-;; Copyright (C) 2009 Olof-Joachim Frahm
+;;; -*- mode: lisp; syntax: common-lisp; coding: utf-8-unix; package: cl-inotify; -*-
-;; This program 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.
+;; Copyright (c) 2011-12, Olof-Joachim Frahm
+;; All rights reserved.
-;; This program 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.
+;; Redistribution and use in source and binary forms, with or without
+;; modification, are permitted provided that the following conditions
+;; are met:
-;; You should have received a copy of the GNU General Public License along
-;; with this program; if not, see <http://www.gnu.org/licenses/>.
+;; 1. Redistributions of source code must retain the above copyright
+;; notice, this list of conditions and the following disclaimer.
-(in-package #:cl-notify)
+;; 2. Redistributions in binary form must reproduce the above copyright
+;; notice, this list of conditions and the following disclaimer in the
+;; documentation and/or other materials provided with the distribution.
+
+;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+;; "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+;; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+;; A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+;; OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+;; SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+;; LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+;; DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+;; THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+;; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+(in-package #:cl-inotify)
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (when (boundp 'in-cloexec)
+ (pushnew 'inotify1 *features*)))
+
+#+cl-inotify::inotify1
+(defbitfield (inotify1-flag :int)
+ (:cloexec #.in-cloexec)
+ (:nonblock #.in-nonblock))
(defbitfield (inotify-flag :uint32)
- (:access #.in-access)
- (:modify #.in-modify)
- (:attrib #.in-attrib)
- (:close-write #.in-close-write)
+ (:access #.in-access)
+ (:modify #.in-modify)
+ (:attrib #.in-attrib)
+ (:close-write #.in-close-write)
(:close-nowrite #.in-close-nowrite)
- (:close #.in-close)
- (:open #.in-open)
- (:moved-from #.in-moved-from)
- (:moved-to #.in-moved-to)
- (:move #.in-move)
- (:create #.in-create)
- (:delete #.in-delete)
- (:delete-self #.in-delete-self)
- (:move-self #.in-move-self)
- (:unmount #.in-unmount)
- (:q-overflow #.in-q-overflow)
- (:ignored #.in-ignored)
- (:onlydir #.in-onlydir)
- (:dont-follow #.in-dont-follow)
- (:mask-add #.in-mask-add)
- (:isdir #.in-isdir)
- (:oneshot #.in-oneshot)
- (:all-events #.in-all-events))
+ (:close #.in-close)
+ (:open #.in-open)
+ (:moved-from #.in-moved-from)
+ (:moved-to #.in-moved-to)
+ (:move #.in-move)
+ (:create #.in-create)
+ (:delete #.in-delete)
+ (:delete-self #.in-delete-self)
+ (:move-self #.in-move-self)
+ (:unmount #.in-unmount)
+ (:q-overflow #.in-q-overflow)
+ (:ignored #.in-ignored)
+ (:onlydir #.in-onlydir)
+ (:dont-follow #.in-dont-follow)
+ (:mask-add #.in-mask-add)
+ (:isdir #.in-isdir)
+ (:oneshot #.in-oneshot)
+ (:all-events #.in-all-events))
(deftype inotify-add/read-flag ()
- "Shared valid flags for the WATCH and READ-EVENT functions."
+ "Shared valid flags for the WATCH-RAW and READ-EVENT functions."
'(member
- :access :attrib
+ :access :attrib
:close-write :close-nowrite :close
:create :delete :delete-self
:modify
:move-self :moved-from :moved-to :move
:open :all-events))
-(deftype inotify-add-flag ()
- "Valid flags for the WATCH function."
- '(or inotify-add/read-flag
- (member :dont-follow :mask-add :oneshot :onlydir)))
-
(deftype inotify-read-flag ()
"Valid flags which are returned from READ-EVENT."
'(or inotify-add/read-flag
(member :ignored :isdir :q-overflow :unmount)))
-(defcfun ("inotify_init" c-inotify-init) :int
+(deftype inotify-add-flag ()
+ "Valid flags for the WATCH-RAW function."
+ '(or inotify-add/read-flag
+ (member :dont-follow :mask-add :oneshot :onlydir)))
+
+(defun valid-watch-flag-p (x)
+ (and (typep x 'inotify-add-flag)
+ (not (eq :mask-add x))
+ (not (eq :oneshot x))))
+
+(defun valid-watch-flag-list-p (list)
+ (every #'valid-watch-flag-p list))
+
+(deftype watch-flag-list ()
+ "Valid flags argument for the WATCH function, a list of keywords from
+INOTIFY-ADD-FLAG. Basically only :MASK-ADD and :ONESHOT are removed.
+The :MASK-ADD behaviour is replicated with the REPLACE-P argument; the
+:ONESHOT behaviour doesn't play well with the WATCH function design (and
+thus should be used only with WATCH-RAW)."
+ '(or (satisfies valid-watch-flag-p)
+ (and list (satisfies valid-watch-flag-list-p))))
+
+(defsyscall inotify-init :int
"Initialises a new inotify event queue.")
-(defcfun ("inotify_add_watch" c-inotify-add-watch) :int
- "Watches a path on a event queue."
+#+cl-inotify::inotify1
+(defsyscall inotify-init1 :int
+ "Initialises a new inotify event queue and passes some flags along."
+ (flags inotify1-flag))
+
+(defsyscall inotify-add-watch :int
+ "Watches a path on an event queue."
(fd :int)
(pathname :string)
(mask inotify-flag))
-(defcfun ("inotify_rm_watch" c-inotify-rm-watch) :int
- "Removes a watched path from a event queue."
+(defsyscall inotify-rm-watch :int
+ "Removes a watched path from an event queue."
(fd :int)
(wd :int))
(name NIL))
(defstruct (inotify-instance
- (:constructor make-inotify-instance ())
- (:conc-name inotify-))
+ (:constructor make-inotify-instance ())
+ (:conc-name inotify-))
"Contains the stream and file descriptor for a inotify instance."
fd
stream
;;;; initialisation and stuff
-(defun init-endian ()
- "Initialises endianess for the BINARY-TYPES library."
- (setf binary-types:*endian*
- #+little-endian :little-endian
- #+big-endian :big-endian
- #-(or little-endian big-endian) (error "unknown endianess")))
-
-;; um, in what evel-when should this be wrapped?
-(init-endian)
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (defun read-new-value (&optional (stream *query-io*))
+ "READs a value from the STREAM and returns it (wrapped in a list)."
+ (format stream "~&Enter a new value (unevaluated): ")
+ (force-output stream)
+ (list (read stream))))
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (defun init-endian ()
+ "Initialises the endianess for the BINARY-TYPES library. Is automatically
+called when the library is loaded."
+ (setf binary-types:*endian*
+ (restart-case #+little-endian :little-endian
+ #+big-endian :big-endian
+ #-(or little-endian big-endian) (error "unknown endianess")
+ (use-value (value)
+ :report "Enter a correct value (either :LITTLE-ENDIAN or :BIG-ENDIAN)."
+ :interactive read-new-value
+ ;; TODO: better way to test for correct value/retry values?
+ (case value
+ ((:little-endian :big-endian) value)
+ (T (error "wrong value supplied (not :LITTLE-ENDIAN or :BIG-ENDIAN)"))))))))
+
+;; initialise the endianess
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (init-endian))
;;;; basic wrapping of the API
(defun read-raw-event-from-stream (stream)
"Reads a raw event from the inotify stream."
(let* ((event (binary-types:read-binary 'inotify-event stream))
- (len (binary-types:read-binary 'binary-types:u32 stream)))
+ (len (binary-types:read-binary 'binary-types:u32 stream)))
(when (plusp len)
(with-slots (name) event
- (setf name (binary-types:read-binary-string stream
- :size len
- :terminators '(0)))))
+ (let ((buffer (make-array len :element-type '(unsigned-byte 8))))
+ (read-sequence buffer stream :end len)
+ (setf name (trivial-utf-8:utf-8-bytes-to-string buffer :end (position 0 buffer))))))
event))
(defun read-event-from-stream (stream)
event))
(defun set-nonblocking (fd nonblocking)
- (let ((flags (sb-posix:fcntl fd sb-posix:f-getfl)))
+ "Enables or disables NONBLOCKING mode on a file descriptor FD."
+ (let ((flags (osicat-posix:fcntl fd osicat-posix:f-getfl)))
;; an error is raised if this fails, so we don't have to do it ourselves
- (sb-posix:fcntl fd sb-posix:f-setfl
- (funcall (if nonblocking #'logior #'logxor)
- flags sb-posix:o-nonblock))))
+ (osicat-posix:fcntl fd osicat-posix:f-setfl
+ (funcall (if nonblocking #'logior #'logxor)
+ flags osicat-posix:o-nonblock)))
+ (values))
-(defun init-unregistered-notify (notify &optional (nonblocking T))
+(defun init-unregistered-inotify (inotify &optional (nonblocking T))
"Creates a new inotify event queue. If NONBLOCKING is set (default),
the file descriptor is set to non-blocking I/O."
- (let ((result (c-inotify-init)))
- (when (minusp result)
- (error "inotify_init failed: ~A" result))
- (with-slots (fd stream (non-block nonblocking)) notify
- (unwind-protect
- ;; file descriptor is collected with auto-close
- (progn
- (setf fd result)
- (when nonblocking
- (set-nonblocking fd T)
- (setf non-block nonblocking))
- (setf stream
- (sb-sys:make-fd-stream
- fd
- :input T
- :element-type '(unsigned-byte 8)
- :name (format NIL "inotify event queue ~A" fd)
- :auto-close T
- :buffering (if nonblocking :none :full))))
- ;; if stream is constructed, gc'ing it will cleanup the file descriptor
- (unless stream
- (sb-posix:close fd)))))
- notify)
-
-(defun make-unregistered-notify ()
- (init-unregistered-notify (make-inotify-instance)))
-
-(defun close-notify (notify)
+ (with-slots (fd stream (non-block nonblocking)) inotify
+ (unwind-protect
+ ;; file descriptor is collected with auto-close
+ (progn
+ (setf non-block nonblocking)
+ #+inotify1
+ (setf fd (inotify-init1 (and non-block :nonblock)))
+ #-inotify1
+ (setf fd (inotify-init))
+ #-inotify1
+ (when non-block
+ (set-nonblocking fd T))
+ (setf stream
+ ;; TODO: what about the blocking?
+ #-(or clisp sbcl)
+ (osicat::make-fd-stream
+ fd
+ :direction :input
+ :element-type '(unsigned-byte 8))
+ #+clisp
+ (ext:make-stream
+ fd
+ :direction :input
+ :element-type '(unsigned-byte 8)
+ :buffered (not nonblocking))
+ #+sbcl
+ (sb-sys:make-fd-stream
+ fd
+ :input T
+ :element-type '(unsigned-byte 8)
+ :name (format NIL "inotify event queue ~A" fd)
+ :auto-close T
+ :buffering (if nonblocking :none :full))))
+ ;; if stream is constructed, gc'ing it will cleanup the file descriptor
+ ;; TODO: is this true for clisp? because the docs say that
+ ;; EXT:MAKE-STREAM uses dup(2)
+ (unless stream
+ (osicat-posix:close fd))))
+ inotify)
+
+(defun make-unregistered-inotify (&optional (nonblocking T))
+ "Creates a new unregistered INOTIFY instance."
+ (init-unregistered-inotify (make-inotify-instance) nonblocking))
+
+(defun close-inotify (inotify)
"Closes the inotify event queue."
- (close (inotify-stream notify))
+ (close (inotify-stream inotify))
(values))
-(defun watch-raw (notify pathname flags)
- "Adds PATHNAME (either pathname or string) to be watched. FLAGS
-determines how exactly (see inotify(7) for detailed information).
-Returns a handle which can be used with UNWATCH."
- (let ((path (princ-to-string pathname))
- result)
- (setf result (c-inotify-add-watch
- (inotify-fd notify)
- path
- (typecase flags
- (list (foreign-bitfield-value 'inotify-flag flags))
- (keyword (foreign-bitfield-value 'inotify-flag
- (list flags)))
- (T flags))))
- (when (minusp result)
- (error "inotify_add_watch failed: ~A" result))
- result))
-
-(defun unwatch-raw (notify handle)
- "Disables watching the path associated with HANDLE."
- (let ((result (c-inotify-rm-watch (inotify-fd notify) handle)))
- (when (minusp result)
- (error "inotify_rm_watch failed: ~A" result)))
+(defun ensure-list (arg)
+ (if (listp arg) arg `(,arg)))
+
+(defun translate-keyword-flags (flags)
+ (typecase flags
+ ((or keyword list)
+ (foreign-bitfield-value 'inotify-flag (ensure-list flags)))
+ (T flags)))
+
+(defun watch-raw (inotify pathname flags)
+ "Adds PATHNAME (either of type PATHNAME or STRING) to be watched. FLAGS
+determines how exactly (see inotify(7) for detailed information) and can
+be of type LIST, KEYWORD or a raw numerical value (which isn't checked
+for validity though). Returns a handle which can be used with UNWATCH-RAW."
+ (let* ((path (etypecase pathname
+ (string pathname)
+ (pathname (namestring pathname)))))
+ (inotify-add-watch (inotify-fd inotify)
+ path (translate-keyword-flags flags))))
+
+(defun unwatch-raw (inotify handle)
+ "Stops watching the path associated with a HANDLE established by WATCH-RAW."
+ (inotify-rm-watch (inotify-fd inotify) handle)
(values))
;;;; support functions, making life easier
(defstruct (registered-inotify-instance
- (:include inotify-instance)
- (:constructor make-registered-inotify-instance ())
- (:conc-name inotify-))
+ (:include inotify-instance)
+ (:constructor make-registered-inotify-instance ())
+ (:conc-name inotify-))
"Additionally to the information in INOTIFY-INSTANCE, records watched
paths in a dictionary."
watched)
-(defun make-notify (&optional (nonblocking T))
+(defun make-inotify (&optional (nonblocking T))
+ "Creates a new registered INOTIFY instance. In NONBLOCKING mode, the file
+descriptor is set to non-blocking mode. The resulting object has to be
+closed with CLOSE-INOTIFY."
(let ((result (make-registered-inotify-instance)))
- (init-unregistered-notify result nonblocking)
+ (init-unregistered-inotify result nonblocking)
(with-slots (watched) result
(setf watched (make-hash-table :test 'equal)))
result))
-(defun watchedp (notify pathname)
- "Returns the tuple (HANDLE . FLAGS) if PATHNAME is being watched by NOTIFY,
-else NIL."
- (awhen (gethash pathname (inotify-watched notify))
- (values (car it) (cdr it))))
-
-;; TODO: handle additional flags, save only list of flags
-(defun watch (notify pathname flags)
- (let ((handle (watch-raw notify pathname flags)))
- (with-slots (watched) notify
+(defun pathname-handle/flags (inotify pathname)
+ "Returns a CONS cell with the values HANDLE and FLAGS if PATHNAME is
+being watched by INOTIFY, else NIL. The match is exact."
+ (gethash pathname (inotify-watched inotify)))
+
+(defun event-pathname/flags (inotify event &optional (handle (slot-value event 'wd)))
+ "Returns two values PATHNAME and FLAGS for an EVENT which were used during
+registration. If HANDLE is specified EVENT is ignored."
+ (block NIL
+ (maphash (lambda (pathname entry)
+ (when (eql (car entry) handle)
+ (return (values pathname (cdr entry)))))
+ (inotify-watched inotify))))
+
+(defun sane-user-flags (inotify pathname flags &key (replace-p T))
+ (check-type flags watch-flag-list)
+ ;; now, :mask-add can't be member of flags
+ ;; merge the flags
+ (let* ((flags (ensure-list flags))
+ (rep-flags (if replace-p
+ (cons :mask-add flags)
+ flags)))
+ (let ((it (gethash pathname (slot-value inotify 'watched))))
+ (if it
+ (union (cdr it) rep-flags :test #'eq)
+ rep-flags))))
+
+(defun watch (inotify pathname flags &key (replace-p T))
+ "Adds PATHNAME (either pathname or string) to be watched and records the
+watched paths. FLAGS (a list of keywords) determines how exactly (see
+inotify(7) for detailed information). Returns a handle which can be used
+with UNWATCH and EVENT-PATHNAME/FLAGS. If REPLACE-P is set to T (default),
+the flags mask is replaced rather than OR-ed to the current mask (if it
+exists). The :MASK-ADD flag is therefore removed from the FLAGS argument."
+ (let* ((flags (sane-user-flags inotify pathname flags :replace-p replace-p))
+ (handle (watch-raw inotify pathname flags)))
+ (with-slots (watched) inotify
(setf (gethash pathname watched) (cons handle flags)))
handle))
-(defun unwatch (notify &key pathname handle)
- (unless (or pathname handle)
- (error "either PATHNAME or HANDLE has to be specified"))
+(defun unwatch (inotify &key pathname event handle)
+ "Disables watching the path associated with the supplied HANDLE (which
+may be one from a given EVENT) or PATHNAME."
+ (unless (or pathname event handle)
+ (error "either PATHNAME, EVENT or HANDLE have to be specified"))
+ (when event
+ (setf handle (slot-value event 'wd)))
(if handle
- (unwatch-raw notify handle)
- (let ((handle (watchedp notify pathname)))
- (unless handle
- (error "PATHNAME ~S isn't being watched" pathname))
- (unwatch-raw notify handle)
- (remhash pathname (inotify-watched notify))))
+ (unwatch-raw inotify handle)
+ (let ((handle (car (pathname-handle/flags inotify pathname))))
+ (unless handle
+ (error "PATHNAME ~S isn't being watched" pathname))
+ ;; remove even if unwatch-raw throws an error (which can happen if :oneshot is specified)
+ (remhash pathname (inotify-watched inotify))
+ (unwatch-raw inotify handle)))
(values))
-(defun list-watched (notify)
- "Returns a list of all watched pathnames in particular order."
- (let (result)
- (maphash (lambda (k v)
- (declare (ignore v))
- (push k result))
- (inotify-watched notify))
- result))
-
-(defun unix-eagainp (fd-stream)
- "Returns T on a FD-STREAM, if trying to read raised a EAGAIN error."
- (multiple-value-bind (result error)
- (sb-unix:unix-read (sb-sys:fd-stream-fd fd-stream) NIL 0)
- (declare (ignore result))
- (= error sb-unix:eagain)))
-
-(defun event-availablep (notify)
+(defun list-watched (inotify)
+ "Returns a LIST of all watched pathnames in no particular order."
+ (loop
+ for pathname being each hash-key in (inotify-watched inotify)
+ collect pathname))
+
+(defun unix-eagain-p (fd)
+ "Returns T on a file descriptor if trying to read raised an EAGAIN
+error."
+ (handler-case (prog1 NIL (osicat-posix:read fd (null-pointer) 0))
+ ;; we have to check for both to be portable, says read(2)
+ (osicat-posix:eagain () T)
+ (osicat-posix:ewouldblock () T)
+ ;; this is set if the kernel is newer than 2.6.21 if the buffer is
+ ;; too small to get the next event (which it certainly is)
+ (osicat-posix:einval () NIL)))
+
+(defun event-available-p (inotify)
"Returns T if an event is available on the queue."
- (if (inotify-nonblocking notify)
- (not (unix-eagainp (inotify-stream notify)))
- (listen (inotify-stream notify))))
+ (if (inotify-nonblocking inotify)
+ (not (unix-eagain-p (inotify-fd inotify)))
+ (listen (inotify-stream inotify))))
-(defun read-event (notify)
+(defun read-event (inotify)
"Reads an event from the queue. Blocks if no event is available."
- (read-event-from-stream (inotify-stream notify)))
+ (read-event-from-stream (inotify-stream inotify)))
-(defun next-event (notify)
+(defun next-event (inotify)
"Reads an event from the queue. Returns NIL if none is available."
- (when (event-availablep notify)
- (read-event notify)))
-
-(defmacro! do-events ((var o!notify) &body body)
- "Loops BODY with VAR bound to the events retrieved from NOTIFY. The macro
-uses NEXT-EVENT, so that reading an event won't block."
- `(loop as ,var = (next-event ,g!notify)
- while ,var
- do (progn ,.body)))
-
-(defun next-events (notify)
- "Reads all available events from the queue. Returns a list of events."
- (let (result)
- (do-events (event notify)
- (push event result))
- (nreverse result)))
+ (when (event-available-p inotify)
+ (read-event inotify)))
+
+(defmacro do-events ((var inotify &key blocking-p) &body body)
+ "Loops BODY with VAR bound to the next events retrieved from INOTIFY.
+The macro uses NEXT-EVENT, so reading an event won't block and the loop
+terminates if no events are available. If BLOCKING-P is set, the loop
+blocks if no events are available, otherwise it exits as soon as no
+events were encountered."
+ (check-type var symbol)
+ (let ((inotify-sym (gensym)))
+ `(loop
+ with ,var and ,inotify-sym = ,inotify
+ ,.(unless blocking-p
+ `(while (event-available-p ,inotify-sym)))
+ do (progn
+ (setf ,var (read-event ,inotify-sym))
+ ,@body))))
+
+(defun next-events (inotify)
+ "Reads all available events from the queue. Returns a LIST of events."
+ (loop
+ while (event-available-p inotify)
+ collect (read-event inotify)))
+
+;;; this has the longer name, because this way you actually have to read
+;;; about the differences, at least i hope so
+(defmacro with-unregistered-inotify ((inotify &optional (nonblocking T) &rest rest) &body body)
+ "Like WITH-INOTIFY, but uses MAKE-UNREGISTERED-INOTIFY and WATCH-RAW
+instead. Useful if you need to monitor just a fixed set of paths."
+ `(let ((,inotify (make-unregistered-inotify ,nonblocking)))
+ (unwind-protect
+ (progn
+ ,.(mapcar (lambda (specifier)
+ `(watch-raw ,inotify ,@specifier))
+ rest)
+ (values)
+ ,@body)
+ (close-inotify ,inotify))))
+
+(defmacro with-inotify ((inotify &optional (nonblocking T) &rest rest) &body body)
+ "Executes BODY with a newly created queue bound to INOTIFY if true.
+See MAKE-INOTIFY for more information about possible arguments.
+
+The REST is a list of argument forms for the WATCH function, i.e. one or
+more forms (PATHNAME FLAGS &KEY (REPLACE-P T)).
+
+Since the QUEUE is closed on unwinding, this macro doesn't bother with
+UNWATCH calls on all WATCHed paths."
+ `(let ((,inotify (make-inotify ,nonblocking)))
+ (unwind-protect
+ (progn
+ ,.(mapcar (lambda (specifier)
+ `(watch ,inotify ,@specifier))
+ rest)
+ (values)
+ ,@body)
+ (close-inotify ,inotify))))