Files
FabledScribe/src/fabledassistant/services/generation_buffer.py
T
bvandeusen 815eed2574 Add tool confirmation UI with Accept/Decline for write operations
Before executing any write tool (create/update/delete), the backend now
pauses with an asyncio.Future and emits a tool_pending SSE event. The
frontend displays a ToolConfirmCard with Accept and Decline buttons.
Clicking Accept resolves the Future and proceeds; Decline records a
declined tool_call chip and falls through to regular streaming. Typing
single-word yes/no responses (e.g. "yes", "cancel") also works as
confirmation. 120s timeout auto-declines if no response.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-02-18 20:43:47 -05:00

136 lines
4.3 KiB
Python

"""In-memory generation event buffer for SSE fan-out.
Each active generation gets a GenerationBuffer keyed by conversation_id.
SSE clients tail the buffer and can reconnect at any point without data loss.
"""
import asyncio
import json
import logging
import time
from dataclasses import dataclass, field
from enum import Enum
logger = logging.getLogger(__name__)
class GenerationState(str, Enum):
RUNNING = "running"
COMPLETED = "completed"
ERRORED = "errored"
@dataclass
class SSEEvent:
index: int
event_type: str # "context", "chunk", "done", "error"
data: dict
@dataclass
class GenerationBuffer:
conversation_id: int
assistant_message_id: int
state: GenerationState = GenerationState.RUNNING
events: list[SSEEvent] = field(default_factory=list)
content_so_far: str = ""
finished_at: float | None = None
cancel_event: asyncio.Event = field(default_factory=asyncio.Event)
_notify: asyncio.Event = field(default_factory=asyncio.Event)
# Tool confirmation — set when a write tool is awaiting user approval
confirmation_future: asyncio.Future | None = None
pending_tool: dict | None = None
def append_event(self, event_type: str, data: dict) -> SSEEvent:
event = SSEEvent(index=len(self.events), event_type=event_type, data=data)
self.events.append(event)
# Wake all waiting SSE clients, then reset for next wait
old = self._notify
self._notify = asyncio.Event()
old.set()
return event
async def wait_for_event(self, after_index: int, timeout: float = 30.0) -> bool:
"""Wait until there are events beyond after_index. Returns True if new events exist."""
if after_index + 1 < len(self.events):
return True
try:
await asyncio.wait_for(self._notify.wait(), timeout=timeout)
return True
except asyncio.TimeoutError:
return False
def events_after(self, index: int) -> list[SSEEvent]:
"""Return events with index > given index (for replay on reconnect)."""
start = index + 1
if start >= len(self.events):
return []
return self.events[start:]
@staticmethod
def format_sse(event: SSEEvent) -> str:
return f"id: {event.index}\nevent: {event.event_type}\ndata: {json.dumps(event.data)}\n\n"
# Module-level singleton registry
_buffers: dict[int | str, GenerationBuffer] = {}
_cleanup_task: asyncio.Task | None = None
_GRACE_PERIOD = 60.0 # seconds to keep completed buffers
def create_buffer(conv_id: int, msg_id: int) -> GenerationBuffer:
existing = _buffers.get(conv_id)
if existing and existing.state == GenerationState.RUNNING:
raise RuntimeError(f"Generation already running for conversation {conv_id}")
buf = GenerationBuffer(conversation_id=conv_id, assistant_message_id=msg_id)
_buffers[conv_id] = buf
return buf
def get_buffer(conv_id: int) -> GenerationBuffer | None:
return _buffers.get(conv_id)
def remove_buffer(conv_id: int) -> None:
_buffers.pop(conv_id, None)
def create_assist_buffer(user_id: int) -> GenerationBuffer:
key = f"assist:{user_id}"
existing = _buffers.get(key)
if existing and existing.state == GenerationState.RUNNING:
raise RuntimeError(f"Assist generation already running for user {user_id}")
buf = GenerationBuffer(conversation_id=0, assistant_message_id=0)
_buffers[key] = buf
return buf
def get_assist_buffer(user_id: int) -> GenerationBuffer | None:
return _buffers.get(f"assist:{user_id}")
def remove_assist_buffer(user_id: int) -> None:
_buffers.pop(f"assist:{user_id}", None)
async def _cleanup_loop() -> None:
"""Remove completed/errored buffers after grace period."""
while True:
await asyncio.sleep(15)
now = time.monotonic()
to_remove = [
key for key, buf in _buffers.items()
if buf.state != GenerationState.RUNNING
and buf.finished_at is not None
and now - buf.finished_at > _GRACE_PERIOD
]
for key in to_remove:
_buffers.pop(key, None)
logger.debug("Cleaned up generation buffer for key %s", key)
def start_cleanup_loop() -> None:
global _cleanup_task
if _cleanup_task is None or _cleanup_task.done():
_cleanup_task = asyncio.create_task(_cleanup_loop())