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import asyncio
from contextlib import suppress
from typing import Any, Optional, Tuple
from .base_protocol import BaseProtocol
from .client_exceptions import (
ClientOSError,
ClientPayloadError,
ServerDisconnectedError,
ServerTimeoutError,
)
from .helpers import BaseTimerContext
from .http import HttpResponseParser, RawResponseMessage
from .streams import EMPTY_PAYLOAD, DataQueue, StreamReader
class ResponseHandler(BaseProtocol, DataQueue[Tuple[RawResponseMessage, StreamReader]]):
"""Helper class to adapt between Protocol and StreamReader."""
def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
BaseProtocol.__init__(self, loop=loop)
DataQueue.__init__(self, loop)
self._should_close = False
self._payload: Optional[StreamReader] = None
self._skip_payload = False
self._payload_parser = None
self._timer = None
self._tail = b""
self._upgraded = False
self._parser: Optional[HttpResponseParser] = None
self._read_timeout: Optional[float] = None
self._read_timeout_handle: Optional[asyncio.TimerHandle] = None
@property
def upgraded(self) -> bool:
return self._upgraded
@property
def should_close(self) -> bool:
if self._payload is not None and not self._payload.is_eof() or self._upgraded:
return True
return (
self._should_close
or self._upgraded
or self.exception() is not None
or self._payload_parser is not None
or len(self) > 0
or bool(self._tail)
)
def force_close(self) -> None:
self._should_close = True
def close(self) -> None:
transport = self.transport
if transport is not None:
transport.close()
self.transport = None
self._payload = None
self._drop_timeout()
def is_connected(self) -> bool:
return self.transport is not None and not self.transport.is_closing()
def connection_lost(self, exc: Optional[BaseException]) -> None:
self._drop_timeout()
if self._payload_parser is not None:
with suppress(Exception):
self._payload_parser.feed_eof()
uncompleted = None
if self._parser is not None:
try:
uncompleted = self._parser.feed_eof()
except Exception:
if self._payload is not None:
self._payload.set_exception(
ClientPayloadError("Response payload is not completed")
)
if not self.is_eof():
if isinstance(exc, OSError):
exc = ClientOSError(*exc.args)
if exc is None:
exc = ServerDisconnectedError(uncompleted)
# assigns self._should_close to True as side effect,
# we do it anyway below
self.set_exception(exc)
self._should_close = True
self._parser = None
self._payload = None
self._payload_parser = None
self._reading_paused = False
super().connection_lost(exc)
def eof_received(self) -> None:
# should call parser.feed_eof() most likely
self._drop_timeout()
def pause_reading(self) -> None:
super().pause_reading()
self._drop_timeout()
def resume_reading(self) -> None:
super().resume_reading()
self._reschedule_timeout()
def set_exception(self, exc: BaseException) -> None:
self._should_close = True
self._drop_timeout()
super().set_exception(exc)
def set_parser(self, parser: Any, payload: Any) -> None:
# TODO: actual types are:
# parser: WebSocketReader
# payload: FlowControlDataQueue
# but they are not generi enough
# Need an ABC for both types
self._payload = payload
self._payload_parser = parser
self._drop_timeout()
if self._tail:
data, self._tail = self._tail, b""
self.data_received(data)
def set_response_params(
self,
*,
timer: Optional[BaseTimerContext] = None,
skip_payload: bool = False,
read_until_eof: bool = False,
auto_decompress: bool = True,
read_timeout: Optional[float] = None,
read_bufsize: int = 2**16,
) -> None:
self._skip_payload = skip_payload
self._read_timeout = read_timeout
self._reschedule_timeout()
self._parser = HttpResponseParser(
self,
self._loop,
read_bufsize,
timer=timer,
payload_exception=ClientPayloadError,
response_with_body=not skip_payload,
read_until_eof=read_until_eof,
auto_decompress=auto_decompress,
)
if self._tail:
data, self._tail = self._tail, b""
self.data_received(data)
def _drop_timeout(self) -> None:
if self._read_timeout_handle is not None:
self._read_timeout_handle.cancel()
self._read_timeout_handle = None
def _reschedule_timeout(self) -> None:
timeout = self._read_timeout
if self._read_timeout_handle is not None:
self._read_timeout_handle.cancel()
if timeout:
self._read_timeout_handle = self._loop.call_later(
timeout, self._on_read_timeout
)
else:
self._read_timeout_handle = None
def _on_read_timeout(self) -> None:
exc = ServerTimeoutError("Timeout on reading data from socket")
self.set_exception(exc)
if self._payload is not None:
self._payload.set_exception(exc)
def data_received(self, data: bytes) -> None:
self._reschedule_timeout()
if not data:
return
# custom payload parser
if self._payload_parser is not None:
eof, tail = self._payload_parser.feed_data(data)
if eof:
self._payload = None
self._payload_parser = None
if tail:
self.data_received(tail)
return
else:
if self._upgraded or self._parser is None:
# i.e. websocket connection, websocket parser is not set yet
self._tail += data
else:
# parse http messages
try:
messages, upgraded, tail = self._parser.feed_data(data)
except BaseException as exc:
if self.transport is not None:
# connection.release() could be called BEFORE
# data_received(), the transport is already
# closed in this case
self.transport.close()
# should_close is True after the call
self.set_exception(exc)
return
self._upgraded = upgraded
payload: Optional[StreamReader] = None
for message, payload in messages:
if message.should_close:
self._should_close = True
self._payload = payload
if self._skip_payload or message.code in (204, 304):
self.feed_data((message, EMPTY_PAYLOAD), 0)
else:
self.feed_data((message, payload), 0)
if payload is not None:
# new message(s) was processed
# register timeout handler unsubscribing
# either on end-of-stream or immediately for
# EMPTY_PAYLOAD
if payload is not EMPTY_PAYLOAD:
payload.on_eof(self._drop_timeout)
else:
self._drop_timeout()
if tail:
if upgraded:
self.data_received(tail)
else:
self._tail = tail