS)
# Server side always get return with no exception.
# If something happened, just drop compress extension
compress, notakeover = ws_ext_parse(extensions, isserver=True)
if compress:
enabledext = ws_ext_gen(compress=compress, isserver=True,
server_notakeover=notakeover)
response_headers[hdrs.SEC_WEBSOCKET_EXTENSIONS] = enabledext
if protocol:
response_headers[hdrs.SEC_WEBSOCKET_PROTOCOL] = protocol
return (response_headers, protocol, compress, notakeover)
def _pre_start(self, request):
self._loop = request.loop
headers, protocol, compress, notakeover = self._handshake(
request)
self._reset_heartbeat()
self.set_status(101)
self.headers.update(headers)
self.force_close()
self._compress = compress
writer = WebSocketWriter(request._protocol,
request._protocol.transport,
compress=compress,
notakeover=notakeover)
return protocol, writer
def _post_start(self, request, protocol, writer):
self._ws_protocol = protocol
self._writer = writer
self._reader = FlowControlDataQueue(
request._protocol, limit=2 ** 16, loop=self._loop)
request.protocol.set_parser(WebSocketReader(
self._reader, compress=self._compress))
# disable HTTP keepalive for WebSocket
request.protocol.keep_alive(False)
def can_prepare(self, request):
if self._writer is not None:
raise RuntimeError('Already started')
try:
_, protocol, _, _ = self._handshake(request)
except HTTPException:
return WebSocketReady(False, None)
else:
return WebSocketReady(True, protocol)
@property
def closed(self):
return self._closed
@property
def close_code(self):
return self._close_code
@property
def ws_protocol(self):
return self._ws_protocol
@property
def compress(self):
return self._compress
def exception(self):
return self._exception
async def ping(self, message='b'):
if self._writer is None:
raise RuntimeError('Call .prepare() first')
await self._writer.ping(message)
async def pong(self, message='b'):
# unsolicited pong
if self._writer is None:
raise RuntimeError('Call .prepare() first')
await self._writer.pong(message)
async def send_str(self, data, compress=None):
if self._writer is None:
raise RuntimeError('Call .prepare() first')
if not isinstance(data, str):
raise TypeError('data argument must be str (%r)' % type(data))
await self._writer.send(data, binary=False, compress=compress)
async def send_bytes(self, data, compress=None):
if self._writer is None:
raise RuntimeError('Call .prepare() first')
if not isinstance(data, (bytes, bytearray, memoryview)):
raise TypeError('data argument must be byte-ish (%r)' %
type(data))
await self._writer.send(data, binary=True, compress=compress)
async def send_json(self, data, compress=None, *, dumps=json.dumps):
await self.send_str(dumps(data), compress=compress)
async def write_eof(self):
if self._eof_sent:
return
if self._payload_writer is None:
raise RuntimeError("Response has not been started")
await self.close()
self._eof_sent = True
async def close(self, *, code=1000, message=b''):
if self._writer is None:
raise RuntimeError('Call .prepare() first')
self._cancel_heartbeat()
# we need to break `receive()` cycle first,
# `close()` may be called from different task
if self._waiting is not None and not self._closed:
self._reader.feed_data(WS_CLOSING_MESSAGE, 0)
await self._waiting
if not self._closed:
self._closed = True
try:
self._writer.close(code, message)
await self._payload_writer.drain()
except (asyncio.CancelledError, asyncio.TimeoutError):
self._close_code = 1006
raise
except Exception as exc:
self._close_code = 1006
self._exception = exc
return True
if self._closing:
return True
try:
with async_timeout.timeout(self._timeout, loop=self._loop):
msg = await self._reader.read()
except asyncio.CancelledError:
self._close_code = 1006
raise
except Exception as exc:
self._close_code = 1006
self._exception = exc
return True
if msg.type == WSMsgType.CLOSE:
self._close_code = msg.data
return True
self._close_code = 1006
self._exception = asyncio.TimeoutError()
return True
else:
return False
async def receive(self, timeout=None):
if self._reader is None:
raise RuntimeError('Call .prepare() first')
while True:
if self._waiting is not None:
raise RuntimeError(
'Concurrent call to receive() is not allowed')
if self._closed:
self._conn_lost += 1
if self._conn_lost >= THRESHOLD_CONNLOST_ACCESS:
raise RuntimeError('WebSocket connection is closed.')
return WS_CLOSED_MESSAGE
elif self._closing:
return WS_CLOSING_MESSAGE
try:
self._waiting = self._loop.create_future()
try:
with async_timeout.timeout(
timeout or self._receive_timeout, loop=self._loop):
msg = await self._reader.read()
self._reset_heartbeat()
finally:
waiter = self._waiting
set_result(waiter, True)
self._waiting = None
except (asyncio.CancelledError, asyncio.TimeoutError):
self._close_code = 1006
raise
except WebSocketError as exc:
self._close_code = exc.code
await self.close(code=exc.code)
return WSMessage(WSMsgType.ERROR, exc, None)
except Exception as exc:
self._exception = exc
self._closing = True
self._close_code = 1006
await self.close()
return WSMessage(WSMsgType.ERROR, exc, None)
if msg.type == WSMsgType.CLOSE:
self._closing = True
self._close_code = msg.data
if not self._closed and self._autoclose:
await self.close()
elif msg.type == WSMsgType.CLOSING:
self._closing = True
elif msg.type == WSMsgType.PING and self._autoping:
await self.pong(msg.data)
continue
elif msg.type == WSMsgType.PONG and self._autoping:
continue
return msg
async def receive_str(self, *, timeout=None):
msg = await self.receive(timeout)
if msg.type != WSMsgType.TEXT:
raise TypeError(
"Received message {}:{!r} is not WSMsgType.TEXT".format(
msg.type, msg.data))
return msg.data
async def receive_bytes(self, *, timeout=None):
msg = await self.receive(timeout)
if msg.type != WSMsgType.BINARY:
raise TypeError(
"Received message {}:{!r} is not bytes".format(msg.type,
msg.data))
return msg.data
async def receive_json(self, *, loads=json.loads, timeout=None):
data = await self.receive_str(timeout=timeout)
return loads(data)
async def write(self, data):
raise RuntimeError("Cannot call .write() for websocket")
def __aiter__(self):
return self
async def __anext__(self):
msg = await self.receive()
if msg.type in (WSMsgType.CLOSE,
WSMsgType.CLOSING,
WSMsgType.CLOSED):
raise StopAsyncIteration # NOQA
return msg
Zerion Mini Shell 1.0