1 #lang racket 2 3 (provide current-conn 4 connect! 5 disconnect! 6 with-db 7 with-tx) 8 9 (require db 10 "../debug.rkt") 11 12 (define current-conn (make-parameter #f)) 13 14 (define (connect! #:path [path 'memory]) 15 (if (connection? (current-conn)) 16 (debug-log (format "Connection already instantiated: ~a" (current-conn))) 17 (begin 18 (current-conn (sqlite3-connect #:database path #:mode 'create)) 19 (query-exec (current-conn) "PRAGMA foreign_keys = ON") 20 (debug-log (format "Connection instantiated: ~a" (current-conn)))))) 21 22 (define (disconnect!) 23 (disconnect (current-conn)) 24 (current-conn #f) 25 (debug-log "Connection disconnected.")) 26 27 (define-syntax-rule (with-db body ...) 28 (begin 29 (connect!) 30 body ...)) 31 32 (define-syntax-rule (with-tx body ...) 33 (call-with-transaction (current-conn) 34 (λ () 35 body ...))) 36 37 (module+ test 38 (require rackunit) 39 (check-equal? (current-conn) #f) 40 (connect!) 41 (check-true (connection? (current-conn))) 42 (disconnect!) 43 (check-equal? (current-conn) #f) 44 (with-db (check-true (connection? (current-conn))))) 45