db/conn.rkt


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#lang racket

(require db)

(provide current-conn
         connect!
         disconnect!
         with-db
         with-tx)

(define current-conn (make-parameter #f))

(define (connect! #:path [path 'memory])
  (cond
    [(connection? (current-conn)) (printf "Database connection already exists: ~e\n" (current-conn))]
    [else
     (current-conn (sqlite3-connect #:database path #:mode 'create))
     (printf "Connected to database: ~a\n" path)]))

(define (disconnect!)
  (disconnect (current-conn))
  (printf "Closing database connection: ~e\n" (current-conn))
  (current-conn #f))

(define-syntax-rule (with-db body ...)
  (begin
    (connect!)
    body ...))

(define-syntax-rule (with-tx body ...)
  (call-with-transaction (current-conn)
                         (λ ()
                           body ...)))

(module+ test
  (require rackunit)
  (check-equal? (current-conn) #f)
  (connect!)
  (check-true (connection? (current-conn)))
  (disconnect!)
  (check-equal? (current-conn) #f)
  (with-db (check-true (connection? (current-conn)))))