Absorb existing domain data.

1 files changed, 41 insertions, 0 deletions

diff --git a/db/conn.rkt b/db/conn.rkt
new file mode 100644
index 0000000..e083d94
--- /dev/null
+++ b/db/conn.rkt
@@ -0,0 +1,41 @@
+#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 "Created database connection at path: ~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)))))