mirror of
https://github.com/langchain-ai/langgraph.git
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William FHandGitHub
4875973ac5
Right now requires that the file be in one of the local packages/dependencies.
63 lines
1.7 KiB
Python
63 lines
1.7 KiB
Python
from contextlib import asynccontextmanager
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from contextvars import ContextVar
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from typing import Any
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from starlette.applications import Starlette
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from starlette.middleware.base import BaseHTTPMiddleware
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from starlette.responses import JSONResponse
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from starlette.routing import Route
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my_context_var: ContextVar[str] = ContextVar("my_context_var", default="")
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LIFESPAN_VAL = ""
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other_context_var = ContextVar("other_context_var", default="")
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@asynccontextmanager
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async def my_lifespan(app):
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global LIFESPAN_VAL
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LIFESPAN_VAL = "foobar-lifespan"
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yield
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assert LIFESPAN_VAL == "foobar-lifespan"
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LIFESPAN_VAL = ""
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class MyContextMiddleware(BaseHTTPMiddleware):
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async def dispatch(self, request: Any, call_next: Any) -> Any:
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token = my_context_var.set("Foobar")
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try:
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response = await call_next(request)
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return response
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finally:
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my_context_var.reset(token)
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async def custom_my_route(request):
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"""A great route."""
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assert my_context_var.get() == "Foobar"
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assert LIFESPAN_VAL == "foobar-lifespan"
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return JSONResponse({"foo": "bar"})
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async def runs_afakeroute(request):
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"""Another great route."""
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assert my_context_var.get() == "Foobar"
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assert LIFESPAN_VAL == "foobar-lifespan"
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return JSONResponse({"foo": "afakeroute"})
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async def other_middleware(request: Any, call_next: Any) -> Any:
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other_context_var.set("foobar")
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response = await call_next(request)
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other_context_var.reset()
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return response
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app = Starlette(
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middleware=[(MyContextMiddleware, {}, {})],
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routes=[
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Route("/custom/my-route", custom_my_route),
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Route("/runs/afakeroute", runs_afakeroute),
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],
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lifespan=my_lifespan,
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)
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