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grillazz
59 lines
1.8 KiB
Python
59 lines
1.8 KiB
Python
"""In-memory conversation/session management for the websocket chat service.
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Sessions are intentionally kept simple (a dict guarded by an ``asyncio.Lock``)
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since each websocket connection owns exactly one session for its lifetime.
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Swapping this for a Redis-backed store later (for multi-worker deployments)
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only requires changing this module; the websocket endpoint only depends on
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the small public API below.
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"""
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import asyncio
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from uuid import UUID, uuid4
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import attrs
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from app.schemas.chat import ChatMessage
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from app.utils.singleton import SingletonMetaNoArgs
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@attrs.define(slots=True)
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class ChatSession:
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id: UUID = attrs.field(factory=uuid4)
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messages: list[ChatMessage] = attrs.field(factory=list)
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def add(self, message: ChatMessage) -> None:
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self.messages.append(message)
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def history(self) -> list[ChatMessage]:
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return list(self.messages)
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class ChatSessionManager(metaclass=SingletonMetaNoArgs):
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"""Tracks active chat sessions keyed by their opaque session id.
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Implemented as a singleton to ensure exactly one instance per application,
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maintaining a consistent registry of all active websocket chat sessions.
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"""
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def __init__(self) -> None:
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self._sessions: dict[UUID, ChatSession] = {}
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self._lock = asyncio.Lock()
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async def create(self) -> ChatSession:
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session = ChatSession()
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async with self._lock:
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self._sessions[session.id] = session
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return session
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async def get(self, session_id: UUID) -> ChatSession | None:
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async with self._lock:
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return self._sessions.get(session_id)
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async def remove(self, session_id: UUID) -> None:
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async with self._lock:
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self._sessions.pop(session_id, None)
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async def count(self) -> int:
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async with self._lock:
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return len(self._sessions)
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