refactor: move background_streaming_task to separate module

- Create new background_streaming.py in response_polling/
- Update endpoints.py to import from new location
- Update __init__.py to export background_streaming_task
- Add tests for module imports and structure

Committed-By-Agent: cursor
This commit is contained in:
Xianzong Xie
2025-12-03 22:50:26 -08:00
parent c464af4c15
commit 1c3c12bb1b
4 changed files with 307 additions and 248 deletions
@@ -1,5 +1,4 @@
import asyncio
import json
from fastapi import APIRouter, Depends, HTTPException, Request, Response
@@ -11,250 +10,6 @@ from litellm.proxy.common_request_processing import ProxyBaseLLMRequestProcessin
router = APIRouter()
async def _background_streaming_task( # noqa: PLR0915
polling_id: str,
data: dict,
polling_handler,
request: Request,
fastapi_response: Response,
user_api_key_dict: UserAPIKeyAuth,
general_settings: dict,
llm_router,
proxy_config,
proxy_logging_obj,
select_data_generator,
user_model,
user_temperature,
user_request_timeout,
user_max_tokens,
user_api_base,
version,
):
"""
Background task to stream response and update cache
Follows OpenAI Response Streaming format:
https://platform.openai.com/docs/api-reference/responses-streaming
Processes streaming events and builds Response object:
https://platform.openai.com/docs/api-reference/responses/object
"""
try:
verbose_proxy_logger.info(f"Starting background streaming for {polling_id}")
# Update status to in_progress (OpenAI format)
await polling_handler.update_state(
polling_id=polling_id,
status="in_progress",
)
# Force streaming mode and remove background flag
data["stream"] = True
data.pop("background", None)
# Create processor
processor = ProxyBaseLLMRequestProcessing(data=data)
# Make streaming request
response = await processor.base_process_llm_request(
request=request,
fastapi_response=fastapi_response,
user_api_key_dict=user_api_key_dict,
route_type="aresponses",
proxy_logging_obj=proxy_logging_obj,
llm_router=llm_router,
general_settings=general_settings,
proxy_config=proxy_config,
select_data_generator=select_data_generator,
model=None,
user_model=user_model,
user_temperature=user_temperature,
user_request_timeout=user_request_timeout,
user_max_tokens=user_max_tokens,
user_api_base=user_api_base,
version=version,
)
# Process streaming response following OpenAI events format
# https://platform.openai.com/docs/api-reference/responses-streaming
output_items = {} # Track output items by ID
accumulated_text = {} # Track accumulated text deltas by (item_id, content_index)
usage_data = None
reasoning_data = None
tool_choice_data = None
tools_data = None
state_dirty = False # Track if state needs to be synced
last_update_time = asyncio.get_event_loop().time()
UPDATE_INTERVAL = 0.150 # 150ms batching interval
async def flush_state_if_needed(force: bool = False) -> None:
"""Flush accumulated state to Redis if interval elapsed or forced"""
nonlocal state_dirty, last_update_time
current_time = asyncio.get_event_loop().time()
if state_dirty and (force or (current_time - last_update_time) >= UPDATE_INTERVAL):
# Convert output_items dict to list for update
output_list = list(output_items.values())
await polling_handler.update_state(
polling_id=polling_id,
output=output_list,
)
state_dirty = False
last_update_time = current_time
# Handle StreamingResponse
if hasattr(response, 'body_iterator'):
async for chunk in response.body_iterator:
# Parse chunk
if isinstance(chunk, bytes):
chunk = chunk.decode('utf-8')
if isinstance(chunk, str) and chunk.startswith("data: "):
chunk_data = chunk[6:].strip()
if chunk_data == "[DONE]":
break
try:
event = json.loads(chunk_data)
event_type = event.get("type", "")
# Process different event types based on OpenAI streaming spec
if event_type == "response.output_item.added":
# New output item added
item = event.get("item", {})
item_id = item.get("id")
if item_id:
output_items[item_id] = item
state_dirty = True
elif event_type == "response.content_part.added":
# Content part added to an output item
item_id = event.get("item_id")
content_part = event.get("part", {})
if item_id and item_id in output_items:
# Update the output item with new content
if "content" not in output_items[item_id]:
output_items[item_id]["content"] = []
output_items[item_id]["content"].append(content_part)
state_dirty = True
elif event_type == "response.output_text.delta":
# Text delta - accumulate text content
# https://platform.openai.com/docs/api-reference/responses-streaming/response-text-delta
item_id = event.get("item_id")
content_index = event.get("content_index", 0)
delta = event.get("delta", "")
if item_id and item_id in output_items:
# Accumulate text delta
key = (item_id, content_index)
if key not in accumulated_text:
accumulated_text[key] = ""
accumulated_text[key] += delta
# Update the content in output_items
if "content" in output_items[item_id]:
content_list = output_items[item_id]["content"]
if content_index < len(content_list):
# Update existing content part with accumulated text
if isinstance(content_list[content_index], dict):
content_list[content_index]["text"] = accumulated_text[key]
state_dirty = True
elif event_type == "response.content_part.done":
# Content part completed
item_id = event.get("item_id")
content_part = event.get("part", {})
content_index = event.get("content_index", 0)
if item_id and item_id in output_items:
# Update with final content from event
if "content" in output_items[item_id]:
content_list = output_items[item_id]["content"]
if content_index < len(content_list):
content_list[content_index] = content_part
state_dirty = True
elif event_type == "response.output_item.done":
# Output item completed - use final item data
item = event.get("item", {})
item_id = item.get("id")
if item_id:
output_items[item_id] = item
state_dirty = True
elif event_type == "response.in_progress":
# Response is now in progress
# https://platform.openai.com/docs/api-reference/responses-streaming/response-in-progress
await polling_handler.update_state(
polling_id=polling_id,
status="in_progress",
)
elif event_type == "response.completed":
# Response completed - includes usage, reasoning, tools, tool_choice
# https://platform.openai.com/docs/api-reference/responses-streaming/response-completed
response_data = event.get("response", {})
usage_data = response_data.get("usage")
reasoning_data = response_data.get("reasoning")
tool_choice_data = response_data.get("tool_choice")
tools_data = response_data.get("tools")
# Also update output from final response if available
if "output" in response_data:
final_output = response_data.get("output", [])
for item in final_output:
item_id = item.get("id")
if item_id:
output_items[item_id] = item
state_dirty = True
# Flush state to Redis if interval elapsed
await flush_state_if_needed()
except json.JSONDecodeError as e:
verbose_proxy_logger.warning(
f"Failed to parse streaming chunk: {e}"
)
pass
# Final flush to ensure all accumulated state is saved
await flush_state_if_needed(force=True)
# Mark as completed with all response data
await polling_handler.update_state(
polling_id=polling_id,
status="completed",
usage=usage_data,
reasoning=reasoning_data,
tool_choice=tool_choice_data,
tools=tools_data,
)
verbose_proxy_logger.info(
f"Completed background streaming for {polling_id}, output_items={len(output_items)}"
)
except Exception as e:
verbose_proxy_logger.error(
f"Error in background streaming task for {polling_id}: {str(e)}"
)
import traceback
verbose_proxy_logger.error(traceback.format_exc())
await polling_handler.update_state(
polling_id=polling_id,
status="failed",
error={
"type": "internal_error",
"message": str(e),
"code": "background_streaming_error"
},
)
@router.post(
"/v1/responses",
dependencies=[Depends(user_api_key_auth)],
@@ -346,6 +101,9 @@ async def responses_api(
from litellm.proxy.response_polling.polling_handler import (
ResponsePollingHandler,
)
from litellm.proxy.response_polling.background_streaming import (
background_streaming_task,
)
verbose_proxy_logger.info(
f"Starting background response with polling for model={data.get('model')}"
@@ -367,9 +125,8 @@ async def responses_api(
)
# Start background task to stream and update cache
import asyncio
asyncio.create_task(
_background_streaming_task(
background_streaming_task(
polling_id=polling_id,
data=data.copy(),
polling_handler=polling_handler,
+8 -1
View File
@@ -1,5 +1,12 @@
"""
Response Polling Module for Background Responses with Cache
"""
from litellm.proxy.response_polling.background_streaming import (
background_streaming_task,
)
from litellm.proxy.response_polling.polling_handler import ResponsePollingHandler
__all__ = [
"ResponsePollingHandler",
"background_streaming_task",
]
@@ -0,0 +1,263 @@
"""
Background Streaming Task for Polling Via Cache Feature
Handles streaming responses from LLM providers and updates Redis cache
with partial results for polling.
Follows OpenAI Response Streaming format:
https://platform.openai.com/docs/api-reference/responses-streaming
"""
import asyncio
import json
from fastapi import Request, Response
from litellm._logging import verbose_proxy_logger
from litellm.proxy.auth.user_api_key_auth import UserAPIKeyAuth
from litellm.proxy.common_request_processing import ProxyBaseLLMRequestProcessing
from litellm.proxy.response_polling.polling_handler import ResponsePollingHandler
async def background_streaming_task( # noqa: PLR0915
polling_id: str,
data: dict,
polling_handler: ResponsePollingHandler,
request: Request,
fastapi_response: Response,
user_api_key_dict: UserAPIKeyAuth,
general_settings: dict,
llm_router,
proxy_config,
proxy_logging_obj,
select_data_generator,
user_model,
user_temperature,
user_request_timeout,
user_max_tokens,
user_api_base,
version,
):
"""
Background task to stream response and update cache
Follows OpenAI Response Streaming format:
https://platform.openai.com/docs/api-reference/responses-streaming
Processes streaming events and builds Response object:
https://platform.openai.com/docs/api-reference/responses/object
"""
try:
verbose_proxy_logger.info(f"Starting background streaming for {polling_id}")
# Update status to in_progress (OpenAI format)
await polling_handler.update_state(
polling_id=polling_id,
status="in_progress",
)
# Force streaming mode and remove background flag
data["stream"] = True
data.pop("background", None)
# Create processor
processor = ProxyBaseLLMRequestProcessing(data=data)
# Make streaming request
response = await processor.base_process_llm_request(
request=request,
fastapi_response=fastapi_response,
user_api_key_dict=user_api_key_dict,
route_type="aresponses",
proxy_logging_obj=proxy_logging_obj,
llm_router=llm_router,
general_settings=general_settings,
proxy_config=proxy_config,
select_data_generator=select_data_generator,
model=None,
user_model=user_model,
user_temperature=user_temperature,
user_request_timeout=user_request_timeout,
user_max_tokens=user_max_tokens,
user_api_base=user_api_base,
version=version,
)
# Process streaming response following OpenAI events format
# https://platform.openai.com/docs/api-reference/responses-streaming
output_items = {} # Track output items by ID
accumulated_text = {} # Track accumulated text deltas by (item_id, content_index)
usage_data = None
reasoning_data = None
tool_choice_data = None
tools_data = None
state_dirty = False # Track if state needs to be synced
last_update_time = asyncio.get_event_loop().time()
UPDATE_INTERVAL = 0.150 # 150ms batching interval
async def flush_state_if_needed(force: bool = False) -> None:
"""Flush accumulated state to Redis if interval elapsed or forced"""
nonlocal state_dirty, last_update_time
current_time = asyncio.get_event_loop().time()
if state_dirty and (force or (current_time - last_update_time) >= UPDATE_INTERVAL):
# Convert output_items dict to list for update
output_list = list(output_items.values())
await polling_handler.update_state(
polling_id=polling_id,
output=output_list,
)
state_dirty = False
last_update_time = current_time
# Handle StreamingResponse
if hasattr(response, 'body_iterator'):
async for chunk in response.body_iterator:
# Parse chunk
if isinstance(chunk, bytes):
chunk = chunk.decode('utf-8')
if isinstance(chunk, str) and chunk.startswith("data: "):
chunk_data = chunk[6:].strip()
if chunk_data == "[DONE]":
break
try:
event = json.loads(chunk_data)
event_type = event.get("type", "")
# Process different event types based on OpenAI streaming spec
if event_type == "response.output_item.added":
# New output item added
item = event.get("item", {})
item_id = item.get("id")
if item_id:
output_items[item_id] = item
state_dirty = True
elif event_type == "response.content_part.added":
# Content part added to an output item
item_id = event.get("item_id")
content_part = event.get("part", {})
if item_id and item_id in output_items:
# Update the output item with new content
if "content" not in output_items[item_id]:
output_items[item_id]["content"] = []
output_items[item_id]["content"].append(content_part)
state_dirty = True
elif event_type == "response.output_text.delta":
# Text delta - accumulate text content
# https://platform.openai.com/docs/api-reference/responses-streaming/response-text-delta
item_id = event.get("item_id")
content_index = event.get("content_index", 0)
delta = event.get("delta", "")
if item_id and item_id in output_items:
# Accumulate text delta
key = (item_id, content_index)
if key not in accumulated_text:
accumulated_text[key] = ""
accumulated_text[key] += delta
# Update the content in output_items
if "content" in output_items[item_id]:
content_list = output_items[item_id]["content"]
if content_index < len(content_list):
# Update existing content part with accumulated text
if isinstance(content_list[content_index], dict):
content_list[content_index]["text"] = accumulated_text[key]
state_dirty = True
elif event_type == "response.content_part.done":
# Content part completed
item_id = event.get("item_id")
content_part = event.get("part", {})
content_index = event.get("content_index", 0)
if item_id and item_id in output_items:
# Update with final content from event
if "content" in output_items[item_id]:
content_list = output_items[item_id]["content"]
if content_index < len(content_list):
content_list[content_index] = content_part
state_dirty = True
elif event_type == "response.output_item.done":
# Output item completed - use final item data
item = event.get("item", {})
item_id = item.get("id")
if item_id:
output_items[item_id] = item
state_dirty = True
elif event_type == "response.in_progress":
# Response is now in progress
# https://platform.openai.com/docs/api-reference/responses-streaming/response-in-progress
await polling_handler.update_state(
polling_id=polling_id,
status="in_progress",
)
elif event_type == "response.completed":
# Response completed - includes usage, reasoning, tools, tool_choice
# https://platform.openai.com/docs/api-reference/responses-streaming/response-completed
response_data = event.get("response", {})
usage_data = response_data.get("usage")
reasoning_data = response_data.get("reasoning")
tool_choice_data = response_data.get("tool_choice")
tools_data = response_data.get("tools")
# Also update output from final response if available
if "output" in response_data:
final_output = response_data.get("output", [])
for item in final_output:
item_id = item.get("id")
if item_id:
output_items[item_id] = item
state_dirty = True
# Flush state to Redis if interval elapsed
await flush_state_if_needed()
except json.JSONDecodeError as e:
verbose_proxy_logger.warning(
f"Failed to parse streaming chunk: {e}"
)
pass
# Final flush to ensure all accumulated state is saved
await flush_state_if_needed(force=True)
# Mark as completed with all response data
await polling_handler.update_state(
polling_id=polling_id,
status="completed",
usage=usage_data,
reasoning=reasoning_data,
tool_choice=tool_choice_data,
tools=tools_data,
)
verbose_proxy_logger.info(
f"Completed background streaming for {polling_id}, output_items={len(output_items)}"
)
except Exception as e:
verbose_proxy_logger.error(
f"Error in background streaming task for {polling_id}: {str(e)}"
)
import traceback
verbose_proxy_logger.error(traceback.format_exc())
await polling_handler.update_state(
polling_id=polling_id,
status="failed",
error={
"type": "internal_error",
"message": str(e),
"code": "background_streaming_error"
},
)
@@ -528,3 +528,35 @@ class TestStreamingEventProcessing:
assert UPDATE_INTERVAL == 0.150
assert UPDATE_INTERVAL * 1000 == 150 # 150 milliseconds
class TestBackgroundStreamingModule:
"""Test cases for background_streaming module imports and structure"""
def test_background_streaming_task_can_be_imported(self):
"""Test that background_streaming_task can be imported from the module"""
from litellm.proxy.response_polling.background_streaming import (
background_streaming_task,
)
assert background_streaming_task is not None
assert callable(background_streaming_task)
def test_module_exports_from_init(self):
"""Test that the module exports are available from __init__"""
from litellm.proxy.response_polling import (
ResponsePollingHandler,
background_streaming_task,
)
assert ResponsePollingHandler is not None
assert background_streaming_task is not None
def test_background_streaming_task_is_async(self):
"""Test that background_streaming_task is an async function"""
import asyncio
from litellm.proxy.response_polling.background_streaming import (
background_streaming_task,
)
assert asyncio.iscoroutinefunction(background_streaming_task)