Files
dotfiles/python/ebook_search/api/bm25_tasks.py
T
Richie c7cd63f8e4 feat(ebook): migrate to async DB/HTTP and parallelize phrase pipeline
Convert the ebook-search web app to async end to end and add concurrency
to the protected-phrase extraction and judging pipeline so large books no
longer block the event loop or the UI.

ORM / infra:
- Add get_async_postgres_engine and factor shared URL/connect_args building
  into build_postgres_url (reused by the sync and async engine builders)
- Add async FastAPI session helpers (get_async_db, AsyncDbSession) with
  expire_on_commit=False to avoid implicit IO under asyncio

App:
- Use AsyncEngine/AsyncSession throughout routes, search, ingest, embeddings,
  answer, rerank and LLM calls; convert handlers to async
- Share a single httpx.AsyncClient in app state for LLM requests; size the
  connection pool for concurrent phrase-judging workers
- Add judge_tasks: run per-book judging as tracked background tasks so a
  book already being judged isn't double-queued

Protected phrases:
- Add a process pool (pool.py) and worker-count config
  (extraction/judge book/phrase workers) to parallelize candidate generation
  and judging
- Split admin actions into all/missing variants for generation and judging

Config:
- Add protected_phrase_extraction_workers, phrase_judge_book_workers,
  phrase_judge_phrase_workers
2026-07-09 11:04:59 -04:00

74 lines
2.5 KiB
Python

"""Background BM25 refresh tasks for the web app.
The refresh is scheduled on the event loop instead of a thread because the async psycopg
driver only works from the loop; a bare thread cannot open a session on the async engine.
"""
from __future__ import annotations
import asyncio
import logging
from typing import TYPE_CHECKING
from sqlalchemy.ext.asyncio import AsyncSession
from python.ebook_search.bm25_corpus import load_bm25_corpus, refresh_bm25_corpus
if TYPE_CHECKING:
from fastapi import FastAPI
from sqlalchemy.ext.asyncio import AsyncEngine
from python.ebook_search.config import EbookSearchConfig
logger = logging.getLogger(__name__)
def schedule_bm25_refresh(app: FastAPI) -> None:
"""Schedule a delayed BM25 corpus refresh, replacing any pending refresh.
Only called from route handlers, so a running event loop is guaranteed.
"""
cancel_bm25_refresh(app)
loop = asyncio.get_running_loop()
def start_refresh() -> None:
app.state.bm25_refresh_task = loop.create_task(refresh_bm25_for_app(app))
app.state.bm25_refresh_timer = loop.call_later(app.state.config.bm25_refresh_delay_seconds, start_refresh)
logger.info(
"ebook_bm25_refresh_scheduled delay_seconds=%s",
app.state.config.bm25_refresh_delay_seconds,
)
def cancel_bm25_refresh(app: FastAPI) -> None:
"""Cancel any pending BM25 corpus refresh timer and in-flight refresh task."""
existing_timer = getattr(app.state, "bm25_refresh_timer", None)
if existing_timer is not None:
existing_timer.cancel()
app.state.bm25_refresh_timer = None
logger.info("ebook_bm25_refresh_cancelled")
existing_task = getattr(app.state, "bm25_refresh_task", None)
if existing_task is not None:
if not existing_task.done():
existing_task.cancel()
app.state.bm25_refresh_task = None
async def refresh_bm25_for_app(app: FastAPI) -> None:
"""Refresh the BM25 corpus using the app engine and config."""
try:
await refresh_bm25_for_engine(app.state.engine, app.state.config)
except Exception:
logger.exception("ebook_bm25_refresh_failed")
async def refresh_bm25_for_engine(engine: AsyncEngine, config: EbookSearchConfig) -> None:
"""Refresh the BM25 corpus using an async SQLAlchemy engine."""
async with AsyncSession(engine) as session:
await refresh_bm25_corpus(session, config)
load_bm25_corpus.cache_clear()
logger.info("ebook_bm25_corpus_cache_cleared_after_refresh")