wrolpi/modules/zim/api.py
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

236 lines
7.5 KiB
Python

import asyncio
import urllib.parse
from http import HTTPStatus
from sanic import Request, response, Blueprint
from sanic_ext import validate
from sanic_ext.extensions.openapi import openapi
from wrolpi import lang
from wrolpi.api_utils import json_response
from wrolpi.common import logger
from wrolpi.db import get_db_session
from wrolpi.downloader import download_manager
from wrolpi.events import Events
from . import lib, schema
from .models import Zims
zim_bp = Blueprint('Zim', '/api/zim')
logger = logger.getChild(__name__)
@zim_bp.get('/')
@openapi.definition(
summary='List all known Zim files',
response=schema.GetZimsResponse,
)
async def get_zims(request: Request):
session = request.ctx.session
zims = lib.get_zims(session)
resp = {
'zims': [i.__json__() for i in zims],
}
return json_response(resp)
@zim_bp.delete('/<zim_ids:[0-9,]+>')
@openapi.definition(
summary='Delete all Zim files',
)
async def delete_zims(request: Request, zim_ids: str):
session = request.ctx.session
zim_ids = [int(i) for i in zim_ids.split(',')]
lib.delete_zims(session, zim_ids)
return response.empty()
@zim_bp.post('/<zim_id:[0-9]+>/auto_search')
@openapi.definition(
summary='Change if a Zim file will be searched by default.',
body=schema.ZimAutoSearchRequest,
)
@validate(schema.ZimAutoSearchRequest)
async def post_set_zim_auto_search(request: Request, zim_id: int, body: schema.ZimAutoSearchRequest):
session = request.ctx.session
zim_id = int(zim_id)
lib.set_zim_auto_search(session, zim_id, body.auto_search)
return response.empty()
@zim_bp.post('/search')
@openapi.definition(
summary='Search all Zim files that have auto_search enabled',
body=schema.ZimSearchRequest,
)
@validate(schema.ZimSearchRequest)
async def search_all_zims(_: Request, body: schema.ZimSearchRequest):
# libzim searches are synchronous and slow; run off the event loop. The session is opened in the
# worker thread: a SQLAlchemy Session must not be shared across threads.
def search():
with get_db_session() as session:
return lib.search_all_zims(session, body.search_str, tag_names=body.tag_names, offset=body.offset,
limit=body.limit)
results = await asyncio.to_thread(search)
return json_response({'zims': results})
@zim_bp.post('/search/<zim_id:[0-9]+>')
@openapi.definition(
summary='Search all entries of a Zim',
body=schema.ZimSearchRequest,
response=schema.ZimSearchResponse,
)
@validate(schema.ZimSearchRequest)
async def search_zim(_: Request, zim_id: int, body: schema.ZimSearchRequest):
def search():
with get_db_session() as session:
return lib.headline_zim(session, body.search_str, zim_id, tag_names=body.tag_names, offset=body.offset,
limit=body.limit)
headlines = await asyncio.to_thread(search)
return json_response({'zim': headlines})
@zim_bp.get('/<zim_id:[0-9]+>/entry/<zim_path:[ -~/]*>')
@openapi.definition(
summary='Read the entry at `zim_path` from the Zim file',
)
async def get_zim_entry(_: Request, zim_id: int, zim_path: str):
zim_path = urllib.parse.unquote(zim_path)
entry = lib.get_entry(zim_path, zim_id=zim_id)
content = bytes(entry.get_item().content)
try:
resp = response.html(content.decode('UTF-8'))
logger.debug(f'Returning ZIM HTML response {repr(str(zim_path))}')
except UnicodeDecodeError:
resp = response.raw(content)
logger.debug(f'Returning ZIM raw response {repr(str(zim_path))}')
return resp
@zim_bp.post('/tag')
@openapi.definition(
summary='Tag a Zim entry',
body=schema.TagZimEntry,
)
@validate(schema.TagZimEntry)
async def post_zim_tag(request: Request, body: schema.TagZimEntry):
session = request.ctx.session
await lib.add_tag(session, body.tag_name, body.zim_id, body.zim_entry)
return response.empty(HTTPStatus.CREATED)
@zim_bp.post('/untag')
@openapi.definition(
summary='Untag a Zim entry',
body=schema.TagZimEntry,
)
@validate(schema.TagZimEntry)
async def post_zim_untag(request: Request, body: schema.TagZimEntry):
session = request.ctx.session
await lib.untag(session, body.tag_name, body.zim_id, body.zim_entry)
return response.empty(HTTPStatus.NO_CONTENT)
@zim_bp.get('/subscribe')
@openapi.definition(
summary='Retrieve Zim subscriptions',
response=schema.ZimSubscriptions,
)
async def get_zim_subscriptions(request: Request):
catalog = lib.get_kiwix_catalog()
session = request.ctx.session
subscriptions = {i: j.__json__() for i, j in lib.get_kiwix_subscriptions(session).items()}
resp = dict(
catalog=catalog,
iso_639_codes=lang.ISO_639_CODES,
subscriptions=subscriptions,
)
return json_response(resp)
@zim_bp.post('/subscribe')
@openapi.definition(
summary='Subscribe to a particular Kiwix Zim',
body=schema.ZimSubscribeRequest,
)
@validate(schema.ZimSubscribeRequest)
async def post_zim_subscribe(request: Request, body: schema.ZimSubscribeRequest):
session = request.ctx.session
await lib.subscribe(session, body.name, body.language)
if download_manager.disabled or download_manager.stopped:
# Downloads are disabled, warn the user.
Events.send_downloads_disabled('Download created. But, downloads are disabled.')
Events.send_created(f'Zim subscription created')
return response.empty(HTTPStatus.CREATED)
@zim_bp.delete('/subscribe/<subscription_id:[0-9]+>')
@openapi.definition(
summary='Unsubscribe to a particular Kiwix Zim',
)
async def delete_zim_subscription(request: Request, subscription_id: int):
session = request.ctx.session
await lib.unsubscribe(session, subscription_id)
Events.send_deleted(f'Zim subscription deleted')
return response.empty(HTTPStatus.NO_CONTENT)
@zim_bp.get('/outdated')
@openapi.definition(
summary='Returns the outdated and current Zim files',
response=schema.OutdatedZims,
)
async def get_outdated_zims(_: Request):
outdated, current = lib.find_outdated_zim_files()
d = dict(outdated=outdated, current=current)
return json_response(d)
@zim_bp.delete('/outdated')
@openapi.definition(
summary='Remove all outdated Zims, if any.'
)
async def delete_outdated_zims(_: Request):
deleted_count = await lib.remove_outdated_zim_files()
if deleted_count:
lib.flag_outdated_zim_files()
Events.send_deleted(f'Deleted {deleted_count} outdated Zims')
return response.empty(HTTPStatus.NO_CONTENT)
@zim_bp.post('/search_estimates')
@validate(json=schema.SearchEstimateRequest)
async def post_search_estimates(request: Request, body: schema.SearchEstimateRequest):
"""Get an estimated count of FileGroups/Zims which may or may not have been tagged."""
if not body.search_str and not body.tag_names:
return response.empty(HTTPStatus.BAD_REQUEST)
def estimate():
zims_estimates = list()
with get_db_session() as session:
if body.tag_names:
# Get actual count of entries tagged with the tag names.
counts = Zims.entries_with_tags(session, body.tag_names)
else:
# Get estimates using libzim.
counts = Zims.estimate(session, body.search_str)
for zim, count in counts.items():
zims_estimates.append(dict(estimate=count, **zim.__json__()))
return zims_estimates
zims_estimates = await asyncio.to_thread(estimate)
ret = dict(
zims_estimates=zims_estimates
)
return json_response(ret)