import asyncio
import asyncio.streams
import traceback
import warnings
from collections import deque
from contextlib import suppress
from html import escape as html_escape
from http import HTTPStatus
from logging import Logger
from typing import (
TYPE_CHECKING,
Any,
Awaitable,
Callable,
Optional,
Type,
cast,
)
import yarl
from .abc import AbstractAccessLogger, AbstractStreamWriter
from .base_protocol import BaseProtocol
from .helpers import CeilTimeout, current_task
from .http import (
HttpProcessingError,
HttpRequestParser,
HttpVersion10,
RawRequestMessage,
StreamWriter,
)
from .log import access_logger, server_logger
from .streams import EMPTY_PAYLOAD, StreamReader
from .tcp_helpers import tcp_keepalive
from .web_exceptions import HTTPException
from .web_log import AccessLogger
from .web_request import BaseRequest
from .web_response import Response, StreamResponse
__all__ = ('RequestHandler', 'RequestPayloadError', 'PayloadAccessError')
if TYPE_CHECKING: # pragma: no cover
from .web_server import Server # noqa
_RequestFactory = Callable[[RawRequestMessage,
StreamReader,
'RequestHandler',
AbstractStreamWriter,
'asyncio.Task[None]'],
BaseRequest]
_RequestHandler = Callable[[BaseRequest], Awaitable[StreamResponse]]
ERROR = RawRequestMessage(
'UNKNOWN', '/', HttpVersion10, {},
{}, True, False, False, False, yarl.URL('/'))
class RequestPayloadError(Exception):
"""Payload parsing error."""
class PayloadAccessError(Exception):
"""Payload was accessed after response was sent."""
class RequestHandler(BaseProtocol):
"""HTTP protocol implementation.
RequestHandler handles incoming HTTP request. It reads request line,
request headers and request payload and calls handle_request() method.
By default it always returns with 404 response.
RequestHandler handles errors in incoming request, like bad
status line, bad headers or incomplete payload. If any error occurs,
connection gets closed.
:param keepalive_timeout: number of seconds before closing
keep-alive connection
:type keepalive_timeout: int or None
:param bool tcp_keepalive: TCP keep-alive is on, default is on
:param bool debug: enable debug mode
:param logger: custom logger object
:type logger: aiohttp.log.server_logger
:param access_log_class: custom class for access_logger
:type access_log_class: aiohttp.abc.AbstractAccessLogger
:param access_log: custom logging object
:type access_log: aiohttp.log.server_logger
:param str access_log_format: access log format string
:param loop: Optional event loop
:param int max_line_size: Optional maximum header line size
:param int max_field_size: Optional maximum header field size
:param int max_headers: Optional maximum header size
"""
KEEPALIVE_RESCHEDULE_DELAY = 1
__slots__ = ('_request_count', '_keep_alive', '_manager',
'_request_handler', '_request_factory', '_tcp_keepalive',
'_keepalive_time', '_keepalive_handle', '_keepalive_timeout',
'_lingering_time', '_messages', '_message_tail',
'_waiter', '_error_handler', '_task_handler',
'_upgrade', '_payload_parser', '_request_parser',
'_reading_paused', 'logger', 'debug', 'access_log',
'access_logger', '_close', '_force_close')
def __init__(self, manager: 'Server', *,
loop: asyncio.AbstractEventLoop,
keepalive_timeout: float=75., # NGINX default is 75 secs
tcp_keepalive: bool=True,
logger: Logger=server_logger,
access_log_class: Type[AbstractAccessLogger]=AccessLogger,
access_log: Logger=access_logger,
access_log_format: str=AccessLogger.LOG_FORMAT,
debug: bool=False,
max_line_size: int=8190,
max_headers: int=32768,
max_field_size: int=8190,
lingering_time: float=10.0):
super().__init__(loop)
self._request_count = 0
self._keepalive = False
self._manager = manager # type: Optional[Server]
self._request_handler = manager.request_handler # type: Optional[_RequestHandler] # noqa
self._request_factory = manager.request_factory # type: Optional[_RequestFactory] # noqa
self._tcp_keepalive = tcp_keepalive
# placeholder to be replaced on keepalive timeout setup
self._keepalive_time = 0.0
self._keepalive_handle = None # type: Optional[asyncio.Handle]
self._keepalive_timeout = keepalive_timeout
self._lingering_time = float(lingering_time)
self._messages = deque() # type: Any # Python 3.5 has no typing.Deque
self._message_tail = b''
self._waiter = None # type: Optional[asyncio.Future[None]]
self._error_handler = None # type: Optional[asyncio.Task[None]]
self._task_handler = None # type: Optional[asyncio.Task[None]]
self._upgrade = False
self._payload_parser = None # type: Any
self._request_parser = HttpRequestParser(
self, loop,
max_line_size=max_line_size,
max_field_size=max_field_size,
max_headers=max_headers,
payload_exception=RequestPayloadError) # type: Optional[HttpRequestParser] # noqa
self.logger = logger
self.debug = debug
self.access_log = access_log
if access_log:
self.access_logger = access_log_class(
access_log, access_log_format) # type: Optional[AbstractAccessLogger] # noqa
else:
self.access_logger = None
self._close = False
self._force_close = False
def __repr__(self) -> str:
return "<{} {}>".format(
self.__class__.__name__,
'connected' if self.transport is not None else 'disconnected')
@property
def keepalive_timeout(self) -> float:
return self._keepalive_timeout
async def shutdown(self, timeout: Optional[float]=15.0) -> None:
"""Worker process is about to exit, we need cleanup everything and
stop accepting requests. It is especially important for keep-alive
connections."""
self._force_close = True
if self._keepalive_handle is not None:
self._keepalive_handle.cancel()
if self._waiter:
self._waiter.cancel()
# wait for handlers
with suppress(asyncio.CancelledError, asyncio.TimeoutError):
with CeilTimeout(timeout, loop=self._loop):
if (self._error_handler is not None and
not self._error_handler.done()):
await self._error_handler
if (self._task_handler is not None and
not self._task_handler.done()):
await self._task_handler
# force-close non-idle handler
if self._task_handler is not None:
self._task_handler.cancel()
if self.transport is not None:
self.transport.close()
self.transport = None
def connection_made(self, transport: asyncio.BaseTransport) -> None:
super().connection_made(transport)
real_transport = cast(asyncio.Transport, transport)
if self._tcp_keepalive:
tcp_keepalive(real_transport)
self._task_handler = self._loop.create_task(self.start())
assert self._manager is not None
self._manager.connection_made(self, real_transport)
def connection_lost(self, exc: Optional[BaseException]) -> None:
if self._manager is None:
return
self._manager.connection_lost(self, exc)
super().connection_lost(exc)
self._manager = None
self._force_close = True
self._request_factory = None
self._request_handler = None
self._request_parser = None
if self._keepalive_handle is not None:
self._keepalive_handle.cancel()
if self._task_handler is not None:
self._task_handler.cancel()
if self._error_handler is not None:
self._error_handler.cancel()
self._task_handler = None
if self._payload_parser is not None:
self._payload_parser.feed_eof()
self._payload_parser = None
def set_parser(self, parser: Any) -> None:
# Actual type is WebReader
assert self._payload_parser is None
self._payload_parser = parser
if self._message_tail:
self._payload_parser.feed_data(self._message_tail)
self._message_tail = b''
def eof_received(self) -> None:
pass
def data_received(self, data: bytes) -> None:
if self._force_close or self._close:
return
# parse http messages
if self._payload_parser is None and not self._upgrade:
assert self._request_parser is not None
try:
messages, upgraded, tail = self._request_parser.feed_data(data)
except HttpProcessingError as exc:
# something happened during parsing
self._error_handler = self._loop.create_task(
self.handle_parse_error(
StreamWriter(self, self._loop),
400, exc, exc.message))
self.close()
except Exception as exc:
# 500: internal error
self._error_handler = self._loop.create_task(
self.handle_parse_error(
StreamWriter(self, self._loop),
500, exc))
self.close()
else:
if messages:
# sometimes the parser returns no messages
for (msg, payload) in messages:
self._request_count += 1
self._messages.append((msg, payload))
waiter = self._waiter
if waiter is not None:
if not waiter.done():
# don't set result twice
waiter.set_result(None)
self._upgrade = upgraded
if upgraded and tail:
self._message_tail = tail
# no parser, just store
elif self._payload_parser is None and self._upgrade and data:
self._message_tail += data
# feed payload
elif data:
eof, tail = self._payload_parser.feed_data(data)
if eof:
self.close()
def keep_alive(self, val: bool) -> None:
"""Set keep-alive connection mode.
:param bool val: new state.
"""
self._keepalive = val
if self._keepalive_handle:
self._keepalive_handle.cancel()
self._keepalive_handle = None
def close(self) -> None:
"""Stop accepting new pipelinig messages and close
connection when handlers done processing messages"""
self._close = True
if self._waiter:
self._waiter.cancel()
def force_close(self) -> None:
"""Force close connection"""
self._force_close = True
if self._waiter:
self._waiter.cancel()
if self.transport is not None:
self.transport.close()
self.transport = None
def log_access(self,
request: BaseRequest,
response: StreamResponse,
time: float) -> None:
if self.access_logger is not None:
self.access_logger.log(request, response, time)
def log_debug(self, *args: Any, **kw: Any) -> None:
if self.debug:
self.logger.debug(*args, **kw)
def log_exception(self, *args: Any, **kw: Any) -> None:
self.logger.exception(*args, **kw)
def _process_keepalive(self) -> None:
if self._force_close or not self._keepalive:
return
next = self._keepalive_time + self._keepalive_timeout
# handler in idle state
if self._waiter:
if self._loop.time() > next:
self.force_close()
return
# not all request handlers are done,
# reschedule itself to next second
self._keepalive_handle = self._loop.call_later(
self.KEEPALIVE_RESCHEDULE_DELAY, self._process_keepalive)
async def start(self) -> None:
"""Process incoming request.
It reads request line, request headers and request payload, then
calls handle_request() method. Subclass has to override
handle_request(). start() handles various exceptions in request
or response handling. Connection is being closed always unless
keep_alive(True) specified.
"""
loop = self._loop
handler = self._task_handler
assert handler is not None
manager = self._manager
assert manager is not None
keepalive_timeout = self._keepalive_timeout
resp = None
assert self._request_factory is not None
assert self._request_handler is not None
while not self._force_close:
if not self._messages:
try:
# wait for next request
self._waiter = loop.create_future()
await self._waiter
except asyncio.CancelledError:
break
finally:
self._waiter = None
message, payload = self._messages.popleft()
if self.access_log:
now = loop.time()
manager.requests_count += 1
writer = StreamWriter(self, loop)
request = self._request_factory(
message, payload, self, writer, handler)
try:
try:
# a new task is used for copy context vars (#3406)
task = self._loop.create_task(
self._request_handler(request))
resp = await task
except HTTPException as exc:
resp = exc
except asyncio.CancelledError:
self.log_debug('Ignored premature client disconnection')
break
except asyncio.TimeoutError as exc:
self.log_debug('Request handler timed out.', exc_info=exc)
resp = self.handle_error(request, 504)
except Exception as exc:
resp = self.handle_error(request, 500, exc)
else:
# Deprecation warning (See #2415)
if getattr(resp, '__http_exception__', False):
warnings.warn(
"returning HTTPException object is deprecated "
"(#2415) and will be removed, "
"please raise the exception instead",
DeprecationWarning)
if self.debug:
if not isinstance(resp, StreamResponse):
if resp is None:
raise RuntimeError("Missing return "
"statement on request handler")
else:
raise RuntimeError("Web-handler should return "
"a response instance, "
"got {!r}".format(resp))
await resp.prepare(request)
await resp.write_eof()
# notify server about keep-alive
self._keepalive = bool(resp.keep_alive)
# log access
if self.access_log:
self.log_access(request, resp, loop.time() - now)
# check payload
if not payload.is_eof():
lingering_time = self._lingering_time
if not self._force_close and lingering_time:
self.log_debug(
'Start lingering close timer for %s sec.',
lingering_time)
now = loop.time()
end_t = now + lingering_time
with suppress(
asyncio.TimeoutError, asyncio.CancelledError):
while not payload.is_eof() and now < end_t:
with CeilTimeout(end_t - now, loop=loop):
# read and ignore
await payload.readany()
now = loop.time()
# if payload still uncompleted
if not payload.is_eof() and not self._force_close:
self.log_debug('Uncompleted request.')
self.close()
payload.set_exception(PayloadAccessError())
except asyncio.CancelledError:
self.log_debug('Ignored premature client disconnection ')
break
except RuntimeError as exc:
if self.debug:
self.log_exception(
'Unhandled runtime exception', exc_info=exc)
self.force_close()
except Exception as exc:
self.log_exception('Unhandled exception', exc_info=exc)
self.force_close()
finally:
if self.transport is None and resp is not None:
self.log_debug('Ignored premature client disconnection.')
elif not self._force_close:
if self._keepalive and not self._close:
# start keep-alive timer
if keepalive_timeout is not None:
now = self._loop.time()
self._keepalive_time = now
if self._keepalive_handle is None:
self._keepalive_handle = loop.call_at(
now + keepalive_timeout,
self._process_keepalive)
else:
break
# remove handler, close transport if no handlers left
if not self._force_close:
self._task_handler = None
if self.transport is not None and self._error_handler is None:
self.transport.close()
def handle_error(self,
request: BaseRequest,
status: int=500,
exc: Optional[BaseException]=None,
message: Optional[str]=None) -> StreamResponse:
"""Handle errors.
Returns HTTP response with specific status code. Logs additional
information. It always closes current connection."""
self.log_exception("Error handling request", exc_info=exc)
ct = 'text/plain'
if status == HTTPStatus.INTERNAL_SERVER_ERROR:
title = '{0.value} {0.phrase}'.format(
HTTPStatus.INTERNAL_SERVER_ERROR
)
msg = HTTPStatus.INTERNAL_SERVER_ERROR.description
tb = None
if self.debug:
with suppress(Exception):
tb = traceback.format_exc()
if 'text/html' in request.headers.get('Accept', ''):
if tb:
tb = html_escape(tb)
msg = 'Traceback:
\n{}'.format(tb)
message = (
""
"{title}"
"\n{title}
"
"\n{msg}\n\n"
).format(title=title, msg=msg)
ct = 'text/html'
else:
if tb:
msg = tb
message = title + '\n\n' + msg
resp = Response(status=status, text=message, content_type=ct)
resp.force_close()
# some data already got sent, connection is broken
if request.writer.output_size > 0 or self.transport is None:
self.force_close()
return resp
async def handle_parse_error(self,
writer: AbstractStreamWriter,
status: int,
exc: Optional[BaseException]=None,
message: Optional[str]=None) -> None:
request = BaseRequest( # type: ignore
ERROR,
EMPTY_PAYLOAD,
self, writer,
current_task(),
self._loop)
resp = self.handle_error(request, status, exc, message)
await resp.prepare(request)
await resp.write_eof()
if self.transport is not None:
self.transport.close()
self._error_handler = None