forked from phoenix-oss/llama-stack-mirror
0fdb15bcc7
# What does this PR do? This fixes the build error ## Test Plan pre-commit run --all-files check for merge conflicts................................................Passed trim trailing whitespace.................................................Passed check for added large files..............................................Passed fix end of files.........................................................Passed Insert license in comments...............................................Passed ruff.....................................................................Passed ruff-format..............................................................Passed blacken-docs.............................................................Passed uv-lock..................................................................Passed uv-export................................................................Passed mypy.....................................................................Passed Distribution Template Codegen............................................Passed
33 lines
1.1 KiB
Python
33 lines
1.1 KiB
Python
# Copyright (c) Meta Platforms, Inc. and affiliates.
|
|
# All rights reserved.
|
|
#
|
|
# This source code is licensed under the terms described in the LICENSE file in
|
|
# the root directory of this source tree.
|
|
|
|
from contextvars import ContextVar
|
|
from typing import AsyncGenerator, List, TypeVar
|
|
|
|
T = TypeVar("T")
|
|
|
|
|
|
def preserve_contexts_async_generator(
|
|
gen: AsyncGenerator[T, None], context_vars: List[ContextVar]
|
|
) -> AsyncGenerator[T, None]:
|
|
"""
|
|
Wraps an async generator to preserve context variables across iterations.
|
|
This is needed because we start a new asyncio event loop for each streaming request,
|
|
and we need to preserve the context across the event loop boundary.
|
|
"""
|
|
|
|
async def wrapper() -> AsyncGenerator[T, None]:
|
|
while True:
|
|
try:
|
|
item = await gen.__anext__()
|
|
context_values = {context_var.name: context_var.get() for context_var in context_vars}
|
|
yield item
|
|
for context_var in context_vars:
|
|
_ = context_var.set(context_values[context_var.name])
|
|
except StopAsyncIteration:
|
|
break
|
|
|
|
return wrapper()
|