two version of R2R are here HEAD master

1 files changed, 220 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/starlette/middleware/base.py b/.venv/lib/python3.12/site-packages/starlette/middleware/base.py
new file mode 100644
index 00000000..2a59337e
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/starlette/middleware/base.py
@@ -0,0 +1,220 @@
+from __future__ import annotations
+
+import typing
+
+import anyio
+
+from starlette._utils import collapse_excgroups
+from starlette.requests import ClientDisconnect, Request
+from starlette.responses import AsyncContentStream, Response
+from starlette.types import ASGIApp, Message, Receive, Scope, Send
+
+RequestResponseEndpoint = typing.Callable[[Request], typing.Awaitable[Response]]
+DispatchFunction = typing.Callable[[Request, RequestResponseEndpoint], typing.Awaitable[Response]]
+T = typing.TypeVar("T")
+
+
+class _CachedRequest(Request):
+    """
+    If the user calls Request.body() from their dispatch function
+    we cache the entire request body in memory and pass that to downstream middlewares,
+    but if they call Request.stream() then all we do is send an
+    empty body so that downstream things don't hang forever.
+    """
+
+    def __init__(self, scope: Scope, receive: Receive):
+        super().__init__(scope, receive)
+        self._wrapped_rcv_disconnected = False
+        self._wrapped_rcv_consumed = False
+        self._wrapped_rc_stream = self.stream()
+
+    async def wrapped_receive(self) -> Message:
+        # wrapped_rcv state 1: disconnected
+        if self._wrapped_rcv_disconnected:
+            # we've already sent a disconnect to the downstream app
+            # we don't need to wait to get another one
+            # (although most ASGI servers will just keep sending it)
+            return {"type": "http.disconnect"}
+        # wrapped_rcv state 1: consumed but not yet disconnected
+        if self._wrapped_rcv_consumed:
+            # since the downstream app has consumed us all that is left
+            # is to send it a disconnect
+            if self._is_disconnected:
+                # the middleware has already seen the disconnect
+                # since we know the client is disconnected no need to wait
+                # for the message
+                self._wrapped_rcv_disconnected = True
+                return {"type": "http.disconnect"}
+            # we don't know yet if the client is disconnected or not
+            # so we'll wait until we get that message
+            msg = await self.receive()
+            if msg["type"] != "http.disconnect":  # pragma: no cover
+                # at this point a disconnect is all that we should be receiving
+                # if we get something else, things went wrong somewhere
+                raise RuntimeError(f"Unexpected message received: {msg['type']}")
+            self._wrapped_rcv_disconnected = True
+            return msg
+
+        # wrapped_rcv state 3: not yet consumed
+        if getattr(self, "_body", None) is not None:
+            # body() was called, we return it even if the client disconnected
+            self._wrapped_rcv_consumed = True
+            return {
+                "type": "http.request",
+                "body": self._body,
+                "more_body": False,
+            }
+        elif self._stream_consumed:
+            # stream() was called to completion
+            # return an empty body so that downstream apps don't hang
+            # waiting for a disconnect
+            self._wrapped_rcv_consumed = True
+            return {
+                "type": "http.request",
+                "body": b"",
+                "more_body": False,
+            }
+        else:
+            # body() was never called and stream() wasn't consumed
+            try:
+                stream = self.stream()
+                chunk = await stream.__anext__()
+                self._wrapped_rcv_consumed = self._stream_consumed
+                return {
+                    "type": "http.request",
+                    "body": chunk,
+                    "more_body": not self._stream_consumed,
+                }
+            except ClientDisconnect:
+                self._wrapped_rcv_disconnected = True
+                return {"type": "http.disconnect"}
+
+
+class BaseHTTPMiddleware:
+    def __init__(self, app: ASGIApp, dispatch: DispatchFunction | None = None) -> None:
+        self.app = app
+        self.dispatch_func = self.dispatch if dispatch is None else dispatch
+
+    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        if scope["type"] != "http":
+            await self.app(scope, receive, send)
+            return
+
+        request = _CachedRequest(scope, receive)
+        wrapped_receive = request.wrapped_receive
+        response_sent = anyio.Event()
+        app_exc: Exception | None = None
+
+        async def call_next(request: Request) -> Response:
+            async def receive_or_disconnect() -> Message:
+                if response_sent.is_set():
+                    return {"type": "http.disconnect"}
+
+                async with anyio.create_task_group() as task_group:
+
+                    async def wrap(func: typing.Callable[[], typing.Awaitable[T]]) -> T:
+                        result = await func()
+                        task_group.cancel_scope.cancel()
+                        return result
+
+                    task_group.start_soon(wrap, response_sent.wait)
+                    message = await wrap(wrapped_receive)
+
+                if response_sent.is_set():
+                    return {"type": "http.disconnect"}
+
+                return message
+
+            async def send_no_error(message: Message) -> None:
+                try:
+                    await send_stream.send(message)
+                except anyio.BrokenResourceError:
+                    # recv_stream has been closed, i.e. response_sent has been set.
+                    return
+
+            async def coro() -> None:
+                nonlocal app_exc
+
+                with send_stream:
+                    try:
+                        await self.app(scope, receive_or_disconnect, send_no_error)
+                    except Exception as exc:
+                        app_exc = exc
+
+            task_group.start_soon(coro)
+
+            try:
+                message = await recv_stream.receive()
+                info = message.get("info", None)
+                if message["type"] == "http.response.debug" and info is not None:
+                    message = await recv_stream.receive()
+            except anyio.EndOfStream:
+                if app_exc is not None:
+                    raise app_exc
+                raise RuntimeError("No response returned.")
+
+            assert message["type"] == "http.response.start"
+
+            async def body_stream() -> typing.AsyncGenerator[bytes, None]:
+                async for message in recv_stream:
+                    assert message["type"] == "http.response.body"
+                    body = message.get("body", b"")
+                    if body:
+                        yield body
+                    if not message.get("more_body", False):
+                        break
+
+            response = _StreamingResponse(status_code=message["status"], content=body_stream(), info=info)
+            response.raw_headers = message["headers"]
+            return response
+
+        streams: anyio.create_memory_object_stream[Message] = anyio.create_memory_object_stream()
+        send_stream, recv_stream = streams
+        with recv_stream, send_stream, collapse_excgroups():
+            async with anyio.create_task_group() as task_group:
+                response = await self.dispatch_func(request, call_next)
+                await response(scope, wrapped_receive, send)
+                response_sent.set()
+                recv_stream.close()
+
+        if app_exc is not None:
+            raise app_exc
+
+    async def dispatch(self, request: Request, call_next: RequestResponseEndpoint) -> Response:
+        raise NotImplementedError()  # pragma: no cover
+
+
+class _StreamingResponse(Response):
+    def __init__(
+        self,
+        content: AsyncContentStream,
+        status_code: int = 200,
+        headers: typing.Mapping[str, str] | None = None,
+        media_type: str | None = None,
+        info: typing.Mapping[str, typing.Any] | None = None,
+    ) -> None:
+        self.info = info
+        self.body_iterator = content
+        self.status_code = status_code
+        self.media_type = media_type
+        self.init_headers(headers)
+        self.background = None
+
+    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        if self.info is not None:
+            await send({"type": "http.response.debug", "info": self.info})
+        await send(
+            {
+                "type": "http.response.start",
+                "status": self.status_code,
+                "headers": self.raw_headers,
+            }
+        )
+
+        async for chunk in self.body_iterator:
+            await send({"type": "http.response.body", "body": chunk, "more_body": True})
+
+        await send({"type": "http.response.body", "body": b"", "more_body": False})
+
+        if self.background:
+            await self.background()