branch: elpa/emacsql
commit d8d4bf4b98c36b50ab9c57e1b6892328ae1084c4
Author: Christopher Wellons <well...@nullprogram.com>
Commit: Christopher Wellons <well...@nullprogram.com>
Add emacsql-with-transaction macro.
---
emacsql.el | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/emacsql.el b/emacsql.el
index 5e8562be48..37ac8cc966 100644
--- a/emacsql.el
+++ b/emacsql.el
@@ -228,6 +228,30 @@ A statement can be a list, containing a statement with its
arguments."
else
collect (append (list 'emacsql 'emacsql--conn) statement))))
+(defvar emacsql--transaction-level 0
+ "Keeps track of nested transactions in `emacsql-with-transaction'.")
+
+(defmacro emacsql-with-transaction (connection &rest body)
+ "Evaluate BODY inside a single transaction, issuing a rollback on error.
+This macro can be nested indefinitely, wrapping everything in a
+single transaction at the lowest level."
+ (declare (indent 1))
+ `(let ((emacsql--connection ,connection)
+ (emacsql--completed nil)
+ (emacsql--transaction-level (1+ emacsql--transaction-level)))
+ (unwind-protect
+ (progn
+ (when (= 1 emacsql--transaction-level)
+ (emacsql emacsql--connection [:begin :transaction]))
+ (let ((result (progn ,@body)))
+ (prog1 result
+ (when (= 1 emacsql--transaction-level)
+ (emacsql emacsql--connection [:commit]))
+ (setf emacsql--completed t))))
+ (when (and (= 1 emacsql--transaction-level)
+ (not emacsql--completed))
+ (emacsql emacsql--connection [:rollback])))))
+
;; User interaction functions:
(defvar emacsql-show-buffer-name "*emacsql-show*"
