Add with-transaction.

* src/cuirass/database.scm (with-transaction): New macro.

.dir-locals.el

@@ -13,6 +13,7 @@
   (eval put 'test-error 'scheme-indent-function 1)
   (eval put 'make-parameter 'scheme-indent-function 1)
   (eval put 'with-database 'scheme-indent-function 0)
+  (eval put 'with-transaction 'scheme-indent-function 0)
  (texinfo-mode
   (indent-tabs-mode)
   (fill-column . 72)

src/cuirass/database.scm

@@ -107,7 +107,8 @@
             ;; Macros.
             exec-query/bind
             with-database
-            with-db-worker-thread))
+            with-db-worker-thread
+            with-transaction))
 
 ;; Maximum priority for a Build or Specification.
 (define max-priority 9)
@@ -273,6 +274,13 @@ DB is bound to the argument of that critical section: the database connection."
                 (number->string receive-timeout)
                 caller-name))))))
 
+(define-syntax-rule (with-transaction exp ...)
+  "Evalute EXP within an SQL transaction."
+  (with-db-worker-thread db
+    (exec-query db "BEGIN TRANSACTION;")
+    exp ...
+    (exec-query db "COMMIT;")))
+
 (define (read-sql-file file-name)
   "Return a list of string containing SQL instructions from FILE-NAME."
   (call-with-input-file file-name