;; Copyright 2006-2017, Matthew Welland.
;;
;; This file is part of Megatest.
;;
;; Megatest is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; Megatest is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with Megatest. If not, see <http://www.gnu.org/licenses/>.
;;
(define (make-cached-writer the-db)
(let ((db the-db)
(queue '()))
(lambda (cacheable . qry-params) ;; fn qry
(if cacheable
(begin
(set! queue (cons qry-params queue))
(call/cc))
(begin
(print "Starting transaction")
(for-each
(lambda (queue-item)
(let ((fn (car queue-item))
(qry (cdr queue-item)))
(print "WRITE to " db ": " qry)
)
(reverse queue))
(print "End transaction")
(print "READ from " db ": " qry-params))))))
(define *cw* (make-cached-writer "the db"))
(define (dbcall cacheable query)
(*cw* cacheable query))
(dbcall #t "insert abc")
(dbcall #t "insert def")
(dbcall #t "insert hij")
(dbcall #f "select foo")