chainlit context 简单说明
context 实际上是一个基于ContextVar 包装的一个变量，可以进行一些上下文信息的共享，同时fastapi 与chainlit 的集成也是基于了context
ChainlitContext 定义
可以看到就是一个session ，emitter 以及active_steps 的包装，通过提供了current_step 以及 current_run 属性，这几个属性在关于step 的使用中比较常见
class ChainlitContext:
loop: asyncio.AbstractEventLoop
emitter: "BaseChainlitEmitter"
session: Union["HTTPSession", "WebsocketSession"]
active_steps: List["Step"]
@property
def current_step(self):
if self.active_steps:
return self.active_steps[-1]
@property
def current_run(self):
if self.active_steps:
return next(
(step for step in self.active_steps if step.name in CL_RUN_NAMES), None
)
def __init__(
self,
session: Union["HTTPSession", "WebsocketSession"],
emitter: Optional["BaseChainlitEmitter"] = None,
):
from chainlit.emitter import BaseChainlitEmitter, ChainlitEmitter
self.loop = asyncio.get_running_loop()
self.session = session
self.active_steps = []
if emitter:
self.emitter = emitter
elif isinstance(self.session, HTTPSession):
self.emitter = BaseChainlitEmitter(self.session)
elif isinstance(self.session, WebsocketSession):
self.emitter = ChainlitEmitter(self.session)
ChainlitContext 的集成
可以与fastapi 以及ws 集成, 都基于了python 的ContextVar
def init_ws_context(session_or_sid: Union[WebsocketSession, str]) -> ChainlitContext:
if not isinstance(session_or_sid, WebsocketSession):
session = WebsocketSession.require(session_or_sid)
else:
session = session_or_sid
context = ChainlitContext(session)
context_var.set(context)
return context
def init_http_context(
thread_id: Optional[str] = None,
user: Optional[Union["User", "PersistedUser"]] = None,
auth_token: Optional[str] = None,
user_env: Optional[Dict[str, str]] = None,
client_type: ClientType = "webapp",
) -> ChainlitContext:
from chainlit.data import get_data_layer
session_id = str(uuid.uuid4())
thread_id = thread_id or str(uuid.uuid4())
session = HTTPSession(
id=session_id,
thread_id=thread_id,
token=auth_token,
user=user,
client_type=client_type,
user_env=user_env,
)
context = ChainlitContext(session)
context_var.set(context)
if data_layer := get_data_layer():
if user_id := getattr(user, "id", None):
asyncio.create_task(
data_layer.update_thread(thread_id=thread_id, user_id=user_id)
)
return context
业务中的使用
刚才说的step 就是一种，如下图，实际还是不少的，包含了action，element，session，chat_context 等，一些场景需要基于context 使用session 、emitter等
参考资料
https://docs.chainlit.io/api-reference/step-decorator
https://docs.chainlit.io/api-reference/chat-profiles
https://docs.chainlit.io/concepts/step
