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Mini Shell
Mini Shell
import asyncio
import base64
import binascii
import hashlib
import json
import sys
from typing import Any, Final, Iterable, Optional, Tuple, cast
import attr
from multidict import CIMultiDict
from . import hdrs
from .abc import AbstractStreamWriter
from .helpers import call_later, set_result
from .http import (
WS_CLOSED_MESSAGE,
WS_CLOSING_MESSAGE,
WS_KEY,
WebSocketError,
WebSocketReader,
WebSocketWriter,
WSCloseCode,
WSMessage,
WSMsgType as WSMsgType,
ws_ext_gen,
ws_ext_parse,
)
from .log import ws_logger
from .streams import EofStream, FlowControlDataQueue
from .typedefs import JSONDecoder, JSONEncoder
from .web_exceptions import HTTPBadRequest, HTTPException
from .web_request import BaseRequest
from .web_response import StreamResponse
if sys.version_info >= (3, 11):
import asyncio as async_timeout
else:
import async_timeout
__all__ = (
"WebSocketResponse",
"WebSocketReady",
"WSMsgType",
)
THRESHOLD_CONNLOST_ACCESS: Final[int] = 5
@attr.s(auto_attribs=True, frozen=True, slots=True)
class WebSocketReady:
ok: bool
protocol: Optional[str]
def __bool__(self) -> bool:
return self.ok
class WebSocketResponse(StreamResponse):
_length_check = False
def __init__(
self,
*,
timeout: float = 10.0,
receive_timeout: Optional[float] = None,
autoclose: bool = True,
autoping: bool = True,
heartbeat: Optional[float] = None,
protocols: Iterable[str] = (),
compress: bool = True,
max_msg_size: int = 4 * 1024 * 1024,
) -> None:
super().__init__(status=101)
self._protocols = protocols
self._ws_protocol: Optional[str] = None
self._writer: Optional[WebSocketWriter] = None
self._reader: Optional[FlowControlDataQueue[WSMessage]] = None
self._closed = False
self._closing = False
self._conn_lost = 0
self._close_code: Optional[int] = None
self._loop: Optional[asyncio.AbstractEventLoop] = None
self._waiting: Optional[asyncio.Future[bool]] = None
self._exception: Optional[BaseException] = None
self._timeout = timeout
self._receive_timeout = receive_timeout
self._autoclose = autoclose
self._autoping = autoping
self._heartbeat = heartbeat
self._heartbeat_cb: Optional[asyncio.TimerHandle] = None
if heartbeat is not None:
self._pong_heartbeat = heartbeat / 2.0
self._pong_response_cb: Optional[asyncio.TimerHandle] = None
self._compress = compress
self._max_msg_size = max_msg_size
def _cancel_heartbeat(self) -> None:
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) -> None:
self._cancel_heartbeat()
if self._heartbeat is not None:
assert self._loop is not None
self._heartbeat_cb = call_later(
self._send_heartbeat,
self._heartbeat,
self._loop,
timeout_ceil_threshold=self._req._protocol._timeout_ceil_threshold
if self._req is not None
else 5,
)
def _send_heartbeat(self) -> None:
if self._heartbeat is not None and not self._closed:
assert self._loop is not None
# fire-and-forget a task is not perfect but maybe ok for
# sending ping. Otherwise we need a long-living heartbeat
# task in the class.
self._loop.create_task(self._writer.ping()) # type: ignore[union-attr]
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,
timeout_ceil_threshold=self._req._protocol._timeout_ceil_threshold
if self._req is not None
else 5,
)
def _pong_not_received(self) -> None:
if self._req is not None and self._req.transport is not None:
self._closed = True
self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
self._exception = asyncio.TimeoutError()
async def prepare(self, request: BaseRequest) -> AbstractStreamWriter:
# 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)
assert payload_writer is not None
self._post_start(request, protocol, writer)
await payload_writer.drain()
return payload_writer
def _handshake(
self, request: BaseRequest
) -> Tuple["CIMultiDict[str]", str, bool, bool]:
headers = request.headers
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=f"Unsupported version: {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=f"Handshake error: {key!r}")
except binascii.Error:
raise HTTPBadRequest(text=f"Handshake error: {key!r}") from None
accept_val = base64.b64encode(
hashlib.sha1(key.encode() + WS_KEY).digest()
).decode()
response_headers = CIMultiDict(
{
hdrs.UPGRADE: "websocket",
hdrs.CONNECTION: "upgrade",
hdrs.SEC_WEBSOCKET_ACCEPT: accept_val,
}
)
notakeover = False
compress = 0
if self._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,
) # type: ignore[return-value]
def _pre_start(self, request: BaseRequest) -> Tuple[str, WebSocketWriter]:
self._loop = request._loop
headers, protocol, compress, notakeover = self._handshake(request)
self.set_status(101)
self.headers.update(headers)
self.force_close()
self._compress = compress
transport = request._protocol.transport
assert transport is not None
writer = WebSocketWriter(
request._protocol, transport, compress=compress, notakeover=notakeover
)
return protocol, writer
def _post_start(
self, request: BaseRequest, protocol: str, writer: WebSocketWriter
) -> None:
self._ws_protocol = protocol
self._writer = writer
self._reset_heartbeat()
loop = self._loop
assert loop is not None
self._reader = FlowControlDataQueue(request._protocol, 2**16, loop=loop)
request.protocol.set_parser(
WebSocketReader(self._reader, self._max_msg_size, compress=self._compress)
)
# disable HTTP keepalive for WebSocket
request.protocol.keep_alive(False)
def can_prepare(self, request: BaseRequest) -> WebSocketReady:
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) -> bool:
return self._closed
@property
def close_code(self) -> Optional[int]:
return self._close_code
@property
def ws_protocol(self) -> Optional[str]:
return self._ws_protocol
@property
def compress(self) -> bool:
return self._compress
def get_extra_info(self, name: str, default: Any = None) -> Any:
"""Get optional transport information.
If no value associated with ``name`` is found, ``default`` is returned.
"""
writer = self._writer
if writer is None:
return default
transport = writer.transport
if transport is None:
return default
return transport.get_extra_info(name, default)
def exception(self) -> Optional[BaseException]:
return self._exception
async def ping(self, message: bytes = b"") -> None:
if self._writer is None:
raise RuntimeError("Call .prepare() first")
await self._writer.ping(message)
async def pong(self, message: bytes = b"") -> None:
# unsolicited pong
if self._writer is None:
raise RuntimeError("Call .prepare() first")
await self._writer.pong(message)
async def send_str(self, data: str, compress: Optional[bool] = None) -> 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: bytes, compress: Optional[bool] = None) -> 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: Any,
compress: Optional[bool] = None,
*,
dumps: JSONEncoder = json.dumps,
) -> None:
await self.send_str(dumps(data), compress=compress)
async def write_eof(self) -> None: # type: ignore[override]
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: int = WSCloseCode.OK, message: bytes = b"", drain: bool = True
) -> bool:
"""Close websocket connection."""
if self._writer is None:
raise RuntimeError("Call .prepare() first")
self._cancel_heartbeat()
reader = self._reader
assert reader is not None
# we need to break `receive()` cycle first,
# `close()` may be called from different task
if self._waiting is not None and not self._closed:
reader.feed_data(WS_CLOSING_MESSAGE, 0)
await self._waiting
if self._closed:
return False
self._closed = True
try:
await self._writer.close(code, message)
writer = self._payload_writer
assert writer is not None
if drain:
await writer.drain()
except (asyncio.CancelledError, asyncio.TimeoutError):
self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
raise
except Exception as exc:
self._exception = exc
self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
return True
if self._closing:
return True
reader = self._reader
assert reader is not None
try:
async with async_timeout.timeout(self._timeout):
msg = await reader.read()
except asyncio.CancelledError:
self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
raise
except Exception as exc:
self._exception = exc
self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
return True
if msg.type == WSMsgType.CLOSE:
self._set_code_close_transport(msg.data)
return True
self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
self._exception = asyncio.TimeoutError()
return True
def _set_code_close_transport(self, code: WSCloseCode) -> None:
"""Set the close code and close the transport."""
self._close_code = code
if self._req is not None and self._req.transport is not None:
self._req.transport.close()
async def receive(self, timeout: Optional[float] = None) -> WSMessage:
if self._reader is None:
raise RuntimeError("Call .prepare() first")
loop = self._loop
assert loop is not None
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 = loop.create_future()
try:
async with async_timeout.timeout(timeout or self._receive_timeout):
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._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
raise
except EofStream:
self._close_code = WSCloseCode.OK
await self.close()
return WSMessage(WSMsgType.CLOSED, None, None)
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 = WSCloseCode.ABNORMAL_CLOSURE
await self.close()
return WSMessage(WSMsgType.ERROR, exc, None)
if msg.type == WSMsgType.CLOSE:
self._closing = True
self._close_code = msg.data
# Could be closed while awaiting reader.
if not self._closed and self._autoclose:
# The client is likely going to close the
# connection out from under us so we do not
# want to drain any pending writes as it will
# likely result writing to a broken pipe.
await self.close(drain=False)
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: Optional[float] = None) -> str:
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 cast(str, msg.data)
async def receive_bytes(self, *, timeout: Optional[float] = None) -> bytes:
msg = await self.receive(timeout)
if msg.type != WSMsgType.BINARY:
raise TypeError(f"Received message {msg.type}:{msg.data!r} is not bytes")
return cast(bytes, msg.data)
async def receive_json(
self, *, loads: JSONDecoder = json.loads, timeout: Optional[float] = None
) -> Any:
data = await self.receive_str(timeout=timeout)
return loads(data)
async def write(self, data: bytes) -> None:
raise RuntimeError("Cannot call .write() for websocket")
def __aiter__(self) -> "WebSocketResponse":
return self
async def __anext__(self) -> WSMessage:
msg = await self.receive()
if msg.type in (WSMsgType.CLOSE, WSMsgType.CLOSING, WSMsgType.CLOSED):
raise StopAsyncIteration
return msg
def _cancel(self, exc: BaseException) -> None:
if self._reader is not None:
self._reader.set_exception(exc)
Zerion Mini Shell 1.0