branch: elpa/elfeed
commit 41ee64bd46821b0093c413c45b8cb73e44708234
Author: Steven Allen <[email protected]>
Commit: Daniel Mendler <[email protected]>
elfeed-db-save: write index atomically
Write the elfeed index atomically to avoid corruption. See #95, #80,
etc.
---
elfeed-db.el | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/elfeed-db.el b/elfeed-db.el
index 83ccaa2eaa..449c2054a3 100644
--- a/elfeed-db.el
+++ b/elfeed-db.el
@@ -269,8 +269,14 @@ The FEED-OR-ID may be a feed struct or a feed ID (url)."
(elfeed-db-ensure)
(setf elfeed-db (plist-put elfeed-db :version elfeed-db-version))
(mkdir elfeed-db-directory t)
- (let ((coding-system-for-write 'utf-8))
- (with-temp-file (expand-file-name "index" elfeed-db-directory)
+ (let* ((coding-system-for-write 'utf-8)
+ (dest (expand-file-name "index" elfeed-db-directory))
+ (temp (concat dest "-tmp"))
+ (write-region-inhibit-fsync nil))
+ ;; We write to a temporary file and rename to avoid corrupting the database
+ ;; on crash. `file-precious-flag' is insufficient as it only works for
+ ;; `save-buffer'.
+ (with-temp-file temp
(let ((standard-output (current-buffer))
(print-level nil)
(print-length nil)
@@ -282,8 +288,9 @@ The FEED-OR-ID may be a feed struct or a feed ID (url)."
(princ ";; Dummy index for backwards compatablity:\n")
(prin1 (elfeed-db--dummy))
(princ "\n\n;; Real index:\n"))
- (prin1 elfeed-db)
- :success))))
+ (prin1 elfeed-db)))
+ (rename-file temp dest t)
+ :success))
(defun elfeed-db-save-safe ()
"Run `elfeed-db-save' without triggering any errors, for use as a safe hook."
