wrolpi/modules/docs
lrnselfreliance 97a6566e3d
Fix API stalls: non-blocking switch worker, threaded searches, indexed Videos page (#678)
* Fix API stalls: non-blocking switch worker, threaded searches, indexed Videos page

Three response-time fixes found by benchmarking the read-only API endpoints
hot and cold on real libraries:

* `switch_worker` runs on the Sanic worker's event loop every 0.1s and called
  the blocking `multiprocessing.Event.wait(timeout=1)`.  With no switch pending
  (the normal state) this froze the loop for a second at a time; about a third
  of all requests, including trivial ones, took ~1,000 ms.  It now polls
  `is_set()` and returns immediately.

* The search handlers (videos, files, archives, docs, zims) and `/api/statistics`
  ran synchronous SQLite queries on the event loop, so one slow search stalled
  every other request on that worker.  They now run via `asyncio.to_thread`.

* The unfiltered Videos page (`POST /api/videos/search` with only an order)
  used `mimetype LIKE 'video/%' OR ...` plus `COUNT(*) OVER()`, which visits
  every video's index entry before LIMIT applies: seconds cold on a large
  library on a spinning disk, and ~10 s hot for a deep page.  It now seeks each
  exact mimetype on the (mimetype, effective_datetime) index for `limit + offset`
  rows and merges them, with the total from a separate count cached for 60 s.
  Results are identical to the generic query.

Also adds `scripts/api_perf.py` (times every read-only endpoint against a host,
optionally restarting the API over SSH for cold numbers) and
`scripts/api_perf_compare.py` (merges per-host results).  Host profiles live in a
gitignored JSON file; an example is included.

Measured on an 8-core docker host with a 10 GB library: median hot request
1,007 ms -> 22 ms; Videos page 1 hot 287 -> 108 ms, page 50 1,345 -> 120 ms.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Serve the video description from its own endpoint instead of Video.__json__

`Video.__json__` computed `description` as `c_text or get_video_description()`,
where the fallback opens and parses the video's info json from disk.  The list
endpoints serialize every result with `__json__`, so any page containing videos
without an indexed description (common: many videos have none) read their info
json files on every request, cold, for a field the list never displays.  The
description is not part of search either: search runs against the FTS copy of
`c_text`, so the fallback never fed the index.

Drop `description` from `__json__` and serve it from
`GET /api/videos/<id>/description`, like comments and captions.  The endpoint
returns the indexed `c_text`, falling back to the info json only there, for a
row indexed before descriptions were stored.  The player page fetches it through
`useVideoExtras` alongside the comments.

Tests assert the list and detail responses never touch the info json, and cover
the endpoint's indexed, fallback, and not-found cases.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Address review: thread-local zim sessions, fast-path equivalence test, comments

* Zim search, single-zim search, and search estimates run libzim off the event
  loop, each opening its own session inside the worker thread rather than
  passing the request's SQLAlchemy Session across threads.
* The Videos fast-path test now runs the same requests through the generic
  query and asserts identical rows and paging for both date orders.  The one
  intentional difference is documented: past the end, the fast path still
  reports the true total.
* switch_worker returns before its try block so the empty path does not clear
  the event; its comment states the invariant only.  The copied "synchronous
  SQLite" comments are reduced to one line in one place.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-29 16:17:53 -06:00
..
test Make doc_modeler resilient to SQLite "database is locked" 2026-07-20 13:44:27 -06:00
__init__.py Make doc_modeler resilient to SQLite "database is locked" 2026-07-20 13:44:27 -06:00
api.py Fix API stalls: non-blocking switch worker, threaded searches, indexed Videos page (#678) 2026-08-29 16:17:53 -06:00
conftest.py Add Docs module for searching and organizing PDFs and EPUBs 2026-03-20 14:17:06 -06:00
extractors.py Adding simple search to epub viewer. 2026-04-13 17:23:20 -06:00
lib.py Postgres -> SQLite hard cutover: the database moves into the media directory. 2026-07-12 14:09:37 -06:00
models.py Postgres -> SQLite hard cutover: the database moves into the media directory. 2026-07-12 14:09:37 -06:00
schema.py Search: fast ABC mode by default, opt-in deep search 2026-07-03 10:32:16 -06:00