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| -rw-r--r-- | Makefile.am | 1 | ||||
| -rw-r--r-- | haunt/inotify.scm | 224 |
2 files changed, 225 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am index e1b6765..f831acb 100644 --- a/Makefile.am +++ b/Makefile.am @@ -46,6 +46,7 @@ bin_SCRIPTS = \ SOURCES = \ haunt/config.scm \ haunt/utils.scm \ + haunt/inotify.scm \ haunt/post.scm \ haunt/page.scm \ haunt/asset.scm \ diff --git a/haunt/inotify.scm b/haunt/inotify.scm new file mode 100644 index 0000000..156ed9f --- /dev/null +++ b/haunt/inotify.scm @@ -0,0 +1,224 @@ +;;;;; Haunt --- Static site generator for GNU Guile +;;; Copyright © 2022 David Thompson <davet@gnu.org> +;;; +;;; This file is part of Haunt. +;;; +;;; Haunt 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. +;;; +;;; Haunt 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 Haunt. If not, see <http://www.gnu.org/licenses/>. + +;;; Commentary: +;; +;; Inotify bindings. +;; +;;; Code: + +(define-module (haunt inotify) + #:use-module (ice-9 binary-ports) + #:use-module (ice-9 format) + #:use-module (ice-9 match) + #:use-module (rnrs bytevectors) + #:use-module (srfi srfi-9) + #:use-module (srfi srfi-9 gnu) + #:use-module (system foreign) + #:export (make-inotify + inotify? + inotify-watches + inotify-add-watch! + inotify-pending-events? + inotify-read-event + inotify-watch? + inotify-watch-id + inotify-watch-file-name + inotify-watch-remove! + inotify-event? + inotify-event-watch + inotify-event-type + inotify-event-cookie + inotify-event-file-name + inotify-event-within-directory?)) + +(define libc (dynamic-link)) + +(define inotify-init + (pointer->procedure int (dynamic-func "inotify_init" libc) '())) + +(define inotify-add-watch + (pointer->procedure int (dynamic-func "inotify_add_watch" libc) + (list int '* uint32))) + +(define inotify-rm-watch + (pointer->procedure int (dynamic-func "inotify_rm_watch" libc) + (list int int))) + +(define IN_ACCESS #x00000001) ; file was accessed. +(define IN_MODIFY #x00000002) ; file was modified. +(define IN_ATTRIB #x00000004) ; metadata changed +(define IN_CLOSE_WRITE #x00000008) ; file opened for writing closed +(define IN_CLOSE_NOWRITE #x00000010) ; file not opened for writing closed +(define IN_OPEN #x00000020) ; file was opened +(define IN_MOVED_FROM #x00000040) ; file was moved from X +(define IN_MOVED_TO #x00000080) ; file was moved to Y +(define IN_CREATE #x00000100) ; subfile was created +(define IN_DELETE #x00000200) ; subfile was deleted +(define IN_DELETE_SELF #x00000400) ; self was deleted +(define IN_MOVE_SELF #x00000800) ; self was moved +;; Kernel flags +(define IN_UNMOUNT #x00002000) ; backing fs was unmounted +(define IN_Q_OVERFLOW #x00004000) ; event queue overflowed +(define IN_IGNORED #x00008000) ; file was ignored +;; Special flags +(define IN_ONLYDIR #x01000000) ; only watch if directory +(define IN_DONT_FOLLOW #x02000000) ; do not follow symlink +(define IN_EXCL_UNLINK #x04000000) ; exclude events on unlinked objects +(define IN_MASK_ADD #x20000000) ; add to the mask of an existing watch +(define IN_ISDIR #x40000000) ; event occurred against directory +(define IN_ONESHOT #x80000000) ; only send event once + +(define mask/symbol (make-hash-table)) +(define symbol/mask (make-hash-table)) + +(for-each (match-lambda + ((sym mask) + (hashq-set! symbol/mask sym mask) + (hashv-set! mask/symbol mask sym))) + `((access ,IN_ACCESS) + (modify ,IN_MODIFY) + (attrib ,IN_ATTRIB) + (close-write ,IN_CLOSE_WRITE) + (close-no-write ,IN_CLOSE_NOWRITE) + (open ,IN_OPEN) + (moved-from ,IN_MOVED_FROM) + (moved-to ,IN_MOVED_TO) + (create ,IN_CREATE) + (delete ,IN_DELETE) + (delete-self ,IN_DELETE_SELF) + (move-self ,IN_MOVE_SELF) + (only-dir ,IN_ONLYDIR) + (dont-follow ,IN_DONT_FOLLOW) + (exclude-unlink ,IN_EXCL_UNLINK) + (is-directory ,IN_ISDIR) + (once ,IN_ONESHOT))) + +(define (symbol->mask sym) + (hashq-ref symbol/mask sym)) + +(define (mask->event-symbol mask) + ;; Only check the first 4 bits, of which only one bit should be set + ;; containing the event type. The other 4 bits may have additional + ;; information. + (hashq-ref mask/symbol (logand #x0000ffff mask))) + +(define-record-type <inotify> + (%make-inotify port buffer buffer-pointer watches) + inotify? + (port inotify-port) + (buffer inotify-buffer) + (buffer-pointer inotify-buffer-pointer) + (watches inotify-watches)) + +(define-record-type <inotify-watch> + (make-inotify-watch id file-name owner) + inotify-watch? + (id inotify-watch-id) + (file-name inotify-watch-file-name) + (owner inotify-watch-owner)) + +(define-record-type <inotify-event> + (make-inotify-event watch type cookie file-name) + inotify-event? + (watch inotify-event-watch) + (type inotify-event-type) + (cookie inotify-event-cookie) + (file-name inotify-event-file-name)) + +(define (display-inotify inotify port) + (format port "#<inotify port: ~a>" (inotify-port inotify))) + +(define (display-inotify-watch watch port) + (format port "#<inotify-watch id: ~d file-name: ~a>" + (inotify-watch-id watch) + (inotify-watch-file-name watch))) + +(define (display-inotify-event event port) + (format port "#<inotify-event type: ~s cookie: ~d file-name: ~a watch: ~a>" + (inotify-event-type event) + (inotify-event-cookie event) + (inotify-event-file-name event) + (inotify-event-watch event))) + +(set-record-type-printer! <inotify> display-inotify) +(set-record-type-printer! <inotify-watch> display-inotify-watch) +(set-record-type-printer! <inotify-event> display-inotify-event) + +(define (make-inotify) + (let ((fd (inotify-init)) + (buffer (make-bytevector 4096))) + (%make-inotify (fdopen fd "r") + buffer + (bytevector->pointer buffer) + (make-hash-table)))) + +(define (inotify-fd inotify) + (port->fdes (inotify-port inotify))) + +(define (absolute-file-name file-name) + (if (absolute-file-name? file-name) + file-name + (string-append (getcwd) "/" file-name))) + +(define (inotify-add-watch! inotify file-name modes) + (let* ((abs-file-name (absolute-file-name file-name)) + (wd (inotify-add-watch (inotify-fd inotify) + (string->pointer abs-file-name) + (apply logior (map symbol->mask modes)))) + (watch (make-inotify-watch wd abs-file-name inotify))) + (hashv-set! (inotify-watches inotify) wd watch) + watch)) + +(define (inotify-watch-remove! watch) + (inotify-rm-watch (inotify-fd (inotify-watch-owner watch)) + (inotify-watch-id watch)) + (hashv-remove! (inotify-watches (inotify-watch-owner watch)) + (inotify-watch-id watch))) + +(define (inotify-pending-events? inotify) + ;; Sometimes an interrupt happens during the char-ready? call and an + ;; exception is thrown. Just return #f in that case and move on + ;; with life. + (false-if-exception (char-ready? (inotify-port inotify)))) + +(define (read-int port buffer) + (get-bytevector-n! port buffer 0 (sizeof int)) + (bytevector-sint-ref buffer 0 (native-endianness) (sizeof int))) + +(define (read-uint32 port buffer) + (get-bytevector-n! port buffer 0 (sizeof uint32)) + (bytevector-uint-ref buffer 0 (native-endianness) (sizeof uint32))) + +(define (read-string port buffer buffer-pointer length) + (and (> length 0) + (begin + (get-bytevector-n! port buffer 0 length) + (pointer->string buffer-pointer)))) + +(define (inotify-read-event inotify) + (let* ((port (inotify-port inotify)) + (buffer (inotify-buffer inotify)) + (wd (read-int port buffer)) + (event-mask (read-uint32 port buffer)) + (cookie (read-uint32 port buffer)) + (len (read-uint32 port buffer)) + (name (read-string port buffer (inotify-buffer-pointer inotify) len))) + (make-inotify-event (hashv-ref (inotify-watches inotify) wd) + (mask->event-symbol event-mask) + cookie name))) |