`with sqlite3.Connection` ends the transaction but keeps the file handle open,
so every cache class leaked one handle per instance until the garbage collector
happened to run. On Windows that makes the database file undeletable while the
process lives (WinError 32), which broke 30 cache tests in teardown and would
also block moving or clearing a cache at runtime.
All eight `with <connection>` sites now go through `closing_connection()`, and a
regression test asserts the schema init leaves no usable connection behind.
On Windows, shutil.rmtree() fails when deleting a directory that contains
an open SQLite database file. The ZIP update path in _download_and_replace_zip()
calls _clean_plugin_folder() which tries to delete the cache/ directory,
but downloaded_versions.sqlite is held open by DownloadedVersionHistoryService.
Fix:
- Add close() method to DownloadedVersionHistoryService to release
the persistent SQLite connection
- Call close() before _clean_plugin_folder() in the ZIP update flow
- Add 'cache' to the skip_files list so the runtime cache directory is
never deleted during plugin updates
The method mark_not_downloaded() was misleading — it doesn't negate
'downloaded' history (the model was indeed downloaded before), but
rather sets is_deleted_override = 1 to indicate the version was
downloaded and subsequently deleted. This flag allows re-download when
the 'skip previously downloaded' setting is enabled.
Rename to mark_as_deleted() to accurately reflect its semantics.
Root cause: 231 concurrent /check-model-exists requests on 175K-lora library
caused ~9.4s wall clock time. The bottleneck was two-fold:
1. DownloadedVersionHistoryService opened a new sqlite3.connect() for every
query under asyncio.Lock. With a large WAL from 175K entries, each
connect() took ~8ms. Serialized by the lock across 231 requests, the
230th request waited ~1848ms just for lock acquisition.
2. check_model_exists always queried download history even when the model
was found locally. The history result (hasBeenDownloaded /
downloadedVersionIds) is only used by the UI when the model is NOT
found locally; when found, the 'in library' indicator takes priority.
Changes:
- downloaded_version_history_service.py: added persistent _get_conn() that
creates the SQLite connection once and reuses it across all queries
- misc_handlers.py: early-return from check_model_exists when the model
exists locally, bypassing the history service entirely (lock skipped)
Expected: per-request wait time drops from ~1912ms to <3ms, wall clock
from ~9.4s to <0.3s for the 175K-lora user's 231-card page.