;;; sqlite.el --- Functions for interacting with sqlite3 databases  -*- lexical-binding: t; -*-

;; Copyright (C) 2021-2024 Free Software Foundation, Inc.

;; This file is part of GNU Emacs.

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;; 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.

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;; 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
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;;; Commentary:

;;

;;; Code:

(declare-function sqlite-transaction "sqlite.c")
(declare-function sqlite-commit "sqlite.c")
(declare-function sqlite-rollback "sqlite.c")

(defmacro with-sqlite-transaction (db &rest body)
  "Execute BODY while holding a transaction for DB.
If BODY completes normally, commit the changes and return
the value of BODY.
If BODY signals an error, or transaction commit fails, roll
back the transaction changes before allowing the signal to
propagate."
  (declare (indent 1) (debug (form body)))
  (let ((db-var (gensym))
        (func-var (gensym))
        (res-var (gensym))
        (commit-var (gensym)))
    `(let ((,db-var ,db)
           (,func-var (lambda () ,@body))
           ,res-var ,commit-var)
       (if (sqlite-available-p)
           (unwind-protect
               (progn
                 (sqlite-transaction ,db-var)
                 (setq ,res-var (funcall ,func-var))
                 (setq ,commit-var (sqlite-commit ,db-var))
                 ,res-var)
             (or ,commit-var (sqlite-rollback ,db-var)))
         (funcall ,func-var)))))

(provide 'sqlite)

;;; sqlite.el ends here
