First commit.

lisp/ux/backups.el

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+;;; backups.el --- Emacs backup system -*- lexical-binding: t; -*-
+;;; Commentary:
+;;; Code:
+
+;; Set up the backups directory.
+(defconst *user-backup-directory* (path-join *user-cache-directory* "backups"))
+;; Set up the autosaves directory.
+(defconst *user-auto-save-directory* (path-join *user-cache-directory* "auto-saves"))
+;; Emacs will create the backup dir automatically, but not the autosaves dir.
+(make-directory *user-auto-save-directory* t)
+
+
+(defun user--backups-config ()
+  "Initialize Emacs backup system."
+  (validate-setq
+   ;; Put backups in the cache directory
+   backup-directory-alist `((".*" . ,*user-backup-directory*))
+   ;; Version-control backup files
+   version-control t
+   ;; Keep 16 new versions and 2 old versions
+   kept-new-versions 6
+   kept-old-versions 2
+   ;; Delete old versions without asking
+   delete-old-versions t
+   ;; Always backup by copy
+   backup-by-copying t)
+
+  (validate-setq
+   ;; Auto-save every minute or 300 events
+   auto-save-interval 300
+   auto-save-timeout 60
+   ;; Always auto-save buffers.
+   auto-save-default t
+   ;; Put autosave files (ie #foo#) and backup files (ie foo~) into a cache dir.
+   auto-save-file-name-transforms `((".*" ,(concat *user-auto-save-directory* "/\\1") t))
+   ;; Put session backups into the cache directory.
+   auto-save-list-file-prefix (path-join *user-auto-save-directory* ".saves-")))
+
+
+(user--backups-config)
+
+
+(provide 'ux/backups)
+;;; backups.el ends here