db-write-lock ( -- lock/f )

Vocabulary

db

Inputs

None

Outputs

lock/f

a lock or f

Word description

Outputs the lock held while one unit of write work runs, or f if the backend needs no application-level serialization. Backends that permit only one writer at a time specialize this word; the default method outputs f.

Notes

The SQLite backend outputs a reentrant per-file lock, since SQLite permits only a single writer per file. Database servers such as PostgreSQL handle concurrency themselves and use the default method, so their writes are unchanged.

Definition

IN: db

HOOK: db-write-lock db-connection ( -- lock/f )

Methods

USING: db ;

M: db-connection db-write-lock f ;


USING: accessors db db.sqlite.private namespaces ;

M: sqlite-db-connection db-write-lock
    db-connection get write-lock>> ;