Delete temporary files when Gnus exits instead of using timers

mm-decode.el (mm-temp-files-to-be-deleted, mm-temp-files-cache-file):
 New internal variables.
(mm-temp-files-delete): New function; add it to gnus-exit-gnus-hook.
(mm-display-external): Use it to delete temporary files instead of
  using timers.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index df62d44..7123f7f 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2013-08-09  Katsumi Yamaoka  <yamaoka@jpl.org>
+
+       * mm-decode.el (mm-temp-files-to-be-deleted, mm-temp-files-cache-file):
+       New internal variables.
+       (mm-temp-files-delete): New function; add it to gnus-exit-gnus-hook.
+       (mm-display-external): Use it to delete temporary files instead of
+       using timers.
+
 2013-08-06  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
        * dgnushack.el (dgnushack-compile): Allow building on Emacs 23.

diff --git a/lisp/mm-decode.el b/lisp/mm-decode.el
index 98d8543..2bfd145 100644 (file)
--- a/lisp/mm-decode.el
+++ b/lisp/mm-decode.el
@@ -47,6 +47,7 @@
 (defvar gnus-current-window-configuration)
 
 (add-hook 'gnus-exit-gnus-hook 'mm-destroy-postponed-undisplay-list)
+(add-hook 'gnus-exit-gnus-hook 'mm-temp-files-delete)
 
 (defgroup mime-display ()
   "Display of MIME in mail and news articles."
@@ -470,6 +471,11 @@ If not set, `default-directory' will be used."
 (defvar mm-content-id-alist nil)
 (defvar mm-postponed-undisplay-list nil)
 (defvar mm-inhibit-auto-detect-attachment nil)
+(defvar mm-temp-files-to-be-deleted nil
+  "List of temporary files scheduled to be deleted.")
+(defvar mm-temp-files-cache-file (concat ".mm-temp-files-" (user-login-name))
+  "Name of a file that caches a list of temporary files to be deleted.
+The file will be saved in the directory `mm-tmp-directory'.")
 
 ;; According to RFC2046, in particular, in a digest, the default
 ;; Content-Type value for a body part is changed from "text/plain" to
@@ -586,6 +592,45 @@ Postpone undisplaying of viewers for types in
     (message "Destroying external MIME viewers")
     (mm-destroy-parts mm-postponed-undisplay-list)))
 
+(defun mm-temp-files-delete ()
+  "Delete temporary files and those parent directories.
+Note that the deletion may fail if a program is catching hold of a file
+under Windows or Cygwin.  In that case, it schedules the deletion of
+files left at the next time."
+  (let* ((coding-system-for-read mm-universal-coding-system)
+        (coding-system-for-write mm-universal-coding-system)
+        (cache-file (expand-file-name mm-temp-files-cache-file
+                                      mm-tmp-directory))
+        (cache (when (file-exists-p cache-file)
+                 (mm-with-multibyte-buffer
+                   (insert-file-contents cache-file)
+                   (split-string (buffer-string) "\n" t))))
+        fails)
+    (dolist (temp (append cache mm-temp-files-to-be-deleted))
+      (unless (and (file-exists-p temp)
+                  (if (file-directory-p temp)
+                      ;; A parent directory left at the previous time.
+                      (progn
+                        (ignore-errors (delete-directory temp))
+                        (not (file-exists-p temp)))
+                    ;; Delete a temporary file and its parent directory.
+                    (ignore-errors (delete-file temp))
+                    (and (not (file-exists-p temp))
+                         (progn
+                           (setq temp (file-name-directory temp))
+                           (ignore-errors (delete-directory temp))
+                           (not (file-exists-p temp))))))
+       (push temp fails)))
+    (if fails
+       ;; Schedule the deletion of the files left at the next time.
+       (progn
+         (write-region (concat (mapconcat 'identity (nreverse fails) "\n")
+                               "\n")
+                       nil cache-file nil 'silent)
+         (set-file-modes cache-file #o600))
+      (when (file-exists-p cache-file)
+       (ignore-errors (delete-file cache-file))))))
+
 (autoload 'message-fetch-field "message")
 
 (defun mm-dissect-buffer (&optional no-strict-mime loose-mime from)
@@ -975,22 +1020,8 @@ external if displayed external."
                                   (buffer buffer)
                                   (command command)
                                   (handle handle))
-                      (run-at-time
-                       30.0 nil
-                       (lambda ()
-                         (ignore-errors
-                           (delete-file file))
-                         (ignore-errors
-                           (delete-directory (file-name-directory file)))))
                       (lambda (process state)
                         (when (eq (process-status process) 'exit)
-                          (run-at-time
-                           10.0 nil
-                           (lambda ()
-                             (ignore-errors
-                               (delete-file file))
-                             (ignore-errors
-                               (delete-directory (file-name-directory file)))))
                           (when (buffer-live-p outbuf)
                             (with-current-buffer outbuf
                               (let ((buffer-read-only nil)
@@ -1007,7 +1038,8 @@ external if displayed external."
                             (kill-buffer buffer)))
                         (message "Displaying %s...done" command)))))
                (mm-handle-set-external-undisplayer
-                handle (cons file buffer)))
+                handle (cons file buffer))
+               (add-to-list 'mm-temp-files-to-be-deleted file t))
              (message "Displaying %s..." command))
            'external)))))))