Node execution, the queue hook and the image monitor all do
get_prompt_by_hash() then save_prompt(). When two of them race on the
same text the second INSERT failed on UNIQUE(hash) and surfaced an
IntegrityError. save_prompt now catches it, re-fetches by hash and
returns the existing id, so eight threads saving one prompt end with a
single row and every record_prompt_use counted.
PromptModel.get_connection() handed every thread the same
check_same_thread=False connection, so a commit or rollback from the
watchdog, executor or queue-hook thread could land on another thread's
half-done write (sqlite3 raised 'bad parameter or other API misuse'
under concurrent saves). Connections now live in threading.local, each
with WAL, Row factory, foreign_keys and busy_timeout, and are tracked so
they can be closed. PromptModel.close() / PromptDatabase.close() close
the calling thread's connection so tests and restores can delete the
file on Windows.
Vito Sansevero