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

;; Copyright (C) 2021-2023 Free Software Foundation, Inc.

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

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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:

(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."
  (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