mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-11-22 07:09:54 +00:00
523 lines
22 KiB
EmacsLisp
523 lines
22 KiB
EmacsLisp
;;; filenotify.el --- watch files for changes on disk -*- lexical-binding:t -*-
|
|
|
|
;; Copyright (C) 2013-2023 Free Software Foundation, Inc.
|
|
|
|
;; Author: Michael Albinus <michael.albinus@gmx.de>
|
|
|
|
;; 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.
|
|
|
|
;; GNU Emacs is distributed in the hope that it will be useful,
|
|
;; 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
|
|
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
;;; Commentary:
|
|
|
|
;; This package is an abstraction layer from the different low-level
|
|
;; file notification packages `inotify', `kqueue', `gfilenotify' and
|
|
;; `w32notify'.
|
|
|
|
;;; Code:
|
|
|
|
(require 'cl-lib)
|
|
(eval-when-compile (require 'subr-x))
|
|
|
|
(defvar file-notify-debug nil
|
|
"Use for debug messages.")
|
|
|
|
(defconst file-notify--library
|
|
(cond
|
|
((featurep 'inotify) 'inotify)
|
|
((featurep 'kqueue) 'kqueue)
|
|
((featurep 'gfilenotify) 'gfilenotify)
|
|
((featurep 'w32notify) 'w32notify))
|
|
"Non-nil when Emacs has been compiled with file notification support.
|
|
The value is the name of the low-level file notification package
|
|
to be used for local file systems. Remote file notifications
|
|
could use another implementation.")
|
|
|
|
(cl-defstruct (file-notify--watch
|
|
(:constructor nil)
|
|
(:constructor
|
|
file-notify--watch-make (directory filename callback)))
|
|
"The internal struct for bookkeeping watched files or directories.
|
|
Used in `file-notify-descriptors'."
|
|
;; Watched directory.
|
|
directory
|
|
;; Watched relative filename, nil if watching the directory.
|
|
filename
|
|
;; Function to propagate events to, or nil if watch is being removed.
|
|
callback)
|
|
|
|
(defun file-notify--watch-absolute-filename (watch)
|
|
"Return the absolute filename observed by WATCH."
|
|
(if (file-notify--watch-filename watch)
|
|
(expand-file-name
|
|
(file-notify--watch-filename watch)
|
|
(file-notify--watch-directory watch))
|
|
(file-notify--watch-directory watch)))
|
|
|
|
(defvar file-notify-descriptors (make-hash-table :test 'equal)
|
|
"Hash table for registered file notification descriptors.
|
|
A key in this hash table is the descriptor as returned from
|
|
`inotify', `kqueue', `gfilenotify', `w32notify' or a file name
|
|
handler. The value in the hash table is a `file-notify--watch'
|
|
struct.")
|
|
|
|
(defun file-notify--rm-descriptor (descriptor)
|
|
"Remove DESCRIPTOR from `file-notify-descriptors'.
|
|
DESCRIPTOR should be an object returned by `file-notify-add-watch'.
|
|
If it is registered in `file-notify-descriptors', a `stopped' event is sent."
|
|
(when-let ((watch (gethash descriptor file-notify-descriptors)))
|
|
(unwind-protect
|
|
;; Send `stopped' event.
|
|
(file-notify-handle-event
|
|
(make-file-notify
|
|
:-event `(,descriptor stopped
|
|
,(file-notify--watch-absolute-filename watch))
|
|
:-callback (file-notify--watch-callback watch)))
|
|
;; Make sure this is the last time the callback was invoked.
|
|
(setf (file-notify--watch-callback watch) nil)
|
|
(remhash descriptor file-notify-descriptors))))
|
|
|
|
(cl-defstruct (file-notify (:type list) :named)
|
|
"A file system monitoring event, coming from the backends."
|
|
-event -callback)
|
|
|
|
;; This function is used by `inotify', `kqueue', `gfilenotify',
|
|
;; `w32notify' and remote file system handlers. Usually, we call the
|
|
;; argument `event' for such handlers. But in the following, `event'
|
|
;; means a part of the argument only, so we call the argument `object'.
|
|
;;;###autoload
|
|
(defun file-notify-handle-event (object)
|
|
"Handle a file system monitoring event, coming from backends.
|
|
If OBJECT is a filewatch event, call its callback.
|
|
Otherwise, signal a `file-notify-error'."
|
|
(declare (completion ignore))
|
|
(interactive "e")
|
|
(when file-notify-debug
|
|
(message "file-notify-handle-event %S" object))
|
|
(if (file-notify-p object)
|
|
(funcall (file-notify--callback object) (file-notify--event object))
|
|
(signal 'file-notify-error
|
|
(cons "Not a valid file-notify-event" object))))
|
|
|
|
(cl-defstruct (file-notify--rename
|
|
(:constructor nil)
|
|
(:constructor
|
|
file-notify--rename-make (watch desc from-file cookie)))
|
|
watch desc from-file cookie)
|
|
|
|
(defvar file-notify--pending-rename nil
|
|
"A pending rename event awaiting the destination file name.
|
|
It is nil or a `file-notify--rename' defstruct where the cookie can be nil.")
|
|
|
|
(defun file-notify--expand-file-name (watch file)
|
|
"Full file name of FILE reported for WATCH."
|
|
(directory-file-name
|
|
(expand-file-name file (file-notify--watch-directory watch))))
|
|
|
|
(cl-defun file-notify--callback-inotify ((desc actions file
|
|
&optional file1-or-cookie))
|
|
"Notification callback for inotify."
|
|
(file-notify--handle-event
|
|
desc
|
|
(delq nil (mapcar (lambda (action)
|
|
(cond
|
|
((eq action 'create) 'created)
|
|
((eq action 'modify) 'changed)
|
|
((eq action 'attrib) 'attribute-changed)
|
|
((memq action '(delete delete-self move-self)) 'deleted)
|
|
((eq action 'moved-from) 'renamed-from)
|
|
((eq action 'moved-to) 'renamed-to)
|
|
((eq action 'ignored) 'stopped)))
|
|
actions))
|
|
file file1-or-cookie))
|
|
|
|
(cl-defun file-notify--callback-kqueue ((desc actions file
|
|
&optional file1-or-cookie))
|
|
"Notification callback for kqueue."
|
|
(file-notify--handle-event
|
|
desc
|
|
(delq nil (mapcar (lambda (action)
|
|
(cond
|
|
((eq action 'create) 'created)
|
|
((eq action 'write) 'changed)
|
|
((memq action '(attrib link)) 'attribute-changed)
|
|
((eq action 'delete) 'deleted)
|
|
((eq action 'rename) 'renamed)))
|
|
actions))
|
|
file file1-or-cookie))
|
|
|
|
(cl-defun file-notify--callback-w32notify ((desc actions file
|
|
&optional file1-or-cookie))
|
|
"Notification callback for w32notify."
|
|
(let ((action (pcase actions
|
|
('added 'created)
|
|
('modified 'changed)
|
|
('removed 'deleted)
|
|
('renamed-from 'renamed-from)
|
|
('renamed-to 'renamed-to))))
|
|
(when action
|
|
(file-notify--handle-event desc (list action) file file1-or-cookie))))
|
|
|
|
(cl-defun file-notify--callback-gfilenotify ((desc actions file
|
|
&optional file1-or-cookie))
|
|
"Notification callback for gfilenotify."
|
|
(file-notify--handle-event
|
|
desc
|
|
(delq nil (mapcar (lambda (action)
|
|
(cond
|
|
((memq action
|
|
'(created changed attribute-changed deleted))
|
|
action)
|
|
((eq action 'moved) 'renamed)))
|
|
(if (consp actions) actions (list actions))))
|
|
file file1-or-cookie))
|
|
|
|
(cl-defun file-notify-callback ((desc actions file &optional file1-or-cookie))
|
|
"Notification callback for file name handlers."
|
|
(file-notify--handle-event
|
|
desc
|
|
;; File name handlers use gfilenotify or inotify actions.
|
|
(delq nil (mapcar
|
|
(lambda (action)
|
|
(cond
|
|
;; gfilenotify actions:
|
|
((memq action '(created changed attribute-changed deleted))
|
|
action)
|
|
((eq action 'moved) 'renamed)
|
|
;; inotify actions:
|
|
((eq action 'create) 'created)
|
|
((eq action 'modify) 'changed)
|
|
((eq action 'attrib) 'attribute-changed)
|
|
((memq action '(delete delete-self move-self)) 'deleted)
|
|
((eq action 'moved-from) 'renamed-from)
|
|
((eq action 'moved-to) 'renamed-to)
|
|
((eq action 'ignored) 'stopped)))
|
|
(if (consp actions) actions (list actions))))
|
|
file file1-or-cookie))
|
|
|
|
(defun file-notify--call-handler (watch desc action file file1)
|
|
"Call the handler of WATCH with the arguments DESC, ACTION, FILE and FILE1."
|
|
(when (or
|
|
;; If there is no relative file name for that
|
|
;; watch, we watch the whole directory.
|
|
(null (file-notify--watch-filename watch))
|
|
;; File matches.
|
|
(string-equal
|
|
(file-notify--watch-filename watch)
|
|
(file-name-nondirectory file))
|
|
|
|
;; Directory matches.
|
|
;; FIXME: What purpose would this condition serve?
|
|
;; Doesn't it just slip through events for files
|
|
;; having the same name as the last component of the
|
|
;; directory of the file that we are really watching?
|
|
;;(string-equal
|
|
;; (file-name-nondirectory file)
|
|
;; (file-name-nondirectory (file-notify--watch-directory watch)))
|
|
|
|
;; File1 matches.
|
|
(and (stringp file1)
|
|
(string-equal (file-notify--watch-filename watch)
|
|
(file-name-nondirectory file1))))
|
|
(when file-notify-debug
|
|
(message
|
|
"file-notify-callback %S %S %S %S %S %S %S"
|
|
desc action file file1 watch
|
|
(file-notify--watch-absolute-filename watch)
|
|
(file-notify--watch-directory watch)))
|
|
(funcall (file-notify--watch-callback watch)
|
|
(if file1
|
|
(list desc action file file1)
|
|
(list desc action file)))))
|
|
|
|
(defun file-notify--handle-event (desc actions file file1-or-cookie)
|
|
"Handle an event returned from file notification.
|
|
DESC is the back-end descriptor. ACTIONS is a list of:
|
|
`created'
|
|
`changed'
|
|
`attribute-changed'
|
|
`deleted'
|
|
`renamed' -- FILE is old name, FILE1-OR-COOKIE is new name or nil
|
|
`renamed-from' -- FILE is old name, FILE1-OR-COOKIE is cookie or nil
|
|
`renamed-to' -- FILE is new name, FILE1-OR-COOKIE is cookie or nil
|
|
`stopped' -- no more events after this should be sent"
|
|
(let* ((watch (gethash desc file-notify-descriptors))
|
|
(file (and watch (file-notify--expand-file-name watch file))))
|
|
(when watch
|
|
(while actions
|
|
(let ((action (pop actions)))
|
|
;; We only handle {renamed,moved}-{from,to} pairs when these
|
|
;; arrive in order without anything else in-between.
|
|
;; If there is a pending rename that does not match this event,
|
|
;; then send the former as a deletion (since we don't know the
|
|
;; rename destination).
|
|
(when file-notify--pending-rename
|
|
(unless (and (equal (file-notify--rename-cookie
|
|
file-notify--pending-rename)
|
|
file1-or-cookie)
|
|
(eq action 'renamed-to))
|
|
(let ((callback (file-notify--watch-callback
|
|
(file-notify--rename-watch
|
|
file-notify--pending-rename))))
|
|
(when callback
|
|
(funcall callback (list (file-notify--rename-desc
|
|
file-notify--pending-rename)
|
|
'deleted
|
|
(file-notify--rename-from-file
|
|
file-notify--pending-rename))))
|
|
(setq file-notify--pending-rename nil))))
|
|
|
|
(let ((file1 nil))
|
|
(cond
|
|
((eq action 'renamed)
|
|
;; A `renamed' event may not have a destination name;
|
|
;; if none, treat it as a deletion.
|
|
(if file1-or-cookie
|
|
(setq file1
|
|
(file-notify--expand-file-name watch file1-or-cookie))
|
|
(setq action 'deleted)))
|
|
((eq action 'stopped)
|
|
(file-notify-rm-watch desc)
|
|
(setq actions nil
|
|
action nil))
|
|
;; Make the event pending.
|
|
((eq action 'renamed-from)
|
|
(setq file-notify--pending-rename
|
|
(file-notify--rename-make watch desc file file1-or-cookie)
|
|
action nil))
|
|
;; Look for pending event.
|
|
((eq action 'renamed-to)
|
|
(if file-notify--pending-rename
|
|
(let ((callback (file-notify--watch-callback
|
|
(file-notify--rename-watch
|
|
file-notify--pending-rename)))
|
|
(pending-desc (file-notify--rename-desc
|
|
file-notify--pending-rename))
|
|
(from-file (file-notify--rename-from-file
|
|
file-notify--pending-rename)))
|
|
(setq file1 file
|
|
file from-file)
|
|
;; If the source is handled by another watch, we
|
|
;; must fire the rename event there as well.
|
|
(when (and (not (equal desc pending-desc))
|
|
callback)
|
|
(funcall callback
|
|
(list pending-desc 'renamed file file1)))
|
|
(setq file-notify--pending-rename nil
|
|
action 'renamed))
|
|
(setq action 'created))))
|
|
|
|
(when action
|
|
(file-notify--call-handler watch desc action file file1))
|
|
|
|
;; Send `stopped' event.
|
|
(when (and (memq action '(deleted renamed))
|
|
;; Not when a file is backed up.
|
|
(not (and (stringp file1) (backup-file-name-p file1)))
|
|
;; Watched file or directory is concerned.
|
|
(string-equal
|
|
file (file-notify--watch-absolute-filename watch)))
|
|
(file-notify-rm-watch desc))))))))
|
|
|
|
(declare-function inotify-add-watch "inotify.c" (file flags callback))
|
|
(declare-function kqueue-add-watch "kqueue.c" (file flags callback))
|
|
(declare-function w32notify-add-watch "w32notify.c" (file flags callback))
|
|
(declare-function gfile-add-watch "gfilenotify.c" (file flags callback))
|
|
|
|
(defun file-notify--add-watch-inotify (_file dir flags)
|
|
"Add a watch for FILE in DIR with FLAGS, using inotify."
|
|
(inotify-add-watch dir
|
|
(append
|
|
'(dont-follow)
|
|
(and (memq 'change flags)
|
|
'(create delete delete-self modify move-self move))
|
|
(and (memq 'attribute-change flags)
|
|
'(attrib)))
|
|
#'file-notify--callback-inotify))
|
|
|
|
(defun file-notify--add-watch-kqueue (file _dir flags)
|
|
"Add a watch for FILE in DIR with FLAGS, using kqueue."
|
|
;; kqueue does not report changes to file contents when watching
|
|
;; directories, so we watch each file directly.
|
|
(kqueue-add-watch file
|
|
(append
|
|
(and (memq 'change flags)
|
|
'(create delete write extend rename))
|
|
(and (memq 'attribute-change flags)
|
|
'(attrib)))
|
|
#'file-notify--callback-kqueue))
|
|
|
|
(defun file-notify--add-watch-w32notify (_file dir flags)
|
|
"Add a watch for FILE in DIR with FLAGS, using w32notify."
|
|
(w32notify-add-watch dir
|
|
(append
|
|
(and (memq 'change flags)
|
|
'(file-name directory-name size last-write-time))
|
|
(and (memq 'attribute-change flags)
|
|
'(attributes)))
|
|
#'file-notify--callback-w32notify))
|
|
|
|
(defun file-notify--add-watch-gfilenotify (_file dir flags)
|
|
"Add a watch for FILE in DIR with FLAGS, using gfilenotify."
|
|
(gfile-add-watch dir
|
|
(append '(watch-mounts send-moved) flags)
|
|
#'file-notify--callback-gfilenotify))
|
|
|
|
(defun file-notify-add-watch (file flags callback)
|
|
"Add a watch for filesystem events pertaining to FILE.
|
|
This arranges for filesystem events pertaining to FILE to be reported
|
|
to Emacs. Use `file-notify-rm-watch' to cancel the watch.
|
|
|
|
The returned value is a descriptor for the added watch. If the
|
|
file cannot be watched for some reason, this function signals a
|
|
`file-notify-error' error.
|
|
|
|
FLAGS is a list of conditions to set what will be watched for. It can
|
|
include the following symbols:
|
|
|
|
`change' -- watch for file changes
|
|
`attribute-change' -- watch for file attributes changes, like
|
|
permissions or modification time
|
|
|
|
If FILE is a directory, `change' watches for file creation or
|
|
deletion in that directory. Some of the file notification
|
|
backends report also file changes. This does not work
|
|
recursively.
|
|
|
|
When any event happens, Emacs will call the CALLBACK function passing
|
|
it a single argument EVENT, which is of the form
|
|
|
|
(DESCRIPTOR ACTION FILE [FILE1])
|
|
|
|
DESCRIPTOR is the same object as the one returned by this function.
|
|
ACTION is the description of the event. It could be any one of the
|
|
following:
|
|
|
|
`created' -- FILE was created
|
|
`deleted' -- FILE was deleted
|
|
`changed' -- FILE has changed
|
|
`renamed' -- FILE has been renamed to FILE1
|
|
`attribute-changed' -- a FILE attribute was changed
|
|
`stopped' -- watching FILE has been stopped
|
|
|
|
FILE is the name of the file whose event is being reported."
|
|
;; Check arguments.
|
|
(unless (stringp file)
|
|
(signal 'wrong-type-argument `(,file)))
|
|
(setq file (expand-file-name file))
|
|
(unless (and (consp flags)
|
|
(null (delq 'change (delq 'attribute-change (copy-tree flags)))))
|
|
(signal 'wrong-type-argument `(,flags)))
|
|
(unless (functionp callback)
|
|
(signal 'wrong-type-argument `(,callback)))
|
|
|
|
(let ((handler (find-file-name-handler file 'file-notify-add-watch))
|
|
(dir (directory-file-name
|
|
(if (file-directory-p file)
|
|
file
|
|
(file-name-directory file)))))
|
|
|
|
(unless (file-directory-p dir)
|
|
(signal 'file-notify-error `("Directory does not exist" ,dir)))
|
|
|
|
(let ((desc
|
|
(if handler
|
|
(funcall handler 'file-notify-add-watch dir flags callback)
|
|
(funcall
|
|
(pcase file-notify--library
|
|
('inotify #'file-notify--add-watch-inotify)
|
|
('kqueue #'file-notify--add-watch-kqueue)
|
|
('w32notify #'file-notify--add-watch-w32notify)
|
|
('gfilenotify #'file-notify--add-watch-gfilenotify)
|
|
(_ (signal 'file-notify-error
|
|
'("No file notification package available"))))
|
|
file dir flags))))
|
|
|
|
;; Modify `file-notify-descriptors'.
|
|
(let ((watch (file-notify--watch-make
|
|
;; We do not want to enter quoted file names into the hash.
|
|
(file-name-unquote dir)
|
|
(unless (file-directory-p file)
|
|
(file-name-nondirectory file))
|
|
callback)))
|
|
(puthash desc watch file-notify-descriptors))
|
|
;; Return descriptor.
|
|
desc)))
|
|
|
|
(defun file-notify-rm-watch (descriptor)
|
|
"Remove an existing watch specified by its DESCRIPTOR.
|
|
DESCRIPTOR should be an object returned by `file-notify-add-watch'."
|
|
(when-let* ((watch (gethash descriptor file-notify-descriptors)))
|
|
;; If we are called from a `stopped' event, do nothing.
|
|
(when (file-notify--watch-callback watch)
|
|
(let ((handler (find-file-name-handler
|
|
(file-notify--watch-directory watch)
|
|
'file-notify-rm-watch)))
|
|
(condition-case nil
|
|
(if handler
|
|
;; A file name handler could exist even if there is no
|
|
;; local file notification support.
|
|
(funcall handler 'file-notify-rm-watch descriptor)
|
|
|
|
(funcall
|
|
(cond
|
|
((eq file-notify--library 'inotify) 'inotify-rm-watch)
|
|
((eq file-notify--library 'kqueue) 'kqueue-rm-watch)
|
|
((eq file-notify--library 'gfilenotify) 'gfile-rm-watch)
|
|
((eq file-notify--library 'w32notify) 'w32notify-rm-watch))
|
|
descriptor))
|
|
(file-notify-error nil)))
|
|
;; Modify `file-notify-descriptors' and send a `stopped' event.
|
|
(file-notify--rm-descriptor descriptor))))
|
|
|
|
(defun file-notify-rm-all-watches ()
|
|
"Remove all existing file notification watches from Emacs."
|
|
(interactive)
|
|
(maphash
|
|
(lambda (key _value)
|
|
(file-notify-rm-watch key))
|
|
file-notify-descriptors))
|
|
|
|
(defun file-notify-valid-p (descriptor)
|
|
"Check a watch specified by its DESCRIPTOR.
|
|
DESCRIPTOR should be an object returned by `file-notify-add-watch'."
|
|
(when-let* ((watch (gethash descriptor file-notify-descriptors)))
|
|
(let ((handler (find-file-name-handler
|
|
(file-notify--watch-directory watch)
|
|
'file-notify-valid-p)))
|
|
(and (if handler
|
|
;; A file name handler could exist even if there is no
|
|
;; local file notification support.
|
|
(funcall handler 'file-notify-valid-p descriptor)
|
|
(funcall
|
|
(cond
|
|
((eq file-notify--library 'inotify) 'inotify-valid-p)
|
|
((eq file-notify--library 'kqueue) 'kqueue-valid-p)
|
|
((eq file-notify--library 'gfilenotify) 'gfile-valid-p)
|
|
((eq file-notify--library 'w32notify) 'w32notify-valid-p))
|
|
descriptor))
|
|
t))))
|
|
|
|
;; TODO:
|
|
|
|
;; * Watching a file in an already watched directory.
|
|
;; If the file is created and *then* a watch is added to that file, the
|
|
;; watch might receive events which occurred prior to it being created,
|
|
;; due to the way events are propagated during idle time. Note: This
|
|
;; may be perfectly acceptable.
|
|
|
|
(provide 'filenotify)
|
|
|
|
;;; filenotify.el ends here
|