MemGPT/letta/server/rest_api/utils.py
Sarah Wooders 85faf5f474
chore: migrate package name to letta (#1775)
Co-authored-by: Charles Packer <packercharles@gmail.com>
Co-authored-by: Shubham Naik <shubham.naik10@gmail.com>
Co-authored-by: Shubham Naik <shub@memgpt.ai>
2024-09-23 09:15:18 -07:00

70 lines
2.1 KiB
Python

import json
import traceback
from enum import Enum
from typing import AsyncGenerator, Union
from pydantic import BaseModel
from letta.server.rest_api.interface import StreamingServerInterface
from letta.server.server import SyncServer
# from letta.orm.user import User
# from letta.orm.utilities import get_db_session
SSE_PREFIX = "data: "
SSE_SUFFIX = "\n\n"
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, separators=(",", ":")) if isinstance(data, dict) else data
return f"data: {data_str}\n\n"
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"
if isinstance(chunk, BaseModel):
chunk = chunk.model_dump()
elif isinstance(chunk, Enum):
chunk = str(chunk.value)
elif not isinstance(chunk, dict):
chunk = str(chunk)
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:
if finish_message:
# Signal that the stream is complete
yield sse_formatter(SSE_FINISH_MSG)
# TODO: why does this double up the interface?
def get_letta_server() -> SyncServer:
# Check if a global server is already instantiated
from letta.server.rest_api.app import server
# assert isinstance(server, SyncServer)
return server
def get_current_interface() -> StreamingServerInterface:
return StreamingServerInterface