sqlite

func DSN ¶

func DSN(path string) string

DSN returns the data source name to open the database at path with, for sqlitedriver.SqliteDB.Open. Open the database you hand to New with it:

sdb := sqlitedriver.New()
err := sdb.Open(ctx, sqlite.DSN("keysmith.db"))

database/sql pools connections and every pooled connection has its own settings, so the DSN is the one place that reaches all of them. Grove's driver runs PRAGMA foreign_keys=ON once at Open, on whichever connection it gets, and sets no busy timeout. DSN adds three settings, applied by modernc.org/sqlite to each connection it opens:

• busy_timeout: a write waits up to BusyTimeout for the write lock. The engine's ValidateKey updates last_used_at in the background, so the next write regularly finds the lock taken.
• foreign_keys: ON DELETE CASCADE holds on every connection, so deleting a key or a scope never leaves keysmith_key_scopes rows behind.
• _txlock=immediate: transactions take the write lock at BEGIN. SQLite skips the busy timeout when a transaction that has already read tries to write, which AssignToKey does, and fails at once with SQLITE_BUSY. Read-only transactions still begin deferred.

path is a file name or a file: URI. Query parameters already on it are kept, and so is any of the three settings it already sets: the caller's _txlock, busy_timeout or foreign_keys wins, and DSN adds only the ones that are missing. If you open the database some other way, such as from a grove extension's config, put the same three parameters on that DSN.