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author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
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committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/httpcore/_async/http2.py | |
parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
download | gn-ai-master.tar.gz |
Diffstat (limited to '.venv/lib/python3.12/site-packages/httpcore/_async/http2.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/httpcore/_async/http2.py | 583 |
1 files changed, 583 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/httpcore/_async/http2.py b/.venv/lib/python3.12/site-packages/httpcore/_async/http2.py new file mode 100644 index 00000000..c6434a04 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/httpcore/_async/http2.py @@ -0,0 +1,583 @@ +from __future__ import annotations + +import enum +import logging +import time +import types +import typing + +import h2.config +import h2.connection +import h2.events +import h2.exceptions +import h2.settings + +from .._backends.base import AsyncNetworkStream +from .._exceptions import ( + ConnectionNotAvailable, + LocalProtocolError, + RemoteProtocolError, +) +from .._models import Origin, Request, Response +from .._synchronization import AsyncLock, AsyncSemaphore, AsyncShieldCancellation +from .._trace import Trace +from .interfaces import AsyncConnectionInterface + +logger = logging.getLogger("httpcore.http2") + + +def has_body_headers(request: Request) -> bool: + return any( + k.lower() == b"content-length" or k.lower() == b"transfer-encoding" + for k, v in request.headers + ) + + +class HTTPConnectionState(enum.IntEnum): + ACTIVE = 1 + IDLE = 2 + CLOSED = 3 + + +class AsyncHTTP2Connection(AsyncConnectionInterface): + READ_NUM_BYTES = 64 * 1024 + CONFIG = h2.config.H2Configuration(validate_inbound_headers=False) + + def __init__( + self, + origin: Origin, + stream: AsyncNetworkStream, + keepalive_expiry: float | None = None, + ): + self._origin = origin + self._network_stream = stream + self._keepalive_expiry: float | None = keepalive_expiry + self._h2_state = h2.connection.H2Connection(config=self.CONFIG) + self._state = HTTPConnectionState.IDLE + self._expire_at: float | None = None + self._request_count = 0 + self._init_lock = AsyncLock() + self._state_lock = AsyncLock() + self._read_lock = AsyncLock() + self._write_lock = AsyncLock() + self._sent_connection_init = False + self._used_all_stream_ids = False + self._connection_error = False + + # Mapping from stream ID to response stream events. + self._events: dict[ + int, + h2.events.ResponseReceived + | h2.events.DataReceived + | h2.events.StreamEnded + | h2.events.StreamReset, + ] = {} + + # Connection terminated events are stored as state since + # we need to handle them for all streams. + self._connection_terminated: h2.events.ConnectionTerminated | None = None + + self._read_exception: Exception | None = None + self._write_exception: Exception | None = None + + async def handle_async_request(self, request: Request) -> Response: + if not self.can_handle_request(request.url.origin): + # This cannot occur in normal operation, since the connection pool + # will only send requests on connections that handle them. + # It's in place simply for resilience as a guard against incorrect + # usage, for anyone working directly with httpcore connections. + raise RuntimeError( + f"Attempted to send request to {request.url.origin} on connection " + f"to {self._origin}" + ) + + async with self._state_lock: + if self._state in (HTTPConnectionState.ACTIVE, HTTPConnectionState.IDLE): + self._request_count += 1 + self._expire_at = None + self._state = HTTPConnectionState.ACTIVE + else: + raise ConnectionNotAvailable() + + async with self._init_lock: + if not self._sent_connection_init: + try: + kwargs = {"request": request} + async with Trace("send_connection_init", logger, request, kwargs): + await self._send_connection_init(**kwargs) + except BaseException as exc: + with AsyncShieldCancellation(): + await self.aclose() + raise exc + + self._sent_connection_init = True + + # Initially start with just 1 until the remote server provides + # its max_concurrent_streams value + self._max_streams = 1 + + local_settings_max_streams = ( + self._h2_state.local_settings.max_concurrent_streams + ) + self._max_streams_semaphore = AsyncSemaphore(local_settings_max_streams) + + for _ in range(local_settings_max_streams - self._max_streams): + await self._max_streams_semaphore.acquire() + + await self._max_streams_semaphore.acquire() + + try: + stream_id = self._h2_state.get_next_available_stream_id() + self._events[stream_id] = [] + except h2.exceptions.NoAvailableStreamIDError: # pragma: nocover + self._used_all_stream_ids = True + self._request_count -= 1 + raise ConnectionNotAvailable() + + try: + kwargs = {"request": request, "stream_id": stream_id} + async with Trace("send_request_headers", logger, request, kwargs): + await self._send_request_headers(request=request, stream_id=stream_id) + async with Trace("send_request_body", logger, request, kwargs): + await self._send_request_body(request=request, stream_id=stream_id) + async with Trace( + "receive_response_headers", logger, request, kwargs + ) as trace: + status, headers = await self._receive_response( + request=request, stream_id=stream_id + ) + trace.return_value = (status, headers) + + return Response( + status=status, + headers=headers, + content=HTTP2ConnectionByteStream(self, request, stream_id=stream_id), + extensions={ + "http_version": b"HTTP/2", + "network_stream": self._network_stream, + "stream_id": stream_id, + }, + ) + except BaseException as exc: # noqa: PIE786 + with AsyncShieldCancellation(): + kwargs = {"stream_id": stream_id} + async with Trace("response_closed", logger, request, kwargs): + await self._response_closed(stream_id=stream_id) + + if isinstance(exc, h2.exceptions.ProtocolError): + # One case where h2 can raise a protocol error is when a + # closed frame has been seen by the state machine. + # + # This happens when one stream is reading, and encounters + # a GOAWAY event. Other flows of control may then raise + # a protocol error at any point they interact with the 'h2_state'. + # + # In this case we'll have stored the event, and should raise + # it as a RemoteProtocolError. + if self._connection_terminated: # pragma: nocover + raise RemoteProtocolError(self._connection_terminated) + # If h2 raises a protocol error in some other state then we + # must somehow have made a protocol violation. + raise LocalProtocolError(exc) # pragma: nocover + + raise exc + + async def _send_connection_init(self, request: Request) -> None: + """ + The HTTP/2 connection requires some initial setup before we can start + using individual request/response streams on it. + """ + # Need to set these manually here instead of manipulating via + # __setitem__() otherwise the H2Connection will emit SettingsUpdate + # frames in addition to sending the undesired defaults. + self._h2_state.local_settings = h2.settings.Settings( + client=True, + initial_values={ + # Disable PUSH_PROMISE frames from the server since we don't do anything + # with them for now. Maybe when we support caching? + h2.settings.SettingCodes.ENABLE_PUSH: 0, + # These two are taken from h2 for safe defaults + h2.settings.SettingCodes.MAX_CONCURRENT_STREAMS: 100, + h2.settings.SettingCodes.MAX_HEADER_LIST_SIZE: 65536, + }, + ) + + # Some websites (*cough* Yahoo *cough*) balk at this setting being + # present in the initial handshake since it's not defined in the original + # RFC despite the RFC mandating ignoring settings you don't know about. + del self._h2_state.local_settings[ + h2.settings.SettingCodes.ENABLE_CONNECT_PROTOCOL + ] + + self._h2_state.initiate_connection() + self._h2_state.increment_flow_control_window(2**24) + await self._write_outgoing_data(request) + + # Sending the request... + + async def _send_request_headers(self, request: Request, stream_id: int) -> None: + """ + Send the request headers to a given stream ID. + """ + end_stream = not has_body_headers(request) + + # In HTTP/2 the ':authority' pseudo-header is used instead of 'Host'. + # In order to gracefully handle HTTP/1.1 and HTTP/2 we always require + # HTTP/1.1 style headers, and map them appropriately if we end up on + # an HTTP/2 connection. + authority = [v for k, v in request.headers if k.lower() == b"host"][0] + + headers = [ + (b":method", request.method), + (b":authority", authority), + (b":scheme", request.url.scheme), + (b":path", request.url.target), + ] + [ + (k.lower(), v) + for k, v in request.headers + if k.lower() + not in ( + b"host", + b"transfer-encoding", + ) + ] + + self._h2_state.send_headers(stream_id, headers, end_stream=end_stream) + self._h2_state.increment_flow_control_window(2**24, stream_id=stream_id) + await self._write_outgoing_data(request) + + async def _send_request_body(self, request: Request, stream_id: int) -> None: + """ + Iterate over the request body sending it to a given stream ID. + """ + if not has_body_headers(request): + return + + assert isinstance(request.stream, typing.AsyncIterable) + async for data in request.stream: + await self._send_stream_data(request, stream_id, data) + await self._send_end_stream(request, stream_id) + + async def _send_stream_data( + self, request: Request, stream_id: int, data: bytes + ) -> None: + """ + Send a single chunk of data in one or more data frames. + """ + while data: + max_flow = await self._wait_for_outgoing_flow(request, stream_id) + chunk_size = min(len(data), max_flow) + chunk, data = data[:chunk_size], data[chunk_size:] + self._h2_state.send_data(stream_id, chunk) + await self._write_outgoing_data(request) + + async def _send_end_stream(self, request: Request, stream_id: int) -> None: + """ + Send an empty data frame on on a given stream ID with the END_STREAM flag set. + """ + self._h2_state.end_stream(stream_id) + await self._write_outgoing_data(request) + + # Receiving the response... + + async def _receive_response( + self, request: Request, stream_id: int + ) -> tuple[int, list[tuple[bytes, bytes]]]: + """ + Return the response status code and headers for a given stream ID. + """ + while True: + event = await self._receive_stream_event(request, stream_id) + if isinstance(event, h2.events.ResponseReceived): + break + + status_code = 200 + headers = [] + for k, v in event.headers: + if k == b":status": + status_code = int(v.decode("ascii", errors="ignore")) + elif not k.startswith(b":"): + headers.append((k, v)) + + return (status_code, headers) + + async def _receive_response_body( + self, request: Request, stream_id: int + ) -> typing.AsyncIterator[bytes]: + """ + Iterator that returns the bytes of the response body for a given stream ID. + """ + while True: + event = await self._receive_stream_event(request, stream_id) + if isinstance(event, h2.events.DataReceived): + amount = event.flow_controlled_length + self._h2_state.acknowledge_received_data(amount, stream_id) + await self._write_outgoing_data(request) + yield event.data + elif isinstance(event, h2.events.StreamEnded): + break + + async def _receive_stream_event( + self, request: Request, stream_id: int + ) -> h2.events.ResponseReceived | h2.events.DataReceived | h2.events.StreamEnded: + """ + Return the next available event for a given stream ID. + + Will read more data from the network if required. + """ + while not self._events.get(stream_id): + await self._receive_events(request, stream_id) + event = self._events[stream_id].pop(0) + if isinstance(event, h2.events.StreamReset): + raise RemoteProtocolError(event) + return event + + async def _receive_events( + self, request: Request, stream_id: int | None = None + ) -> None: + """ + Read some data from the network until we see one or more events + for a given stream ID. + """ + async with self._read_lock: + if self._connection_terminated is not None: + last_stream_id = self._connection_terminated.last_stream_id + if stream_id and last_stream_id and stream_id > last_stream_id: + self._request_count -= 1 + raise ConnectionNotAvailable() + raise RemoteProtocolError(self._connection_terminated) + + # This conditional is a bit icky. We don't want to block reading if we've + # actually got an event to return for a given stream. We need to do that + # check *within* the atomic read lock. Though it also need to be optional, + # because when we call it from `_wait_for_outgoing_flow` we *do* want to + # block until we've available flow control, event when we have events + # pending for the stream ID we're attempting to send on. + if stream_id is None or not self._events.get(stream_id): + events = await self._read_incoming_data(request) + for event in events: + if isinstance(event, h2.events.RemoteSettingsChanged): + async with Trace( + "receive_remote_settings", logger, request + ) as trace: + await self._receive_remote_settings_change(event) + trace.return_value = event + + elif isinstance( + event, + ( + h2.events.ResponseReceived, + h2.events.DataReceived, + h2.events.StreamEnded, + h2.events.StreamReset, + ), + ): + if event.stream_id in self._events: + self._events[event.stream_id].append(event) + + elif isinstance(event, h2.events.ConnectionTerminated): + self._connection_terminated = event + + await self._write_outgoing_data(request) + + async def _receive_remote_settings_change(self, event: h2.events.Event) -> None: + max_concurrent_streams = event.changed_settings.get( + h2.settings.SettingCodes.MAX_CONCURRENT_STREAMS + ) + if max_concurrent_streams: + new_max_streams = min( + max_concurrent_streams.new_value, + self._h2_state.local_settings.max_concurrent_streams, + ) + if new_max_streams and new_max_streams != self._max_streams: + while new_max_streams > self._max_streams: + await self._max_streams_semaphore.release() + self._max_streams += 1 + while new_max_streams < self._max_streams: + await self._max_streams_semaphore.acquire() + self._max_streams -= 1 + + async def _response_closed(self, stream_id: int) -> None: + await self._max_streams_semaphore.release() + del self._events[stream_id] + async with self._state_lock: + if self._connection_terminated and not self._events: + await self.aclose() + + elif self._state == HTTPConnectionState.ACTIVE and not self._events: + self._state = HTTPConnectionState.IDLE + if self._keepalive_expiry is not None: + now = time.monotonic() + self._expire_at = now + self._keepalive_expiry + if self._used_all_stream_ids: # pragma: nocover + await self.aclose() + + async def aclose(self) -> None: + # Note that this method unilaterally closes the connection, and does + # not have any kind of locking in place around it. + self._h2_state.close_connection() + self._state = HTTPConnectionState.CLOSED + await self._network_stream.aclose() + + # Wrappers around network read/write operations... + + async def _read_incoming_data(self, request: Request) -> list[h2.events.Event]: + timeouts = request.extensions.get("timeout", {}) + timeout = timeouts.get("read", None) + + if self._read_exception is not None: + raise self._read_exception # pragma: nocover + + try: + data = await self._network_stream.read(self.READ_NUM_BYTES, timeout) + if data == b"": + raise RemoteProtocolError("Server disconnected") + except Exception as exc: + # If we get a network error we should: + # + # 1. Save the exception and just raise it immediately on any future reads. + # (For example, this means that a single read timeout or disconnect will + # immediately close all pending streams. Without requiring multiple + # sequential timeouts.) + # 2. Mark the connection as errored, so that we don't accept any other + # incoming requests. + self._read_exception = exc + self._connection_error = True + raise exc + + events: list[h2.events.Event] = self._h2_state.receive_data(data) + + return events + + async def _write_outgoing_data(self, request: Request) -> None: + timeouts = request.extensions.get("timeout", {}) + timeout = timeouts.get("write", None) + + async with self._write_lock: + data_to_send = self._h2_state.data_to_send() + + if self._write_exception is not None: + raise self._write_exception # pragma: nocover + + try: + await self._network_stream.write(data_to_send, timeout) + except Exception as exc: # pragma: nocover + # If we get a network error we should: + # + # 1. Save the exception and just raise it immediately on any future write. + # (For example, this means that a single write timeout or disconnect will + # immediately close all pending streams. Without requiring multiple + # sequential timeouts.) + # 2. Mark the connection as errored, so that we don't accept any other + # incoming requests. + self._write_exception = exc + self._connection_error = True + raise exc + + # Flow control... + + async def _wait_for_outgoing_flow(self, request: Request, stream_id: int) -> int: + """ + Returns the maximum allowable outgoing flow for a given stream. + + If the allowable flow is zero, then waits on the network until + WindowUpdated frames have increased the flow rate. + https://tools.ietf.org/html/rfc7540#section-6.9 + """ + local_flow: int = self._h2_state.local_flow_control_window(stream_id) + max_frame_size: int = self._h2_state.max_outbound_frame_size + flow = min(local_flow, max_frame_size) + while flow == 0: + await self._receive_events(request) + local_flow = self._h2_state.local_flow_control_window(stream_id) + max_frame_size = self._h2_state.max_outbound_frame_size + flow = min(local_flow, max_frame_size) + return flow + + # Interface for connection pooling... + + def can_handle_request(self, origin: Origin) -> bool: + return origin == self._origin + + def is_available(self) -> bool: + return ( + self._state != HTTPConnectionState.CLOSED + and not self._connection_error + and not self._used_all_stream_ids + and not ( + self._h2_state.state_machine.state + == h2.connection.ConnectionState.CLOSED + ) + ) + + def has_expired(self) -> bool: + now = time.monotonic() + return self._expire_at is not None and now > self._expire_at + + def is_idle(self) -> bool: + return self._state == HTTPConnectionState.IDLE + + def is_closed(self) -> bool: + return self._state == HTTPConnectionState.CLOSED + + def info(self) -> str: + origin = str(self._origin) + return ( + f"{origin!r}, HTTP/2, {self._state.name}, " + f"Request Count: {self._request_count}" + ) + + def __repr__(self) -> str: + class_name = self.__class__.__name__ + origin = str(self._origin) + return ( + f"<{class_name} [{origin!r}, {self._state.name}, " + f"Request Count: {self._request_count}]>" + ) + + # These context managers are not used in the standard flow, but are + # useful for testing or working with connection instances directly. + + async def __aenter__(self) -> AsyncHTTP2Connection: + return self + + async def __aexit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + await self.aclose() + + +class HTTP2ConnectionByteStream: + def __init__( + self, connection: AsyncHTTP2Connection, request: Request, stream_id: int + ) -> None: + self._connection = connection + self._request = request + self._stream_id = stream_id + self._closed = False + + async def __aiter__(self) -> typing.AsyncIterator[bytes]: + kwargs = {"request": self._request, "stream_id": self._stream_id} + try: + async with Trace("receive_response_body", logger, self._request, kwargs): + async for chunk in self._connection._receive_response_body( + request=self._request, stream_id=self._stream_id + ): + yield chunk + except BaseException as exc: + # If we get an exception while streaming the response, + # we want to close the response (and possibly the connection) + # before raising that exception. + with AsyncShieldCancellation(): + await self.aclose() + raise exc + + async def aclose(self) -> None: + if not self._closed: + self._closed = True + kwargs = {"stream_id": self._stream_id} + async with Trace("response_closed", logger, self._request, kwargs): + await self._connection._response_closed(stream_id=self._stream_id) |