MemGPT/memgpt/server/rest_api/utils.py
2024-08-16 19:52:47 -07:00

61 lines
2.4 KiB
Python

import asyncio
import json
import traceback
from typing import AsyncGenerator, Generator, Union
from memgpt.constants import JSON_ENSURE_ASCII
SSE_FINISH_MSG = "[DONE]" # mimic openai
SSE_ARTIFICIAL_DELAY = 0.1
def sse_formatter(data: Union[dict, str]) -> str:
"""Prefix with 'data: ', and always include double newlines"""
assert type(data) in [dict, str], f"Expected type dict or str, got type {type(data)}"
data_str = json.dumps(data, ensure_ascii=JSON_ENSURE_ASCII) if isinstance(data, dict) else data
return f"data: {data_str}\n\n"
async def sse_generator(generator: Generator[dict, None, None]) -> Generator[str, None, None]:
"""Generator that returns 'data: dict' formatted items, e.g.:
data: {"id":"chatcmpl-9E0PdSZ2IBzAGlQ3SEWHJ5YwzucSP","object":"chat.completion.chunk","created":1713125205,"model":"gpt-4-0613","system_fingerprint":null,"choices":[{"index":0,"delta":{"tool_calls":[{"index":0,"function":{"arguments":"}"}}]},"logprobs":null,"finish_reason":null}]}
data: {"id":"chatcmpl-9E0PdSZ2IBzAGlQ3SEWHJ5YwzucSP","object":"chat.completion.chunk","created":1713125205,"model":"gpt-4-0613","system_fingerprint":null,"choices":[{"index":0,"delta":{},"logprobs":null,"finish_reason":"tool_calls"}]}
data: [DONE]
"""
try:
for msg in generator:
yield sse_formatter(msg)
if SSE_ARTIFICIAL_DELAY:
await asyncio.sleep(SSE_ARTIFICIAL_DELAY) # Sleep to prevent a tight loop, adjust time as needed
except Exception as e:
yield sse_formatter({"error": f"{str(e)}"})
yield sse_formatter(SSE_FINISH_MSG) # Signal that the stream is complete
async def sse_async_generator(generator: AsyncGenerator, finish_message=True):
"""
Wraps a generator for use in Server-Sent Events (SSE), handling errors and ensuring a completion message.
Args:
- generator: An asynchronous generator yielding data chunks.
Yields:
- Formatted Server-Sent Event strings.
"""
try:
async for chunk in generator:
# yield f"data: {json.dumps(chunk)}\n\n"
yield sse_formatter(chunk)
except Exception as e:
print("stream decoder hit error:", e)
print(traceback.print_stack())
yield sse_formatter({"error": "stream decoder encountered an error"})
finally:
# yield "data: [DONE]\n\n"
if finish_message:
yield sse_formatter(SSE_FINISH_MSG) # Signal that the stream is complete